import os
import io
import arrow
import datetime
import tempfile
import shutil
import markdown

from django.conf import settings
from django.db import models
from django.contrib.staticfiles.templatetags.staticfiles import static
from django.core.files.base import ContentFile
from django.core.files import File
from django.core.urlresolvers import reverse
from django.utils import timezone
from taggit.managers import TaggableManager
from versatileimagefield.fields import VersatileImageField

from funkwhale_api.taskapp import celery
from funkwhale_api import downloader
from funkwhale_api import musicbrainz
from . import importers
from . import lyrics as lyrics_utils


class APIModelMixin(models.Model):
    mbid = models.UUIDField(unique=True, db_index=True, null=True, blank=True)
    api_includes = []
    creation_date = models.DateTimeField(default=timezone.now)
    import_hooks = []
    class Meta:
        abstract = True
        ordering = ['-creation_date']

    @classmethod
    def get_or_create_from_api(cls, mbid):
        try:
            return cls.objects.get(mbid=mbid), False
        except cls.DoesNotExist:
            return cls.create_from_api(id=mbid), True

    def get_api_data(self):
        return self.__class__.api.get(id=self.mbid, includes=self.api_includes)[self.musicbrainz_model]

    @classmethod
    def create_from_api(cls, **kwargs):
        if kwargs.get('id'):
            raw_data = cls.api.get(id=kwargs['id'], includes=cls.api_includes)[cls.musicbrainz_model]
        else:
            raw_data = cls.api.search(**kwargs)['{0}-list'.format(cls.musicbrainz_model)][0]
        cleaned_data = cls.clean_musicbrainz_data(raw_data)
        return importers.load(cls, cleaned_data, raw_data, cls.import_hooks)

    @classmethod
    def clean_musicbrainz_data(cls, data):
        cleaned_data = {}
        mapping = importers.Mapping(cls.musicbrainz_mapping)
        for key, value in data.items():
            try:
                cleaned_key, cleaned_value = mapping.from_musicbrainz(key, value)
                cleaned_data[cleaned_key] = cleaned_value
            except KeyError as e:
                pass
        return cleaned_data

class Artist(APIModelMixin):
    name = models.CharField(max_length=255)

    musicbrainz_model = 'artist'
    musicbrainz_mapping = {
        'mbid': {
            'musicbrainz_field_name': 'id'
        },
        'name': {
            'musicbrainz_field_name': 'name'
        }
    }
    api = musicbrainz.api.artists

    def __str__(self):
        return self.name

    @property
    def tags(self):
        t = []
        for album in self.albums.all():
            for tag in album.tags:
                t.append(tag)
        return set(t)

def import_artist(v):
    a = Artist.get_or_create_from_api(mbid=v[0]['artist']['id'])[0]
    return a

def parse_date(v):
    if len(v) == 4:
        return datetime.date(int(v), 1, 1)
    d = arrow.get(v).date()
    return d


def import_tracks(instance, cleaned_data, raw_data):
    for track_data in raw_data['medium-list'][0]['track-list']:
        track_cleaned_data = Track.clean_musicbrainz_data(track_data['recording'])
        track_cleaned_data['album'] = instance
        track_cleaned_data['position'] = int(track_data['position'])
        track = importers.load(Track, track_cleaned_data, track_data, Track.import_hooks)

class Album(APIModelMixin):
    title = models.CharField(max_length=255)
    artist = models.ForeignKey(Artist, related_name='albums')
    release_date = models.DateField(null=True)
    cover = VersatileImageField(upload_to='albums/covers/%Y/%m/%d', null=True, blank=True)
    TYPE_CHOICES = (
        ('album', 'Album'),
    )
    type = models.CharField(choices=TYPE_CHOICES, max_length=30, default='album')

    api_includes = ['artist-credits', 'recordings', 'media']
    api = musicbrainz.api.releases
    musicbrainz_model = 'release'
    musicbrainz_mapping = {
        'mbid': {
            'musicbrainz_field_name': 'id',
        },
        'position': {
            'musicbrainz_field_name': 'release-list',
            'converter': lambda v: int(v[0]['medium-list'][0]['position']),
        },
        'title': {
            'musicbrainz_field_name': 'title',
        },
        'release_date': {
            'musicbrainz_field_name': 'date',
            'converter': parse_date,

