from pydantic import BaseModel, Field, constr
from typing import Optional

class ProductBase(BaseModel):
    name: constr(min_length=1) = Field(..., description="Product name")
    description: Optional[str] = Field(None, description="Product description")
    price: float = Field(..., gt=0, description="Product price")
    stock_quantity: int = Field(..., ge=0, description="Product stock quantity")

    class Config:
        schema_extra = {
            "example": {
                "name": "Product Name",
                "description": "This is a product description",
                "price": 9.99,
                "stock_quantity": 100
            }
        }

class ProductCreate(ProductBase):
    pass

class ProductResponse(ProductBase):
    id: int

    class Config:
        orm_mode = True