Update message count on command "select <folder>"

[more-wl.git] / elmo / elmo-imap4.el

;;; elmo-imap4.el --- IMAP4 Interface for ELMO.

;; Copyright (C) 1998,1999,2000 Yuuichi Teranishi <teranisi@gohome.org>
;; Copyright (C) 1999,2000      Kenichi OKADA <okada@opaopa.org>
;; Copyright (C) 2000           OKAZAKI Tetsurou <okazaki@be.to>
;; Copyright (C) 2000           Daiki Ueno <ueno@unixuser.org>

;; Author: Yuuichi Teranishi <teranisi@gohome.org>
;;      Kenichi OKADA <okada@opaopa.org>
;;      OKAZAKI Tetsurou <okazaki@be.to>
;;      Daiki Ueno <ueno@unixuser.org>
;; Keywords: mail, net news

;; This file is part of ELMO (Elisp Library for Message Orchestration).

;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;

;;; Commentary:
;;
;; Origin of IMAP parser part is imap.el, included in Gnus.
;;
;;    Copyright (C) 1998, 1999, 2000
;;    Free Software Foundation, Inc.
;;    Author: Simon Josefsson <jas@pdc.kth.se>
;;

;;; Code:
(require 'elmo-vars)
(require 'elmo-util)
(require 'elmo-date)
(require 'elmo-msgdb)
(require 'elmo-cache)
(require 'elmo)
(require 'elmo-net)
(require 'utf7)
(require 'elmo-mime)
(require 'time-stamp)

(eval-when-compile (require 'cl))

(defvar elmo-imap4-disuse-server-flag-mailbox-regexp "^#mh" ; UW imapd
  "Regexp to match IMAP4 mailbox names whose message flags on server should be ignored (For STATUS command).")

(defvar elmo-imap4-overview-fetch-chop-length 200
  "*Number of overviews to fetch in one request.")

;; c.f. rfc2683 3.2.1.5 Long Command Lines
;;
;; "A client should limit the length of the command lines it generates
;;  to approximately 1000 octets (including all quoted strings but not
;;  including literals). If the client is unable to group things into
;;  ranges so that the command line is within that length, it should
;;  split the request into multiple commands. The client should use
;;  literals instead of long quoted strings, in order to keep the command
;;  length down.
;;  For its part, a server should allow for a command line of at least
;;  8000 octets. This provides plenty of leeway for accepting reasonable
;;  length commands from clients. The server should send a BAD response
;;  to a command that does not end within the server's maximum accepted
;;  command length. "

;; To limit command line length, chop number set.
(defvar elmo-imap4-number-set-chop-length 1000
  "*Number of messages to specify as a number-set argument for one request.")

(defvar elmo-imap4-force-login nil
  "*Non-nil forces to try 'login' if there is no 'auth' capability in imapd.")

(defvar elmo-imap4-use-select-to-update-status nil
  "*Some imapd have to send select command to update status.
\(ex. UW imapd 4.5-BETA?\).  For these imapd, you must set this variable t.")

(defvar elmo-imap4-use-modified-utf7 nil
  "*Use mofidied UTF-7 (rfc2060) encoding for IMAP4 folder name.")

(defvar elmo-imap4-use-cache t
  "Use cache in imap4 folder.")

(defvar elmo-imap4-extra-namespace-alist
  '(("^\\({.*/nntp}\\).*$" . ".")) ; Default is for UW's remote nntp mailbox...
  "Extra namespace alist.
A list of cons cell like: (REGEXP . DELIMITER).
REGEXP should have a grouping for namespace prefix.")
;;
;;; internal variables
;;
(defvar elmo-imap4-seq-prefix "elmo-imap4")
(defvar elmo-imap4-seqno 0)
(defvar elmo-imap4-use-uid t
  "Use UID as message number.")

(defvar elmo-imap4-current-response nil)
(defvar elmo-imap4-status nil)
(defvar elmo-imap4-reached-tag "elmo-imap40")

;;; buffer local variables
(defvar elmo-imap4-default-hierarchy-delimiter "/")

(defvar elmo-imap4-server-capability nil)
(defvar elmo-imap4-server-namespace nil)

(defvar elmo-imap4-parsing nil) ; indicates parsing.

(defvar elmo-imap4-fetch-callback nil)
(defvar elmo-imap4-fetch-callback-data nil)
(defvar elmo-imap4-status-callback nil)
(defvar elmo-imap4-status-callback-data nil)

(defvar elmo-imap4-server-diff-async-callback nil)
(defvar elmo-imap4-server-diff-async-callback-data nil)

;;; progress...(no use?)
(defvar elmo-imap4-count-progress nil)
(defvar elmo-imap4-count-progress-message nil)
(defvar elmo-imap4-progress-count nil)

;;; XXX Temporal implementation
(defvar elmo-imap4-current-msgdb nil)
(defvar elmo-imap4-seen-messages nil)

(defvar elmo-imap4-local-variables
  '(elmo-imap4-status
    elmo-imap4-current-response
    elmo-imap4-seqno
    elmo-imap4-parsing
    elmo-imap4-reached-tag
    elmo-imap4-count-progress
    elmo-imap4-count-progress-message
    elmo-imap4-progress-count
    elmo-imap4-fetch-callback
    elmo-imap4-fetch-callback-data
    elmo-imap4-status-callback
    elmo-imap4-status-callback-data
    elmo-imap4-current-msgdb
    elmo-imap4-seen-messages))

;;;;

(defconst elmo-imap4-quoted-specials-list '(?\\ ?\"))

(defconst elmo-imap4-non-atom-char-regex
  (eval-when-compile
    (concat "[^" "]!#$&'+,./0-9:;<=>?@A-Z[^_`a-z|}~-" "]")))

(defconst elmo-imap4-non-text-char-regex
  (eval-when-compile
    (concat "[^"
            "]\x01-\x09\x0b\x0c\x0e-\x1f\x7f !\"#$%&'()*+,./0-9:;<=>?@A-Z[\\^_`a-z{|}~-"
            "]")))

(defconst elmo-imap4-literal-threshold 1024
 "Limitation of characters that can be used in a quoted string.")

(defconst elmo-imap4-flag-specs '((important "\\Flagged")
                                  (read "\\Seen")
                                  (unread "\\Seen" 'remove)
                                  (answered "\\Answered")
                                  ;; draft-melnikov-imap-keywords-03.txt
                                  (forwarded "$Forwarded")
                                  (work "$Work")
                                  (personal "$Personal")
                                  (shouldreply "$ShouldReply")))

(defconst elmo-imap4-folder-name-syntax
  `(mailbox
    (?: [user "^[A-Za-z]"] (?/ [auth ".+"]))
    ,@elmo-net-folder-name-syntax))

;; For debugging.
(defvar elmo-imap4-debug nil
  "Non-nil forces IMAP4 folder as debug mode.
Debug information is inserted in the buffer \"*IMAP4 DEBUG*\"")

(defvar elmo-imap4-debug-inhibit-logging nil)

;;; ELMO IMAP4 folder
(eval-and-compile
  (luna-define-class elmo-imap4-folder (elmo-net-folder)
                     (mailbox))
  (luna-define-internal-accessors 'elmo-imap4-folder))

;;; Session
(eval-and-compile
  (luna-define-class elmo-imap4-session (elmo-network-session)
                     (capability current-mailbox read-only flags))
  (luna-define-internal-accessors 'elmo-imap4-session))

(defmacro elmo-imap4-session-capable-p (session capability)
  `(memq ,capability (elmo-imap4-session-capability-internal ,session)))

;;; MIME-ELMO-IMAP Location
(eval-and-compile
  (luna-define-class mime-elmo-imap-location
                     (mime-imap-location)
                     (folder number rawbuf strategy))
  (luna-define-internal-accessors 'mime-elmo-imap-location))

;;; Debug
(defmacro elmo-imap4-debug (message &rest args)
  `(if elmo-imap4-debug
       (elmo-imap4-debug-1 ,message ,@args)))

(defun elmo-imap4-debug-1 (message &rest args)
  (with-current-buffer (get-buffer-create "*IMAP4 DEBUG*")
    (goto-char (point-max))
    (if elmo-imap4-debug-inhibit-logging
        (insert "NO LOGGING\n")
      (insert (apply 'format message args) "\n"))))

(defsubst elmo-imap4-decode-folder-string (string)
  (if elmo-imap4-use-modified-utf7
      (utf7-decode string 'imap)
    string))

(defsubst elmo-imap4-encode-folder-string (string)
  (if elmo-imap4-use-modified-utf7
      (utf7-encode string 'imap)
    string))

;;; Response

(defmacro elmo-imap4-response-continue-req-p (response)
  "Returns non-nil if RESPONSE is '+' response."
  `(assq 'continue-req ,response))

(defmacro elmo-imap4-response-ok-p (response)
  "Returns non-nil if RESPONSE is an 'OK' response."
  `(assq 'ok ,response))

(defmacro elmo-imap4-response-bye-p (response)
  "Returns non-nil if RESPONSE is an 'BYE' response."
  `(assq 'bye ,response))

(defmacro elmo-imap4-response-garbage-p (response)
  "Returns non-nil if RESPONSE is an 'garbage' response."
  `(assq 'garbage ,response))

(defmacro elmo-imap4-response-value (response symbol)
  "Get value of the SYMBOL from RESPONSE."
  `(nth 1 (assq ,symbol ,response)))

(defsubst elmo-imap4-response-value-all (response symbol)
  "Get all value of the SYMBOL from RESPONSE."
  (let (matched)
    (while response
      (if (eq (car (car response)) symbol)
          (setq matched (nconc matched (nth 1 (car response)))))
      (setq response (cdr response)))
    matched))

(defmacro elmo-imap4-response-error-text (response)
  "Returns text of NO, BAD, BYE response."
  `(nth 1 (or (elmo-imap4-response-value ,response 'no)
              (elmo-imap4-response-value ,response 'bad)
              (elmo-imap4-response-value ,response 'bye))))

(defmacro elmo-imap4-response-bodydetail-text (response)
  "Returns text of BODY[section]<partial>."
  `(nth 3 (assq 'bodydetail ,response)))

;;; Session commands.

; (defun elmo-imap4-send-command-wait (session command)
;   "Send COMMAND to the SESSION and wait for response.
; Returns RESPONSE (parsed lisp object) of IMAP session."
;   (elmo-imap4-read-response session
;                           (elmo-imap4-send-command
;                            session
;                            command)))

(defun elmo-imap4-send-command-wait (session command)
  "Send COMMAND to the SESSION.
Returns RESPONSE (parsed lisp object) of IMAP session.
If response is not `OK', causes error with IMAP response text."
  (elmo-imap4-accept-ok session
                        (elmo-imap4-send-command
                         session
                         command)))

(defun elmo-imap4-send-command (session command)
  "Send COMMAND to the SESSION.
Returns a TAG string which is assigned to the COMMAND."
  (let* ((command-args (if (listp command)
                           command
                         (list command)))
         (process (elmo-network-session-process-internal session))
         cmdstr tag token kind)
    (with-current-buffer (process-buffer process)
      (setq tag (concat elmo-imap4-seq-prefix
                        (number-to-string
                         (setq elmo-imap4-seqno (+ 1 elmo-imap4-seqno)))))
      (setq cmdstr (concat tag " "))
      ;; (erase-buffer) No need.
      (goto-char (point-min))
      (when (elmo-imap4-response-bye-p elmo-imap4-current-response)
        (elmo-imap4-process-bye session))
      (setq elmo-imap4-current-response nil)
      (when elmo-imap4-parsing
        (message "Waiting for IMAP response...")
        (accept-process-output (elmo-network-session-process-internal
                                session))
        (message "Waiting for IMAP response...done"))
      (setq elmo-imap4-parsing t)
      (while (setq token (car command-args))
        (cond ((stringp token)   ; formatted
               (setq cmdstr (concat cmdstr token)))
              ((listp token)     ; unformatted
               (setq kind (car token))
               (cond ((eq kind 'atom)
                      (setq cmdstr (concat cmdstr (nth 1 token))))
                     ((eq kind 'quoted)
                      (setq cmdstr (concat
                                    cmdstr
                                    (elmo-imap4-format-quoted (nth 1 token)))))
                     ((eq kind 'literal)
                      (if (elmo-imap4-session-capable-p session 'literal+)
                          ;; rfc2088
                          (progn
                            (setq cmdstr (concat cmdstr
                                                 (format "{%d+}" (nth 2 token))
                                                 "\r\n"))
                            (process-send-string process cmdstr)
                            (setq cmdstr nil))
                        (setq cmdstr (concat cmdstr
                                             (format "{%d}" (nth 2 token))
                                             "\r\n"))
                        (process-send-string process cmdstr)
                        (setq cmdstr nil)
                        (elmo-imap4-accept-continue-req session))
                      (cond ((stringp (nth 1 token))
                             (setq cmdstr (nth 1 token)))
                            ((bufferp (nth 1 token))
                             (with-current-buffer (nth 1 token)
                               (process-send-region
                                process
                                (point-min)
                                (+ (point-min) (nth 2 token)))))
                            (t
                             (error "Wrong argument for literal"))))
                     (t
                      (error "Unknown token kind %s" kind))))
              (t
               (error "Invalid argument")))
        (setq command-args (cdr command-args)))
      (elmo-imap4-debug "[%s] <- %s" (time-stamp-hh:mm:ss) cmdstr)
      (process-send-string process (concat cmdstr "\r\n"))
      tag)))

(defun elmo-imap4-send-string (session string)
  "Send STRING to the SESSION."
  (with-current-buffer (process-buffer
                        (elmo-network-session-process-internal session))
    (setq elmo-imap4-current-response nil)
    (goto-char (point-min))
    (elmo-imap4-debug "[%s] <-- %s" (time-stamp-hh:mm:ss) string)
    (process-send-string (elmo-network-session-process-internal session)
                         string)
    (process-send-string (elmo-network-session-process-internal session)
                         "\r\n")))

