"""
Keyboard-Interactive Authentication Implementation

Implements SSH keyboard-interactive authentication method according to RFC 4256.
"""

from typing import Any, List, Tuple
from ..exceptions import AuthenticationException


class KeyboardInteractiveAuth:
    """
    SSH keyboard-interactive authentication implementation.
    
    Handles interactive authentication with support for
    multi-factor authentication and custom prompts.
    """
    
    def __init__(self, transport: Any) -> None:
        """
        Initialize keyboard-interactive authentication.
        
        Args:
            transport: SSH transport instance
        """
        self._transport = transport
    
    def authenticate(
        self, 
        username: str, 
        handler: Any
    ) -> bool:
        """
        Perform keyboard-interactive authentication.
        
        Args:
            username: Username for authentication
            handler: Interactive handler for prompts
            
        Returns:
            True if authentication successful
            
        Raises:
            AuthenticationException: If authentication fails
        """
        # Implementation will be added in later tasks
        raise NotImplementedError("KeyboardInteractiveAuth.authenticate will be implemented in task 4.2")