# Copyright (C) 2008-2010 Adam Olsen
#
# 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 this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
#
# The developers of the Exaile media player hereby grant permission
# for non-GPL compatible GStreamer and Exaile plugins to be used and
# distributed together with GStreamer and Exaile. This permission is
# above and beyond the permissions granted by the GPL license by which
# Exaile is covered. If you modify this code, you may extend this
# exception to your version of the code, but you are not obligated to
# do so. If you do not wish to do so, delete this exception statement
# from your version.

import gio
from xl import metadata, settings
from xl.trax.track import Track
from xl.trax.search import search_tracks, TracksMatcher


def is_valid_track(location):
    """
        Returns whether the file at the given location is a valid track

        :param location: the location to check
        :type location: string
        :returns: whether the file is a valid track
        :rtype: boolean
    """
    extension = gio.File(location).get_basename().split(".")[-1]
    return extension.lower() in metadata.formats

def get_uris_from_tracks(tracks):
    """
        Returns all URIs for tracks

        :param tracks: the tracks to retrieve the URIs from
        :type tracks: list of :class:`xl.trax.Track`
        :returns: the uris
        :rtype: list of string
    """
    return [track.get_loc_for_io() for track in tracks]

def get_tracks_from_uri(uri):
    """
        Returns all valid tracks located at uri
        
        :param uri: the uri to retrieve the tracks from
        :type uri: string
        :returns: the retrieved tracks
        :rtype: list of :class:`xl.trax.Track`
    """
    tracks = []

    gloc = gio.File(uri)
    # don't do advanced checking on streaming-type uris as it can fail or
    # otherwise be terribly slow.
    # TODO: move uri definition somewhere more common for easy reuse?

    if gloc.get_uri_scheme() in ('http', 'mms', 'cdda'):
        return [Track(uri)]

    file_type = gloc.query_info("standard::type").get_file_type()
    if file_type == gio.FILE_TYPE_DIRECTORY:
        # TODO: refactor Library so we dont need the collection obj
        from xl.collection import Library, Collection
        tracks = Collection('scanner')
        lib = Library(uri)
        lib.set_collection(tracks)
        lib.rescan()
        tracks = tracks.get_tracks()
    else:
        tracks = [Track(uri)]
    return tracks

def sort_tracks(fields, iter, trackfunc=None, reverse=False):
    """
        Sorts tracks.

        :param fields: tag names to sort by
        :type fields: iterable
        :param iter: the tracks to sort,
            alternatively use *trackfunc*
        :type iter: iterable
        :param trackfunc: function to get a *Track*
            from an item in the iterable
        :type trackfunc: function or None
        :param reverse: whether to sort in reversed order
        :type reverse: boolean
    """
    fields = list(fields) # we need the index method
    artist_compilations = True
    if trackfunc is None:
        trackfunc = lambda tr: tr
    keyfunc = lambda tr: [trackfunc(tr).get_tag_sort(field,
        artist_compilations=artist_compilations) for field in fields]
    return sorted(iter, key=keyfunc, reverse=reverse)

def sort_result_tracks(fields, trackiter, reverse=False):
    """
        Sorts SearchResultTracks, ie. the output from a search.

        Same params as sort_tracks.
    """
    return sort_tracks(fields, trackiter, lambda tr: tr.track, reverse)

def get_rating_from_tracks(tracks):
    """
        Returns the common rating for all tracks or
        simply 0 if not all tracks have the same
        rating. Same goes if the amount of tracks
        is 0 or more than the internal limit.

        :param tracks: the tracks to retrieve the rating from
        :type tracks: iterable
    """
    if len(tracks) < 1:
        return 0

# TODO: still needed?
#    if len(tracks) > settings.get_option('rating/tracks_limit', 100):
#        return 0

    rating = tracks[0].get_rating()

    for track in tracks:
        if track.get_rating() != rating:
            return 0

    return rating



def get_album_tracks(tracksiter, track, artist_compilations=True):
    """
        Get any tracks from the given iterable that appear to be part of
        the same album as track. If track is in the iterable, it will be
        included in the result. If there is insufficient information to
        determine the album, the empty list will be returned, even if the
        track is in the iterable.
    """
    if not all(track.get_tag_raw(t) for t in ['artist', 'album']):
        return []
    matchers = map(lambda t: TracksMatcher(track.get_tag_search(t, artist_compilations=artist_compilations)), ['artist', 'album'])
    return (r.track for r in search_tracks(tracksiter, matchers))