(defun elmo-imap4-read-response (session tag)
  "Read parsed response from SESSION.
TAG is the tag of the command"
  (with-current-buffer (process-buffer
                        (elmo-network-session-process-internal session))
    (while (not (or (string= tag elmo-imap4-reached-tag)
                    (elmo-imap4-response-bye-p elmo-imap4-current-response)
                    (when (elmo-imap4-response-garbage-p
                           elmo-imap4-current-response)
                      (message "Garbage response: %s"
                               (elmo-imap4-response-value
                                elmo-imap4-current-response
                                'garbage))
                      t)))
      (when (memq (process-status
                   (elmo-network-session-process-internal session))
                  '(open run))
        (accept-process-output (elmo-network-session-process-internal session)
                               1)))
    (elmo-imap4-debug "[%s] =>%s" (time-stamp-hh:mm:ss) (prin1-to-string elmo-imap4-current-response))
    (setq elmo-imap4-parsing nil)
    elmo-imap4-current-response))

(defsubst elmo-imap4-read-untagged (process)
  (with-current-buffer (process-buffer process)
    (while (not elmo-imap4-current-response)
      (accept-process-output process 1))
    (elmo-imap4-debug "[%s] =>%s" (time-stamp-hh:mm:ss) (prin1-to-string elmo-imap4-current-response))
    elmo-imap4-current-response))

(defun elmo-imap4-read-continue-req (session)
  "Returns a text following to continue-req in SESSION.
If response is not `+' response, returns nil."
  (elmo-imap4-response-value
   (elmo-imap4-read-untagged
    (elmo-network-session-process-internal session))
   'continue-req))

(defun elmo-imap4-process-bye (session)
  (with-current-buffer (elmo-network-session-buffer session)
    (let ((r elmo-imap4-current-response))
      (setq elmo-imap4-current-response nil)
      (elmo-network-close-session session)
      (signal 'elmo-imap4-bye-error
              (list (concat (elmo-imap4-response-error-text r))
                    "Try Again")))))

(defun elmo-imap4-accept-continue-req (session)
  "Returns non-nil if `+' (continue-req) response is arrived in SESSION.
If response is not `+' response, cause an error."
  (let (response)
    (setq response
          (elmo-imap4-read-untagged
           (elmo-network-session-process-internal session)))
    (or (elmo-imap4-response-continue-req-p response)
        (error "IMAP error: %s"
               (or (elmo-imap4-response-error-text response)
                   "No continut-req from server.")))))

(defun elmo-imap4-read-ok (session tag)
  "Returns non-nil if `OK' response of the command with TAG is arrived
in SESSION. If response is not `OK' response, returns nil."
  (elmo-imap4-response-ok-p
   (elmo-imap4-read-response session tag)))

(defun elmo-imap4-accept-ok (session tag)
  "Accept only `OK' response from SESSION.
If response is not `OK' response, causes error with IMAP response text."
  (let ((response (elmo-imap4-read-response session tag)))
    (if (elmo-imap4-response-ok-p response)
        response
      (if (elmo-imap4-response-bye-p response)
          (elmo-imap4-process-bye session)
        (error "IMAP error: %s"
               (or (elmo-imap4-response-error-text response)
                   "No `OK' response from server."))))))

;;; MIME-ELMO-IMAP Location
(luna-define-method mime-imap-location-section-body ((location
                                                      mime-elmo-imap-location)
                                                     section)
  (if (and (stringp section)
           (string= section "HEADER"))
      ;; Even in the section mode, header fields should be saved to the
      ;; raw buffer .
      (with-current-buffer (mime-elmo-imap-location-rawbuf-internal location)
        (erase-buffer)
        (elmo-message-fetch
         (mime-elmo-imap-location-folder-internal location)
         (mime-elmo-imap-location-number-internal location)
         (mime-elmo-imap-location-strategy-internal location)
         'unseen
         section)
        (buffer-string))
    (elmo-message-fetch-string
     (mime-elmo-imap-location-folder-internal location)
     (mime-elmo-imap-location-number-internal location)
     (mime-elmo-imap-location-strategy-internal location)
     'unseen
     section)))


(luna-define-method mime-imap-location-bodystructure
  ((location mime-elmo-imap-location))
  (elmo-message-fetch-bodystructure
   (mime-elmo-imap-location-folder-internal location)
   (mime-elmo-imap-location-number-internal location)
   (mime-elmo-imap-location-strategy-internal location)))

(luna-define-method mime-imap-location-fetch-entity-p
  ((location mime-elmo-imap-location) entity)
  (or (not elmo-message-displaying) ; Fetching entity to save or force display.
      ;; cache exists
      (file-exists-p
       (expand-file-name
        (mmimap-entity-section (mime-entity-node-id-internal entity))
        (elmo-fetch-strategy-cache-path
         (mime-elmo-imap-location-strategy-internal location))))
      ;; not too large to fetch.
      (> elmo-message-fetch-threshold
         (or (mime-imap-entity-size-internal entity) 0))))

;;;

(defun elmo-imap4-session-check (session)
  (with-current-buffer (elmo-network-session-buffer session)
    (setq elmo-imap4-fetch-callback nil)
    (setq elmo-imap4-fetch-callback-data nil))
  (elmo-imap4-send-command session "check"))

(defun elmo-imap4-atom-p (string)
  "Return t if STRING is an atom defined in rfc2060."
  (if (string= string "")
      nil
    (save-match-data
      (not (string-match elmo-imap4-non-atom-char-regex string)))))

(defun elmo-imap4-quotable-p (string)
  "Return t if STRING can be formatted as a quoted defined in rfc2060."
  (save-match-data
    (not (string-match elmo-imap4-non-text-char-regex string))))

(defun elmo-imap4-nil (string)
  "Return a list represents the special atom \"NIL\" defined in rfc2060, \
if STRING is nil.
Otherwise return nil."
  (if (eq string nil)
      (list 'atom "NIL")))

(defun elmo-imap4-atom (string)
  "Return a list represents STRING as an atom defined in rfc2060.
Return nil if STRING is not an atom.  See `elmo-imap4-atom-p'."
  (if (elmo-imap4-atom-p string)
      (list 'atom string)))

(defun elmo-imap4-quoted (string)
  "Return a list represents STRING as a quoted defined in rfc2060.
Return nil if STRING can not be formatted as a quoted.  See `elmo-imap4-quotable-p'."
  (if (elmo-imap4-quotable-p string)
      (list 'quoted string)))

(defun elmo-imap4-literal-1 (string-or-buffer length)
  "Internal function for `elmo-imap4-literal' and `elmo-imap4-buffer-literal'.
Return a list represents STRING-OR-BUFFER as a literal defined in rfc2060.
STRING-OR-BUFFER must be an encoded string or a single-byte string or a single-byte buffer.
LENGTH must be the number of octets for STRING-OR-BUFFER."
  (list 'literal string-or-buffer length))

(defun elmo-imap4-literal (string)
  "Return a list represents STRING as a literal defined in rfc2060.
STRING must be an encoded or a single-byte string."
  (elmo-imap4-literal-1 string (length string)))

(defun elmo-imap4-buffer-literal (buffer)
  "Return a list represents BUFFER as a literal defined in rfc2060.
BUFFER must be a single-byte buffer."
  (elmo-imap4-literal-1 buffer (with-current-buffer buffer
                                 (buffer-size))))

(defun elmo-imap4-string-1 (string length)
  "Internal function for `elmo-imap4-string' and `elmo-imap4-buffer-string'.
Return a list represents STRING as a string defined in rfc2060.
STRING must be an encoded or a single-byte string.
LENGTH must be the number of octets for STRING."
  (or (elmo-imap4-quoted string)
      (elmo-imap4-literal-1 string length)))

(defun elmo-imap4-string (string)
  "Return a list represents STRING as a string defined in rfc2060.
STRING must be an encoded or a single-byte string."
  (let ((length (length string)))
    (if (< elmo-imap4-literal-threshold length)
        (elmo-imap4-literal-1 string length)
      (elmo-imap4-string-1 string length))))

(defun elmo-imap4-buffer-string (buffer)
  "Return a list represents BUFFER as a string defined in rfc2060.
BUFFER must be a single-byte buffer."
  (let ((length (with-current-buffer buffer
                  (buffer-size))))
    (if (< elmo-imap4-literal-threshold length)
        (elmo-imap4-literal-1 buffer length)
      (elmo-imap4-string-1 (with-current-buffer buffer
                             (buffer-string))
                           length))))

(defun elmo-imap4-astring-1 (string length)
  "Internal function for `elmo-imap4-astring' and `elmo-imap4-buffer-astring'.
Return a list represents STRING as an astring defined in rfc2060.
STRING must be an encoded or a single-byte string.
LENGTH must be the number of octets for STRING."
  (or (elmo-imap4-atom string)
      (elmo-imap4-string-1 string length)))

(defun elmo-imap4-astring (string)
  "Return a list represents STRING as an astring defined in rfc2060.
STRING must be an encoded or a single-byte string."
  (let ((length (length string)))
    (if (< elmo-imap4-literal-threshold length)
        (elmo-imap4-literal-1 string length)
      (elmo-imap4-astring-1 string length))))

(defun elmo-imap4-buffer-astring (buffer)
  "Return a list represents BUFFER as an astring defined in rfc2060.
BUFFER must be a single-byte buffer."
  (let ((length (with-current-buffer buffer
                  (buffer-size))))
    (if (< elmo-imap4-literal-threshold length)
        (elmo-imap4-literal-1 buffer length)
      (elmo-imap4-astring-1 (with-current-buffer buffer
                              (buffer-string))
                            length))))

(defun elmo-imap4-nstring (string)
  "Return a list represents STRING as a nstring defined in rfc2060.
STRING must be an encoded or a single-byte string."
   (or (elmo-imap4-nil string)
       (elmo-imap4-string string)))

(defun elmo-imap4-buffer-nstring (buffer)
  "Return a list represents BUFFER as a nstring defined in rfc2060.
BUFFER must be a single-byte buffer."
   (or (elmo-imap4-nil buffer)
       (elmo-imap4-buffer-string buffer)))

(defalias 'elmo-imap4-mailbox 'elmo-imap4-astring)
(defalias 'elmo-imap4-field-body 'elmo-imap4-astring)
(defalias 'elmo-imap4-userid 'elmo-imap4-astring)
(defalias 'elmo-imap4-password 'elmo-imap4-astring)

(defun elmo-imap4-format-quoted (string)
  "Return STRING in a form of the quoted-string defined in rfc2060."
  (concat "\""
          (std11-wrap-as-quoted-pairs string elmo-imap4-quoted-specials-list)
          "\""))

(defsubst elmo-imap4-response-get-selectable-mailbox-list (response)
  (delq nil
        (mapcar
         (lambda (entry)
           (if (and (eq 'list (car entry))
                    (not (elmo-string-member-ignore-case "\\Noselect" (nth 1 (nth 1 entry)))))
               (car (nth 1 entry))))
         response)))

(luna-define-method elmo-message-fetch-bodystructure ((folder
                                                       elmo-imap4-folder)
                                                      number strategy)
  (if (elmo-fetch-strategy-use-cache strategy)
      (elmo-object-load
       (elmo-file-cache-expand-path
        (elmo-fetch-strategy-cache-path strategy)
        "bodystructure"))
    (let ((session (elmo-imap4-get-session folder))
          bodystructure)
      (elmo-imap4-session-select-mailbox
       session
       (elmo-imap4-folder-mailbox-internal folder))
      (with-current-buffer (elmo-network-session-buffer session)
        (setq elmo-imap4-fetch-callback nil)
        (setq elmo-imap4-fetch-callback-data nil))
      (prog1 (setq bodystructure
                   (elmo-imap4-response-value
                    (elmo-imap4-response-value
                     (elmo-imap4-send-command-wait
                      session
                      (format
                       (if elmo-imap4-use-uid
                           "uid fetch %s bodystructure"
                         "fetch %s bodystructure")
                       number))
                     'fetch)
                    'bodystructure))
        (when (elmo-fetch-strategy-save-cache strategy)
          (elmo-file-cache-delete
           (elmo-fetch-strategy-cache-path strategy))
          (elmo-object-save
           (elmo-file-cache-expand-path
            (elmo-fetch-strategy-cache-path strategy)
            "bodystructure")
           bodystructure))))))

;;; Backend methods.
(luna-define-method elmo-create-folder-plugged ((folder elmo-imap4-folder))
  (elmo-imap4-send-command-wait
   (elmo-imap4-get-session folder)
   (list "create " (elmo-imap4-mailbox
                    (elmo-imap4-folder-mailbox-internal folder)))))

(defun elmo-imap4-get-session (folder &optional if-exists)
  (elmo-network-get-session 'elmo-imap4-session
                            (concat
                             (if (elmo-folder-biff-internal folder)
                                 "BIFF-")
                             "IMAP")
                            folder if-exists))

