#
#    Copyright (C) 2009 Anton Khirnov <wyskas@gmail.com>
#
#    Nephilim 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 3 of the License, or
#    (at your option) any later version.
#
#    Nephilim 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 Nephilim.  If not, see <http://www.gnu.org/licenses/>.
#

from PyQt4        import QtGui, QtCore, QtNetwork

import os
import re
from   lxml import etree

from ..plugin import Plugin
from ..       import common, metadata_fetcher
from ..       import icons

class LyricsWidget(QtGui.QWidget):
    #public
    lyrics_loaded = None

    # public, read-only
    plugin        = None  # plugin
    logger        = None

    # private
    __text_view = None  # text-object
    __toolbar   = None
    __label     = None

    #### private
    def __init__(self, plugin):
        QtGui.QWidget.__init__(self)
        self.plugin = plugin
        self.logger = plugin.logger
        self.curLyrics = ''

        self.__label = QtGui.QLabel(self)
        self.__label.setWordWrap(True)

        # add text area
        self.__text_view = QtGui.QTextEdit(self)
        self.__text_view.setReadOnly(True)

        # add toolbar
        self.__toolbar = QtGui.QToolBar('Lyrics toolbar', self)
        self.__toolbar.setOrientation(QtCore.Qt.Vertical)

        self.__toolbar.addAction(QtGui.QIcon(':icons/refresh.png'), 'Refresh lyrics', self.plugin.refresh)
        edit = self.__toolbar.addAction(QtGui.QIcon(':icons/edit.png'), 'Edit lyrics')
        edit.setCheckable(True)
        edit.toggled.connect(self.__toggle_editable)

        self.__toolbar.addAction(QtGui.QIcon(':icons/save.png'), 'Save lyrics', self.__save_lyrics)
        self.__toolbar.addAction(QtGui.QIcon(':icons/delete.png'), 'Delete stored file', self.plugin.del_lyrics_file)

        self.setLayout(QtGui.QGridLayout())
        self.layout().setSpacing(0)
        self.layout().setMargin(0)
        self.layout().addWidget(self.__toolbar, 0, 0, -1, 1, QtCore.Qt.AlignTop)
        self.layout().addWidget(self.__label, 0, 1)
        self.layout().addWidget(self.__text_view, 1, 1)

    def __save_lyrics(self):
        self.plugin.save_lyrics_file(self.__text_view.toPlainText())

    def __toggle_editable(self, val):
        self.__text_view.setReadOnly(not val)

    #### public ####
    def set_lyrics(self, song, lyrics, flags = 0):
        """Set currently displayed lyrics (unicode string) for song. flags parameter is
           unused now."""
        if not song:
            self.__label.clear()
            return self.__text_view.clear()

        # a late thread might call this for a previous song
        if song != self.plugin.mpclient.cur_song:
            return

        self.__text_view.clear()
        self.__label.setText('<b>%s</b> by <u>%s</u> on <u>%s</u>'\
                             %(song['?title'], song['?artist'], song['?album']))
        if lyrics:
            self.logger.info('Setting new lyrics.')
            self.__text_view.insertPlainText(lyrics)
            self.lyrics_loaded = True
        else:
            self.logger.info('Lyrics not found.')
            self.__text_view.insertPlainText('Lyrics not found.')

class Lyrics(Plugin):
    # public, const
    info = 'Show (and fetch) the lyrics of the currently playing song.'

    # public, read-only
    o           = None

    # private
    DEFAULTS          = {'fetchers' : ['Lyricwiki', 'Animelyrics'], 'lyricdir' : '${musicdir}/${songdir}',
                         'lyricname' : '.lyrics_%s_${artist}_${album}_${title}'%common.APPNAME, 'store' : 1}
    "implemented fetchers"
    available_fetchers = None   #XXX SettingsWidget currently uses it
    "enabled fetchers, those with higher priority first"
    __fetchers        = None
    "number of returned results from last refresh() call"
    __results         = None
    "index/priority of current lyrics"
    __index           = None
    "metadata paths"
    __lyrics_dir      = None
    __lyrics_path     = None

