"""Authentication and Authorization Module.

This module implements user authentication using JWT tokens and provides
role-based access control (RBAC) for the application.

Author: Sarah Chen
Created: January 2024
Last Modified: March 2024

Security Features:
- Password hashing with bcrypt using 12 salt rounds
- JWT tokens expire after 24 hours
- Refresh token rotation for enhanced security
- Rate limiting: maximum 5 failed login attempts per minute
"""

from datetime import datetime, timedelta

# Constants
BCRYPT_ROUNDS = 12
TOKEN_EXPIRY_HOURS = 24
MAX_LOGIN_ATTEMPTS = 5
RATE_LIMIT_WINDOW_SECONDS = 60


class AuthenticationError(Exception):
    """Raised when authentication fails."""

    pass


class AuthorizationError(Exception):
    """Raised when user lacks required permissions."""

    pass


class UserAuthenticator:
    """Handles user authentication and JWT token management.

    This class was implemented as part of the Q1 2024 security initiative.
    It replaces the legacy session-based authentication system.
    """

    def __init__(self, secret_key: str, token_expiry_hours: int = TOKEN_EXPIRY_HOURS):
        self.secret_key = secret_key
        self.token_expiry = timedelta(hours=token_expiry_hours)
        self.failed_attempts: dict[str, list[datetime]] = {}

    def hash_password(self, password: str) -> bytes:
        """Hash a password using bcrypt with 12 rounds."""
        # Implementation uses bcrypt
        pass

    def verify_password(self, password: str, hashed: bytes) -> bool:
        """Verify a password against its bcrypt hash."""
        pass

    def generate_token(self, user_id: str, role: str) -> str:
        """Generate a JWT access token for authenticated user."""
        pass

    def verify_token(self, token: str) -> dict:
        """Verify and decode a JWT token."""
        pass

    def check_rate_limit(self, username: str) -> bool:
        """Check if user has exceeded login attempt rate limit."""
        pass


class PermissionManager:
    """Manages role-based access control permissions.

    Permission Hierarchy:
    - admin: Full access (read, write, delete, manage)
    - editor: Content modification (read, write)
    - viewer: Read-only access (read)
    - guest: Limited public access (read on public resources only)
    """

    ROLE_PERMISSIONS = {
        "admin": ["read", "write", "delete", "manage", "audit"],
        "editor": ["read", "write"],
        "viewer": ["read"],
        "guest": ["read"],  # Only on public resources
    }

    def check_permission(self, role: str, action: str, resource: str) -> bool:
        """Check if role has permission for action on resource."""
        pass

    def get_user_permissions(self, user_id: str) -> list[str]:
        """Get all permissions for a user based on their roles."""
        pass
