from django.contrib import admin
from django.utils.translation import gettext_lazy as _
from django.urls import reverse
from django.utils.html import format_html
from django.db import models
from unfold.admin import ModelAdmin, StackedInline, TabularInline
from django.contrib.admin import SimpleListFilter
from unfold.widgets import UnfoldAdminSelectWidget

from unfold.decorators import display, action
from django import forms

from utils.admin import project_admin_site
from unfold.sections import TableSection

from apps.podcast.models import *


class PodcastPlaylistInCollectionInlineForCollection(TabularInline):
    model = PodcastPlaylistInCollection
    extra = 1
    autocomplete_fields = ('playlist',)
    fields = ('playlist', 'order')
    ordering = ('order',)
    verbose_name = _('Playlist')
    verbose_name_plural = _('Playlists')
    tab = True


class PodcastCollectionAdminBase(ModelAdmin):
    list_display = ('get_title', 'get_display_position', 'status', 'order', 'count_playlists')
    list_filter = ('status', 'order')
    search_fields = ('title',)
    ordering = ('order',)
    list_filter_submit = True
    warn_unsaved_form = True
    change_form_show_cancel_button = True
    inlines = [PodcastPlaylistInCollectionInlineForCollection]
    

    fieldsets = (
        (None, {
            'fields': ('title', 'summary', 'thumbnail', 'status', 'pin_top', 'order')
        }),
    )

    exclude = ('display_position',)

    @display(description=_('Title'))
    def get_title(self, obj):
        return str(obj.title)

    @display(description=_('Display Position'))
    def get_display_position(self, obj):
        if obj.display_position == PodcastCollection.DisplayPosition.PINNED:
            return format_html('<span style="color: #0066cc; font-weight: bold;">📌 Pinned (Top)</span>')
        else:
            return format_html('<span style="color: #666;">📋 Regular (Middle)</span>')

    @display(description=_('Number of Playlists'))
    def count_playlists(self, obj):
        count = obj.related_playlists.count()
        if count > 0:
            url = reverse('admin:podcast_podcastplaylist_changelist') + f'?collections__id__exact={obj.id}'
            return format_html('<a href="{}">{}</a>', url, count)
        return count


class PinnedPodcastCollectionForm(forms.ModelForm):
    class Meta:
        model = PinnedPodcastCollection
        exclude = ('slug',)

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['thumbnail'].required = True
        
class PinnedPodcastCollectionAdmin(PodcastCollectionAdminBase):
    form = PinnedPodcastCollectionForm
    
    # Add help text to clarify this is for top section
    class Media:
        css = {
            'all': ()
        }
    
    def get_queryset(self, request):
        return super().get_queryset(request).filter(display_position=PodcastCollection.DisplayPosition.PINNED)

    def save_model(self, request, obj, form, change):
        obj.display_position = PodcastCollection.DisplayPosition.PINNED
        super().save_model(request, obj, form, change)

    @display(description=_('Title'))
    def get_title(self, obj):
        from django.templatetags.static import static
        thumbnail_path = obj.thumbnail.url if obj.thumbnail else None
        return obj.title 
        
class MiddlePodcastCollectionAdmin(PodcastCollectionAdminBase):
    
    fieldsets = (
        (None, {
            'fields': ('title', 'status', 'pin_top', 'order')
        }),
    )
    
    # Add help text to clarify this is for middle section
    class Media:
        css = {
            'all': ()
        }

    def get_queryset(self, request):
        return super().get_queryset(request).filter(display_position=PodcastCollection.DisplayPosition.MIDDLE)

    def save_model(self, request, obj, form, change):
        obj.display_position = PodcastCollection.DisplayPosition.MIDDLE
        super().save_model(request, obj, form, change)


class PodcastCategoryAdmin(ModelAdmin):
    list_display = ('title', 'slug', 'status', 'order', 'count_playlists', 'created_at')
    list_filter = ('status', 'created_at', 'updated_at')
    search_fields = ('title', 'slug')
    search_help_text = _("Search by title or slug")
    search_fields_placeholder = _("Search categories")