    #### private ####
    def __init__(self, parent, mpclient, name):
        Plugin.__init__(self, parent, mpclient, name)

        self.__fetchers         = []
        self.available_fetchers = [FetchLyricwiki, FetchAnimelyrics]

    def __new_lyrics_fetched(self, song, lyrics):
        self.logger.info('Got new lyrics.')
        self.__results += 1

        i = self.__fetchers.index(self.sender())
        if lyrics and i < self.__index:
            if int(self.settings.value(self.name + '/store')) and self.__lyrics_path:
                self.save_lyrics_file(lyrics)
            self.__index = i
            return self.o.set_lyrics(song, lyrics)
        elif self.__results >= len(self.__fetchers) and not self.o.lyrics_loaded:
            self.o.set_lyrics(song, None)

    class SettingsWidgetLyrics(Plugin.SettingsWidget):
        # private
        lyricdir  = None
        lyricname = None
        store     = None
        fetcherlist  = None

        def __init__(self, plugin):
            Plugin.SettingsWidget.__init__(self, plugin)
            self.settings.beginGroup(self.plugin.name)


            # store lyrics groupbox
            self.store = QtGui.QGroupBox('Store lyrics.')
            self.store.setToolTip('Should %s store its own copy of lyrics?'%common.APPNAME)
            self.store.setCheckable(True)
            self.store.setChecked(int(self.settings.value('store')))
            self.store.setLayout(QtGui.QGridLayout())

            # paths to lyrics
            self.lyricdir  = QtGui.QLineEdit(self.settings.value('lyricdir'))
            self.lyricdir.setToolTip('Where should %s store lyrics.\n'
                                     '${musicdir} will be expanded to path to MPD music library (as set by user)\n'
                                     '${songdir} will be expanded to path to the song (relative to ${musicdir}\n'
                                     'other tags same as in lyricname'
                                      %common.APPNAME)
            self.lyricname = QtGui.QLineEdit(self.settings.value('lyricname'))
            self.lyricname.setToolTip('Filename for %s lyricsfiles.\n'
                                      'All tags supported by MPD will be expanded to their\n'
                                      'values for current song, e.g. ${title}, ${track}, ${artist},\n'
                                      '${album}, ${genre} etc.'%common.APPNAME)
            self.store.layout().addWidget(QtGui.QLabel('Lyrics directory'), 0, 0)
            self.store.layout().addWidget(self.lyricdir, 0, 1)
            self.store.layout().addWidget(QtGui.QLabel('Lyrics filename'), 1, 0)
            self.store.layout().addWidget(self.lyricname, 1, 1)

            # fetchers list
            fetchers          = self.settings.value('fetchers')
            self.fetcherlist = QtGui.QListWidget(self)
            self.fetcherlist.setDragDropMode(QtGui.QAbstractItemView.InternalMove)
            for fetcher in fetchers:
                it = QtGui.QListWidgetItem(fetcher)
                it.setCheckState(QtCore.Qt.Checked)
                self.fetcherlist.addItem(it)
            for fetcher in self.plugin.available_fetchers:
                if not fetcher.name in fetchers:
                    it = QtGui.QListWidgetItem(fetcher.name)
                    it.setCheckState(QtCore.Qt.Unchecked)
                    self.fetcherlist.addItem(it)

            self.setLayout(QtGui.QVBoxLayout())
            self.layout().addWidget(self.store)
            self._add_widget(self.fetcherlist, label = 'Sites', tooltip = 'A list of sources used for fetching lyrics.\n'
                                                                    'Use drag and drop to change their priority.')

            self.settings.endGroup()

        def save_settings(self):
            self.settings.beginGroup(self.plugin.name)
            self.settings.setValue('lyricdir',  self.lyricdir.text())
            self.settings.setValue('lyricname', self.lyricname.text())
            self.settings.setValue('store',     int(self.store.isChecked()))

            fetchers = []
            for i in range(self.fetcherlist.count()):
                it = self.fetcherlist.item(i)
                if it.checkState() == QtCore.Qt.Checked:
                    fetchers.append(it.text())
            self.settings.setValue('fetchers', fetchers)

            self.settings.endGroup()
            self.plugin.refresh_fetchers()
            self.plugin.refresh()

