from datetime import datetime
from typing import List, Optional

from pydantic import BaseModel, Field


# Shared properties
class CartItemBase(BaseModel):
    product_id: int
    quantity: int = Field(..., gt=0)

# Properties to receive on cart item creation
class CartItemCreate(CartItemBase):
    pass

# Properties to receive on cart item update
class CartItemUpdate(BaseModel):
    quantity: int = Field(..., gt=0)

# Properties shared by models stored in DB
class CartItemInDBBase(CartItemBase):
    id: int
    user_id: int
    unit_price: float
    created_at: datetime
    updated_at: Optional[datetime] = None

    class Config:
        from_attributes = True

# Properties to return to client
class CartItem(CartItemInDBBase):
    pass

# Properties to return for cart summary
class CartSummary(BaseModel):
    items: List[CartItem]
    total: float