from rest_framework import serializers

from .models import (
	User,
	Address,
	Product,
	Order,
	OrderDetail,
)


class UserSerializer(serializers.ModelSerializer):
	password = serializers.CharField(write_only=True, required=False)

	class Meta:
		model = User
		fields = [
			'id',
			'username',
			'email',
			'password',
			'full_name',
			'user_age',
			'user_gender',
			'created_at',
		]
		read_only_fields = ['id', 'created_at']

	def create(self, validated_data):
		password = validated_data.pop('password', None)
		user = User(**validated_data)
		if password:
			user.set_password(password)
		user.save()
		return user

	def update(self, instance, validated_data):
		password = validated_data.pop('password', None)
		for attr, value in validated_data.items():
			setattr(instance, attr, value)
		if password:
			instance.set_password(password)
		instance.save()
		return instance


class AddressSerializer(serializers.ModelSerializer):
	# user is set server-side from the authenticated request
	user = serializers.PrimaryKeyRelatedField(read_only=True)

	class Meta:
		model = Address
		fields = [
			'id',
			'user',
			'line1',
			'line2',
			'city',
			'state',
			'country',
			'pincode',
			'is_default',
			'created_at',
		]
		read_only_fields = ['id', 'created_at']


class ProductSerializer(serializers.ModelSerializer):
	display_price = serializers.SerializerMethodField()
	is_price_adjusted = serializers.SerializerMethodField()

	class Meta:
		model = Product
		fields = [
			'id',
			'product_name',
			'base_price',
			'display_price',
			'is_price_adjusted',
			'stock_quantity',
		]
		read_only_fields = ['id']

	def get_display_price(self, obj):
		"""Return base_price + 10% markup if user is predicted to be a high returner."""
		markup = self.context.get('return_risk_markup', {})
		if markup.get('apply'):
			from decimal import Decimal
			return str(round(float(obj.base_price) * 1.10, 2))
		return str(obj.base_price)

	def get_is_price_adjusted(self, obj):
		markup = self.context.get('return_risk_markup', {})
		return markup.get('apply', False)


class OrderDetailSerializer(serializers.ModelSerializer):
	product = ProductSerializer(read_only=True)
	product_id = serializers.PrimaryKeyRelatedField(
		write_only=True, queryset=Product.objects.all(), source='product'
	)
	order = serializers.PrimaryKeyRelatedField(queryset=Order.objects.all())

	class Meta:
		model = OrderDetail
		fields = [
			'id',
			'order',
			'product',
			'product_id',
			'order_quantity',
			'product_price',
			'discount_applied',
			'return_status',
			'return_date',
			'return_reason',
			'days_to_return',
			'is_exchanged',
			'exchange_order',
		]
		read_only_fields = ['id']


class OrderSerializer(serializers.ModelSerializer):
	user = serializers.PrimaryKeyRelatedField(read_only=True)
	shipping_address = AddressSerializer(read_only=True)
	items = OrderDetailSerializer(many=True, read_only=True)

	class Meta:
		model = Order
		fields = [
			'id',
			'user',
			'shipping_address',
			'order_date',
			'payment_method',
			'shipping_method',
			'items',
		]
		read_only_fields = ['id', 'order_date']