# -*- coding: utf-8 -*-
# This file is part of beets.
# Copyright 2015, Bruno Cauet
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

"""Create freedesktop.org-compliant thumnails for album folders"""

from __future__ import (division, absolute_import, print_function,
                        unicode_literals)

from hashlib import md5
import os
import shutil
from pathlib import PurePosixPath

from xdg import BaseDirectory

from beets.plugins import BeetsPlugin
from beets.ui import Subcommand, decargs
from beets.util import syspath, displayable_path
from beets.util.artresizer import ArtResizer


BASE_DIR = os.path.join(BaseDirectory.xdg_cache_home, "thumbnails")
NORMAL_DIR = os.path.join(BASE_DIR, "normal")
LARGE_DIR = os.path.join(BASE_DIR, "large")


class ThumbnailsPlugin(BeetsPlugin):
    def __init__(self):
        super(ThumbnailsPlugin, self).__init__()
        if self._check_local_ok():
            self.register_listener('album_imported', self.imported)

    def commands(self):
        thumbnails_command = Subcommand("thumbnails",
                                        help="Create album thumbnails")
        thumbnails_command.func = self.process_query
        return [thumbnails_command]

    def imported(self, lib, album):
        self.process_album(album)

    def process_query(self, lib, opts, args):
        if self._check_local_ok():
            for album in lib.albums(decargs(args)):
                self.process_album(album)

    def _check_local_ok(self):
        if not ArtResizer.local:
            self._log.warning("No local image resizing capabilities, "
                              "cannot generate thumbnails")
            return False

        for dir in (NORMAL_DIR, LARGE_DIR):
            if not os.path.exists(dir):
                os.makedirs(dir)

        return True

    def process_album(self, album):
        """Produce a thumbnail for the album folder

        The thumbnail is a PNG of resolution either 256x256 or lower than
        128x128
        """
        if not album.artpath:
            self._log.info(u'album {0} has no art', album)
            return

        # FIXME should handle covers smaller than 256x256
        # see http://standards.freedesktop.org/thumbnail-spec/latest/x122.html

        target = os.path.join(BaseDirectory.xdg_cache_home,
                              "thumbnails", "large",
                              self.thumbnail_file_name(album.path))

        resized = ArtResizer.shared.resize(256,
                                           syspath(album.artpath),
                                           syspath(target))

        # FIXME should add tags
        # see http://standards.freedesktop.org/thumbnail-spec/latest/x142.html

        shutil.move(resized, target)
        self._log.info(u'wrote thumbnail for {0}', album)
        self._log.debug(u'thumbnail is at {0}', displayable_path(target))

    @staticmethod
    def thumbnail_file_name(path):
        # http://standards.freedesktop.org/thumbnail-spec/latest/x227.html
        uri = PurePosixPath(path).as_uri()
        hash = md5(uri).hexdigest()
        return "{0}.png".format(hash)