(defun elmo-imap4-session-select-mailbox (session mailbox
                                                  &optional force no-error)
  "Select MAILBOX in SESSION.
If optional argument FORCE is non-nil, select mailbox even if current mailbox
is same as MAILBOX.
If second optional argument NO-ERROR is non-nil, don't cause an error when
selecting folder was failed.
If NO-ERROR is 'notify-bye, only BYE response is reported as error.
Returns response value if selecting folder succeed. "
  (when (or force
            (not (string=
                  (elmo-imap4-session-current-mailbox-internal session)
                  mailbox)))
    (let (response result)
      (unwind-protect
          (setq response
                (elmo-imap4-read-response
                 session
                 (elmo-imap4-send-command
                  session
                  (list
                   "select "
                   (elmo-imap4-mailbox mailbox)))))
        (if (setq result (elmo-imap4-response-ok-p response))
            (progn
              (elmo-imap4-session-set-current-mailbox-internal session mailbox)
              (elmo-imap4-session-set-read-only-internal
               session
               (nth 1 (assq 'read-only (assq 'ok response))))
              (elmo-imap4-session-set-flags-internal
               session
               (nth 1 (or (assq 'permanentflags response)
                          (assq 'flags response)))))
          (elmo-imap4-session-set-current-mailbox-internal session nil)
          (if (and (eq no-error 'notify-bye)
                   (elmo-imap4-response-bye-p response))
              (elmo-imap4-process-bye session)
            (unless no-error
              (error "%s"
                     (or (elmo-imap4-response-error-text response)
                         (format "Select %s failed" mailbox)))))))
      (and result response))))

(defun elmo-imap4-check-validity (spec validity-file)
;;; Not used.
;;;(elmo-imap4-send-command-wait
;;;(elmo-imap4-get-session spec)
;;;(list "status "
;;;      (elmo-imap4-mailbox
;;;       (elmo-imap4-spec-mailbox spec))
;;;      " (uidvalidity)")))
  )

(defun elmo-imap4-sync-validity  (spec validity-file)
  ;; Not used.
  )

(defun elmo-imap4-elist (folder query tags)
  (let ((session (elmo-imap4-get-session folder)))
    (elmo-imap4-session-select-mailbox
     session
     (elmo-imap4-folder-mailbox-internal folder))
    (let ((answer (elmo-imap4-response-value
                   (elmo-imap4-send-command-wait
                    session query) 'esearch))
          tag result)
      (while answer
        (setq tag (intern (downcase (car answer))))
        (cond ((eq tag 'uid)
               nil)
              ((memq tag tags)
               (setq result
                     (append result
                             (if (eq tag 'all)
                                 (sort
                                  (elmo-number-set-to-number-list
                                   (mapcar #'(lambda (x)
                                               (let ((y (split-string x ":")))
                                                 (if (null (cdr y))
                                                     (string-to-number (car y))
                                                   (cons (string-to-number (car y))
                                                         (string-to-number (cadr y))))))
                                           (split-string (cadr answer) "\,"))) '<)
                               (string-to-number (cadr answer))))))
              (t nil))
        (setq answer (cdr answer)))
      result)))

(defun elmo-imap4-list (folder flag)
  (let ((session (elmo-imap4-get-session folder)))
    (elmo-imap4-session-select-mailbox
     session
     (elmo-imap4-folder-mailbox-internal folder))
    (if (elmo-imap4-session-capable-p session 'esearch)
        (elmo-imap4-elist folder
                          (concat (if elmo-imap4-use-uid "uid " "")
                                  "search return (all) " flag) '(all))
      (elmo-imap4-response-value
       (elmo-imap4-send-command-wait
        session
        (format (if elmo-imap4-use-uid "uid search %s"
                  "search %s") flag))
       'search))))

(defun elmo-imap4-session-flag-available-p (session flag)
  (case flag
    ((read unread) (elmo-string-member-ignore-case
                    "\\seen" (elmo-imap4-session-flags-internal session)))
    (important
     (elmo-string-member-ignore-case
      "\\flagged" (elmo-imap4-session-flags-internal session)))
    (digest
     (or (elmo-string-member-ignore-case
          "\\seen" (elmo-imap4-session-flags-internal session))
         (elmo-string-member-ignore-case
          "\\flagged" (elmo-imap4-session-flags-internal session))))
    (answered
     (elmo-string-member-ignore-case
      (concat "\\" (symbol-name flag))
      (elmo-imap4-session-flags-internal session)))
    (t
     (member "\\*" (elmo-imap4-session-flags-internal session)))))

(defun elmo-imap4-flag-to-imap-search-key (flag)
  (case flag
    (read "seen")
    (unread "unseen")
    (important "flagged")
    (answered "answered")
    (new "new")
    (t (concat
        "keyword "
        (or (car (cdr (assq flag elmo-imap4-flag-specs)))
            (symbol-name flag))))))

(defun elmo-imap4-flag-to-imap-criteria (flag)
  (case flag
    ((any digest)
     (let ((criteria "flagged")
           (global-flags (delq 'important (elmo-get-global-flags t t))))
       (dolist (flag (delete 'new
                             (delete 'cached
                                     (copy-sequence
                                      (case flag
                                        (any
                                         elmo-preserved-flags)
                                        (digest
                                         elmo-digest-flags))))))
         (setq criteria (concat "or "
                                (elmo-imap4-flag-to-imap-search-key flag)
                                " "
                                criteria)))
       (while global-flags
         (setq criteria (concat "or keyword "
                                (symbol-name (car global-flags))
                                " "
                                criteria))
         (setq global-flags (cdr global-flags)))
       criteria))
    (t
     (elmo-imap4-flag-to-imap-search-key flag))))

(defun elmo-imap4-folder-list-flagged (folder flag)
  "List flagged message numbers in the FOLDER.
FLAG is one of the `unread', `read', `important', `answered', `any'."
  (let ((session (elmo-imap4-get-session folder))
        (criteria (elmo-imap4-flag-to-imap-criteria flag)))
    (if (elmo-imap4-session-flag-available-p session flag)
        (elmo-imap4-list folder criteria)
      ;; List flagged messages in the msgdb.
      (elmo-msgdb-list-flagged (elmo-folder-msgdb folder) flag))))

(defvar elmo-imap4-rfc822-size "RFC822\.SIZE")
(defvar elmo-imap4-rfc822-text "RFC822\.TEXT")
(defvar elmo-imap4-rfc822-header "RFC822\.HEADER")
(defvar elmo-imap4-header-fields "HEADER\.FIELDS")

(defun elmo-imap4-make-number-set-list (msg-list &optional chop-length)
  "Make RFC2060's message set specifier from MSG-LIST.
Returns a list of (NUMBER . SET-STRING).
SET-STRING is the message set specifier described in RFC2060.
NUMBER is contained message number in SET-STRING.
Every SET-STRING does not contain number of messages longer than CHOP-LENGTH.
If CHOP-LENGTH is not specified, message set is not chopped."
  (let (count cont-list set-list)
    (setq msg-list (sort (copy-sequence msg-list) '<))
    (while msg-list
      (setq cont-list nil)
      (setq count 0)
      (unless chop-length
        (setq chop-length (length msg-list)))
      (while (and (not (null msg-list))
                  (< count chop-length))
        (setq cont-list
              (elmo-number-set-append
               cont-list (car msg-list)))
        (incf count)
        (setq msg-list (cdr msg-list)))
      (setq set-list
            (cons
             (cons
              count
              (mapconcat
               (lambda (x)
                 (cond ((consp x)
                        (format "%s:%s" (car x) (cdr x)))
                       ((integerp x)
                        (int-to-string x))))
               cont-list
               ","))
             set-list)))
    (nreverse set-list)))

;;
;; app-data:
;; cons of flag-table and folder structure
(defsubst elmo-imap4-fetch-callback-1-subr (entity flags app-data)
  "A msgdb entity callback function."
  (let ((use-flag (elmo-folder-use-flag-p (cdr app-data)))
        (flag-table (car app-data))
        (msg-id (elmo-message-entity-field entity 'message-id))
        saved-flags flag-list)
;;    (when (elmo-string-member-ignore-case "\\Flagged" flags)
;;      (elmo-msgdb-global-mark-set msg-id elmo-msgdb-important-mark))
    (setq saved-flags (elmo-flag-table-get flag-table msg-id)
          flag-list
          (if use-flag
              (append
               (and (memq 'new saved-flags)
                    (not (elmo-string-member-ignore-case "\\Seen" flags))
                    '(new))
               (and (elmo-string-member-ignore-case "\\Flagged" flags)
                    '(important))
               (and (not (elmo-string-member-ignore-case "\\Seen" flags))
                    '(unread))
               (and (elmo-string-member-ignore-case "\\Answered" flags)
                    '(answered))
               (and (elmo-file-cache-exists-p msg-id)
                    '(cached)))
            saved-flags))
    (when (and (or (memq 'important flag-list)
                   (memq 'answered flag-list))
               (memq 'unread flag-list))
      (setq elmo-imap4-seen-messages
            (cons (elmo-message-entity-number entity)
                  elmo-imap4-seen-messages)))
    (elmo-msgdb-append-entity elmo-imap4-current-msgdb
                              entity
                              flag-list)))

;; Current buffer is process buffer.
(defun elmo-imap4-fetch-callback-1 (element app-data)
  (let ((handler (elmo-msgdb-message-entity-handler elmo-imap4-current-msgdb)))
    (elmo-imap4-fetch-callback-1-subr
     (with-temp-buffer
       (insert (or (elmo-imap4-response-bodydetail-text element)
                   ""))
       ;; Replace all CRLF with LF.
       (elmo-delete-cr-buffer)
       (elmo-msgdb-create-message-entity-from-buffer
        handler
        (elmo-imap4-response-value element 'uid)
        :size (elmo-imap4-response-value element 'rfc822size)))
     (elmo-imap4-response-value element 'flags)
     app-data)
    (elmo-progress-notify 'elmo-folder-msgdb-create)))

(defun elmo-imap4-parse-capability (string)
  (if (string-match "^\\*\\(.*\\)$" string)
      (read
       (concat "(" (downcase (elmo-match-string 1 string)) ")"))))

(defun elmo-imap4-clear-login (session)
  (when (elmo-imap4-session-capable-p session 'logindisabled)
    (signal 'elmo-authenticate-error '(elmo-imap4-clear-login)))
  (let ((elmo-imap4-debug-inhibit-logging t))
    (prog1
        (or
         (elmo-imap4-read-ok
          session
          (elmo-imap4-send-command
           session
           (list "login "
                 (elmo-imap4-userid (elmo-network-session-user-internal session))
                 " "
                 (elmo-imap4-password
                  (elmo-get-passwd (elmo-network-session-password-key session))))))
         (signal 'elmo-authenticate-error '(elmo-imap4-clear-login)))
;; Fix for Zimbra
;; Some servers return reduced capabilities when client asks for them before login
      (elmo-imap4-session-set-capability-internal
       session
       (elmo-imap4-response-value
        (elmo-imap4-send-command-wait session "capability")
        'capability)))))

(defun elmo-imap4-auth-login (session)
  (let ((tag (elmo-imap4-send-command session "authenticate login"))
        (elmo-imap4-debug-inhibit-logging t))
    (or (elmo-imap4-read-continue-req session)
        (signal 'elmo-authenticate-error '(elmo-imap4-auth-login)))
    (elmo-imap4-send-string session
                            (elmo-base64-encode-string
                             (elmo-network-session-user-internal session)))
    (or (elmo-imap4-read-continue-req session)
        (signal 'elmo-authenticate-error '(elmo-imap4-auth-login)))
    (elmo-imap4-send-string session
                            (elmo-base64-encode-string
                             (elmo-get-passwd
                              (elmo-network-session-password-key session))))
    (or (elmo-imap4-read-ok session tag)
        (signal 'elmo-authenticate-error '(elmo-imap4-auth-login)))
    (setq elmo-imap4-status 'auth)))

(luna-define-method
  elmo-network-initialize-session-buffer :after ((session
                                                  elmo-imap4-session) buffer)
  (with-current-buffer buffer
    (mapcar 'make-variable-buffer-local elmo-imap4-local-variables)
    (setq elmo-imap4-seqno 0)
    (setq elmo-imap4-status 'initial)))

(luna-define-method elmo-network-initialize-session ((session
                                                      elmo-imap4-session))
  (let ((process (elmo-network-session-process-internal session)))
    (with-current-buffer (process-buffer process)
      ;; Skip garbage output from process before greeting.
      (while (and (memq (process-status process) '(open run))
                  (goto-char (point-max))
                  (or (/= (forward-line -1) 0)
                      (not (elmo-imap4-parse-greeting))))
        (accept-process-output process 1))
      (erase-buffer)
      (set-process-filter process 'elmo-imap4-arrival-filter)
      (set-process-sentinel process 'elmo-imap4-sentinel)
;;;   (while (and (memq (process-status process) '(open run))
;;;               (eq elmo-imap4-status 'initial))
;;;     (message "Waiting for server response...")
;;;     (accept-process-output process 1))
;;;   (message "")
      (unless (memq elmo-imap4-status '(nonauth auth))
        (signal 'elmo-open-error
                (list 'elmo-network-initialize-session)))
      (elmo-imap4-session-set-capability-internal
       session
       (elmo-imap4-response-value
        (elmo-imap4-send-command-wait session "capability")
        'capability))
      (when (eq (elmo-network-stream-type-symbol
                 (elmo-network-session-stream-type-internal session))
                'starttls)
        (or (elmo-imap4-session-capable-p session 'starttls)
            (signal 'elmo-open-error
                    '(elmo-imap4-starttls-error)))
        (elmo-imap4-send-command-wait session "starttls")
        (starttls-negotiate process)
        (elmo-imap4-session-set-capability-internal
         session
         (elmo-imap4-response-value
          (elmo-imap4-send-command-wait session "capability")
          'capability))))))

