# -*- coding: utf-8 -*-
# This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
#
from collections import OrderedDict
import json
from collections import namedtuple
from django.db import models
from django.utils.translation import ugettext_lazy as _
import jsonfield
from fnpdjango.utils.text.slughifi import slughifi
from mutagen import MutagenError

from catalogue.fields import OverwritingFileField


def _file_upload_to(i, _n):
    return 'book/%(ext)s/%(name)s.%(ext)s' % {'ext': i.ext(), 'name': slughifi(i.name)}


class BookMedia(models.Model):
    """Represents media attached to a book."""
    FileFormat = namedtuple("FileFormat", "name ext")
    formats = OrderedDict([
        ('mp3', FileFormat(name='MP3', ext='mp3')),
        ('ogg', FileFormat(name='Ogg Vorbis', ext='ogg')),
        ('daisy', FileFormat(name='DAISY', ext='daisy.zip')),
    ])
    format_choices = [(k, _('%s file' % t.name)) for k, t in formats.items()]

    type = models.CharField(_('type'), db_index=True, choices=format_choices, max_length=20)
    name = models.CharField(_('name'), max_length=512)
    file = OverwritingFileField(_('file'), max_length=600, upload_to=_file_upload_to)
    uploaded_at = models.DateTimeField(_('creation date'), auto_now_add=True, editable=False, db_index=True)
    extra_info = jsonfield.JSONField(_('extra information'), default={}, editable=False)
    book = models.ForeignKey('Book', related_name='media')
    source_sha1 = models.CharField(null=True, blank=True, max_length=40, editable=False)

    def __unicode__(self):
        return "%s (%s)" % (self.name, self.file.name.split("/")[-1])

    class Meta:
        ordering = ('type', 'name')
        verbose_name = _('book media')
        verbose_name_plural = _('book media')
        app_label = 'catalogue'

    def save(self, *args, **kwargs):
        from catalogue.utils import ExistingFile, remove_zip

        try:
            old = BookMedia.objects.get(pk=self.pk)
        except BookMedia.DoesNotExist:
            old = None
        else:
            # if name changed, change the file name, too
            if slughifi(self.name) != slughifi(old.name):
                self.file.save(None, ExistingFile(self.file.path), save=False, leave=True)

        super(BookMedia, self).save(*args, **kwargs)

        # remove the zip package for book with modified media
        if old:
            remove_zip("%s_%s" % (old.book.slug, old.type))
        remove_zip("%s_%s" % (self.book.slug, self.type))

        extra_info = self.extra_info
        if isinstance(extra_info, basestring):
            # Walkaround for weird jsonfield 'no-decode' optimization.
            extra_info = json.loads(extra_info)
        extra_info.update(self.read_meta())
        self.extra_info = extra_info
        self.source_sha1 = self.read_source_sha1(self.file.path, self.type)
        return super(BookMedia, self).save(*args, **kwargs)

    def read_meta(self):
        """
            Reads some metadata from the audiobook.
        """
        import mutagen
        from mutagen import id3

        artist_name = director_name = project = funded_by = ''
        if self.type == 'mp3':
            try:
                audio = id3.ID3(self.file.path)
                artist_name = ', '.join(', '.join(tag.text) for tag in audio.getall('TPE1'))
                director_name = ', '.join(', '.join(tag.text) for tag in audio.getall('TPE3'))
                project = ", ".join([
                    t.data for t in audio.getall('PRIV')
                    if t.owner == 'wolnelektury.pl?project'])
                funded_by = ", ".join([
                    t.data for t in audio.getall('PRIV')
                    if t.owner == 'wolnelektury.pl?funded_by'])
            except MutagenError:
                pass
        elif self.type == 'ogg':
            try:
                audio = mutagen.File(self.file.path)
                artist_name = ', '.join(audio.get('artist', []))
                director_name = ', '.join(audio.get('conductor', []))
                project = ", ".join(audio.get('project', []))
                funded_by = ", ".join(audio.get('funded_by', []))
            except (MutagenError, AttributeError):
                pass
        else:
            return {}
        return {'artist_name': artist_name, 'director_name': director_name,
                'project': project, 'funded_by': funded_by}

    def ext(self):
        return self.formats[self.type].ext

    @staticmethod
    def read_source_sha1(filepath, filetype):
        """
            Reads source file SHA1 from audiobok metadata.
        """
        import mutagen
        from mutagen import id3

        if filetype == 'mp3':
            try:
                audio = id3.ID3(filepath)
                return [t.data for t in audio.getall('PRIV')
                        if t.owner == 'wolnelektury.pl?flac_sha1'][0]
            except MutagenError:
                return None
        elif filetype == 'ogg':
            try:
                audio = mutagen.File(filepath)
                return audio.get('flac_sha1', [None])[0]
            except (MutagenError, AttributeError):
                return None
        else:
            return None