from pydantic import BaseModel, ConfigDict, Field
from typing import Optional, List
from datetime import datetime, date
from decimal import Decimal


class PurchaseOrderItemCreate(BaseModel):
    product_id: int
    quantity: int = Field(..., gt=0, description="采购数量")
    unit_price: Optional[Decimal] = Field(None, description="单价（可选，不填则使用物料成本价格）")
    remark: Optional[str] = None


class PurchaseOrderCreate(BaseModel):
    supplier_id: int
    expected_date: Optional[date] = None
    remark: Optional[str] = None
    items: List[PurchaseOrderItemCreate] = Field(min_length=1)


class PurchaseOrderResponse(BaseModel):
    id: int
    order_no: str
    supplier_name: str
    order_date: datetime
    expected_date: Optional[date]
    status: str
    receipt_status: str  # "pending" | "partial_received" | "received" | "cancelled"
    payment_status: str  # "unpaid" | "paid"
    total_amount: Decimal
    paid_amount: Decimal
    remark: Optional[str]
    created_at: datetime
    received_date: Optional[datetime]
    paid_date: Optional[datetime]

    model_config = ConfigDict(from_attributes=True)


class PurchaseOrderItemResponse(BaseModel):
    id: int
    product_id: int
    product_sku: str
    product_name: str
    quantity: int
    received_quantity: int
    unit_price: Decimal
    amount: Decimal
    remark: Optional[str] = None


class PurchaseOrderDetailResponse(PurchaseOrderResponse):
    supplier_id: int
    items: List[PurchaseOrderItemResponse]


class PurchaseOrderReceiveItem(BaseModel):
    item_id: int
    receive_quantity: int = Field(gt=0)


class PurchaseOrderReceiveRequest(BaseModel):
    warehouse_id: Optional[int] = None
    items: List[PurchaseOrderReceiveItem] = Field(min_length=1)
    remark: Optional[str] = None