dispatch_email.py

   1 import os, sys, re, string, logging, time
   2 import random, anydbm, smtplib
   3
   4 ALL_STORIES = set(range(1, 101+1))
   5 WWW_URL = "http://nearfar.org/dailyzen/"
   6 UNSUBSCRIBE_URL = WWW_URL + "do.cgi/unsubscribe/%s,%s"
   7 VERIFICATION_URL = WWW_URL + "do.cgi/verify/%s,%s"
   8 DBFILE = "/home/protected/data/dailyzen.db"
   9
  10 # TODO: unused (From: is same as To:). do something about it.
  11 FROM_ADDR = "mail@nearfar.org"
  12
  13 # Decorator: Call the function once, and return the same return value always.
  14 def call_once(func):
  15     ret = func()
  16     return lambda: ret
  17
  18 ## Logging, error handling bits
  19
  20 # FIXME: is call_once necessary?
  21 @call_once
  22 def logging_handler():
  23     "Return the desired and default logging handler"
  24     hdlr = logging.FileHandler("/home/protected/logs/dailyzen.log")
  25     formatter = logging.Formatter("%(asctime)s %(levelname)s %(message)s")
  26     hdlr.setFormatter(formatter)
  27     return hdlr
  28
  29 dz = logging.getLogger("dailyzen")
  30 dz.addHandler(logging_handler())
  31 dz.setLevel(logging.DEBUG)
  32
  33 class UserError(Exception):
  34     pass
  35
  36
  37 ## Register/Validate mechanism
  38
  39 def register_user(email):
  40     """Just register the user giving him (via email) an unique url
  41     to valid himself against the given email address.
  42
  43     On clicking the URL, `validate_user' function would be called."""
  44     EMAIL_MSG = r"""Hey there,
  45
  46 Just to make sure that it is really you, please click on this link.
  47 %s
  48
  49 You will then be receiving your daily Zen story shortly.
  50
  51 PS: Not initiated by you? simply ignore this email.
  52
  53 """
  54     db = anydbm.open(DBFILE, "c")
  55     if email in db.keys():
  56         raise UserError, "email address already found"
  57     user = dict(email=email, id=random_string(), sent_stories=[], valid=False)
  58     db[email] = repr(user)
  59     db.close()
  60     # send email
  61     verification_url = VERIFICATION_URL % (email, user["id"])
  62     send_email(email, [email], "DailyZen Verification", EMAIL_MSG % verification_url)
  63     dz.info("Verification code sent to %s", email)
  64
  65 def validate_user(email, id):
  66     db = anydbm.open(DBFILE)
  67     if email in db.keys():
  68         user = eval(db[email])
  69         db.close()
  70         if user['id'] == id and user['valid'] is False:
  71             # user validated!
  72             user['valid'] = True
  73             write_user(user)
  74             dz.info("Validated %s", email)
  75         else:
  76             raise UserError, "Invalid request"
  77
  78     else:
  79         db.close()
  80         raise UserError, "Email address (%s) not found" % email
  81
  82 def delete_user(email, id):
  83     db = anydbm.open(DBFILE, "w")
  84     if email in db.keys():
  85         user = eval(db[email])
  86         if user["id"] == id:
  87             del db[email]
  88         else:
  89             raise UserError, "Invalid request"
  90     else:
  91         raise UserError, "Email address not found (Perhaps already unsubscribed?)"
  92
  93 def random_string(length=15):
  94     char_domain = string.ascii_letters + string.digits
  95     id = []
  96     for x in range(length):
  97         id.append(random.choice(char_domain))
  98     return''.join(id)
  99
 100
 101 ## Users management
 102
 103 def read_users():
 104     db = anydbm.open(DBFILE, "c")
 105     users = []
 106     for k in db.keys():
 107         user = eval(db[k])
 108         if user['valid']:
 109             users.append(user)
 110     db.close()
 111     return users
 112
 113 def write_user(user):
 114     db = anydbm.open(DBFILE, "w")
 115     db[user['email']] = repr(user)
 116     db.close()
 117
 118
 119 def get_story(number):
 120     f = open("101zenstories/%d.html.txt" % number)
 121     title = f.readline().strip()
 122     f.readline() # empty line
 123     story = f.read()
 124     return title, story
 125
 126 def send_email(from_, toaddrs, subject, body):
 127     SENDMAIL = "sendmail" # sendmail location
 128     p = os.popen("%s -t" % SENDMAIL, "w")
 129     p.write("From: %s\n" % from_)
 130     p.write("To: %s\n" % ",".join(toaddrs))
 131     p.write("Subject: %s\n" % subject)
 132     p.write("\n")
 133     p.write(body)
 134     sts = p.close()
 135     if sts is not None and sts != 0:
 136         dz.error("sendmail failed with exit status: %d", sts)
 137
 138 # not used: fails in nfshost
 139 def send_email_SMTP(from_, toaddrs, subject, body):
 140     msg = "From: %s\nSubject: %s\n\n%s" % (from_, subject, body)
 141     s = smtplib.SMTP('127.0.0.1')
 142     s.sendmail(from_, toaddrs, msg)
 143
 144
 145 def send_random_story_to_user(user):
 146     sent_stories = set(user['sent_stories'])
 147     unsent_stories = ALL_STORIES.difference(sent_stories)
 148     if len(unsent_stories) == 0:
 149         # nothing left for this user
 150         # TODO: should we remove him from db?
 151         return
 152
 153     if len(sent_stories) == 0:
 154         # send his first story
 155         notice_msg = "Welcome. Here is your first story. From now on, you would get a random story that you were not sent before.\n---\n\n"
 156     else:
 157         notice_msg = ""
 158
 159     next = random.choice(list(unsent_stories))
 160     user["sent_stories"].append(next)
 161     title, story = get_story(next)
 162     email = user["email"]
 163
 164     unsubscribe_url = UNSUBSCRIBE_URL % (user["email"], user["id"])
 165     signature = "\n\n----\n%s\n\nTo unsubsubcribe,\n%s" % (WWW_URL, unsubscribe_url)
 166     send_email(email, [email], title, notice_msg + story + signature)
 167     dz.debug("email: To=%s %s (%d)", email, title, next)
 168     write_user(user)
 169
 170 def now():
 171     return long(time.time())
 172
 173 def secs(n): return n
 174 def mins(n): return 60*secs(n)
 175 def hrs(n):  return 60*mins(n)
 176 def days(n): return 24*hrs(n)
 177
 178 def dispatch_all():
 179     dz.info("Broadcast operation started")
 180     for user in read_users():
 181         send_random_story_to_user(user)
 182
 183
 184 ## TEST
 185 if __name__ == '__main__':
 186     print 'TEST'
 187     if not read_users():
 188         # add sample users
 189         write_user(dict(email="srid@nearfar.org", id="12345", sent_stories=[1,6,23], valid=True))
 190         # write_user(dict(email="foo@example.com", id="84854", sent_stories=[51,78,99, 2, 3]))
 191     dispatch_all()
 192
 193