from datetime import datetime, timezone
from typing import Optional
from sqlmodel import SQLModel, Field


class SleepSession(SQLModel, table=True):
    __tablename__ = "sleep_session"

    id: Optional[int] = Field(default=None, primary_key=True)
    start_time: datetime = Field(index=True, nullable=False)
    end_time: Optional[datetime] = Field(default=None, nullable=True, index=True)
    created_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
    updated_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))