    #### public ####
    def _load(self):
        self.refresh_fetchers()
        self.o = LyricsWidget(self)
        self.mpclient.song_changed.connect(self.refresh)

        self.refresh()
    def _unload(self):
        self.o          = None
        self.__fetchers = None
        self.mpclient.song_changed.disconnect(self.refresh)
    def _get_dock_widget(self):
        return self._create_dock(self.o)

    def refresh(self):
        """Attempt to automatically get lyrics first from a file, then from the internet."""
        self.logger.info('Autorefreshing lyrics.')
        self.__results = 0
        self.__index   = len(self.__fetchers)
        self.o.lyrics_loaded = False
        song = self.mpclient.cur_song
        if not song:
            self.__lyrics_dir  = ''
            self.__lyrics_path = ''
            return self.o.set_lyrics(None, None)

        self.logger.info('Trying to read lyrics from stickers.')
        self.mpclient.sticker_get(song['file'], 'lyrics', callback = lambda lyrics: self._refresh2(song, lyrics))

    def _refresh2(self, song, lyrics):
        if lyrics:
            lyrics = lyrics.replace('\\n', '\n')
            self.logger.info('Found the lyrics sticker.')
            return self.o.set_lyrics(song, lyrics)

        (self.__lyrics_dir, self.__lyrics_path) = common.generate_metadata_path(song,
                                                                          self.settings.value(self.name + '/lyricdir'),
                                                                          self.settings.value(self.name + '/lyricname'))
        try:
            self.logger.info('Nothing in the sticker database. Trying to read lyrics from file %s.'%self.__lyrics_path)
            file   = open(self.__lyrics_path, 'r')
            lyrics = file.read().decode('utf-8')
            file.close()
            if lyrics:
                return self.o.set_lyrics(song, lyrics)
        except IOError, e:
            self.logger.info('Error reading lyrics file: %s.'%e)

        for fetcher in self.__fetchers:
            fetcher.fetch(song)

    def save_lyrics_file(self, lyrics, path = None):
        """Save lyrics (unicode string) to a file specified in path.
           If path is None, then a default value is used."""
        self.logger.info('Saving lyrics...')
        try:
            if path:
                file = open(path, 'w')
            else:
                file = open(self.__lyrics_path, 'w')
            file.write(lyrics.encode('utf-8'))
            file.close()
            self.logger.info('Lyrics successfully saved.')
        except IOError, e:
            self.logger.error('Error writing lyrics: %s', e)
        self.mpclient.sticker_set(self.mpclient.cur_song['file'], 'lyrics', lyrics.replace('\n', '\\n'))

    def del_lyrics_file(self, song = None):
        """Delete a lyrics file for song. If song is not specified
           current song is used."""
        if not song:
            path = self.__lyrics_path
        else:
            path = common.generate_metadata_path(song, self.settings.value(self.name + '/lyricdir'),
                                               self.settings.value(self.name + '/lyricname'))

        try:
            os.remove(path)
        except (IOError, OSError), e:
            self.logger.error('Error removing lyrics file %s: %s'%(path, e))

    def get_settings_widget(self):
        return self.SettingsWidgetLyrics(self)

    def refresh_fetchers(self):
        """Refresh the list of available fetchers."""
        self.__fetchers = []
        # append fetchers in order they are stored in settings
        for name in self.settings.value('%s/fetchers'%self.name):
            for fetcher in self.available_fetchers:
                if fetcher.name == name:
                    self.__fetchers.append(fetcher(self))
                    self.__fetchers[-1].finished.connect(self.__new_lyrics_fetched)

class FetchLyricwiki(metadata_fetcher.MetadataFetcher):
    name = 'Lyricwiki'

