import logging
from typing import Callable, Union, Any, Optional

from django.contrib.auth.models import User
from django.contrib.auth.models import User
from django.db import models
from django.db.models.functions import Lower
from YtManagerApp.utils.youtube import YoutubeAPI, YoutubeChannelInfo, YoutubePlaylistInfo

# help_text = user shown text
# verbose_name = user shown name
# null = nullable, blank = user is allowed to set value to empty


class UserSettings(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    mark_deleted_as_watched = models.BooleanField(null=True)
    delete_watched = models.BooleanField(null=True)
    auto_download = models.BooleanField(null=True)
    download_global_limit = models.IntegerField(null=True)
    download_subscription_limit = models.IntegerField(null=True)
    download_order = models.TextField(null=True)
    download_path = models.TextField(null=True)
    download_file_pattern = models.TextField(null=True)
    download_format = models.TextField(null=True)
    download_subtitles = models.BooleanField(null=True)
    download_autogenerated_subtitles = models.BooleanField(null=True)
    download_subtitles_all = models.BooleanField(null=True)
    download_subtitles_langs = models.TextField(null=True)
    download_subtitles_format = models.TextField(null=True)

    @staticmethod
    def find_by_user(user: User):
        result = UserSettings.objects.filter(user=user)
        if len(result) > 0:
            return result.first()
        return None

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

    def to_dict(self):
        ret = {}

        if self.mark_deleted_as_watched is not None:
            ret['MarkDeletedAsWatched'] = self.mark_deleted_as_watched
        if self.delete_watched is not None:
            ret['DeleteWatched'] = self.delete_watched
        if self.auto_download is not None:
            ret['AutoDownload'] = self.auto_download
        if self.download_global_limit is not None:
            ret['DownloadGlobalLimit'] = self.download_global_limit
        if self.download_subscription_limit is not None:
            ret['DownloadSubscriptionLimit'] = self.download_subscription_limit
        if self.download_order is not None:
            ret['DownloadOrder'] = self.download_order
        if self.download_path is not None:
            ret['DownloadPath'] = self.download_path
        if self.download_file_pattern is not None:
            ret['DownloadFilePattern'] = self.download_file_pattern
        if self.download_format is not None:
            ret['DownloadFormat'] = self.download_format
        if self.download_subtitles is not None:
            ret['DownloadSubtitles'] = self.download_subtitles
        if self.download_autogenerated_subtitles is not None:
            ret['DownloadAutogeneratedSubtitles'] = self.download_autogenerated_subtitles
        if self.download_subtitles_all is not None:
            ret['DownloadSubtitlesAll'] = self.download_subtitles_all
        if self.download_subtitles_langs is not None:
            ret['DownloadSubtitlesLangs'] = self.download_subtitles_langs
        if self.download_subtitles_format is not None:
            ret['DownloadSubtitlesFormat'] = self.download_subtitles_format

        return ret


class SubscriptionFolder(models.Model):
    name = models.CharField(null=False, max_length=250)
    parent = models.ForeignKey('self', on_delete=models.CASCADE, null=True, blank=True)
    user = models.ForeignKey(User, on_delete=models.CASCADE, null=False, blank=False)

    class Meta:
        ordering = [Lower('parent__name'), Lower('name')]

    def __str__(self):
        s = ""
        current = self
        while current is not None:
            s = current.name + " > " + s
            current = current.parent
        return s[:-3]

    def delete_folder(self, keep_subscriptions: bool):
        if keep_subscriptions:

            def visit(node: Union["SubscriptionFolder", "Subscription"]):
                if isinstance(node, Subscription):
                    node.parent_folder = None
                    node.save()

            SubscriptionFolder.traverse(self.id, self.user, visit)

        self.delete()

    @staticmethod
    def traverse(root_folder_id: Optional[int],
                 user: User,
                 visit_func: Callable[[Union["SubscriptionFolder", "Subscription"]], Any]):

        data_collected = []

        def collect(data):
            if data is not None:
                data_collected.append(data)

        # Visit root
        if root_folder_id is not None:
            root_folder = SubscriptionFolder.objects.get(id=root_folder_id)
            collect(visit_func(root_folder))

        queue = [root_folder_id]
        visited = []

        while len(queue) > 0:
            folder_id = queue.pop()

            if folder_id in visited:
                logging.error('Found folder tree cycle for folder id %d.', folder_id)
                continue
            visited.append(folder_id)

            for folder in SubscriptionFolder.objects.filter(parent_id=folder_id, user=user).order_by(Lower('name')):
                collect(visit_func(folder))
                queue.append(folder.id)

            for subscription in Subscription.objects.filter(parent_folder_id=folder_id, user=user).order_by(Lower('name')):
                collect(visit_func(subscription))

        return data_collected


class Channel(models.Model):
    channel_id = models.TextField(null=False, unique=True)
    username = models.TextField(null=True, unique=True)
    custom_url = models.TextField(null=True, unique=True)
    name = models.TextField()
    description = models.TextField()
    icon_default = models.TextField()
    icon_best = models.TextField()
    upload_playlist_id = models.TextField()

    def __str__(self):
        return self.name

    @staticmethod
    def find_by_channel_id(channel_id):
        result = Channel.objects.filter(channel_id=channel_id)
        if len(result) > 0:
            return result.first()
        return None

