Youtube Parser

--[[
 Youtube playlist importer for VLC media player 1.1 and 2.0
 Copyright 2012 Guillaume Le Maout

 Authors:  Guillaume Le Maout
 Contact: http://addons.videolan.org/messages/?action=newmessage&username=exebetche

 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 of the License, 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 this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
--]]

--[[
 MODified by Kai Gillmann, 19.01.2013, kaigillmann@googlemail.com:
 VLC HAS already a youtube importer, but not for playlists. IMO this mentioned one is
 better than this one, because it opens the video in the best possible video resolution.
 So i decided to remove all parts of the code which is not responsible for list handling.
 Now this lua script parses the list, as wanted, but for each video opened, the vlc default
 Youtube script is used, so the videos will be displayed properly.
--]]

 --[[
    Extension modified to handle bigger playlist mods done by Ginzo Milani, June 7th, 2017 Lf2owner@hotmail.com :
    Kai had done a great job already, while there was improvements that could be done to better sort metadata, I was more
    interested in just hearing the rest of my songs, thusly I've fixed his playlist plugin to allow bigger playlists from Youtube.
    Interested in donating? Lf2owner@hotmail.com is my paypal, if it helped or suggestions feel free to email me those too!
 --]]
-- Helper function to get a parameter's value in a URL
function get_url_param( url, name )
     local _, _, res = string.find( url, "[&?]"..name.."=([^&]*)" )
     return res
end

-- Probe function.
function probe()
     if vlc.access ~= "http" and vlc.access ~= "https" then
         return false
     end

     return string.match(vlc.path:match("([^/]+)"),"%w+.youtube.com") and (string.match(vlc.path, "list="))
end

-- Parse function.
function parse()
    if string.match( vlc.path, "list=" ) then
        local playlist_parsed, playlistData, line, s, item
        local p = {}
        local id_ref = {}
        local index = 1
        local playlistID = get_url_param( vlc.path, "list" )
        local videoID = get_url_param( vlc.path, "v" )
        local playlistURL = "http://www.youtube.com/list_ajax?action_get_list=1&style=xml&list="..playlistID

        while true do
            playlistData = ""
            line = ""
            s = nil
            s = vlc.stream(playlistURL.."&index="..index)
            while line do
                playlistData = playlistData..line
                line = s:readline()
            end

            playlist_parsed = nil
            playlist_parsed = parse_xml(playlistData).root.video

            for i, video in ipairs(playlist_parsed) do
                vlc.msg.err(i.." "..video.encrypted_id.CDATA)
                if id_ref[video.encrypted_id.CDATA]
                and id_ref[video.encrypted_id.CDATA] == i
                then
                    return p
                else
                    id_ref[video.encrypted_id.CDATA] = i
                end

                item = nil
                item = {}

                if video.encrypted_id
                and video.encrypted_id.CDATA then
                    item.path = "http://www.youtube.com/watch?v="..video.encrypted_id.CDATA
                end

                if video.title
                and video.title.CDATA then
                    item.title = video.title.CDATA
                end

                if video.artist
                and video.artist.CDATA then
                    item.artist = video.artist.CDATA
                end

                if video.thumbnail
                and video.thumbnail.CDATA then
                    item.arturl = video.thumbnail.CDATA
                end

                if video.description
                and video.description.CDATA then
                    item.description = video.description.CDATA
                end

                --~ item.rating = video.rating
                table.insert (p, item)
            end
            -- 1 to 200, 199 diff  (first 199 difference then 99 difference),
            -- this should be a catch all for any future changes to the playlist count.
            -- 200 to 299, 99 diff
            -- 299 to 398, 99 diff
            vlc.msg.info("[Youtube Playlist] Parsed: " .. tostring(#playlist_parsed) )
            if #playlist_parsed > 99 then
                index = #playlist_parsed + index
            elseif #playlist_parsed == 99 then
                index = index + 99
            else
                return p
            end
        end
    end
end


function parse_xml(data)
    local tree = {}
    local stack = {}
    local tmp = {}
    local tmpTag = ""
    local level = 0

    table.insert(stack, tree)

    for op, tag, attr, empty, val in string.gmatch(
        data,
        "<(%p?)([^%s>/]+)([^>]-)(%/?)>[%s\r\n\t]*([^<]*)[%s\r\n\t]*") do
        if op=="?" then
            --~ DOCTYPE
        elseif op=="/" then
            if level>0 then
            level = level - 1
            table.remove(stack)
            end
        else
        level = level + 1

        if op=="!" then
            stack[level]['CDATA'] = vlc.strings.resolve_xml_special_chars(
            string.gsub(tag..attr, "%[CDATA%[(.+)%]%]", "%1"))
            attr = ""
            level = level - 1
        elseif type(stack[level][tag]) == "nil" then
            stack[level][tag] = {}
            table.insert(stack, stack[level][tag])
        else
            if type(stack[level][tag][1]) == "nil" then
             tmp = nil
             tmp = stack[level][tag]
             stack[level][tag] = nil
             stack[level][tag] = {}
             table.insert(stack[level][tag], tmp)
            end
            tmp = nil
            tmp = {}
            table.insert(stack[level][tag], tmp)
            table.insert(stack, tmp)
            end

            if val~="" then
            stack[level][tag]['CDATA'] = {}
            stack[level][tag]['CDATA'] = vlc.strings.resolve_xml_special_chars(val)
            end

            if attr ~= "" then
            stack[level][tag]['ATTR'] = {}
                string.gsub(attr,
                "(%w+)=([\"'])(.-)%2",
                function (name, _, value)
                 stack[level][tag]['ATTR'][name] = value
                end)
            end

            if empty ~= "" then
                level = level - 1
                table.remove(stack)
            end
        end
    end
    return tree
end