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

class BaseLake(BaseModel):
    name: str = Field(..., index=True, description="Name of the lake")
    area: float = Field(..., gt=0, description="Area of the lake in square kilometers")
    depth: float = Field(..., gt=0, description="Maximum depth of the lake in meters")
    location: str = Field(..., description="Location or address of the lake")

    @validator('name')
    def name_must_be_capitalized(cls, value):
        if not value.istitle():
            raise ValueError('Lake name must be capitalized')
        return value

    class Config:
        schema_extra = {
            "example": {
                "name": "Lake Superior",
                "area": 82100.0,
                "depth": 406.0,
                "location": "North America"
            }
        }


class LakeCreate(BaseLake):
    pass


class LakeResponse(BaseLake):
    id: int

    class Config:
        orm_mode = True