        },
        'type': {
            'musicbrainz_field_name': 'type',
            'converter': lambda v: v.lower(),
        },
        'artist': {
            'musicbrainz_field_name': 'artist-credit',
            'converter': import_artist,
        }
    }

    def get_image(self):
        image_data =  musicbrainz.api.images.get_front(str(self.mbid))
        f = ContentFile(image_data)
        self.cover.save('{0}.jpg'.format(self.mbid), f)
        return self.cover.file

    def __str__(self):
        return self.title

    @property
    def tags(self):
        t = []
        for track in self.tracks.all():
            for tag in track.tags.all():
                t.append(tag)
        return set(t)

def import_tags(instance, cleaned_data, raw_data):
    MINIMUM_COUNT = 2
    tags_to_add = []
    for tag_data in raw_data.get('tag-list', []):
        try:
            if int(tag_data['count']) < MINIMUM_COUNT:
                continue
        except ValueError:
            continue
        tags_to_add.append(tag_data['name'])
    instance.tags.add(*tags_to_add)

def import_album(v):
    a = Album.get_or_create_from_api(mbid=v[0]['id'])[0]
    return a


def link_recordings(instance, cleaned_data, raw_data):
    tracks = [
        r['target']
        for r in raw_data['recording-relation-list']
    ]
    Track.objects.filter(mbid__in=tracks).update(work=instance)


def import_lyrics(instance, cleaned_data, raw_data):
    try:
        url = [
            url_data
            for url_data in raw_data['url-relation-list']
            if url_data['type'] == 'lyrics'
        ][0]['target']
    except (IndexError, KeyError):
        return
    l, _ = Lyrics.objects.get_or_create(work=instance, url=url)

    return l


class Work(APIModelMixin):
    language = models.CharField(max_length=20)
    nature = models.CharField(max_length=50)
    title = models.CharField(max_length=255)

    api = musicbrainz.api.works
    api_includes = ['url-rels', 'recording-rels']
    musicbrainz_model = 'work'
    musicbrainz_mapping = {
        'mbid': {
            'musicbrainz_field_name': 'id'
        },
        'title': {
            'musicbrainz_field_name': 'title'
        },
        'language': {
            'musicbrainz_field_name': 'language',
        },
        'nature': {
            'musicbrainz_field_name': 'type',
            'converter': lambda v: v.lower(),
        },
    }
    import_hooks = [
        import_lyrics,
        link_recordings
    ]

    def fetch_lyrics(self):
        l = self.lyrics.first()
        if l:
            return l
        data = self.api.get(self.mbid, includes=['url-rels'])['work']
        l = import_lyrics(self, {}, data)

        return l


class Lyrics(models.Model):
    work = models.ForeignKey(Work, related_name='lyrics', null=True, blank=True)
    url = models.URLField(unique=True)
    content = models.TextField(null=True, blank=True)

    @celery.app.task(name='Lyrics.fetch_content', filter=celery.task_method)
    def fetch_content(self):
        html = lyrics_utils._get_html(self.url)
        content = lyrics_utils.extract_content(html)
        cleaned_content = lyrics_utils.clean_content(content)
        self.content = cleaned_content
        self.save()