(luna-define-method elmo-network-authenticate-session ((session
                                                        elmo-imap4-session))
  (with-current-buffer (process-buffer
                        (elmo-network-session-process-internal session))
    (let* ((auth (elmo-network-session-auth-internal session))
           (auth (if (listp auth) auth (list auth))))
      (unless (or (eq elmo-imap4-status 'auth)
                  (null auth))
        (cond
         ((eq 'clear (car auth))
          (elmo-imap4-clear-login session))
         ((eq 'login (car auth))
          (elmo-imap4-auth-login session))
         (t
          (let* ((elmo-imap4-debug-inhibit-logging t)
                 (sasl-mechanisms
                  (delq nil
                        (mapcar
                         '(lambda (cap)
                            (if (string-match "^auth=\\(.*\\)$"
                                              (symbol-name cap))
                                (match-string 1 (upcase (symbol-name cap)))))
                         (elmo-imap4-session-capability-internal session))))
                 (mechanism
                  (sasl-find-mechanism
                   (delq nil
                         (mapcar '(lambda (cap) (upcase (symbol-name cap)))
                                 (if (listp auth)
                                     auth
                                   (list auth)))))) ;)
                 client name step response tag
                 sasl-read-passphrase)
            (unless mechanism
              (if (or elmo-imap4-force-login
                      (y-or-n-p
                       (format
                        "There's no %s capability in server. continue?"
                        (elmo-list-to-string
                         (elmo-network-session-auth-internal session)))))
                  (setq mechanism (sasl-find-mechanism
                                   sasl-mechanisms))
                (signal 'elmo-authenticate-error
                        '(elmo-imap4-auth-no-mechanisms))))
            (setq client
                  (sasl-make-client
                   mechanism
                   (elmo-network-session-user-internal session)
                   "imap"
                   (elmo-network-session-server-internal session)))
;;;         (if elmo-imap4-auth-user-realm
;;;             (sasl-client-set-property client 'realm elmo-imap4-auth-user-realm))
            (setq name (sasl-mechanism-name mechanism)
                  step (sasl-next-step client nil))
            (elmo-network-session-set-auth-internal
             session
             (intern (downcase name)))
            (setq sasl-read-passphrase
                  (function
                   (lambda (prompt)
                     (elmo-get-passwd
                      (elmo-network-session-password-key session)))))
            (setq tag
                  (elmo-imap4-send-command
                   session
                   (concat "AUTHENTICATE " name
                           (and (sasl-step-data step)
                                (concat
                                 " "
                                 (elmo-base64-encode-string
                                  (sasl-step-data step)
                                  'no-lin-break))))))
            (catch 'done
              (while t
                (setq response
                      (elmo-imap4-read-untagged
                       (elmo-network-session-process-internal session)))
                (if (elmo-imap4-response-ok-p response)
                    (if (sasl-next-step client step)
                        ;; Bogus server?
                        (signal 'elmo-authenticate-error
                                (list (intern
                                       (concat "elmo-imap4-auth-"
                                               (downcase name)))))
                      ;; The authentication process is finished.
                      (throw 'done nil)))
                (unless (elmo-imap4-response-continue-req-p response)
                  ;; response is NO or BAD.
                  (signal 'elmo-authenticate-error
                          (list (intern
                                 (concat "elmo-imap4-auth-"
                                         (downcase name))))))
                (sasl-step-set-data
                 step
                 (elmo-base64-decode-string
                  (elmo-imap4-response-value response 'continue-req)))
                (setq step (sasl-next-step client step))
                (setq tag
                      (elmo-imap4-send-string
                       session
                       (if (sasl-step-data step)
                           (elmo-base64-encode-string (sasl-step-data step)
                                                      'no-line-break)
                         ""))))))))))))

(luna-define-method elmo-network-setup-session ((session
                                                 elmo-imap4-session))
  (with-current-buffer (elmo-network-session-buffer session)
    (when (elmo-imap4-session-capable-p session 'namespace)
      (setq elmo-imap4-server-namespace
            (elmo-imap4-response-value
             (elmo-imap4-send-command-wait session "namespace")
             'namespace)))))

(defun elmo-imap4-setup-send-buffer (&optional string)
  (let ((send-buf (get-buffer-create " *elmo-imap4-setup-send-buffer*"))
        (source-buf (unless string (current-buffer))))
    (save-excursion
      (save-match-data
        (set-buffer send-buf)
        (erase-buffer)
        (set-buffer-multibyte nil)
        (if string
            (insert string)
          (with-current-buffer source-buf
            (copy-to-buffer send-buf (point-min) (point-max))))
        (goto-char (point-min))
        (if (eq (re-search-forward "^$" nil t)
                (point-max))
            (insert "\n"))
        (goto-char (point-min))
        (while (search-forward "\n" nil t)
          (replace-match "\r\n"))))
    send-buf))

(defun elmo-imap4-setup-send-buffer-from-file (file)
  (let ((tmp-buf (get-buffer-create
                  " *elmo-imap4-setup-send-buffer-from-file*")))
    (save-excursion
      (save-match-data
        (set-buffer tmp-buf)
        (erase-buffer)
        (as-binary-input-file
         (insert-file-contents file))
        (goto-char (point-min))
        (if (eq (re-search-forward "^$" nil t)
                (point-max))
            (insert "\n"))
        (goto-char (point-min))
        (while (search-forward "\n" nil t)
          (replace-match "\r\n"))))
    tmp-buf))

(luna-define-method elmo-delete-message-safe ((folder elmo-imap4-folder)
                                              number msgid)
  (let ((session (elmo-imap4-get-session folder))
        candidates)
    (elmo-imap4-session-select-mailbox
     session
     (elmo-imap4-folder-mailbox-internal folder))
    (setq candidates
          (elmo-imap4-response-value
           (elmo-imap4-send-command-wait session
                                         (list
                                          (if elmo-imap4-use-uid
                                              "uid search header message-id "
                                            "search header message-id ")
                                          (elmo-imap4-field-body msgid)))
           'search))
    (if (memq number candidates)
        (elmo-folder-delete-messages folder (list number)))))

(defun elmo-imap4-server-diff-async-callback-1 (status data)
  (funcall elmo-imap4-server-diff-async-callback
           (list (elmo-imap4-response-value status 'recent)
                 (elmo-imap4-response-value status 'unseen)
                 (elmo-imap4-response-value status 'messages))
           data))

(defun elmo-imap4-server-diff-async (folder)
  (let ((session (elmo-imap4-get-session folder)))
    ;; We should `check' folder to obtain newest information here.
    ;; But since there's no asynchronous check mechanism in elmo yet,
    ;; checking is not done here.
    (with-current-buffer (elmo-network-session-buffer session)
      (setq elmo-imap4-status-callback
            'elmo-imap4-server-diff-async-callback-1)
      (setq elmo-imap4-status-callback-data
            elmo-imap4-server-diff-async-callback-data))
    (elmo-imap4-send-command session
                             (list
                              "status "
                              (elmo-imap4-mailbox
                               (elmo-imap4-folder-mailbox-internal folder))
                              " (recent unseen messages)"))))

(luna-define-method elmo-server-diff-async ((folder elmo-imap4-folder))
  (let ((session (elmo-imap4-get-session folder)))
    ;; commit.
    ;; (elmo-imap4-commit spec)
    (with-current-buffer (elmo-network-session-buffer session)
      (setq elmo-imap4-status-callback
            'elmo-imap4-server-diff-async-callback-1)
      (setq elmo-imap4-status-callback-data
            elmo-imap4-server-diff-async-callback-data))
    (elmo-imap4-send-command session
                             (list
                              "status "
                              (elmo-imap4-mailbox
                               (elmo-imap4-folder-mailbox-internal folder))
                              " (recent unseen messages)"))))

;;; IMAP parser.

(defvar elmo-imap4-server-eol "\r\n"
  "The EOL string sent from the server.")

(defvar elmo-imap4-client-eol "\r\n"
  "The EOL string we send to the server.")

(defvar elmo-imap4-literal-progress-reporter nil)

(defun elmo-imap4-find-next-line ()
  "Return point at end of current line, taking into account literals.
Return nil if no complete line has arrived."
  (when (re-search-forward (concat elmo-imap4-server-eol "\\|{\\([0-9]+\\)}"
                                   elmo-imap4-server-eol)
                           nil t)
    (if (match-string 1)
        (if (< (point-max) (+ (point) (string-to-number (match-string 1))))
            (progn
              (when elmo-imap4-literal-progress-reporter
                (elmo-progress-notify
                 'elmo-retrieve-message
                 :set (- (point-max) (point))
                 :total (string-to-number (match-string 1))))
              nil)
          (goto-char (+ (point) (string-to-number (match-string 1))))
          (elmo-imap4-find-next-line))
      (point))))

(defun elmo-imap4-sentinel (process string)
  (delete-process process))

(defun elmo-imap4-arrival-filter (proc string)
  "IMAP process filter."
  (when (buffer-live-p (process-buffer proc))
  (with-current-buffer (process-buffer proc)
    (goto-char (point-max))
    (insert string)
    (let (end)
      (goto-char (point-min))
      (while (setq end (elmo-imap4-find-next-line))
        (save-restriction
          (narrow-to-region (point-min) end)
          (delete-backward-char (length elmo-imap4-server-eol))
          (goto-char (point-min))
          (unwind-protect
              (case elmo-imap4-status
                (initial
                 (setq elmo-imap4-current-response
                       (list
                        (list 'greeting (elmo-imap4-parse-greeting)))))
                ((auth nonauth selected examine)
                 (setq elmo-imap4-current-response
                       (cons (elmo-imap4-parse-response)
                             elmo-imap4-current-response)))
                (t
                 (message "Unknown state %s in arrival filter"
                          elmo-imap4-status)))
            (delete-region (point-min) (point-max)))))))))

;; IMAP parser.

(defsubst elmo-imap4-forward ()
  (or (eobp) (forward-char 1)))

(defsubst elmo-imap4-parse-number ()
  (when (looking-at "[0-9]+")
    (prog1
        (string-to-number (match-string 0))
      (goto-char (match-end 0)))))

(defsubst elmo-imap4-parse-literal ()
  (when (looking-at "{\\([0-9]+\\)}\r\n")
    (let ((pos (match-end 0))
          (len (string-to-number (match-string 1))))
      (if (< (point-max) (+ pos len))
          nil
        (goto-char (+ pos len))
        (buffer-substring pos (+ pos len))))))
;;;     (list ' pos (+ pos len))))))

(defsubst elmo-imap4-parse-string ()
  (cond ((eq (char-after (point)) ?\")
         (forward-char 1)
         (let ((p (point)) (name ""))
           (skip-chars-forward "^\"\\\\")
           (setq name (buffer-substring p (point)))
           (while (eq (char-after (point)) ?\\)
             (setq p (1+ (point)))
             (forward-char 2)
             (skip-chars-forward "^\"\\\\")
             (setq name (concat name (buffer-substring p (point)))))
           (forward-char 1)
           name))
        ((eq (char-after (point)) ?{)
         (elmo-imap4-parse-literal))))

(defsubst elmo-imap4-parse-nil ()
  (if (looking-at "NIL")
      (goto-char (match-end 0))))

(defsubst elmo-imap4-parse-nstring ()
  (or (elmo-imap4-parse-string)
      (and (elmo-imap4-parse-nil)
           nil)))

(defsubst elmo-imap4-parse-astring ()
  (or (elmo-imap4-parse-string)
      (buffer-substring (point)
                        (if (re-search-forward "[(){ \r\n%*\"\\]" nil t)
                            (goto-char (1- (match-end 0)))
                          (end-of-line)
                          (point)))))

(defsubst elmo-imap4-parse-address ()
  (let (address)
    (when (eq (char-after (point)) ?\()
      (elmo-imap4-forward)
      (setq address (vector (prog1 (elmo-imap4-parse-nstring)
                              (elmo-imap4-forward))
                            (prog1 (elmo-imap4-parse-nstring)
                              (elmo-imap4-forward))
                            (prog1 (elmo-imap4-parse-nstring)
                              (elmo-imap4-forward))
                            (elmo-imap4-parse-nstring)))
      (when (eq (char-after (point)) ?\))
        (elmo-imap4-forward)
        address))))

(defsubst elmo-imap4-parse-address-list ()
  (if (eq (char-after (point)) ?\()
      (let (address addresses)
        (elmo-imap4-forward)
        (while (and (not (eq (char-after (point)) ?\)))
                    ;; next line for MS Exchange bug
                    (progn (and (eq (char-after (point)) ? ) (elmo-imap4-forward)) t)
                    (setq address (elmo-imap4-parse-address)))
          (setq addresses (cons address addresses)))
        (when (eq (char-after (point)) ?\))
          (elmo-imap4-forward)
          (nreverse addresses)))
    (assert (elmo-imap4-parse-nil))))

(defsubst elmo-imap4-parse-mailbox ()
  (let ((mailbox (elmo-imap4-parse-astring)))
    (if (string-equal "INBOX" (upcase mailbox))
        "INBOX"
      mailbox)))

(defun elmo-imap4-parse-greeting ()
  "Parse a IMAP greeting."
  (cond ((looking-at "\\* OK ")
         (setq elmo-imap4-status 'nonauth))
        ((looking-at "\\* PREAUTH ")
         (setq elmo-imap4-status 'auth))
        ((looking-at "\\* BYE ")
         (setq elmo-imap4-status 'closed))))

