from pydantic import BaseModel
from typing import Optional, List
from datetime import datetime


class ProductCreate(BaseModel):
    sku: str
    name: str
    description: Optional[str] = None
    category: Optional[str] = None
    unit: str = "件"
    item_type: str = "finished"
    cost_price: float = 0
    sale_price: float = 0
    min_stock: int = 0
    max_stock: int = 1000


class ProductResponse(BaseModel):
    id: int
    sku: str
    name: str
    description: Optional[str]
    category: Optional[str]
    unit: str
    item_type: str
    cost_price: float
    sale_price: float
    min_stock: int
    max_stock: int
    material_cost: float = 0
    is_active: bool
    created_at: datetime

    class Config:
        from_attributes = True


class ProductMaterialItemUpdate(BaseModel):
    material_id: int
    quantity: float


class ProductBOMUpdate(BaseModel):
    items: List[ProductMaterialItemUpdate]


class ProductMaterialItemResponse(BaseModel):
    material_id: int
    material_sku: str
    material_name: str
    quantity: float
    unit_cost: float
    line_cost: float


class ProductBOMResponse(BaseModel):
    product_id: int
    product_name: str
    total_material_cost: float
    items: List[ProductMaterialItemResponse]