from django.contrib import admin
from django.utils.html import format_html
import nested_admin
from .models import ProductCategory, ProductTag, Product, ProductKit, KitItem
from .models import ProductPhoto, ProductKitPhoto, ProductCategoryPhoto
from .models import ProductVariantGroup, KitItemPriority, SKUCounter


@admin.register(ProductVariantGroup)
class ProductVariantGroupAdmin(admin.ModelAdmin):
    list_display = ['name', 'get_products_count', 'created_at']
    search_fields = ['name', 'description']
    list_filter = ['created_at']
    readonly_fields = ['created_at', 'updated_at']

    def get_products_count(self, obj):
        return obj.products.count()
    get_products_count.short_description = 'Товаров'


class ProductCategoryAdmin(admin.ModelAdmin):
    list_display = ('photo_preview', 'name', 'sku', 'slug', 'parent', 'is_active')
    list_filter = ('is_active', 'parent')
    prepopulated_fields = {'slug': ('name',)}
    search_fields = ('name', 'sku')
    readonly_fields = ('photo_preview_large',)

    def photo_preview(self, obj):
        """Превью фото в списке категорий"""
        first_photo = obj.photos.first()
        if first_photo and first_photo.image:
            return format_html(
                '<img src="{}" style="width: 50px; height: 50px; object-fit: cover; border-radius: 4px;" />',
                first_photo.image.url
            )
        return "Нет фото"
    photo_preview.short_description = "Фото"

    def photo_preview_large(self, obj):
        """Большое превью фото в форме редактирования"""
        first_photo = obj.photos.first()
        if first_photo and first_photo.image:
            return format_html(
                '<img src="{}" style="max-width: 300px; max-height: 300px; border-radius: 8px;" />',
                first_photo.image.url
            )
        return "Нет фото"
    photo_preview_large.short_description = "Превью основного фото"


class ProductTagAdmin(admin.ModelAdmin):
    list_display = ('name', 'slug')
    prepopulated_fields = {'slug': ('name',)}
    search_fields = ('name',)


class ProductAdmin(admin.ModelAdmin):
    list_display = ('photo_preview', 'name', 'sku', 'get_categories_display', 'cost_price', 'sale_price', 'get_variant_groups_display', 'is_active')
    list_filter = ('is_active', 'categories', 'tags', 'variant_groups')
    search_fields = ('name', 'sku', 'description', 'search_keywords')
    filter_horizontal = ('categories', 'tags', 'variant_groups')
    readonly_fields = ('photo_preview_large',)
    autocomplete_fields = []

    fieldsets = (
        ('Основная информация', {
            'fields': ('name', 'sku', 'variant_suffix', 'description', 'categories', 'unit')
        }),
        ('Цены', {
            'fields': ('cost_price', 'sale_price')
        }),
        ('Дополнительно', {
            'fields': ('tags', 'variant_groups', 'is_active')
        }),
        ('Поиск', {
            'fields': ('search_keywords',),
            'classes': ('collapse',),
            'description': 'Поле для улучшенного поиска. Автоматически генерируется при сохранении, но вы можете добавить дополнительные ключевые слова (синонимы, альтернативные названия и т.д.).'
        }),
        ('Фото', {
            'fields': ('photo_preview_large',),
            'classes': ('collapse',),
        }),
    )

    def get_categories_display(self, obj):
        categories = obj.categories.all()[:3]
        if not categories:
            return "-"
        result = ", ".join([cat.name for cat in categories])
        if obj.categories.count() > 3:
            result += f" (+{obj.categories.count() - 3})"
        return result
    get_categories_display.short_description = 'Категории'

    def get_variant_groups_display(self, obj):
        groups = obj.variant_groups.all()[:3]
        if not groups:
            return "-"
        result = ", ".join([g.name for g in groups])
        if obj.variant_groups.count() > 3:
            result += f" (+{obj.variant_groups.count() - 3})"
        return result
    get_variant_groups_display.short_description = 'Группы вариантов'

    def photo_preview(self, obj):
        """Превью фото в списке товаров"""
        first_photo = obj.photos.first()
        if first_photo and first_photo.image:
            return format_html(
                '<img src="{}" style="width: 50px; height: 50px; object-fit: cover; border-radius: 4px;" />',
                first_photo.image.url
            )
        return "Нет фото"
    photo_preview.short_description = "Фото"

    def photo_preview_large(self, obj):
        """Большое превью фото в форме редактирования"""
        first_photo = obj.photos.first()
        if first_photo and first_photo.image:
            return format_html(
                '<img src="{}" style="max-width: 300px; max-height: 300px; border-radius: 8px;" />',
                first_photo.image.url
            )
        return "Нет фото"
    photo_preview_large.short_description = "Превью основного фото"


class ProductKitAdmin(admin.ModelAdmin):
    list_display = ('photo_preview', 'name', 'slug', 'get_categories_display', 'pricing_method', 'is_active')
    list_filter = ('is_active', 'pricing_method', 'categories', 'tags')
    prepopulated_fields = {'slug': ('name',)}
    filter_horizontal = ('categories', 'tags')
    readonly_fields = ('photo_preview_large',)

    def get_categories_display(self, obj):
        categories = obj.categories.all()[:3]
        if not categories:
            return "-"
        result = ", ".join([cat.name for cat in categories])
        if obj.categories.count() > 3:
            result += f" (+{obj.categories.count() - 3})"
        return result
    get_categories_display.short_description = 'Категории'

    def photo_preview(self, obj):
        """Превью фото в списке комплектов"""
        first_photo = obj.photos.first()
        if first_photo and first_photo.image:
            return format_html(
                '<img src="{}" style="width: 50px; height: 50px; object-fit: cover; border-radius: 4px;" />',
                first_photo.image.url
            )
        return "Нет фото"
    photo_preview.short_description = "Фото"

    def photo_preview_large(self, obj):
        """Большое превью фото в форме редактирования"""
        first_photo = obj.photos.first()
        if first_photo and first_photo.image:
            return format_html(
                '<img src="{}" style="max-width: 300px; max-height: 300px; border-radius: 8px;" />',
                first_photo.image.url
            )
        return "Нет фото"
    photo_preview_large.short_description = "Превью основного фото"


class KitItemPriorityInline(nested_admin.NestedTabularInline):
    model = KitItemPriority
    extra = 0  # Не показывать пустые формы
    fields = ['product', 'priority']
    autocomplete_fields = ['product']

    def get_queryset(self, request):
        qs = super().get_queryset(request)
        return qs.select_related('product')

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        """Показывать только товары из выбранной группы вариантов"""
        if db_field.name == "product":
            # Получаем kit_item из родительского объекта через request
            # Это будет работать автоматически с nested_admin
            pass
        return super().formfield_for_foreignkey(db_field, request, **kwargs)


class KitItemInline(nested_admin.NestedStackedInline):
    model = KitItem
    extra = 0  # Не показывать пустые формы
    fields = ['product', 'variant_group', 'quantity', 'notes']
    autocomplete_fields = ['product']
    inlines = [KitItemPriorityInline]

    class Media:
        css = {
            'all': ('admin/css/custom_nested.css',)
        }


class ProductPhotoInline(admin.TabularInline):
    model = ProductPhoto
    extra = 1
    readonly_fields = ('image_preview',)
    fields = ('image', 'image_preview', 'order')

    def image_preview(self, obj):
        """Превью загруженного фото"""
        if obj.image:
            return format_html(
                '<img src="{}" style="max-width: 200px; max-height: 200px; border-radius: 4px;" />',
                obj.image.url
            )
        return "Нет изображения"
    image_preview.short_description = "Превью"

class ProductKitPhotoInline(nested_admin.NestedTabularInline):
    model = ProductKitPhoto
    extra = 0  # Не показывать пустые формы
    readonly_fields = ('image_preview',)
    fields = ('image', 'image_preview', 'order')

    def image_preview(self, obj):
        """Превью загруженного фото"""
        if obj.image:
            return format_html(
                '<img src="{}" style="max-width: 200px; max-height: 200px; border-radius: 4px;" />',
                obj.image.url
            )
        return "Нет изображения"
    image_preview.short_description = "Превью"

class ProductCategoryPhotoInline(admin.TabularInline):
    model = ProductCategoryPhoto
    extra = 1
    readonly_fields = ('image_preview',)
    fields = ('image', 'image_preview', 'order')

    def image_preview(self, obj):
        """Превью загруженного фото"""
        if obj.image:
            return format_html(
                '<img src="{}" style="max-width: 200px; max-height: 200px; border-radius: 4px;" />',
                obj.image.url
            )
        return "Нет изображения"
    image_preview.short_description = "Превью"

class ProductKitAdminWithItems(ProductKitAdmin):
    inlines = [KitItemInline]


# Update admin classes to include photo inlines
class ProductAdminWithPhotos(ProductAdmin):
    inlines = [ProductPhotoInline]

class ProductKitAdminWithItemsAndPhotos(nested_admin.NestedModelAdmin, ProductKitAdmin):
    inlines = [KitItemInline, ProductKitPhotoInline]

class ProductCategoryAdminWithPhotos(ProductCategoryAdmin):
    inlines = [ProductCategoryPhotoInline]


@admin.register(KitItem)
class KitItemAdmin(admin.ModelAdmin):
    list_display = ['__str__', 'kit', 'get_type', 'quantity', 'has_priorities']
    list_filter = ['kit']
    list_select_related = ['kit', 'product', 'variant_group']
    inlines = [KitItemPriorityInline]
    fields = ['kit', 'product', 'variant_group', 'quantity', 'notes']

    def get_type(self, obj):
        if obj.variant_group:
            return format_html('<span style="color: #0066cc;">Группа: {}</span>', obj.variant_group.name)
        return f"Товар: {obj.product.name if obj.product else '-'}"
    get_type.short_description = 'Тип'

    def has_priorities(self, obj):
        return obj.priorities.exists()
    has_priorities.boolean = True
    has_priorities.short_description = 'Приоритеты настроены'


@admin.register(SKUCounter)
class SKUCounterAdmin(admin.ModelAdmin):
    list_display = ['counter_type', 'current_value', 'get_next_preview']
    list_filter = ['counter_type']
    readonly_fields = ['get_next_preview']

    def get_next_preview(self, obj):
        """Показывает, каким будет следующий артикул"""
        next_val = obj.current_value + 1
        if obj.counter_type == 'product':
            return format_html('<strong>PROD-{:06d}</strong>', next_val)
        elif obj.counter_type == 'kit':
            return format_html('<strong>KIT-{:06d}</strong>', next_val)
        elif obj.counter_type == 'category':
            return format_html('<strong>CAT-{:04d}</strong>', next_val)
        return str(next_val)
    get_next_preview.short_description = 'Следующий артикул'

    def has_delete_permission(self, request, obj=None):
        # Запрещаем удаление счетчиков
        return False


admin.site.register(ProductCategory, ProductCategoryAdminWithPhotos)
admin.site.register(ProductTag, ProductTagAdmin)
admin.site.register(Product, ProductAdminWithPhotos)
admin.site.register(ProductKit, ProductKitAdminWithItemsAndPhotos)