(defun elmo-imap4-parse-response ()
  "Parse a IMAP command response."
  (elmo-imap4-debug "[%s] -> %s" (time-stamp-hh:mm:ss) (buffer-substring (point) (point-max)))
  (let (token)
    (case (setq token (read (current-buffer)))
      (+ (progn
           (skip-chars-forward " ")
           (list 'continue-req (buffer-substring (point) (point-max)))))
      (* (case (prog1 (setq token (read (current-buffer)))
                 (elmo-imap4-forward))
           (OK         (elmo-imap4-parse-resp-text-code))
           (NO         (elmo-imap4-parse-resp-text-code))
           (BAD        (elmo-imap4-parse-resp-text-code))
           (BYE        (elmo-imap4-parse-bye))
           (FLAGS      (list 'flags
                             (elmo-imap4-parse-flag-list)))
           (LIST       (list 'list (elmo-imap4-parse-data-list)))
           (LSUB       (list 'lsub (elmo-imap4-parse-data-list)))
           (SEARCH     (list
                        'search
                        (read (concat "("
                                      (buffer-substring (point) (point-max))
                                      ")"))))
           (ESEARCH     (list
                         'esearch
                         (cddr (split-string (buffer-substring (point) (point-max)) " " "\,"))))
           (STATUS     (elmo-imap4-parse-status))
           ;; Added
           (NAMESPACE  (elmo-imap4-parse-namespace))
           (CAPABILITY (list 'capability
                             (read
                              (concat "(" (downcase (buffer-substring
                                                     (point) (point-max)))
                                      ")"))))
           (ACL (elmo-imap4-parse-acl))
           (t       (case (prog1 (read (current-buffer))
                            (elmo-imap4-forward))
                      (EXISTS  (list 'exists token))
                      (RECENT  (list 'recent token))
                      (EXPUNGE (list 'expunge token))
                      (FETCH   (elmo-imap4-parse-fetch token))
                      (t       (list 'garbage (buffer-string)))))))
      (t (if (not (string-match elmo-imap4-seq-prefix (symbol-name token)))
             (list 'garbage (buffer-string))
           (case (prog1 (read (current-buffer))
                   (elmo-imap4-forward))
             (OK  (progn
                    (setq elmo-imap4-parsing nil)
                    (setq token (symbol-name token))
                    (elmo-unintern token)
                    (elmo-imap4-debug "*%s* OK arrived" token)
                    (setq elmo-imap4-reached-tag token)
                    (list 'ok (elmo-imap4-parse-resp-text-code))))
             (NO  (progn
                    (setq elmo-imap4-parsing nil)
                    (setq token (symbol-name token))
                    (elmo-unintern token)
                    (elmo-imap4-debug "*%s* NO arrived" token)
                    (setq elmo-imap4-reached-tag token)
                    (let (code text)
                      (when (eq (char-after (point)) ?\[)
                        (setq code (buffer-substring (point)
                                                     (search-forward "]")))
                        (elmo-imap4-forward))
                      (setq text (buffer-substring (point) (point-max)))
                      (list 'no (list code text)))))
             (BAD (progn
                    (setq elmo-imap4-parsing nil)
                    (elmo-imap4-debug "*%s* BAD arrived" token)
                    (setq token (symbol-name token))
                    (elmo-unintern token)
                    (setq elmo-imap4-reached-tag token)
                    (let (code text)
                      (when (eq (char-after (point)) ?\[)
                        (setq code (buffer-substring (point)
                                                     (search-forward "]")))
                        (elmo-imap4-forward))
                      (setq text (buffer-substring (point) (point-max)))
                      (list 'bad (list code text)))))
             (t   (list 'garbage (buffer-string)))))))))

(defun elmo-imap4-parse-bye ()
  (let (code text)
    (when (eq (char-after (point)) ?\[)
      (setq code (buffer-substring (point)
                                   (search-forward "]")))
      (elmo-imap4-forward))
    (setq text (buffer-substring (point) (point-max)))
    (list 'bye (list code text))))

(defun elmo-imap4-parse-text ()
  (goto-char (point-min))
  (when (search-forward "[" nil t)
    (search-forward "]")
    (elmo-imap4-forward))
  (list 'text (buffer-substring (point) (point-max))))

(defun elmo-imap4-parse-resp-text-code ()
  (when (eq (char-after (point)) ?\[)
    (elmo-imap4-forward)
    (cond ((search-forward "PERMANENTFLAGS " nil t)
           (list 'permanentflags (elmo-imap4-parse-flag-list)))
          ((search-forward "UIDNEXT " nil t)
           (list 'uidnext (read (current-buffer))))
          ((search-forward "UNSEEN " nil t)
           (list 'unseen (read (current-buffer))))
          ((looking-at "UIDVALIDITY \\([0-9]+\\)")
           (list 'uidvalidity (match-string 1)))
          ((search-forward "READ-ONLY" nil t)
           (list 'read-only t))
          ((search-forward "READ-WRITE" nil t)
           (list 'read-write t))
          ((search-forward "NEWNAME " nil t)
           (let (oldname newname)
             (setq oldname (elmo-imap4-parse-string))
             (elmo-imap4-forward)
             (setq newname (elmo-imap4-parse-string))
             (list 'newname newname oldname)))
          ((search-forward "TRYCREATE" nil t)
           (list 'trycreate t))
          ((looking-at "APPENDUID \\([0-9]+\\) \\([0-9]+\\)")
           (list 'appenduid
                 (list (match-string 1)
                       (string-to-number (match-string 2)))))
          ((looking-at "COPYUID \\([0-9]+\\) \\([0-9,:]+\\) \\([0-9,:]+\\)")
           (list 'copyuid (list (match-string 1)
                                (match-string 2)
                                (match-string 3))))
          ((search-forward "ALERT] " nil t)
           (message "IMAP server information: %s"
                    (buffer-substring (point) (point-max))))
          (t (list 'unknown)))))

(defun elmo-imap4-parse-data-list ()
  (let (flags delimiter mailbox)
    (setq flags (elmo-imap4-parse-flag-list))
    (when (looking-at " NIL\\| \"\\\\?\\(.\\)\"")
      (setq delimiter (match-string 1))
      (goto-char (1+ (match-end 0)))
      (when (setq mailbox (elmo-imap4-parse-mailbox))
        (list mailbox flags delimiter)))))

(defsubst elmo-imap4-parse-header-list ()
  (when (eq (char-after (point)) ?\()
    (let (strlist)
      (while (not (eq (char-after (point)) ?\)))
        (elmo-imap4-forward)
        (push (elmo-imap4-parse-astring) strlist))
      (elmo-imap4-forward)
      (nreverse strlist))))

(defsubst elmo-imap4-parse-fetch-body-section ()
  (let ((section
         (buffer-substring (point)
                           (1-
                            (progn (re-search-forward "[] ]" nil t)
                                   (point))))))
    (if (eq (char-before) ? )
        (prog1
            (mapconcat 'identity
                       (cons section (elmo-imap4-parse-header-list)) " ")
          (search-forward "]" nil t))
      section)))

(defun elmo-imap4-parse-fetch (response)
  (when (eq (char-after (point)) ?\()
    (let (element list)
      (while (not (eq (char-after (point)) ?\)))
        (elmo-imap4-forward)
        (let ((token (read (current-buffer))))
          (elmo-imap4-forward)
          (setq element
                (cond ((eq token 'UID)
                       (list 'uid (condition-case nil
                                      (read (current-buffer))
                                    (error nil))))
                      ((eq token 'FLAGS)
                       (list 'flags (elmo-imap4-parse-flag-list)))
                      ((eq token 'ENVELOPE)
                       (list 'envelope (elmo-imap4-parse-envelope)))
                      ((eq token 'INTERNALDATE)
                       (list 'internaldate (elmo-imap4-parse-string)))
                      ((eq token 'RFC822)
                       (list 'rfc822 (elmo-imap4-parse-nstring)))
                      ((eq token (intern elmo-imap4-rfc822-header))
                       (list 'rfc822header (elmo-imap4-parse-nstring)))
                      ((eq token (intern elmo-imap4-rfc822-text))
                       (list 'rfc822text (elmo-imap4-parse-nstring)))
                      ((eq token (intern elmo-imap4-rfc822-size))
                       (list 'rfc822size (read (current-buffer))))
                      ((eq token 'BODY)
                       (if (eq (char-before) ?\[)
                           (list
                            'bodydetail
                            (upcase (elmo-imap4-parse-fetch-body-section))
                            (and
                             (eq (char-after (point)) ?<)
                             (buffer-substring (1+ (point))
                                               (progn
                                                 (search-forward ">" nil t)
                                                 (point))))
                            (progn (elmo-imap4-forward)
                                   (elmo-imap4-parse-nstring)))
                         (list 'body (elmo-imap4-parse-body))))
                      ((eq token 'BODYSTRUCTURE)
                       (list 'bodystructure (elmo-imap4-parse-body)))))
          (setq list (cons element list))))
      (and elmo-imap4-fetch-callback
           (funcall elmo-imap4-fetch-callback
                    list elmo-imap4-fetch-callback-data))
      (list 'fetch list))))

(defun elmo-imap4-parse-status ()
  (let ((mailbox (elmo-imap4-parse-mailbox))
        status)
    (when (and mailbox (search-forward "(" nil t))
      (while (not (eq (char-after (point)) ?\)))
        (setq status
              (cons
               (let ((token (read (current-buffer))))
                 (case (intern (upcase (symbol-name token)))
                   (MESSAGES
                    (list 'messages (read (current-buffer))))
                   (RECENT
                    (list 'recent (read (current-buffer))))
                   (UIDNEXT
                    (list 'uidnext (read (current-buffer))))
                   (UIDVALIDITY
                    (and (looking-at " \\([0-9]+\\)")
                         (prog1 (list 'uidvalidity (match-string 1))
                           (goto-char (match-end 1)))))
                   (UNSEEN
                    (list 'unseen (read (current-buffer))))
                   (t 
                    (message
                     "Unknown status data %s in mailbox %s ignored"
                     token mailbox))))
               status))
        (skip-chars-forward " ")))
    (and elmo-imap4-status-callback
         (funcall elmo-imap4-status-callback
                  status
                  elmo-imap4-status-callback-data))
    (list 'status status)))


(defmacro elmo-imap4-value (value)
  `(if (eq ,value 'NIL)
       nil
     ,value))

(defmacro elmo-imap4-nth (pos list)
  `(let ((value (nth ,pos ,list)))
     (elmo-imap4-value value)))

(defun elmo-imap4-parse-namespace ()
  (list 'namespace
        (nconc
         (copy-sequence elmo-imap4-extra-namespace-alist)
         (elmo-imap4-parse-namespace-subr
          (read (concat "(" (buffer-substring
                             (point) (point-max))
                        ")"))))))

(defun elmo-imap4-parse-namespace-subr (ns)
  (let (prefix delim namespace-alist default-delim)
    ;; 0: personal, 1: other, 2: shared
    (dotimes (i 3)
      (setq namespace-alist
            (nconc namespace-alist
                   (delq nil
                         (mapcar
                          (lambda (namespace)
                            (setq prefix (elmo-imap4-nth 0 namespace)
                                  delim (elmo-imap4-nth 1 namespace))
                            (if (and prefix delim
                                     (string-match
                                      (concat (regexp-quote delim) "\\'")
                                      prefix))
                                (setq prefix (substring prefix 0
                                                        (match-beginning 0))))
                            (if (eq (length prefix) 0)
                                (progn (setq default-delim delim) nil)
                              (cons
                               (concat "^\\("
                                       (if (string= (downcase prefix) "inbox")
                                           "[Ii][Nn][Bb][Oo][Xx]"
                                         (regexp-quote prefix))
                                       "\\).*$")
                               delim)))
                          (elmo-imap4-nth i ns))))))
    (if default-delim
        (setq namespace-alist
              (nconc namespace-alist
                     (list (cons "^.*$" default-delim)))))
    namespace-alist))

(defun elmo-imap4-parse-acl ()
  (let ((mailbox (elmo-imap4-parse-mailbox))
        identifier rights acl)
    (while (eq (char-after (point)) ?\ )
      (elmo-imap4-forward)
      (setq identifier (elmo-imap4-parse-astring))
      (elmo-imap4-forward)
      (setq rights (elmo-imap4-parse-astring))
      (setq acl (append acl (list (cons identifier rights)))))
    (list 'acl acl mailbox)))

(defun elmo-imap4-parse-flag-list ()
  (let ((str (buffer-substring (+ (point) 1)
                               (progn (search-forward ")" nil t)
                                      (- (point) 1)))))
    (unless (eq (length str) 0)
      (split-string str))))

(defun elmo-imap4-parse-envelope ()
  (when (eq (char-after (point)) ?\()
    (elmo-imap4-forward)
    (vector (prog1 (elmo-imap4-parse-nstring);; date
              (elmo-imap4-forward))
            (prog1 (elmo-imap4-parse-nstring);; subject
              (elmo-imap4-forward))
            (prog1 (elmo-imap4-parse-address-list);; from
              (elmo-imap4-forward))
            (prog1 (elmo-imap4-parse-address-list);; sender
              (elmo-imap4-forward))
            (prog1 (elmo-imap4-parse-address-list);; reply-to
              (elmo-imap4-forward))
            (prog1 (elmo-imap4-parse-address-list);; to
              (elmo-imap4-forward))
            (prog1 (elmo-imap4-parse-address-list);; cc
              (elmo-imap4-forward))
            (prog1 (elmo-imap4-parse-address-list);; bcc
              (elmo-imap4-forward))
            (prog1 (elmo-imap4-parse-nstring);; in-reply-to
              (elmo-imap4-forward))
            (prog1 (elmo-imap4-parse-nstring);; message-id
              (elmo-imap4-forward)))))

(defsubst elmo-imap4-parse-string-list ()
  (cond ((eq (char-after (point)) ?\();; body-fld-param
         (let (strlist str)
           (elmo-imap4-forward)
           (while (setq str (elmo-imap4-parse-string))
             (push str strlist)
             (elmo-imap4-forward))
           (nreverse strlist)))
        ((elmo-imap4-parse-nil)
         nil)))

(defun elmo-imap4-parse-body-extension ()
  (if (eq (char-after (point)) ?\()
      (let (b-e)
        (elmo-imap4-forward)
        (push (elmo-imap4-parse-body-extension) b-e)
        (while (eq (char-after (point)) ?\ )
          (elmo-imap4-forward)
          (push (elmo-imap4-parse-body-extension) b-e))
        (assert (eq (char-after (point)) ?\)))
        (elmo-imap4-forward)
        (nreverse b-e))
    (or (elmo-imap4-parse-number)
        (elmo-imap4-parse-nstring))))

