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

if TYPE_CHECKING:
    from src.models.conversation import Conversation

class User(SQLModel, table=True):
    """User model representing an authenticated user of the application."""

    __tablename__ = "users"

    id: Optional[int] = Field(default=None, primary_key=True)
    email: str = Field(unique=True, index=True, max_length=255)
    hashed_password: str = Field(max_length=255)
    created_at: datetime = Field(default_factory=datetime.utcnow)
    updated_at: datetime = Field(default_factory=datetime.utcnow)

    # Relationships
    tasks: List["Task"] = Relationship(back_populates="user")
    conversations: List["Conversation"] = Relationship(back_populates="user")

    class Config:
        json_schema_extra = {
            "example": {
                "id": 1,
                "email": "user@example.com",
                "created_at": "2026-02-05T10:00:00Z",
                "updated_at": "2026-02-05T10:00:00Z"
            }
        }