    @property
    def content_rendered(self):
        return markdown.markdown(
            self.content,
            safe_mode=True,
            enable_attributes=False,
            extensions=['markdown.extensions.nl2br'])


class Track(APIModelMixin):
    title = models.CharField(max_length=255)
    artist = models.ForeignKey(Artist, related_name='tracks')
    position = models.PositiveIntegerField(null=True, blank=True)
    album = models.ForeignKey(Album, related_name='tracks', null=True, blank=True)
    work = models.ForeignKey(Work, related_name='tracks', null=True, blank=True)

    musicbrainz_model = 'recording'
    api = musicbrainz.api.recordings
    api_includes = ['artist-credits', 'releases', 'media', 'tags', 'work-rels']
    musicbrainz_mapping = {
        'mbid': {
            'musicbrainz_field_name': 'id'
        },
        'title': {
            'musicbrainz_field_name': 'title'
        },
        'artist': {
            'musicbrainz_field_name': 'artist-credit',
            'converter': lambda v: Artist.get_or_create_from_api(mbid=v[0]['artist']['id'])[0],
        },
        'album': {
            'musicbrainz_field_name': 'release-list',
            'converter': import_album,
        },
    }
    import_hooks = [
        import_tags
    ]
    tags = TaggableManager()

    def __str__(self):
        return self.title

    def save(self, **kwargs):
        try:
            self.artist
        except  Artist.DoesNotExist:
            self.artist = self.album.artist
        super().save(**kwargs)

    def get_work(self):
        if self.work:
            return self.work
        data = self.api.get(self.mbid, includes=['work-rels'])
        try:
            work_data = data['recording']['work-relation-list'][0]['work']
        except (IndexError, KeyError):
            return
        work, _ = Work.get_or_create_from_api(mbid=work_data['id'])
        return work

    def get_lyrics_url(self):
        return reverse('api:tracks-lyrics', kwargs={'pk': self.pk})

    @property
    def full_name(self):
        try:
            return '{} - {} - {}'.format(
                self.artist.name,
                self.album.title,
                self.title,
            )
        except AttributeError:
            return '{} - {}'.format(
                self.artist.name,
                self.title,
            )


class TrackFile(models.Model):
    track = models.ForeignKey(Track, related_name='files')
    audio_file = models.FileField(upload_to='tracks/%Y/%m/%d', max_length=255)
    source = models.URLField(null=True, blank=True)
    duration = models.IntegerField(null=True, blank=True)

    def download_file(self):
        # import the track file, since there is not any
        # we create a tmp dir for the download
        tmp_dir = tempfile.mkdtemp()
        data = downloader.download(
            self.source,
            target_directory=tmp_dir)
        self.duration = data.get('duration', None)
        self.audio_file.save(
            os.path.basename(data['audio_file_path']),
            File(open(data['audio_file_path'], 'rb'))
        )
        shutil.rmtree(tmp_dir)
        return self.audio_file

    @property
    def path(self):
        if settings.USE_SAMPLE_TRACK:
            return static('music/sample1.ogg')
        return self.audio_file.url

class ImportBatch(models.Model):
    creation_date = models.DateTimeField(default=timezone.now)
    submitted_by = models.ForeignKey('users.User', related_name='imports')

    class Meta:
        ordering = ['-creation_date']

    def __str__(self):
        return str(self.pk)

    @property
    def status(self):
        pending = any([job.status == 'pending' for job in self.jobs.all()])
        if pending:
            return 'pending'
        return 'finished'

class ImportJob(models.Model):
    batch = models.ForeignKey(ImportBatch, related_name='jobs')
    source = models.URLField()
    mbid = models.UUIDField(editable=False)
    STATUS_CHOICES = (
        ('pending', 'Pending'),
        ('finished', 'finished'),
    )
    status = models.CharField(choices=STATUS_CHOICES, default='pending', max_length=30)

    @celery.app.task(name='ImportJob.run', filter=celery.task_method)
    def run(self, replace=False):
        try:
            track, created = Track.get_or_create_from_api(mbid=self.mbid)
            track_file = None
            if replace:
                track_file = track.files.first()
            elif track.files.count() > 0:
                return

            track_file = track_file or TrackFile(track=track, source=self.source)
            track_file.download_file()
            track_file.save()
            self.status = 'finished'
            self.save()
            return track.pk

        except Exception as exc:
            if not settings.DEBUG:
                raise ImportJob.run.retry(args=[self], exc=exc, countdown=30, max_retries=3)
            raise