from __future__ import annotations

from datetime import datetime
from decimal import Decimal
from typing import Annotated

from pydantic import BaseModel, ConfigDict, Field, StrictInt, model_validator

from app.models.order import OrderStatusEnum


class OrderCreateItem(BaseModel):
    model_config = ConfigDict(extra="forbid")

    product_id: Annotated[StrictInt, Field(gt=0)]
    quantity: Annotated[StrictInt, Field(gt=0, le=1000)]


class OrderCreate(BaseModel):
    model_config = ConfigDict(extra="forbid")

    items: Annotated[list[OrderCreateItem], Field(min_length=1, max_length=100)]

    @model_validator(mode="after")
    def validate_unique_products(self) -> "OrderCreate":
        product_ids = [item.product_id for item in self.items]
        if len(product_ids) != len(set(product_ids)):
            raise ValueError("Each product may only appear once per order")
        return self


class OrderItemResponse(BaseModel):
    model_config = ConfigDict(from_attributes=True, extra="forbid")

    id: int
    product_id: int
    product_name: str
    quantity: int
    unit_price: Decimal
    subtotal: Decimal


class OrderResponse(BaseModel):
    model_config = ConfigDict(from_attributes=True, extra="forbid")

    id: int
    status: OrderStatusEnum
    total_amount: Decimal
    created_at: datetime
    paid_at: datetime | None
    items: list[OrderItemResponse]