import re

from sqlalchemy import Boolean, Column, String
from sqlalchemy.orm import validates

from app.db.base_class import Base


class User(Base):
    """
    User model with flexible authentication (username or email).
    """
    username = Column(String, unique=True, index=True, nullable=True)
    email = Column(String, unique=True, index=True, nullable=True)
    hashed_password = Column(String, nullable=False)
    is_active = Column(Boolean, default=True)
    is_superuser = Column(Boolean, default=False)

    @validates('email')
    def validate_email(self, key, email):
        if email is None:
            return email

        # Simple email validation regex
        if not re.match(r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$', email):
            raise ValueError('Invalid email format')
        return email

    @validates('username')
    def validate_username(self, key, username):
        if username is None:
            return username

        # Username validation: alphanumeric + underscore, 3-20 chars
        if not re.match(r'^[a-zA-Z0-9_]{3,20}$', username):
            raise ValueError(
                'Username must be 3-20 characters and contain only letters, numbers, '
                'and underscores'
            )
        return username