from decimal import Decimal

from django.conf import settings
from rest_framework import serializers

from apps.billing.models import RechargeOrder


class GenerateTitleRequestSerializer(serializers.Serializer):
    prompt = serializers.CharField(trim_whitespace=True, allow_blank=False)
    model = serializers.CharField(
        required=False,
        allow_blank=True,
        trim_whitespace=True,
        max_length=64,
    )
    image_url = serializers.URLField(required=False, allow_blank=True)
    image_base64 = serializers.CharField(required=False, allow_blank=True)
    resolution = serializers.CharField(
        required=False,
        allow_blank=True,
        trim_whitespace=True,
        default="1K",
    )
    parameters = serializers.DictField(required=False, default=dict)


class GenerateImageRequestSerializer(serializers.Serializer):
    prompt = serializers.CharField(trim_whitespace=True, allow_blank=False)
    model = serializers.CharField(
        required=False,
        allow_blank=True,
        trim_whitespace=True,
        max_length=64,
    )
    image_url = serializers.URLField(required=False, allow_blank=True)
    image_base64 = serializers.CharField(required=False, allow_blank=True)
    resolution = serializers.CharField(
        required=False,
        allow_blank=True,
        trim_whitespace=True,
        default="1K",
    )
    aspect_ratio = serializers.CharField(
        required=False,
        allow_blank=True,
        trim_whitespace=True,
        default="1:1",
    )
    parameters = serializers.DictField(required=False, default=dict)


class VisionImageInputSerializer(serializers.Serializer):
    image_url = serializers.URLField(required=False, allow_blank=True)
    image_base64 = serializers.CharField(required=False, allow_blank=True)

    def validate(self, attrs):
        has_url = bool(str(attrs.get("image_url") or "").strip())
        has_base64 = bool(str(attrs.get("image_base64") or "").strip())
        if has_url == has_base64:
            raise serializers.ValidationError(
                "每张图片必须且只能提供 image_url 或 image_base64。"
            )
        return attrs


class AnalyzeImagesRequestSerializer(serializers.Serializer):
    prompt = serializers.CharField(trim_whitespace=True, allow_blank=False)
    model = serializers.CharField(
        required=False,
        allow_blank=True,
        trim_whitespace=True,
        max_length=64,
    )
    images = VisionImageInputSerializer(many=True, allow_empty=False)
    parameters = serializers.DictField(required=False, default=dict)

    def validate_images(self, value):
        max_images = max(1, int(settings.VISION_MAX_IMAGES))
        if len(value) > max_images:
            raise serializers.ValidationError(f"单次最多上传 {max_images} 张图片。")
        return value


class RechargeCreateRequestSerializer(serializers.Serializer):
    amount = serializers.DecimalField(
        max_digits=12,
        decimal_places=2,
        min_value=Decimal("0.01"),
    )
    pay_method = serializers.ChoiceField(choices=RechargeOrder.PayMethod.values)

    def validate_amount(self, value):
        max_amount = Decimal(str(settings.RECHARGE_MAX_AMOUNT_CNY))
        if value > max_amount:
            raise serializers.ValidationError(f"单笔充值金额不能超过 {max_amount:.2f} CNY")
        return value


class RechargeStatusRequestSerializer(serializers.Serializer):
    order_no = serializers.CharField(
        trim_whitespace=True,
        allow_blank=False,
        max_length=64,
    )