(defsubst elmo-imap4-parse-body-ext ()
  (let (ext)
    (when (eq (char-after (point)) ?\ );; body-fld-dsp
      (elmo-imap4-forward)
      (let (dsp)
        (if (eq (char-after (point)) ?\()
            (progn
              (elmo-imap4-forward)
              (push (elmo-imap4-parse-string) dsp)
              (elmo-imap4-forward)
              (push (elmo-imap4-parse-string-list) dsp)
              (elmo-imap4-forward))
          (assert (elmo-imap4-parse-nil)))
        (push (nreverse dsp) ext))
      (when (eq (char-after (point)) ?\ );; body-fld-lang
        (elmo-imap4-forward)
        (if (eq (char-after (point)) ?\()
            (push (elmo-imap4-parse-string-list) ext)
          (push (elmo-imap4-parse-nstring) ext))
        (while (eq (char-after (point)) ?\ );; body-extension
          (elmo-imap4-forward)
          (setq ext (append (elmo-imap4-parse-body-extension) ext)))))
    ext))

(defun elmo-imap4-parse-body ()
  (let (body)
    (when (eq (char-after (point)) ?\()
      (elmo-imap4-forward)
      (if (eq (char-after (point)) ?\()
          (let (subbody)
            (while (and (eq (char-after (point)) ?\()
                        (setq subbody (elmo-imap4-parse-body)))
              (push subbody body))
            (elmo-imap4-forward)
            (push (elmo-imap4-parse-string) body);; media-subtype
            (when (eq (char-after (point)) ?\ );; body-ext-mpart:
              (elmo-imap4-forward)
              (if (eq (char-after (point)) ?\();; body-fld-param
                  (push (elmo-imap4-parse-string-list) body)
                (push (and (elmo-imap4-parse-nil) nil) body))
              (setq body
                    (append (elmo-imap4-parse-body-ext) body)));; body-ext-...
            (assert (eq (char-after (point)) ?\)))
            (elmo-imap4-forward)
            (nreverse body))

        (push (elmo-imap4-parse-string) body);; media-type
        (elmo-imap4-forward)
        (push (elmo-imap4-parse-string) body);; media-subtype
        (elmo-imap4-forward)
        ;; next line for Sun SIMS bug
        (and (eq (char-after (point)) ? ) (elmo-imap4-forward))
        (if (eq (char-after (point)) ?\();; body-fld-param
            (push (elmo-imap4-parse-string-list) body)
          (push (and (elmo-imap4-parse-nil) nil) body))
        (elmo-imap4-forward)
        (push (elmo-imap4-parse-nstring) body);; body-fld-id
        (elmo-imap4-forward)
        (push (elmo-imap4-parse-nstring) body);; body-fld-desc
        (elmo-imap4-forward)
        (push (elmo-imap4-parse-string) body);; body-fld-enc
        (elmo-imap4-forward)
        (push (elmo-imap4-parse-number) body);; body-fld-octets

        ;; ok, we're done parsing the required parts, what comes now is one
        ;; of three things:
        ;;
        ;; envelope       (then we're parsing body-type-msg)
        ;; body-fld-lines (then we're parsing body-type-text)
        ;; body-ext-1part (then we're parsing body-type-basic)
        ;;
        ;; the problem is that the two first are in turn optionally followed
        ;; by the third.  So we parse the first two here (if there are any)...

        (when (eq (char-after (point)) ?\ )
          (elmo-imap4-forward)
          (let (lines)
            (cond ((eq (char-after (point)) ?\();; body-type-msg:
                   (push (elmo-imap4-parse-envelope) body);; envelope
                   (elmo-imap4-forward)
                   (push (elmo-imap4-parse-body) body);; body
                   (elmo-imap4-forward)
                   (push (elmo-imap4-parse-number) body));; body-fld-lines
                  ((setq lines (elmo-imap4-parse-number));; body-type-text:
                   (push lines body));; body-fld-lines
                  (t
                   (backward-char)))));; no match...

        ;; ...and then parse the third one here...

        (when (eq (char-after (point)) ?\ );; body-ext-1part:
          (elmo-imap4-forward)
          (push (elmo-imap4-parse-nstring) body);; body-fld-md5
          (setq body
                (append (elmo-imap4-parse-body-ext) body)));; body-ext-1part..

        (assert (eq (char-after (point)) ?\)))
        (elmo-imap4-forward)
        (nreverse body)))))

(luna-define-method elmo-folder-initialize ((folder elmo-imap4-folder) name)
  (let ((default-user   elmo-imap4-default-user)
        (default-server elmo-imap4-default-server)
        (default-port   elmo-imap4-default-port)
        (elmo-network-stream-type-alist
         (if elmo-imap4-stream-type-alist
             (append elmo-imap4-stream-type-alist
                     elmo-network-stream-type-alist)
           elmo-network-stream-type-alist))
        tokens)
    (when (string-match "\\(.*\\)@\\(.*\\)" default-server)
      ;; case: imap4-default-server is specified like
      ;; "hoge%imap.server@gateway".
      (setq default-user (elmo-match-string 1 default-server))
      (setq default-server (elmo-match-string 2 default-server)))
    (setq tokens (car (elmo-parse-separated-tokens
                       name
                       elmo-imap4-folder-name-syntax)))
    ;; mailbox
    (elmo-imap4-folder-set-mailbox-internal folder
                                            (elmo-imap4-encode-folder-string
                                             (cdr (assq 'mailbox tokens))))
    ;; user
    (elmo-net-folder-set-user-internal 
     folder
     (let ((user (cdr (assq 'user tokens))))
       (if user
           (if (string-match "*" user)
               (replace-match "@" nil nil user)
             user)
         default-user)))

    ;; auth
    (elmo-net-folder-set-auth-internal
     folder
     (let ((auth (cdr (assq 'auth tokens))))
       (or (and auth (intern auth))
           elmo-imap4-default-authenticate-type
           'clear)))
    ;; network
    (elmo-net-folder-set-parameters
     folder
     tokens
     (list :server      default-server
           :port        default-port
           :stream-type
           (elmo-get-network-stream-type elmo-imap4-default-stream-type)))
    folder))

;;; ELMO IMAP4 folder
(luna-define-method elmo-folder-expand-msgdb-path ((folder
                                                    elmo-imap4-folder))
  (convert-standard-filename
   (let ((mailbox (elmo-imap4-folder-mailbox-internal folder)))
     (if (string= "inbox" (downcase mailbox))
         (setq mailbox "inbox"))
     (if (eq (string-to-char mailbox) ?/)
         (setq mailbox (substring mailbox 1 (length mailbox))))
     ;; don't use expand-file-name (e.g. %~/something)
     (concat
      (expand-file-name
       (or (elmo-net-folder-user-internal folder) "nobody")
       (expand-file-name (or (elmo-net-folder-server-internal folder)
                             "nowhere")
                         (expand-file-name
                          "imap"
                          elmo-msgdb-directory)))
      "/" mailbox))))

(luna-define-method elmo-folder-status-plugged ((folder
                                                 elmo-imap4-folder))
  (elmo-imap4-folder-status-plugged folder))

(defun elmo-imap4-folder-status-plugged (folder)
  (let ((session (elmo-imap4-get-session folder))
        (killed (elmo-msgdb-killed-list-load
                 (elmo-folder-msgdb-path folder)))
        status)
    (with-current-buffer (elmo-network-session-buffer session)
      (setq elmo-imap4-status-callback nil)
      (setq elmo-imap4-status-callback-data nil))
    (setq status (elmo-imap4-response-value
                  (elmo-imap4-send-command-wait
                   session
                   (list "status "
                         (elmo-imap4-mailbox
                          (elmo-imap4-folder-mailbox-internal folder))
                         " (uidnext messages)"))
                  'status))
    (cons
     (- (elmo-imap4-response-value status 'uidnext) 1)
     (if killed
         (-
          (elmo-imap4-response-value status 'messages)
          (elmo-msgdb-killed-list-length killed))
       (elmo-imap4-response-value status 'messages)))))

(defun elmo-imap4-folder-list-range (folder min max)
  (elmo-imap4-list
   folder
   (concat
    (let ((killed
          (elmo-folder-killed-list-internal
           folder)))
      (if (and killed
              (eq (length killed) 1)
              (consp (car killed))
              (eq (car (car killed)) 1))
;; What about elmo-imap4-use-uid?
         (format "uid %d:%s" (cdr (car killed)) max)
       (format "uid %s:%s" min max)))
    " undeleted")))

(luna-define-method elmo-folder-list-messages-plugged ((folder
                                                        elmo-imap4-folder)
                                                       &optional
                                                       enable-killed)

  (let* ((old (elmo-msgdb-list-messages (elmo-folder-msgdb folder)))
         (new (elmo-imap4-folder-list-range folder
               (1+ (or (elmo-folder-get-info-max folder) 0)) "*"))
         (united-old-new (elmo-union old new)))
    (if (= (length united-old-new) (or (elmo-folder-get-info-length folder) 0))
        united-old-new
      (elmo-union new
                  (elmo-imap4-folder-list-range
                   folder
                   1 (1+ (or (elmo-folder-get-info-max folder) 0)))))))

(luna-define-method elmo-folder-list-flagged-plugged
  ((folder elmo-imap4-folder) flag)
  (elmo-imap4-folder-list-flagged folder flag))

(luna-define-method elmo-folder-use-flag-p ((folder elmo-imap4-folder))
  (not (string-match elmo-imap4-disuse-server-flag-mailbox-regexp
                     (elmo-imap4-folder-mailbox-internal folder))))

(luna-define-method elmo-folder-list-subfolders ((folder elmo-imap4-folder)
                                                 &optional one-level)
  (let* ((root (elmo-imap4-folder-mailbox-internal folder))
         (session (elmo-imap4-get-session folder))
         (prefix (elmo-folder-prefix-internal folder))
         (namespace-assoc
                  (elmo-string-matched-assoc
                   root
                   (with-current-buffer (elmo-network-session-buffer session)
                     elmo-imap4-server-namespace)))
         (delim (or (cdr namespace-assoc)
                 elmo-imap4-default-hierarchy-delimiter))
         ;; Append delimiter when root with namespace.
         (root-nodelim root)
         (root (if (and namespace-assoc
                        (match-end 1)
                        (string= (substring root (match-end 1))
                                 ""))
                   (concat root delim)
                 root))
         result append-serv type)
    (setq result (elmo-imap4-response-get-selectable-mailbox-list
                  (elmo-imap4-send-command-wait
                   session
                   (list "list " (elmo-imap4-mailbox root) " *"))))
    ;; The response of Courier-imap doesn't contain a specified folder itself.
    (unless (member root result)
      (setq result
            (append result
                    (elmo-imap4-response-get-selectable-mailbox-list
                     (elmo-imap4-send-command-wait
                      session
                      (list "list \"\" " (elmo-imap4-mailbox
                                          root-nodelim)))))))
    (when (or (not (string= (elmo-net-folder-user-internal folder)
                            elmo-imap4-default-user))
              (not (eq (elmo-net-folder-auth-internal folder)
                       (or elmo-imap4-default-authenticate-type 'clear))))
      (setq append-serv (concat ":"
                                (elmo-quote-syntactical-element
                                 (elmo-net-folder-user-internal folder)
                                 'user elmo-imap4-folder-name-syntax))))
    (unless (eq (elmo-net-folder-auth-internal folder)
                (or elmo-imap4-default-authenticate-type 'clear))
      (setq append-serv
            (concat append-serv "/"
                    (symbol-name (elmo-net-folder-auth-internal folder)))))
    (unless (string= (elmo-net-folder-server-internal folder)
                     elmo-imap4-default-server)
      (setq append-serv (concat append-serv "@"
                                (elmo-net-folder-server-internal folder))))
    (unless (eq (elmo-net-folder-port-internal folder) elmo-imap4-default-port)
      (setq append-serv (concat append-serv ":"
                                (int-to-string
                                 (elmo-net-folder-port-internal folder)))))
    (setq type (elmo-net-folder-stream-type-internal folder))
    (unless (eq (elmo-network-stream-type-symbol type)
                elmo-imap4-default-stream-type)
      (if type
          (setq append-serv (concat append-serv
                                    (elmo-network-stream-type-spec-string
                                     type)))))
    (if one-level
        (let ((re-delim (regexp-quote delim))
              (case-fold-search nil)
              folder ret has-child-p)
          ;; Append delimiter
          (when (and root
                     (not (string= root ""))
                     (not (string-match
                           (concat "\\(.*\\)" re-delim "\\'")
                           root)))
            (setq root (concat root delim)))
          (while (setq folder (car result))
            (setq has-child-p
                  (when (string-match
                         (concat "^\\(" (regexp-quote root) "[^" re-delim "]" "+\\)"
                                 re-delim)
                         folder)
                    (setq folder (match-string 1 folder))))
            (setq result (delq
                          nil
                          (mapcar (lambda (fld)
                                    (if (string-match
                                         (concat "^" (regexp-quote folder)
                                                 "\\(" re-delim "\\|\\'\\)")
                                         fld)
                                        (progn (setq has-child-p t) nil)
                                      fld))
                                  (cdr result)))
                  folder (concat prefix
                                 (elmo-quote-syntactical-element
                                  (elmo-imap4-decode-folder-string folder)
                                  'mailbox elmo-imap4-folder-name-syntax)
                                 (and append-serv
                                      (eval append-serv)))
                  ret (append ret (if has-child-p
                                      (list (list folder))
                                    (list folder)))))
          ret)
      (mapcar (lambda (fld)
                (concat prefix
                        (elmo-quote-syntactical-element
                         (elmo-imap4-decode-folder-string fld)
                         'mailbox elmo-imap4-folder-name-syntax)
                        (and append-serv
                             (eval append-serv))))
              result))))