    __apiaddress = 'http://lyrics.wikia.com/api.php'

    def fetch(self, song):
        url = QtCore.QUrl(self.__apiaddress)
        url.setQueryItems([('func', 'getArtist'), ('artist', song['?artist']),
                                ('fmt', 'xml'), ('action', 'lyrics')])
        self.fetch2(song, url)
        self.rep.finished.connect(self.__handle_artist_res)

    def __handle_artist_res(self):
        artist = None
        xml    = QtCore.QXmlStreamReader(self.rep)
        while not xml.atEnd():
            token = xml.readNext()
            if token == QtCore.QXmlStreamReader.StartElement:
                if xml.name() == 'artist':
                    artist = xml.readElementText()
                    xml.clear()
        if not artist:
            self.logger.info('Didn\'t find artist in %s artist search results.'%self.name)
            return self.finish()
        self.logger.info('Found artist: %s'%artist)

        url = QtCore.QUrl(self.__apiaddress)
        url.setQueryItems([('action', 'lyrics'), ('func', 'getSong'), ('artist', artist),
                           ('song', self.song['?title']), ('fmt', 'xml')])
        self.rep = self.nam.get(QtNetwork.QNetworkRequest(url))
        self.rep.finished.connect(self.__handle_search_res)
        self.rep.error.connect(self.handle_error)

    def __handle_search_res(self):
        url = None

        # the page is borked utf-8 as of nov 2009, qxmlstreamreader chokes
        # on it => use regexps
        match = re.search('<url>(.*)</url>', str(self.rep.readAll()).decode('utf-8', 'replace'),
                          re.DOTALL|re.IGNORECASE)
        if match and not 'action=edit' in match.group(1):
            url = QtCore.QUrl() # the url is already percent-encoded
            url.setEncodedUrl(match.group(1))

        if not url:
            self.logger.info('Didn\'t find the song on Lyricwiki.')
            return self.finish()
        self.logger.info('Found Lyricwiki song URL: %s.'%url.toString())

        req = QtNetwork.QNetworkRequest(url)
        self.rep = self.nam.get(req)
        self.rep.finished.connect(self.__handle_lyrics)
        self.rep.error.connect(self.handle_error)

    def __handle_lyrics(self):
        # the page isn't valid xml, so use regexps
        lyrics = ''
        for it in re.finditer('<div class=\'lyricbox\'>(?:<div.*?>.*?</div>)?(.*?)(?:<div.*?>.*?</div>)?</div>',
                              str(self.rep.readAll()).decode('utf-8'), re.DOTALL):
            gr = re.sub('<br />', '\n', it.group(1))
            gr = re.sub(re.compile('<.*>', re.DOTALL), '', gr)
            lyrics += gr + '\n'
        self.finish(common.decode_htmlentities(lyrics))

class FetchAnimelyrics(metadata_fetcher.MetadataFetcher):
    name = 'Animelyrics'

    def fetch(self, song):
        url = QtCore.QUrl('http://www.animelyrics.com/search.php')
        url.setQueryItems([('t', 'performer'), ('q', song['?artist'])])
        self.fetch2(song, url)
        self.rep.finished.connect(self.__handle_search_res)

    def __handle_search_res(self):
        # TODO use Qt xml functions
        try:
            tree = etree.HTML(unicode(self.rep.readAll(), encoding = 'utf-8', errors='ignore'))
        except etree.XMLSyntaxError, e:
            self.logger.error('Error parsing lyrics: %s' %e)
            return self.finish()

        url = None
        for elem in tree.iterfind('.//a'):
            if ('href' in elem.attrib) and elem.text and (self.song['?title'] in elem.text):
                url = QtCore.QUrl('http://www.animelyrics.com/%s'%elem.get('href'))

        if not url:
            self.logger.info('Didn\'t find the URL in Animelyrics search results.')
            return self.finish()
        self.logger.info('Found Animelyrics song URL: %s.'%url)

        self.rep = self.nam.get(QtNetwork.QNetworkRequest(url))
        self.rep.finished.connect(self.__handle_lyrics)
        self.rep.error.connect(self.handle_error)

    def __handle_lyrics(self):
        lyrics = ''
        try:
            tree   = etree.HTML(unicode(self.rep.readAll(), encoding = 'utf-8'))
        except etree.XMLSyntaxError, e:
            self.logger.error('Error parsing lyrics: %s' %e)
            return self.finish()
        for elem in tree.iterfind('.//pre'):
            if elem.get('class') == 'lyrics':
                lyrics += '%s\n\n'%etree.tostring(elem, method = 'text', encoding = 'utf-8')

        self.finish(lyrics)