from pydantic import BaseModel, Field
from typing import Optional
from datetime import datetime
from uuid import UUID

class CountryBase(BaseModel):
    name: str = Field(..., description="Country name")
    landmass_size: float = Field(..., gt=0, description="Size of country's landmass")

class CountryCreate(CountryBase):
    pass

class CountryUpdate(BaseModel):
    name: Optional[str] = Field(None, description="Country name")
    landmass_size: Optional[float] = Field(None, gt=0, description="Size of country's landmass")

class CountrySchema(CountryBase):
    id: UUID
    created_at: datetime
    updated_at: datetime

    class Config:
        orm_mode = True
        schema_extra = {
            "example": {
                "id": "f47ac10b-58cc-4372-a567-0e02b2c3d479",
                "name": "United States",
                "landmass_size": 9833517.0,
                "created_at": "2023-01-01T12:00:00",
                "updated_at": "2023-01-01T12:00:00"
            }
        }