(luna-define-method elmo-folder-exists-p-plugged ((folder elmo-imap4-folder))
  (let ((session (elmo-imap4-get-session folder)))
    (if (string=
         (elmo-imap4-session-current-mailbox-internal session)
         (elmo-imap4-folder-mailbox-internal folder))
        t
      (elmo-imap4-session-select-mailbox
       session
       (elmo-imap4-folder-mailbox-internal folder)
       'force 'notify-bye))))

(luna-define-method elmo-folder-creatable-p ((folder elmo-imap4-folder))
  t)

(luna-define-method elmo-folder-writable-p ((folder elmo-imap4-folder))
  t)

(luna-define-method elmo-folder-delete ((folder elmo-imap4-folder))
  (let* ((exists (elmo-folder-exists-p folder))
         (msgs (and exists
                    (elmo-folder-list-messages folder))))
    (when (yes-or-no-p (format "%sDelete msgdb and substance of \"%s\"? "
                               (if (> (length msgs) 0)
                                   (format "%d msg(s) exists. " (length msgs))
                                 "")
                               (elmo-folder-name-internal folder)))
      (let ((session (elmo-imap4-get-session folder)))
        (when (elmo-imap4-folder-mailbox-internal folder)
          (when msgs (elmo-folder-delete-messages-internal folder msgs))
          ;; close selected mailbox except one with \Noselect attribute
          (when exists
            (elmo-imap4-send-command-wait session "close"))
          (elmo-imap4-send-command-wait
           session
           (list "delete "
                 (elmo-imap4-mailbox
                  (elmo-imap4-folder-mailbox-internal folder)))))
        (elmo-imap4-session-set-current-mailbox-internal session nil))
      (elmo-msgdb-delete-path folder)
      t)))

(luna-define-method elmo-folder-rename-internal ((folder elmo-imap4-folder)
                                                 new-folder)
  (let ((session (elmo-imap4-get-session folder)))
    ;; make sure the folder is selected.
    (elmo-imap4-session-select-mailbox session
                                       (elmo-imap4-folder-mailbox-internal
                                        folder))
    (elmo-imap4-send-command-wait session "close")
    (elmo-imap4-send-command-wait
     session
     (list "rename "
           (elmo-imap4-mailbox
            (elmo-imap4-folder-mailbox-internal folder))
           " "
           (elmo-imap4-mailbox
            (elmo-imap4-folder-mailbox-internal new-folder))))
    (elmo-imap4-session-set-current-mailbox-internal
     session (elmo-imap4-folder-mailbox-internal new-folder))))

(defun elmo-imap4-copy-messages (src-folder dst-folder numbers)
  (let ((session (elmo-imap4-get-session src-folder))
        (set-list (elmo-imap4-make-number-set-list
                   numbers
                   elmo-imap4-number-set-chop-length))
        succeeds)
    (elmo-imap4-session-select-mailbox session
                                       (elmo-imap4-folder-mailbox-internal
                                        src-folder))
    (while set-list
      (if (elmo-imap4-send-command-wait session
                                        (list
                                         (format
                                          (if elmo-imap4-use-uid
                                              "uid copy %s "
                                            "copy %s ")
                                          (cdr (car set-list)))
                                         (elmo-imap4-mailbox
                                          (elmo-imap4-folder-mailbox-internal
                                           dst-folder))))
          (setq succeeds (append succeeds numbers)))
      (setq set-list (cdr set-list)))
    succeeds))

(defun elmo-imap4-set-flag (folder numbers flag &optional remove)
  "Set flag on messages.
FOLDER is the ELMO folder structure.
NUMBERS is the message numbers to be flagged.
FLAG is the flag name.
If optional argument REMOVE is non-nil, remove FLAG."
  (let ((session (elmo-imap4-get-session folder))
        response set-list)
    (elmo-imap4-session-select-mailbox session
                                       (elmo-imap4-folder-mailbox-internal
                                        folder))
    (when (or (elmo-string-member-ignore-case
               flag
               (elmo-imap4-session-flags-internal session))
              (member "\\*" (elmo-imap4-session-flags-internal session))
              (string= flag "\\Deleted")) ; XXX Humm..
      (setq set-list (elmo-imap4-make-number-set-list
                      numbers
                      elmo-imap4-number-set-chop-length))
      (while set-list
        (with-current-buffer (elmo-network-session-buffer session)
          (setq elmo-imap4-fetch-callback nil)
          (setq elmo-imap4-fetch-callback-data nil))
        (unless (elmo-imap4-response-ok-p
                 (elmo-imap4-send-command-wait
                  session
                  (format
                   (if elmo-imap4-use-uid
                       "uid store %s %sflags.silent (%s)"
                     "store %s %sflags.silent (%s)")
                   (cdr (car set-list))
                   (if remove "-" "+")
                   flag)))
          (setq response 'fail))
        (setq set-list (cdr set-list)))
      (not (eq response 'fail)))))

(luna-define-method elmo-folder-delete-messages-plugged
  ((folder elmo-imap4-folder) numbers)
  (let ((session (elmo-imap4-get-session folder))
        (expunge
         (or (null (elmo-imap4-list folder "deleted"))
             (y-or-n-p
              "There's hidden deleted messages, expunge anyway?"))))
    (elmo-imap4-session-select-mailbox
     session
     (elmo-imap4-folder-mailbox-internal folder))
    (unless (elmo-imap4-set-flag folder numbers "\\Deleted")
      (error "Failed to set deleted flag"))
    (when expunge
      (elmo-imap4-send-command session "expunge"))
    t))

(defmacro elmo-imap4-detect-search-charset (string)
  `(with-temp-buffer
     (insert ,string)
     (detect-mime-charset-region (point-min) (point-max))))

(defun elmo-imap4-search-internal-primitive (folder session filter from-msgs)
  (let ((search-key (elmo-filter-key filter))
        (imap-search-keys '("bcc" "body" "cc" "from" "subject" "to"
                            "larger" "smaller" "flag"))
        (total 0)
        (length (length from-msgs))
        charset set-list end results)
    (cond
     ((string= "last" search-key)
      (let ((numbers (or from-msgs (elmo-folder-list-messages folder))))
        (nthcdr (max (- (length numbers)
                        (string-to-number (elmo-filter-value filter)))
                     0)
                numbers)))
     ((string= "first" search-key)
      (let* ((numbers (or from-msgs (elmo-folder-list-messages folder)))
             (rest (nthcdr (string-to-number (elmo-filter-value filter) )
                           numbers)))
        (mapcar '(lambda (x) (delete x numbers)) rest)
        numbers))
     ((string= "flag" search-key)
      (elmo-imap4-folder-list-flagged
       folder (intern (elmo-filter-value filter))))
     ((or (string= "since" search-key)
          (string= "before" search-key))
      (setq search-key (concat "sent" search-key)
            set-list (elmo-imap4-make-number-set-list
                      from-msgs
                      elmo-imap4-number-set-chop-length)
            end nil)
      (while (not end)
        (setq results
              (append
               results
               (elmo-imap4-response-value
                (elmo-imap4-send-command-wait
                 session
                 (format
                  (if elmo-imap4-use-uid
                      "uid search %s%s%s %s"
                    "search %s%s%s %s")
                  (if from-msgs
                      (concat
                       (if elmo-imap4-use-uid "uid ")
                       (cdr (car set-list))
                       " ")
                    "")
                  (if (eq (elmo-filter-type filter)
                          'unmatch)
                      "not " "")
                  search-key
                  (elmo-date-get-description
                   (elmo-date-get-datevec
                    (elmo-filter-value filter)))))
                'search)))
        (setq set-list (cdr set-list)
              end (null set-list)))
      results)
     (t
      (setq charset
            (if (eq (length (elmo-filter-value filter)) 0)
                (setq charset 'us-ascii)
              (elmo-imap4-detect-search-charset
               (elmo-filter-value filter)))
            set-list (elmo-imap4-make-number-set-list
                      from-msgs
                      elmo-imap4-number-set-chop-length)
            end nil)
      (while (not end)
        (setq results
              (append
               results
               (elmo-imap4-response-value
                (elmo-imap4-send-command-wait
                 session
                 (list
                  (if elmo-imap4-use-uid "uid ")
                  "search "
                  "CHARSET "
                  (elmo-imap4-astring
                   (symbol-name charset))
                  " "
                  (if from-msgs
                      (concat
                       (if elmo-imap4-use-uid "uid ")
                       (cdr (car set-list))
                       " ")
                    "")
                  (if (eq (elmo-filter-type filter)
                          'unmatch)
                      "not " "")
                  (format "%s%s "
                          (if (member
                               (elmo-filter-key filter)
                               imap-search-keys)
                              ""
                            "header ")
                          (elmo-filter-key filter))
                  (elmo-imap4-astring
                   (encode-mime-charset-string
                    (elmo-filter-value filter) charset))))
                'search)))
        (setq set-list (cdr set-list)
              end (null set-list)))
      results))))

(defun elmo-imap4-search-internal (folder session condition from-msgs)
  (let (result)
    (cond
     ((vectorp condition)
      (setq result (elmo-imap4-search-internal-primitive
                    folder session condition from-msgs)))
     ((eq (car condition) 'and)
      (setq result (elmo-imap4-search-internal folder session (nth 1 condition)
                                               from-msgs)
            result (elmo-list-filter result
                                     (elmo-imap4-search-internal
                                      folder session (nth 2 condition)
                                      from-msgs))))
     ((eq (car condition) 'or)
      (setq result (elmo-imap4-search-internal
                    folder session (nth 1 condition) from-msgs)
            result (elmo-uniq-list
                    (nconc result
                           (elmo-imap4-search-internal
                            folder session (nth 2 condition) from-msgs)))
            result (sort result '<))))))

(luna-define-method elmo-folder-search :around ((folder elmo-imap4-folder)
                                                condition &optional numbers)
  (if (elmo-folder-plugged-p folder)
      (save-excursion
        (let ((session (elmo-imap4-get-session folder))
              ret)
          (message "Searching...")
          (elmo-imap4-session-select-mailbox
           session
           (elmo-imap4-folder-mailbox-internal folder))
          (setq ret (elmo-imap4-search-internal folder session condition numbers))
          (message "Searching...done")
          ret))
    (luna-call-next-method)))

(luna-define-method elmo-folder-msgdb-create-plugged
  ((folder elmo-imap4-folder) numbers flag-table)
  (when numbers
    (let ((session (elmo-imap4-get-session folder))
          (headers
           (elmo-uniq-list
            (append
             '("Subject" "From" "To" "Cc" "Date"
               "Message-Id" "References" "In-Reply-To")
             (mapcar #'capitalize (elmo-msgdb-extra-fields 'non-virtual)))))
          (total 0)
          print-length print-depth
          rfc2060 set-list)
      (setq rfc2060 (elmo-imap4-session-capable-p session 'imap4rev1))
      (elmo-with-progress-display (elmo-folder-msgdb-create (length numbers))
          "Creating msgdb"
        (elmo-imap4-session-select-mailbox
         session (elmo-imap4-folder-mailbox-internal folder))
        (setq set-list (elmo-imap4-make-number-set-list
                        numbers
                        elmo-imap4-overview-fetch-chop-length))
        ;; Setup callback.
        (with-current-buffer (elmo-network-session-buffer session)
          (setq elmo-imap4-current-msgdb (elmo-make-msgdb)
                elmo-imap4-seen-messages nil
                elmo-imap4-fetch-callback 'elmo-imap4-fetch-callback-1
                elmo-imap4-fetch-callback-data (cons flag-table folder))
          (while set-list
            (elmo-imap4-send-command-wait
             session
             ;; get overview entity from IMAP4
             (format "%sfetch %s (%s rfc822.size flags)"
                     (if elmo-imap4-use-uid "uid " "")
                     (cdr (car set-list))
                     (if rfc2060
                         (format "body.peek[header.fields %s]" headers)
                       (format "%s" headers))))
            (setq set-list (cdr set-list)))
          (when elmo-imap4-seen-messages
            (elmo-imap4-set-flag folder elmo-imap4-seen-messages "\\Seen"))
          ;; cannot setup the global flag while retrieval.
          (dolist (number (elmo-msgdb-list-messages elmo-imap4-current-msgdb))
            (elmo-global-flags-set (elmo-msgdb-flags elmo-imap4-current-msgdb
                                                     number)
                                   folder number
                                   (elmo-message-entity-field
                                    (elmo-msgdb-message-entity
                                     elmo-imap4-current-msgdb number)
                                    'message-id)))
          elmo-imap4-current-msgdb)))))

(luna-define-method elmo-folder-set-flag-plugged ((folder elmo-imap4-folder)
                                                  numbers flag)
  (let ((spec (cdr (assq flag elmo-imap4-flag-specs))))
    (elmo-imap4-set-flag folder numbers (or (car spec)
                                            (capitalize (symbol-name flag)))
                         (nth 1 spec))))

(luna-define-method elmo-folder-unset-flag-plugged ((folder elmo-imap4-folder)
                                                    numbers flag)
  (let ((spec (cdr (assq flag elmo-imap4-flag-specs))))
    (elmo-imap4-set-flag folder numbers (or (car spec)
                                            (capitalize (symbol-name flag)))
                         (not (nth 1 spec)))))

(luna-define-method elmo-message-use-cache-p ((folder elmo-imap4-folder)
                                              number)
  elmo-imap4-use-cache)

(luna-define-method elmo-folder-message-appendable-p ((folder elmo-imap4-folder))
  (if (elmo-folder-plugged-p folder)
      (not (elmo-imap4-session-read-only-internal
            (elmo-imap4-get-session folder)))
    elmo-enable-disconnected-operation)) ; offline refile.

