"""User business logic."""

from typing import Optional
from sqlalchemy.orm import Session
from app.models.user import User
from app.schemas.user import UserCreate
from app.auth.password import hash_password, verify_password


class UserService:
    """Service for user operations."""

    def __init__(self, db: Session):
        self.db = db

    def get_by_id(self, user_id: int) -> Optional[User]:
        """Get user by ID."""
        return self.db.query(User).filter(User.id == user_id).first()

    def get_by_email(self, email: str) -> Optional[User]:
        """Get user by email."""
        return self.db.query(User).filter(User.email == email).first()

    def get_by_username(self, username: str) -> Optional[User]:
        """Get user by username."""
        return self.db.query(User).filter(User.username == username).first()

    def create(self, user_data: UserCreate) -> User:
        """Create a new user."""
        user = User(
            email=user_data.email,
            username=user_data.username,
            hashed_password=hash_password(user_data.password),
        )
        self.db.add(user)
        self.db.commit()
        self.db.refresh(user)
        return user

    def authenticate(self, username: str, password: str) -> Optional[User]:
        """Authenticate user by username and password."""
        user = self.get_by_username(username)
        if not user:
            return None
        if not verify_password(password, user.hashed_password):
            return None
        return user