from django.db import models
from django.utils.translation import gettext_lazy as _
from django.conf import settings
import datetime
from filer.fields.image import FilerImageField
from utils import generate_slug_for_model
from utils.mixins import LowercaseSlugMixin
from django.core.validators import FileExtensionValidator
from django.core.exceptions import ValidationError


class VideoCategory(LowercaseSlugMixin, models.Model):
    title = models.CharField(max_length=255, verbose_name=_('title'))
    slug = models.SlugField(allow_unicode=True, unique=True, verbose_name=_('slug'))

    status = models.BooleanField(default=True, verbose_name=_('status'))
    order = models.PositiveIntegerField(default=0, verbose_name=_('order'))
    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_('created at'))
    updated_at = models.DateTimeField(auto_now=True, verbose_name=_('updated at'))

    def __str__(self):
        return self.title

    class Meta:
        verbose_name = _('Video Category')
        verbose_name_plural = _('Video Categories')
        ordering = ['order']


class VideoCollection(LowercaseSlugMixin, models.Model):
    class DisplayPosition(models.TextChoices):
        PINNED = 'pinned', _('Pinned')
        MIDDLE = 'middle', _('Middle Section')

    title = models.CharField(max_length=255)
    slug = models.SlugField(max_length=255, unique=True, allow_unicode=True)
    summary = models.CharField(max_length=512, null=True, blank=True, help_text=_('could be null'))
    thumbnail = models.ImageField(upload_to='video/collection/', null=True, blank=True, help_text=_('image allowed'))
    order = models.IntegerField(default=0, verbose_name=_('order'))

    status = models.BooleanField(default=True, verbose_name=_('status'))
    display_position = models.CharField(
        max_length=20,
        choices=DisplayPosition.choices,
        default=DisplayPosition.PINNED,
        verbose_name=_('Display Position')
    )
    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_('created at'))
    updated_at = models.DateTimeField(auto_now=True, verbose_name=_('updated at'))

    def __str__(self):
        return f'Collection #{self.id}/{self.title}'

    class Meta:
        verbose_name = _('Video Collection')
        verbose_name_plural = _('Video Collections')

class PinnedVideoCollection(VideoCollection):
    class Meta:
        proxy = True
        verbose_name = _('Pinned Video Collection')
        verbose_name_plural = _('Pinned Video Collections')


class MiddleVideoCollection(VideoCollection):
    class Meta:
        proxy = True
        verbose_name = _('Middle Section Video Collection')
        verbose_name_plural = _('Middle Section Video Collections')




class Video(LowercaseSlugMixin, models.Model):
    slug_source_field = 'title'
    class VedioTypeChoices(models.TextChoices):
        YOUTUBE_LINK = 'youtube_link', 'Youtube Link'
        VIDEO_FILE = 'video_file', 'Video File'

    title = models.CharField(max_length=255, null=True)
    slug = models.SlugField(allow_unicode=True, unique=True)
    thumbnail = models.ImageField(upload_to='video/thumbnails/', null=True, blank=True, help_text=_('image allowed'))
    description = models.TextField(null=True)
    
    video_type = models.CharField(max_length=255, choices=VedioTypeChoices.choices)
    video_file = models.FileField(upload_to='video/videos/', null=True, blank=True ,validators=[
            FileExtensionValidator(
                allowed_extensions=['mp4', 'mov', 'avi', 'mkv', 'webm']
            )
        ])
    video_url = models.CharField(max_length=655, null=True, blank=True)
    video_time = models.TimeField()

    view_count = models.PositiveBigIntegerField(default=0, verbose_name=_('view count'))

    status = models.BooleanField(default=True, verbose_name=_('status'))

    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_('created at'))
    updated_at = models.DateTimeField(auto_now=True, verbose_name=_('updated at'))

    def __str__(self):
        return self.title

    @property
    def share_link(self):
        if self.slug:
            return f"{settings.DOVODI_DOMAIN}/videos/{self.slug}"
        return None

    def increment_view_count(self):
        """Increment the view count for this video"""
        self.view_count += 1
        self.save(update_fields=['view_count'])
        return self.view_count

    def clean(self):
        super().clean()
        if self.video_type == self.VedioTypeChoices.YOUTUBE_LINK and not self.video_url:
            raise ValidationError({
                'video_url': _('This field is required when video type is Link.')
            })
        if self.video_type == self.VedioTypeChoices.VIDEO_FILE and not self.video_file:
            raise ValidationError({
                'video_file': _('This field is required when video type is File.')
            })

    def save(self, *args, **kwargs):
        is_new = self.pk is None
        file_changed = False
        
        if not is_new:
            try:
                old_instance = Video.objects.get(pk=self.pk)
                if old_instance.video_file != self.video_file:
                    file_changed = True
            except Video.DoesNotExist:
                pass
        else:
            file_changed = True
            
        if not self.video_time:
            self.video_time = datetime.time(0, 0, 0)
            
        super().save(*args, **kwargs)
        
        if (file_changed or self.video_time == datetime.time(0, 0, 0)) and self.video_file and self.video_type == self.VedioTypeChoices.VIDEO_FILE:
            from utils.media import get_media_duration_time
            try:
                duration_time = get_media_duration_time(self.video_file.path)
                if duration_time:
                    self.video_time = duration_time
                    Video.objects.filter(pk=self.pk).update(video_time=duration_time)
                    