(luna-define-method elmo-folder-check-plugged ((folder elmo-imap4-folder))
  (let ((session (elmo-imap4-get-session folder 'if-exists)))
    (when session
      (if (string=
           (elmo-imap4-session-current-mailbox-internal session)
           (elmo-imap4-folder-mailbox-internal folder))
          (if elmo-imap4-use-select-to-update-status
              (elmo-imap4-session-select-mailbox
               session
               (elmo-imap4-folder-mailbox-internal folder)
               'force)
            (elmo-imap4-session-check session))))))

(defsubst elmo-imap4-folder-diff-plugged (folder)
  (let ((session (elmo-imap4-get-session folder))
        messages new unread response killed uidnext)
;;; (elmo-imap4-commit spec)
    (with-current-buffer (elmo-network-session-buffer session)
      (setq elmo-imap4-status-callback nil)
      (setq elmo-imap4-status-callback-data nil))
    (if elmo-imap4-use-select-to-update-status
        (elmo-imap4-session-select-mailbox
         session
         (elmo-imap4-folder-mailbox-internal folder)))
    (setq response
          (elmo-imap4-send-command-wait session
                                        (list
                                         "status "
                                         (elmo-imap4-mailbox
                                          (elmo-imap4-folder-mailbox-internal
                                           folder))
                                         " (recent unseen messages uidnext)")))
    (setq response (elmo-imap4-response-value response 'status))
    (setq messages (elmo-imap4-response-value response 'messages))
    (setq uidnext (elmo-imap4-response-value response 'uidnext))
    (setq killed (elmo-msgdb-killed-list-load (elmo-folder-msgdb-path folder)))
    ;;
    (when killed
      (when (and (consp (car killed))
                 (eq (car (car killed)) 1))
        (setq messages (- uidnext (cdr (car killed)) 1)))
      (setq messages (- messages
                        (elmo-msgdb-killed-list-length (cdr killed)))))
    (setq new (elmo-imap4-response-value response 'recent)
          unread (elmo-imap4-response-value response 'unseen))
    (if (< unread new) (setq new unread))
    (list new unread messages)))

(luna-define-method elmo-folder-diff-plugged ((folder elmo-imap4-folder))
  (elmo-imap4-folder-diff-plugged folder))

(luna-define-method elmo-folder-diff-async ((folder elmo-imap4-folder))
  (setq elmo-imap4-server-diff-async-callback
        elmo-folder-diff-async-callback)
  (setq elmo-imap4-server-diff-async-callback-data
        elmo-folder-diff-async-callback-data)
  (elmo-imap4-server-diff-async folder))

(luna-define-method elmo-folder-open :around ((folder elmo-imap4-folder)
                                              &optional load-msgdb)
  (if (elmo-folder-plugged-p folder)
      (let (session mailbox msgdb result response tag)
        (condition-case err
            (progn
              (setq session (elmo-imap4-get-session folder)
                    mailbox (elmo-imap4-folder-mailbox-internal folder)
                    tag (elmo-imap4-send-command session
                                                 (list "select "
                                                       (elmo-imap4-mailbox
                                                        mailbox))))
              (message "Selecting %s..."
                       (elmo-folder-name-internal folder))
              (if load-msgdb
                  (setq msgdb (elmo-folder-msgdb-load folder 'silent)))
              (elmo-folder-set-killed-list-internal
               folder
               (elmo-msgdb-killed-list-load (elmo-folder-msgdb-path folder)))
              (if (setq result (elmo-imap4-response-ok-p
                                (setq response
                                      (elmo-imap4-read-response session tag))))
                  (progn
                    (let ((exists (assq 'exists response))) ; update message count,
                      (when exists                          ; so merge update can go
                        (elmo-folder-set-info-hashtb folder nil (cadr exists))))
                    (elmo-imap4-session-set-current-mailbox-internal
                     session mailbox)
                    (elmo-imap4-session-set-read-only-internal
                     session
                     (nth 1 (assq 'read-only (assq 'ok response))))
                    (elmo-imap4-session-set-flags-internal
                     session
                     (nth 1 (or (assq 'permanentflags response)
                                (assq 'flags response)))))
                (elmo-imap4-session-set-current-mailbox-internal session nil)
                (if (elmo-imap4-response-bye-p response)
                    (elmo-imap4-process-bye session)
                  (error "%s"
                         (or (elmo-imap4-response-error-text response)
                             (format "Select %s failed" mailbox)))))
              (message "Selecting %s...done"
                       (elmo-folder-name-internal folder))
              (elmo-folder-set-msgdb-internal
               folder msgdb))
          (quit
           (if (elmo-imap4-response-ok-p response)
               (elmo-imap4-session-set-current-mailbox-internal
                session mailbox)
             (and session
                  (elmo-imap4-session-set-current-mailbox-internal
                   session nil))))
          (error
           (if (elmo-imap4-response-ok-p response)
               (elmo-imap4-session-set-current-mailbox-internal
                session mailbox)
             (and session
                  (elmo-imap4-session-set-current-mailbox-internal
                   session nil))))))
    (luna-call-next-method)))

;; elmo-folder-open-internal: do nothing.

(luna-define-method elmo-find-fetch-strategy ((folder elmo-imap4-folder) number
                                              &optional
                                              ignore-cache
                                              require-entireness)
  (let ((entity (elmo-message-entity folder number)))
    (if (null entity)
        (elmo-make-fetch-strategy 'entire)
      (let* ((size (elmo-message-entity-field entity 'size))
             (message-id (elmo-message-entity-field entity 'message-id))
             (cache-file (elmo-file-cache-get message-id))
             (use-cache (and (not ignore-cache)
                             (elmo-message-use-cache-p folder number)
                             (if require-entireness
                                 (eq (elmo-file-cache-status cache-file)
                                     'entire)
                               (elmo-file-cache-status cache-file)))))
        (elmo-make-fetch-strategy
         (if use-cache
             (elmo-file-cache-status cache-file)
           (if (and (not require-entireness)
                    elmo-message-fetch-threshold
                    (integerp size)
                    (>= size elmo-message-fetch-threshold)
                    (or (not elmo-message-fetch-confirm)
                        (not (prog1
                                 (y-or-n-p
                                  (format
                                   "Fetch entire message at once? (%dbytes)"
                                   size))
                               (message "")))))
               'section
             'entire))
         use-cache
         (elmo-message-use-cache-p folder number)
         (elmo-file-cache-path cache-file))))))

(luna-define-method elmo-folder-create-plugged ((folder elmo-imap4-folder))
  (elmo-imap4-send-command-wait
   (elmo-imap4-get-session folder)
   (list "create "
         (elmo-imap4-mailbox
          (elmo-imap4-folder-mailbox-internal folder)))))

(defun elmo-imap4-flags-to-imap (flags)
  "Convert FLAGS to the IMAP flag string."
  (let ((imap-flag (if (not (memq 'unread flags)) "\\Seen")))
    (dolist (flag flags)
      (unless (memq flag '(new read unread cached))
        (setq imap-flag
              (concat imap-flag
                      (if imap-flag " ")
                      (or (car (cdr (assq flag elmo-imap4-flag-specs)))
                          (capitalize (symbol-name flag)))))))
    imap-flag))

(luna-define-method elmo-folder-append-buffer
  ((folder elmo-imap4-folder) &optional flags number)
  (if (elmo-folder-plugged-p folder)
      (let ((session (elmo-imap4-get-session folder))
            send-buffer result)
        (elmo-imap4-session-select-mailbox session
                                           (elmo-imap4-folder-mailbox-internal
                                            folder))
        (setq send-buffer (elmo-imap4-setup-send-buffer))
        (unwind-protect
            (setq result
                  (elmo-imap4-send-command-wait
                   session
                   (list
                    "append "
                    (elmo-imap4-mailbox (elmo-imap4-folder-mailbox-internal
                                         folder))
                    (if (and flags (elmo-folder-use-flag-p folder))
                        (concat " (" (elmo-imap4-flags-to-imap flags) ") ")
                      " () ")
                    (elmo-imap4-buffer-literal send-buffer))))
          (kill-buffer send-buffer))
        (when result
          (elmo-folder-preserve-flags
           folder (elmo-msgdb-get-message-id-from-buffer) flags))
        result)
    ;; Unplugged
    (if elmo-enable-disconnected-operation
        (elmo-folder-append-buffer-dop folder flags number)
      (error "Unplugged"))))

(eval-when-compile
  (defmacro elmo-imap4-identical-system-p (folder1 folder2)
    "Return t if FOLDER1 and FOLDER2 are in the same IMAP4 system."
    `(and (string= (elmo-net-folder-server-internal ,folder1)
                   (elmo-net-folder-server-internal ,folder2))
          (eq (elmo-net-folder-port-internal ,folder1)
              (elmo-net-folder-port-internal ,folder2))
          (string= (elmo-net-folder-user-internal ,folder1)
                   (elmo-net-folder-user-internal ,folder2)))))

(luna-define-method elmo-folder-next-message-number-plugged
  ((folder elmo-imap4-folder))
  (let ((session (elmo-imap4-get-session folder))
        messages new unread response killed uidnext)
    (with-current-buffer (elmo-network-session-buffer session)
      (setq elmo-imap4-status-callback nil)
      (setq elmo-imap4-status-callback-data nil))
    (if elmo-imap4-use-select-to-update-status
        (elmo-imap4-session-select-mailbox
         session
         (elmo-imap4-folder-mailbox-internal folder)))
    (setq response
          (elmo-imap4-send-command-wait session
                                        (list
                                         "status "
                                         (elmo-imap4-mailbox
                                          (elmo-imap4-folder-mailbox-internal
                                           folder))
                                         " (uidnext)"))
          response (elmo-imap4-response-value response 'status))
    (elmo-imap4-response-value response 'uidnext)))

(defun elmo-folder-append-messages-imap4-imap4 (dst-folder
                                                src-folder
                                                numbers
                                                same-number)
  (if (and (elmo-imap4-identical-system-p dst-folder src-folder)
           (elmo-folder-plugged-p dst-folder))
      ;; Plugged
      (prog1
          (elmo-imap4-copy-messages src-folder dst-folder numbers)
        (elmo-progress-notify 'elmo-folder-move-messages (length numbers)))
    (elmo-folder-append-messages dst-folder src-folder numbers same-number
                                 'elmo-folder-append-messages-imap4-imap4)))

(luna-define-method elmo-message-deletable-p ((folder elmo-imap4-folder)
                                              number)
  (if (elmo-folder-plugged-p folder)
      (not (elmo-imap4-session-read-only-internal
            (elmo-imap4-get-session folder)))
    elmo-enable-disconnected-operation)) ; offline refile.

;(luna-define-method elmo-message-fetch-unplugged
;  ((folder elmo-imap4-folder)
;   number strategy  &optional section outbuf unseen)
;  (error "%d%s is not cached." number (if section
;                                         (format "(%s)" section)
;                                       "")))

(defsubst elmo-imap4-message-fetch (folder number strategy
                                           section outbuf unseen)
  (let ((session (elmo-imap4-get-session folder))
        response)
    (elmo-imap4-session-select-mailbox session
                                       (elmo-imap4-folder-mailbox-internal
                                        folder))
    (with-current-buffer (elmo-network-session-buffer session)
      (setq elmo-imap4-fetch-callback nil)
      (setq elmo-imap4-fetch-callback-data nil))
    (elmo-with-progress-display (elmo-retrieve-message
                                 (elmo-message-field folder number :size)
                                 elmo-imap4-literal-progress-reporter)
        "Retrieving"
      (setq response
            (elmo-imap4-send-command-wait session
                                          (format
                                           (if elmo-imap4-use-uid
                                               "uid fetch %s body%s[%s]"
                                             "fetch %s body%s[%s]")
                                           number
                                           (if unseen ".peek" "")
                                           (or section "")))))
    (if (setq response (elmo-imap4-response-bodydetail-text
                        (elmo-imap4-response-value-all
                         response 'fetch)))
        (with-current-buffer outbuf
          (erase-buffer)
          (insert response)
          (elmo-delete-cr-buffer)
          t))))

(luna-define-method elmo-message-fetch-plugged ((folder elmo-imap4-folder)
                                                number strategy
                                                &optional section
                                                outbuf unseen)
  (elmo-imap4-set-flag folder (list number) "\\Seen")
  (elmo-imap4-message-fetch folder number strategy section outbuf unseen))

(luna-define-method elmo-message-fetch-field ((folder elmo-imap4-folder)
                                              number field)
  (let ((session (elmo-imap4-get-session folder)))
    (elmo-imap4-session-select-mailbox session
                                       (elmo-imap4-folder-mailbox-internal
                                        folder))
    (with-current-buffer (elmo-network-session-buffer session)
      (setq elmo-imap4-fetch-callback nil)
      (setq elmo-imap4-fetch-callback-data nil))
    (with-temp-buffer
      (insert
       (elmo-imap4-response-bodydetail-text
        (elmo-imap4-response-value
         (elmo-imap4-send-command-wait session
                                       (concat
                                        (if elmo-imap4-use-uid
                                            "uid ")
                                        (format
                                         "fetch %s (body.peek[header.fields (%s)])"
                                         number field)))
         'fetch)))
      (elmo-delete-cr-buffer)
      (goto-char (point-min))
      (std11-field-body (symbol-name field)))))

(luna-define-method elmo-folder-search-requires-msgdb-p ((folder
                                                          elmo-imap4-folder)
                                                         condition)
  nil)

(autoload 'elmo-global-flags-set "elmo-flag")
(autoload 'elmo-get-global-flags "elmo-flag")

(require 'product)
(product-provide (provide 'elmo-imap4) (require 'elmo-version))

;;; elmo-imap4.el ends here