    @admin.display(description=_('Number of Playlists'))
    def count_playlists(self, obj):
        count = obj.playlists.filter(status=True).count()
        if count > 0:
            url = reverse('admin:podcast_podcastplaylist_changelist') + f'?categories__id__exact={obj.id}'
            return format_html('<a href="{}">{}</a>', url, count)
        return count
    
    def get_form(self, request, obj=None, change=False, **kwargs):
        form = super().get_form(request, obj, change, **kwargs)
        if form.base_fields.get('slug'):
            form.base_fields['slug'].required = False
        return form


class PodcastAdmin(ModelAdmin):
    list_display = ('title', 'slug', 'status', 'view_count', 'created_at')
    list_filter = ('status', 'created_at', 'updated_at')
    search_fields = ('title', 'slug', 'description')
    autocomplete_fields = ('categories',)
    save_as = True
    search_help_text = _("Search by title, slug, or description")
    search_fields_placeholder = _("Search podcasts")

    fieldsets = (
        (None, {
            'fields': ('title', 'slug', 'description', 'thumbnail', 'categories')
        }),
        (_('Audio Information'), {
            'fields': ('audio_file', 'audio_time')
        }),
        (_('Status'), {
            'fields': ('status',)
        }),
        (_('Statistics'), {
            'fields': ('view_count', 'download_count')
        }),
    )
    
    def get_form(self, request, obj=None, change=False, **kwargs):
        form = super().get_form(request, obj, change, **kwargs)
        if form.base_fields.get('slug'):
            form.base_fields['slug'].required = False
        if form.base_fields.get('thumbnail'):
            form.base_fields['thumbnail'].required = True
        return form


class PodcastPlaylistItemForm(forms.ModelForm):
    class Meta:
        model = PlaylistItem
        fields = ('podcast', 'priority')
    
    def clean_podcast(self):
        podcast = self.cleaned_data.get('podcast')
        if not podcast:
            return podcast
            
        # If we're editing, exclude the current instance from the check
        instance = getattr(self, 'instance', None)
        if instance and instance.pk and instance.podcast == podcast:
            return podcast
            
        # Check if this podcast exists in another playlist
        existing_item = PlaylistItem.objects.filter(podcast=podcast).first()
        if existing_item:
            playlist_name = existing_item.playlist.title
            raise forms.ValidationError(
                _('This podcast is already used in playlist "{}". Each podcast can only be in one playlist.').format(playlist_name)
            )
        return podcast
    

class PodcastPlaylistItemInline(StackedInline):
    model = PlaylistItem
    form = PodcastPlaylistItemForm
    extra = 1
    autocomplete_fields = ('podcast',)
    fields = ('podcast', 'priority')
    ordering = ('priority',)
    verbose_name = _('Playlist Item')
    verbose_name_plural = _('Playlist Items')


class PodcastPlaylistInCollectionInline(TabularInline):
    model = PodcastPlaylistInCollection
    extra = 1
    raw_id_fields = ('collection',)
    fields = ('collection', 'order')
    ordering = ('order',)
    verbose_name = _('Collection')
    verbose_name_plural = _('Collections')
    tab = True


class PodcastPlaylistAdmin(ModelAdmin):
    list_display = ('title', 'slug', 'status', 'order', 'view_count', 'count_podcasts', 'created_at')
    list_filter = ('status', 'created_at', 'categories')
    search_fields = ('title', 'slug', 'slogan', 'description')
    autocomplete_fields = ('categories',)
    list_filter_submit = True
    warn_unsaved_form = True
    change_form_show_cancel_button = True
    inlines = [PodcastPlaylistItemInline, PodcastPlaylistInCollectionInline]
    
