from pydantic import BaseModel, Field
from typing import Optional

# Base schema
class DogBase(BaseModel):
    name: str = Field(..., description="Name of the dog")
    breed: str = Field(..., description="Breed of the dog")
    age: int = Field(..., gt=0, description="Age of the dog in years")
    owner_id: Optional[str] = Field(None, description="ID of the owner (foreign key)")

# Schema for creating a new Dog
class DogCreate(DogBase):
    pass

# Schema for Dog responses
class Dog(DogBase):
    id: int

    class Config:
        orm_mode = True
        schema_extra = {
            "example": {
                "name": "Buddy",
                "breed": "Labrador",
                "age": 5,
                "owner_id": "user123"
            }
        }