from sqlmodel import Field, SQLModel, Relationship
from typing import Optional, TYPE_CHECKING
from datetime import datetime

if TYPE_CHECKING:
    from .user import User


class Task(SQLModel, table=True):
    """Task model representing a todo item belonging to a specific user."""

    __tablename__ = "tasks"

    id: Optional[int] = Field(default=None, primary_key=True)
    title: str = Field(max_length=200, min_length=1)
    description: Optional[str] = Field(default=None, max_length=2000)
    completed: bool = Field(default=False)
    user_id: int = Field(foreign_key="users.id", index=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)
    updated_at: datetime = Field(default_factory=datetime.utcnow)

    # Relationships
    owner: "User" = Relationship(back_populates="tasks")