share/playlist/youtube.lua

   1 -- libquvi-scripts
   2 -- Copyright (C) 2012  Toni Gundogdu <legatvs@gmail.com>
   3 --
   4 -- This file is part of libquvi-scripts <http://quvi.sourceforge.net/>.
   5 --
   6 -- This program is free software: you can redistribute it and/or
   7 -- modify it under the terms of the GNU Affero General Public
   8 -- License as published by the Free Software Foundation, either
   9 -- version 3 of the License, or (at your option) any later version.
  10 --
  11 -- This program is distributed in the hope that it will be useful,
  12 -- but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 -- GNU Affero General Public License for more details.
  15 --
  16 -- You should have received a copy of the GNU Affero General
  17 -- Public License along with this program.  If not, see
  18 -- <http://www.gnu.org/licenses/>.
  19 --
  20
  21 local YouTube = {} -- Utility functions unique to this script
  22
  23 -- Identify the playlist script.
  24 function ident(qargs)
  25   return {
  26     domains = table.concat({'youtube.com'}, ','),
  27     can_parse_url = YouTube.can_parse_url(qargs)
  28   }
  29 end
  30
  31 -- Parse playlist properties.
  32 function parse(qargs)
  33
  34   qargs.id = qargs.input_url:match('list=(%w+)')
  35   while #qargs.id > 16 do -- Strip playlist ID prefix (e.g. "PL")
  36     qargs.id = qargs.id:gsub("^%w", "")
  37   end
  38   if #qargs.id < 16 then
  39     error('no match: playlist ID')
  40   end
  41
  42   local Y = require 'quvi/youtube'
  43   local P = require 'lxp.lom'
  44
  45   local max_results = 25
  46   local start_index = 1
  47
  48   qargs.media = {}
  49
  50   local C = require 'quvi/const'
  51   local o = { [C.qfo_type] = C.qft_playlist }
  52
  53   local r = {}
  54
  55   -- TODO: Return playlist thumbnail URL
  56   -- TODO: Return playlist title
  57
  58   repeat -- Get the entire playlist.
  59     local u = YouTube.config_url(qargs, start_index, max_results)
  60     local c = quvi.fetch(u, o)
  61     local x = P.parse(c)
  62
  63     YouTube.chk_error_resp(x)
  64     r = YouTube.parse_media_urls(x)
  65
  66     for _,u in pairs(r) do
  67       local t = {
  68         url = u
  69       }
  70       table.insert(qargs.media, t)
  71     end
  72
  73     start_index = start_index + #r
  74   until #r == 0
  75
  76   return qargs
  77 end
  78
  79 --
  80 -- Utility functions
  81 --
  82
  83 function YouTube.can_parse_url(qargs)
  84   local U = require 'socket.url'
  85   local t = U.parse(qargs.input_url)
  86   if t and t.scheme and t.scheme:lower():match('^https?$')
  87        and t.host   and t.host:lower():match('youtube%.com$')
  88        and t.query  and t.query:lower():match('list=%w+')
  89   then
  90     return true
  91   else
  92     return false
  93   end
  94 end
  95
  96 function YouTube.config_url(qargs, start_index, max_results)
  97   return string.format( -- Refer to http://is.gd/0msY8X
  98     'http://gdata.youtube.com/feeds/api/playlists/%s?v=2'
  99     .. '&start-index=%s&max-results=%s&strict=true',
 100       qargs.id, start_index, max_results)
 101 end
 102
 103 function YouTube.parse_media_urls(t)
 104   -- TODO: Return media duration_ms
 105   -- TODO: Return media title
 106   local r = {}
 107   if not t then return r end
 108   for i=1, #t do
 109     if t[i].tag == 'entry' then
 110       for j=1, #t[i] do
 111         if t[i][j].tag == 'link' then
 112           if t[i][j].attr['rel'] == 'alternate' then
 113             table.insert(r, t[i][j].attr['href'])
 114           end
 115         end
 116       end
 117     end
 118   end
 119   return r
 120 end
 121
 122 function YouTube.chk_error_resp(t)
 123   if not t then return end
 124   local r = {}
 125   for i=1, #t do
 126     if t[i].tag == 'error' then
 127       for j=1, #t[i] do
 128         if t[i][j].tag == 'domain' then
 129           r.domain = t[i][j][1]
 130         end
 131         if t[i][j].tag == 'code' then
 132           r.code = t[i][j][1]
 133         end
 134         if t[i][j].tag == 'internalReason' then
 135           r.reason = t[i][j][1]
 136         end
 137         if t[i][j].tag == 'location' then -- Ignores 'type' attribute.
 138           r.location = t[i][j][1]
 139         end
 140       end
 141     end
 142   end
 143   if #r >0 then
 144     local m
 145     for k,v in pairs(r) do
 146       m = m .. string.format("%s=%s ", k,v)
 147     end
 148     error(m)
 149   end
 150 end
 151
 152 -- vim: set ts=2 sw=2 tw=72 expandtab: