from rest_framework import serializers
from django.db.models import Avg

from core.apps.accounts.choices import AccountType
from core.apps.api.models import AdModel, AdVariant, Category, AdImage, AdOption
from core.apps.accounts.models import UserLike
from core.apps.api.choices import AdVariantType


class AdOptionSerializer(serializers.ModelSerializer):
    class Meta:
        model = AdOption
        fields = [
            "id",
            "name",
            "value",
        ]


class CategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Category
        fields = ["id", "name"]


class AdImageSerializer(serializers.ModelSerializer):
    class Meta:
        model = AdImage
        fields = [
            "image",
            "ad_variant"
        ]

    def to_representation(self, instance):
        data = super().to_representation(instance)

        if instance.ad_variant is None:
            data.pop("ad_variant", None)

        return data


class AdVariantSerializer(serializers.ModelSerializer):
    class Meta:
        model = AdVariant
        fields = [
            "id",
            "variant",
            "value",
            "is_available",
            "price",
            "discount",
        ]


class BaseAdSerializer(serializers.ModelSerializer):
    is_liked = serializers.SerializerMethodField()
    star = serializers.SerializerMethodField()
    comment_count = serializers.SerializerMethodField()

    class Meta:
        model = AdModel
        fields = [
            "id",
            "name",
            "price",
            "image",
            "is_liked",
            "star",
            "comment_count",
        ]

    def get_star(self, obj):
        avg = obj.feedback.aggregate(avg=Avg("star"))["avg"]
        return avg or 0

    def get_comment_count(self, obj):
        count = obj.feedback.count()
        return count or 0

    def get_is_liked(self, obj):
        request = self.context.get("request")
        user = getattr(request, "user", None)

        if not user or not user.is_authenticated:
            return False

        return UserLike.objects.filter(user=user, ad=obj).exists()


class ListAdSerializer(BaseAdSerializer):
    price = serializers.SerializerMethodField()
    discount = serializers.SerializerMethodField()

    class Meta(BaseAdSerializer.Meta):
        fields = [
            "id",
            "name",
            "price",
            "image",
            "star",
            "comment_count",
            "discount",
            "is_liked",
        ]

    def _get_first_variant(self, obj):
        if not hasattr(self, "_variant_cache"):
            self._variant_cache = {}
        if obj.id not in self._variant_cache:
            self._variant_cache[obj.id] = obj.variants.order_by("price").first()
        return self._variant_cache[obj.id]

    def get_price(self, obj):
        variant = self._get_first_variant(obj)
        if not variant:
            return obj.price
        return variant.price if variant else 0

    def get_discount(self, obj):
        variant = self._get_first_variant(obj)
        return variant.discount if variant else -1.0


class FullListAdSerializer(serializers.Serializer):
    ads = ListAdSerializer(many=True)
    categories = serializers.SerializerMethodField()
    colors = serializers.SerializerMethodField()
    sizes = serializers.SerializerMethodField()
    min_price = serializers.SerializerMethodField()
    max_price = serializers.SerializerMethodField()

    def get_categories(self, obj):
        ads = obj.get("ads", [])

        category_ids = set()
        categories = []

        for ad in ads:
            category = ad.category
            if category and category.id not in category_ids:
                category_ids.add(category.id)
                categories.append(category)

        return CategorySerializer(categories, many=True).data

    def get_colors(self, obj):
        ads = obj.get("ads", [])
        color_values = set()

        for ad in ads:
            variants = getattr(ad, "variants", [])
            for v in variants.all():
                if v.variant == AdVariantType.COLOR:
                    color_values.add(v.value)

        return list(color_values)

    def get_sizes(self, obj):
        ads = obj.get("ads", [])
        size_values = set()

        for ad in ads:
            variants = getattr(ad, "variants", [])
            for v in variants.all():
                if v.variant == AdVariantType.SIZE:
                    size_values.add(v.value)

        return list(size_values)

    def get_min_price(self, obj):
        ads = obj.get("ads", [])
        prices = []

        for ad in ads:
            ad_data = ListAdSerializer(ad, context=self.context).data
            price = ad_data.get("price")
            if price is not None:
                prices.append(price)

        return min(prices) if prices else None

    def get_max_price(self, obj):
        ads = obj.get("ads", [])
        prices = []

        for ad in ads:
            ad_data = ListAdSerializer(ad, context=self.context).data
            price = ad_data.get("price")
            if price is not None:
                prices.append(price)

        return max(prices) if prices else None


class RetrieveAdSerializer(BaseAdSerializer):
    variants = AdVariantSerializer(many=True, read_only=True)
    images = serializers.SerializerMethodField()
    colors = serializers.SerializerMethodField()
    sizes = serializers.SerializerMethodField()
    creator = serializers.SerializerMethodField()
    options = AdOptionSerializer(many=True, read_only=True)

    class Meta(BaseAdSerializer.Meta):
        fields = [
            "id",
            "name",
            "price",
            "image",
            "star",
            "comment_count",
            "is_liked",
            "images",
            "variants",
            "colors",
            "sizes",
            "creator",
            "description",
            "options"
        ]

    def get_images(self, obj):
        objects = obj.images.all()
        return AdImageSerializer(objects, many=True, context=self.context).data

    def get_colors(self, obj):
        color_values = set()

        variants = getattr(obj, "variants", [])
        for v in variants.all():
            if v.variant == AdVariantType.COLOR:
                color_values.add(v.value)

        return list(color_values)

    def get_sizes(self, obj):
        size_values = set()

        variants = getattr(obj, "variants", [])
        for v in variants.all():
            if v.variant == AdVariantType.SIZE:
                size_values.add(v.value)
        return list(size_values)

    def get_creator(self, obj):
        user = obj.user
        user_type = user.account_type
        request = self.context.get("request")

        avatar_url = request.build_absolute_uri(user.avatar.url) if user.avatar else None

        if user_type == AccountType.BUSINESS:
            return {
                "username": user.business.name,
                "avatar": avatar_url,
                "create_at": user.validated_at,
                "last_live": "endi qo'shamiz! waiting pls ))"
            }
        else:
            username = f"{user.first_name} {user.last_name}"
            return {
                "username": username,
                "avatar": avatar_url,
                "create_at": user.validated_at,
                "last_live": "endi qo'shamiz! waiting pls ))"
            }


class CreateAdSerializer(BaseAdSerializer):
    class Meta(BaseAdSerializer.Meta): ...