    @staticmethod
    def find_by_username(username):
        result = Channel.objects.filter(username=username)
        if len(result) > 0:
            return result.first()
        return None

    @staticmethod
    def find_by_custom_url(custom_url):
        result = Channel.objects.filter(custom_url=custom_url)
        if len(result) > 0:
            return result.first()
        return None

    def fill(self, yt_channel_info: YoutubeChannelInfo):
        self.channel_id = yt_channel_info.getId()
        self.custom_url = yt_channel_info.getCustomUrl()
        self.name = yt_channel_info.getTitle()
        self.description = yt_channel_info.getDescription()
        self.icon_default = yt_channel_info.getDefaultThumbnailUrl()
        self.icon_best = yt_channel_info.getBestThumbnailUrl()
        self.upload_playlist_id = yt_channel_info.getUploadsPlaylist()
        self.save()

    @staticmethod
    def get_or_create(url_type: str, url_id: str, yt_api: YoutubeAPI):
        channel: Channel = None
        info_channel: YoutubeChannelInfo = None

        if url_type == 'user':
            channel = Channel.find_by_username(url_id)
            if not channel:
                info_channel = yt_api.get_channel_info_by_username(url_id)
                channel = Channel.find_by_channel_id(info_channel.getId())

        elif url_type == 'channel_id':
            channel = Channel.find_by_channel_id(url_id)
            if not channel:
                info_channel = yt_api.get_channel_info(url_id)

        elif url_type == 'channel_custom':
            channel = Channel.find_by_custom_url(url_id)
            if not channel:
                found_channel_id = yt_api.search_channel(url_id)
                channel = Channel.find_by_channel_id(found_channel_id)
                if not channel:
                    info_channel = yt_api.get_channel_info(found_channel_id)

        # If we downloaded information about the channel, store information
        # about the channel here.
        if info_channel:
            if not channel:
                channel = Channel()
            if url_type == 'user':
                channel.username = url_id
            channel.fill(info_channel)

        return channel


class Subscription(models.Model):
    name = models.CharField(null=False, max_length=1024)
    parent_folder = models.ForeignKey(SubscriptionFolder, on_delete=models.CASCADE, null=True, blank=True)
    playlist_id = models.CharField(null=False, max_length=128)
    description = models.TextField()
    channel = models.ForeignKey(Channel, on_delete=models.CASCADE)
    icon_default = models.CharField(max_length=1024)
    icon_best = models.CharField(max_length=1024)
    user = models.ForeignKey(User, on_delete=models.CASCADE)

    # overrides
    auto_download = models.BooleanField(null=True, blank=True)
    download_limit = models.IntegerField(null=True, blank=True)
    download_order = models.CharField(null=True, blank=True, max_length=128)
    manager_delete_after_watched = models.BooleanField(null=True, blank=True)

    def fill_from_playlist(self, info_playlist: YoutubePlaylistInfo):
        self.name = info_playlist.getTitle()
        self.playlist_id = info_playlist.getId()
        self.description = info_playlist.getDescription()
        self.icon_default = info_playlist.getDefaultThumbnailUrl()
        self.icon_best = info_playlist.getBestThumbnailUrl()

    def copy_from_channel(self):
        # No point in storing info about the 'uploads from X' playlist
        self.name = self.channel.name
        self.playlist_id = self.channel.upload_playlist_id
        self.description = self.channel.description
        self.icon_default = self.channel.icon_default
        self.icon_best = self.channel.icon_best

    def fetch_from_url(self, url, yt_api: YoutubeAPI):
        url_type, url_id = yt_api.parse_channel_url(url)
        if url_type == 'playlist_id':
            info_playlist = yt_api.get_playlist_info(url_id)
            self.channel = Channel.get_or_create('channel_id', info_playlist.getChannelId(), yt_api)
            self.fill_from_playlist(info_playlist)
        else:
            self.channel = Channel.get_or_create(url_type, url_id, yt_api)
            self.copy_from_channel()

    def delete_subscription(self, keep_downloaded_videos: bool):
        self.delete()

    def __str__(self):
        return self.name


class Video(models.Model):
    video_id = models.TextField(null=False)
    name = models.TextField(null=False)
    description = models.TextField()
    watched = models.BooleanField(default=False, null=False)
    downloaded_path = models.TextField(null=True, blank=True)
    subscription = models.ForeignKey(Subscription, on_delete=models.CASCADE)
    playlist_index = models.IntegerField(null=False)
    publish_date = models.DateTimeField(null=False)
    icon_default = models.TextField()
    icon_best = models.TextField()
    uploader_name = models.TextField(null=False)
    views = models.IntegerField(null=False, default=0)
    rating = models.FloatField(null=False, default=0.5)

    def __str__(self):
        return self.name