                    # Update playlists that contain this video
                    for appearance in self.playlist_appearances.all():
                        playlist = appearance.playlist
                        playlist.total_time = playlist.calculate_total_time()
                        playlist.save(update_fields=['total_time'])
            except Exception as e:
                pass



class VideoPlaylist(LowercaseSlugMixin, models.Model):
    title = models.CharField(max_length=255, verbose_name=_('title'))
    slug = models.SlugField(allow_unicode=True, unique=True, null=True, blank=True, verbose_name=_('slug'))
    slogan = models.CharField(max_length=512, null=True, blank=True, verbose_name=_('slogan'))
    description = models.TextField(null=True, blank=True, verbose_name=_('description'))
    thumbnail = models.ImageField(upload_to='video/playlist/thumbnails/', null=True, blank=True, verbose_name=_('thumbnail'))
    
    categories = models.ManyToManyField(
        VideoCategory,
        related_name='playlists',
        verbose_name=_('categories'),
        blank=True,
    )
    collections = models.ManyToManyField(
        VideoCollection,
        through='VideoPlaylistInCollection',
        related_name='related_playlists',
        verbose_name=_('collections'),
        blank=True
    )
    
    order = models.PositiveIntegerField(default=0, verbose_name=_('order'))
    status = models.BooleanField(default=True, verbose_name=_('status'))
    view_count = models.PositiveBigIntegerField(default=0, verbose_name=_('view count'))
    total_time = models.DurationField(null=True, blank=True, verbose_name=_('total time'))
    
    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_('created at'))
    updated_at = models.DateTimeField(auto_now=True, verbose_name=_('updated at'))
    
    def __str__(self):
        return self.title
    
    def increment_view_count(self):
        """Increment the view count for this playlist"""
        self.view_count += 1
        self.save(update_fields=['view_count'])
        return self.view_count
    
    def calculate_total_time(self):
        """Calculate total duration of all videos in this playlist"""
        from datetime import timedelta
        total_seconds = 0
        
        for item in self.playlist_items.select_related('video'):
            video_time = item.video.video_time
            total_seconds += video_time.hour * 3600 + video_time.minute * 60 + video_time.second
        
        return timedelta(seconds=total_seconds)
    
    class Meta:
        verbose_name = _('Video Playlist')
        verbose_name_plural = _('Video Playlists')
        ordering = ['order', '-created_at']


class VideoPlaylistInCollection(models.Model):
    collection = models.ForeignKey(
        VideoCollection,
        on_delete=models.CASCADE,
        related_name='collection_playlists',
        verbose_name=_('collection')
    )
    playlist = models.ForeignKey(
        VideoPlaylist,
        on_delete=models.CASCADE,
        related_name='playlist_collections',
        verbose_name=_('playlist')
    )
    order = models.PositiveIntegerField(default=0, verbose_name=_('order'))
    
    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_('created at'))
    updated_at = models.DateTimeField(auto_now=True, verbose_name=_('updated at'))
    
    def __str__(self):
        return f"{self.collection.title} - {self.playlist.title}"
    
    class Meta:
        verbose_name = _('Video Playlist in Collection')
        verbose_name_plural = _('Video Playlists in Collections')
        ordering = ['order']
        unique_together = ['collection', 'playlist']


class PlaylistItem(models.Model):
    playlist = models.ForeignKey(
        VideoPlaylist, 
        on_delete=models.CASCADE, 
        related_name='playlist_items',
        verbose_name=_('playlist')
    )
    video = models.ForeignKey(
        Video, 
        on_delete=models.CASCADE, 
        related_name='playlist_appearances',
        verbose_name=_('video')
    )
    priority = models.PositiveIntegerField(default=0, verbose_name=_('priority'))
    
    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_('created at'))
    updated_at = models.DateTimeField(auto_now=True, verbose_name=_('updated at'))
    
    def __str__(self):
        return f"{self.playlist.title} - {self.video.title} (Priority: {self.priority})"
    
    class Meta:
        verbose_name = _('Playlist Item')
        verbose_name_plural = _('Playlist Items')
        ordering = ['priority']
        unique_together = ['playlist', 'video']