    fieldsets = (
        (None, {
            'fields': ('title', 'slug', 'slogan', 'description', 'thumbnail')
        }),
        (_('Categories'), {
            'fields': ('categories',)
        }),
        (_('Display Settings'), {
            'fields': ('order', 'status')
        }),
        (_('Statistics'), {
            'fields': ('view_count', 'total_time')
        }),
    )
    
    def get_form(self, request, obj=None, change=False, **kwargs):
        form = super().get_form(request, obj, change, **kwargs)
        if form.base_fields.get('slug'):
            form.base_fields['slug'].required = False
        if form.base_fields.get('thumbnail'):
            form.base_fields['thumbnail'].required = False
        if form.base_fields.get('total_time'):
            form.base_fields['total_time'].required = False
            form.base_fields['total_time'].help_text = _('Will be auto-calculated from podcasts')
        return form
    
        
    @display(description=_('Number of Podcasts'))
    def count_podcasts(self, obj):
        count = obj.playlist_items.count()
        if count > 0:
            return format_html('<span>{}</span>', count)
        return count
    
    def save_model(self, request, obj, form, change):
        super().save_model(request, obj, form, change)
        # Auto-calculate total_time
        obj.total_time = obj.calculate_total_time()
        obj.save(update_fields=['total_time'])
        
    def save_formset(self, request, form, formset, change):
        """
        Additional validation to ensure each podcast is used in only one playlist
        """
        instances = formset.save(commit=False)
        
        # Collect all podcasts that are being saved
        podcasts_to_save = []
        for instance in instances:
            if instance.podcast:
                podcasts_to_save.append(instance.podcast)
        
        # Check for duplicate podcasts in this formset
        podcast_counts = {}
        for podcast in podcasts_to_save:
            podcast_counts[podcast.id] = podcast_counts.get(podcast.id, 0) + 1
            
        duplicate_podcasts = [podcast_id for podcast_id, count in podcast_counts.items() if count > 1]
        if duplicate_podcasts:
            # If there are duplicate podcasts in this form, show an error
            formset._non_form_errors = formset.error_class(
                [_('A podcast cannot be used multiple times in the same playlist.')]
            )
            return
        
        # Check if podcasts are used in other playlists
        for instance in instances:
            if instance.podcast:  # For both new and edited items
                playlist_id = form.instance.pk
                query = PlaylistItem.objects.filter(
                    podcast=instance.podcast
                ).exclude(
                    playlist_id=playlist_id
                )
                
                # If we're editing an existing item, exclude it from the check
                if instance.pk:
                    query = query.exclude(pk=instance.pk)
                
                existing_item = query.first()
                
                if existing_item:
                    playlist_name = existing_item.playlist.title
                    formset._non_form_errors = formset.error_class(
                        [_('Podcast "{}" is already used in playlist "{}". Each podcast can only be in one playlist.').format(
                            instance.podcast.title, playlist_name
                        )]
                    )
                    return
        
        # If all validations pass, save the formset
        super().save_formset(request, form, formset, change)


class UserPlaylistAdmin(ModelAdmin):
    list_display = ('user', 'podcast', 'status', 'created_at', 'updated_at')
    list_filter = ('status', 'created_at', 'updated_at')
    search_fields = ('user__username', 'podcast__title')
    autocomplete_fields = ('user', 'podcast')
    
    fieldsets = (
        (None, {
            'fields': ('user', 'podcast', 'status')
        }),
    )


project_admin_site.register(PodcastCategory, PodcastCategoryAdmin)
project_admin_site.register(Podcast, PodcastAdmin)
project_admin_site.register(PinnedPodcastCollection, PinnedPodcastCollectionAdmin)
project_admin_site.register(MiddlePodcastCollection, MiddlePodcastCollectionAdmin)
project_admin_site.register(PodcastPlaylist, PodcastPlaylistAdmin)
project_admin_site.register(UserPlaylist, UserPlaylistAdmin)