# -*- coding: utf-8 -*-
################################################################################
#  Copyright (C) 2014  Travis Shirk <travis@pobox.com>
#
#  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, see <http://www.gnu.org/licenses/>.
#
################################################################################
from __future__ import print_function
import os
import hashlib
from eyed3.utils import art
from eyed3 import compat
from eyed3.utils import guessMimetype
from eyed3.utils import makeUniqueFileName
from eyed3.plugins import LoaderPlugin
from eyed3.utils.console import printMsg, printWarning
from eyed3.id3.frames import ImageFrame

try:
    import PIL                                                            # noqa
    _have_PIL = True
except ImportError:
    _have_PIL = False


DESCR_FNAME_PREFIX = "filename: "


class ArtFile(object):
    def __init__(self, file_path):
        self.art_type = art.matchArtFile(file_path)
        self.file_path = file_path
        self.id3_art_type = (art.TO_ID3_ART_TYPES[self.art_type][0]
                             if self.art_type else None)
        self._img_data = None
        self._mime_type = None

    @property
    def image_data(self):
        if self._img_data:
            return self._img_data
        with open(self.file_path, "rb") as f:
            self._img_data = f.read()
        return self._img_data

    @property
    def mime_type(self):
        if self._mime_type:
            return self._mime_type
        self._mime_type = guessMimetype(self.file_path)
        return self._mime_type


class ArtPlugin(LoaderPlugin):
    SUMMARY = u"Art for albums, artists, etc."
    DESCRIPTION = u""
    NAMES = ["art"]

    def __init__(self, arg_parser):
        super(ArtPlugin, self).__init__(arg_parser, cache_files=True,
                                        track_images=True)
        self._retval = 0

        g = self.arg_group
        g.add_argument("--update-files", action="store_true",
                       help="Write art files from tag images.")
        g.add_argument("--update-tags", action="store_true",
                       help="Write tag image from art files.")

    def start(self, args, config):
        if args.update_files and args.update_tags:
            # Not using add_mutually_exclusive_group from argparse because
            # the options belong to the plugin opts group (self.arg_group)
            raise StopIteration("The --update-tags and --update-files options "
                                "are mutually exclusive, use only one at a "
                                "time.")
        super(ArtPlugin, self).start(args, config)

    def handleDirectory(self, d, _):
        global md5_file_cache
        md5_file_cache.clear()

        try:
            if not self._file_cache:
                print("%s: nothing to do." % d)
                return

            printMsg("\nProcessing %s" % d)

            # File images
            dir_art = []
            for img_file in self._dir_images:
                img_base = os.path.basename(img_file)
                art_file = ArtFile(img_file)
                try:
                    pil_img = pilImage(img_file)
                except IOError as ex:
                    printWarning(compat.unicode(ex))
                    continue

                if art_file.art_type:
                    printMsg("file %s: %s\n\t%s" % (img_base, art_file.art_type,
                                                    pilImageDetails(pil_img)))
                    dir_art.append(art_file)
                else:
                    printMsg("file %s: unknown (ignored)" % img_base)

            if not dir_art:
                print("No art files found.")
                self._retval += 1

            # Tag images
            all_tags = sorted([f.tag for f in self._file_cache],
                              key=lambda x: x.file_info.name)
            for tag in all_tags:
                file_base = os.path.basename(tag.file_info.name)
                for img in tag.images:
                    try:
                        pil_img = pilImage(img)
                    except IOError as ex:
                        printWarning(compat.unicode(ex))
                        continue

                    if img.picture_type in art.FROM_ID3_ART_TYPES:
                        img_type = art.FROM_ID3_ART_TYPES[img.picture_type]
                        printMsg("tag %s: %s (Description: %s)\n\t%s" %
                                 (file_base, img_type, img.description,
                                  pilImageDetails(pil_img)))
                        if self.args.update_files:
                            assert(not self.args.update_tags)
                            path = os.path.dirname(tag.file_info.name)
                            if img.description.startswith(DESCR_FNAME_PREFIX):
                                # Use filename from Image description
                                fname = img.description[
                                          len(DESCR_FNAME_PREFIX):].strip()
                                fname = os.path.splitext(fname)[0]
                            else:
                                fname = art.FILENAMES[img_type][0].strip("*")
                            fname = img.makeFileName(name=fname)

                            if (md5File(os.path.join(path, fname)) ==
                                    md5Data(img.image_data)):
                                printMsg("Skipping writing of %s, file "
                                         "exists and is exactly the same." %
                                         img_file)
                            else:
                                img_file = makeUniqueFileName(
                                    os.path.join(path, fname),
                                    uniq=img.description)
                                printWarning("Writing %s..." % img_file)
                                with open(img_file, "wb") as fp:
                                    fp.write(img.image_data)
                    else:
                        printMsg("tag %s: unhandled image type %d (ignored)" %
                                 (file_base, img.picture_type))

            # Copy file art to tags.
            if self.args.update_tags:
                assert(not self.args.update_files)
                for tag in all_tags:
                    for art_file in dir_art:
                        descr = "filename: %s" % \
                                os.path.splitext(
                                      os.path.basename(art_file.file_path))[0]
                        tag.images.set(art_file.id3_art_type,
                                       art_file.image_data, art_file.mime_type,
                                       description=descr)
                    tag.save()

        finally:
            # Cleans up...
            super(ArtPlugin, self).handleDirectory(d, _)

    def handleDone(self):
        return self._retval


def pilImage(source):
    if not _have_PIL:
        return None

    from PIL import Image
    if isinstance(source, ImageFrame):
        return Image.open(compat.StringIO(source.image_data))
    else:
        return Image.open(source)


def pilImageDetails(img):
    if not img:
        return ''
    return "[%dx%d %s md5:%s]" % (img.size[0], img.size[1],
                                  img.format.lower(),
                                  md5Data(img.tobytes()))


def md5Data(data):
    md5 = hashlib.md5()
    md5.update(data)
    return md5.hexdigest()


md5_file_cache = {}


def md5File(file_name):
    '''Compute md5 hash for contents of ``file_name``.'''

    global md5_file_cache
    if file_name in md5_file_cache:
        return md5_file_cache[file_name]

    md5 = hashlib.md5()
    try:
        with open(file_name, "rb") as f:
            md5.update(f.read())

        md5_file_cache[file_name] = md5.hexdigest()
        return md5_file_cache[file_name]
    except IOError:
        return None
