import hashlib
import secrets
import uuid
from datetime import datetime, timedelta, timezone

from sqlalchemy import DateTime, ForeignKey, String
from sqlalchemy.orm import Mapped, mapped_column

from app.db import Base

SESSION_TTL = timedelta(days=14)


class AuthSession(Base):
    __tablename__ = "auth_sessions"

    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)
    user_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("users.id"))
    token_hash: Mapped[str] = mapped_column(String(64), unique=True, index=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
    )
    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True))


def generate_session_token() -> tuple[str, str]:
    raw = secrets.token_urlsafe(32)
    return raw, hash_token(raw)


def hash_token(raw: str) -> str:
    return hashlib.sha256(raw.encode()).hexdigest()