"""User model for authentication and authorization."""
from datetime import datetime
from typing import Optional

from flask_login import UserMixin

from app.extensions import db


class User(db.Model, UserMixin):
    """User model for application authentication.
    
    Attributes:
        id: Primary key
        username: Unique username for login
        password: Bcrypt hashed password
        role: User role (user or admin)
        theme: UI theme preference (light or dark)
        created_at: Account creation timestamp
        last_login: Last successful login timestamp
    """
    __tablename__ = 'user'
    
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False, index=True)
    password = db.Column(db.String(120), nullable=False)
    role = db.Column(db.String(20), nullable=False, default='user', index=True)
    theme = db.Column(db.String(20), default='light')
    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)
    last_login = db.Column(db.DateTime, nullable=True)
    
    def __repr__(self) -> str:
        """String representation of User."""
        return f'<User {self.username} (role={self.role})>'
    
    @property
    def is_admin(self) -> bool:
        """Check if user has admin role."""
        return self.role == 'admin'
    
    def update_last_login(self) -> None:
        """Update last login timestamp."""
        self.last_login = datetime.utcnow()