"""Authentication and authorization module."""

import os
import secrets
from functools import wraps
from flask import session, redirect, url_for, request
from typing import Dict, Optional
from .database import Database
from .utils import get_logger

logger = get_logger(__name__)

# Initialize database
db = Database()


def login_required(f):
    """
    Decorator to require login for routes.

    Usage:
        @app.route('/protected')
        @login_required
        def protected_route():
            return 'Protected content'
    """
    @wraps(f)
    def decorated_function(*args, **kwargs):
        if 'user_id' not in session:
            # Save the original URL to redirect after login
            return redirect(url_for('login', next=request.url))

        # Check if session is still valid in database
        session_id = session.get('session_id')
        if session_id:
            db_session = db.get_session(session_id)
            if not db_session:
                # Session expired or invalid
                session.clear()
                return redirect(url_for('login', next=request.url))

        return f(*args, **kwargs)
    return decorated_function


def authenticate_user(username: str, password: str) -> Dict:
    """
    Authenticate user with username and password.

    Args:
        username: Username
        password: Plain text password

    Returns:
        Dictionary with 'success' boolean and either 'user' dict or 'error' message
    """
    try:
        # Import werkzeug for password verification
        from werkzeug.security import check_password_hash

        # Check test user first (hardcoded for testing)
        if username == 'tester' and password == 'oliveradmin':
            user = db.get_user_by_username('tester')
            if user:
                logger.info(f"Test user '{username}' authenticated successfully")
                return {'success': True, 'user': user}

        # Check database for other users
        user = db.get_user_by_username(username)

        if user and user.get('password_hash'):
            if check_password_hash(user['password_hash'], password):
                logger.info(f"User '{username}' authenticated successfully (database)")
                return {'success': True, 'user': user}

        logger.warning(f"Authentication failed for user '{username}'")
        return {'success': False, 'error': 'Invalid username or password'}

    except ImportError:
        logger.error("werkzeug not available - cannot verify passwords")
        return {'success': False, 'error': 'Authentication system not available'}
    except Exception as e:
        logger.error(f"Authentication error: {e}")
        return {'success': False, 'error': 'Authentication error occurred'}


def create_user_session(user: Dict, ip_address: Optional[str] = None, user_agent: Optional[str] = None) -> str:
    """
    Create a new session for authenticated user.

    Args:
        user: User dictionary from database
        ip_address: Client IP address
        user_agent: Client user agent string

    Returns:
        Session ID
    """
    session_id = secrets.token_urlsafe(32)
    user_id = user['id']

    # Create session in database
    success = db.create_session(
        user_id=user_id,
        session_id=session_id,
        expires_in_hours=24,
        ip_address=ip_address,
        user_agent=user_agent
    )

    if success:
        # Update last login timestamp
        db.update_last_login(user_id)

        # Log the login action
        db.log_action(user_id, 'login', f'IP: {ip_address}')

        logger.info(f"Created session for user {user['username']} (ID: {user_id})")
        return session_id
    else:
        logger.error(f"Failed to create session for user {user_id}")
        return None


def destroy_user_session(session_id: str, user_id: Optional[int] = None):
    """
    Destroy user session (logout).

    Args:
        session_id: Session ID to destroy
        user_id: Optional user ID for logging
    """
    db.delete_session(session_id)

    if user_id:
        db.log_action(user_id, 'logout', f'Session: {session_id}')
        logger.info(f"User {user_id} logged out")


def get_current_user() -> Optional[Dict]:
    """
    Get current logged-in user from session.

    Returns:
        User dictionary or None if not logged in
    """
    user_id = session.get('user_id')
    if user_id:
        return db.get_user_by_id(user_id)
    return None


def cleanup_sessions():
    """Clean up expired sessions from database."""
    db.cleanup_expired_sessions()


class MicrosoftSSO:
    """Microsoft SSO authentication handler using MSAL."""

    def __init__(self):
        """Initialize Microsoft SSO with environment variables."""
        self.client_id = os.getenv('AZURE_CLIENT_ID')
        self.client_secret = os.getenv('AZURE_CLIENT_SECRET')
        self.tenant_id = os.getenv('AZURE_TENANT_ID')
        self.redirect_uri = os.getenv('REDIRECT_URI', 'http://localhost:5001/auth/callback')

        # Check if SSO is configured
        if not all([self.client_id, self.client_secret, self.tenant_id]):
            self.enabled = False
            logger.warning("Microsoft SSO not configured (missing Azure credentials)")
            return

        try:
            import msal
            self.authority = f"https://login.microsoftonline.com/{self.tenant_id}"
            self.app = msal.ConfidentialClientApplication(
                self.client_id,
                authority=self.authority,
                client_credential=self.client_secret
            )
            self.enabled = True
            logger.info("Microsoft SSO initialized successfully")
        except ImportError:
            self.enabled = False
            logger.warning("Microsoft SSO not available (msal library not installed)")
        except Exception as e:
            self.enabled = False
            logger.error(f"Failed to initialize Microsoft SSO: {e}")

    def get_auth_url(self, state: Optional[str] = None) -> Optional[str]:
        """
        Get Microsoft login URL.

        Args:
            state: State parameter for CSRF protection

        Returns:
            Authorization URL or None if SSO not enabled
        """
        if not self.enabled:
            return None

        try:
            return self.app.get_authorization_request_url(
                scopes=["User.Read"],
                state=state,
                redirect_uri=self.redirect_uri
            )
        except Exception as e:
            logger.error(f"Error generating auth URL: {e}")
            return None

    def acquire_token(self, auth_code: str) -> Optional[Dict]:
        """
        Exchange authorization code for access token.

        Args:
            auth_code: Authorization code from Microsoft

        Returns:
            Token result dictionary or None if failed
        """
        if not self.enabled:
            return None

        try:
            result = self.app.acquire_token_by_authorization_code(
                auth_code,
                scopes=["User.Read"],
                redirect_uri=self.redirect_uri
            )
            return result
        except Exception as e:
            logger.error(f"Error acquiring token: {e}")
            return None

    def get_user_info(self, access_token: str) -> Optional[Dict]:
        """
        Get user info from Microsoft Graph API.

        Args:
            access_token: Access token from Microsoft

        Returns:
            User info dictionary or None if failed
        """
        if not self.enabled:
            return None

        try:
            import requests
            headers = {'Authorization': f'Bearer {access_token}'}
            response = requests.get(
                'https://graph.microsoft.com/v1.0/me',
                headers=headers,
                timeout=10
            )

            if response.status_code == 200:
                return response.json()
            else:
                logger.error(f"Graph API error: {response.status_code}")
                return None

        except Exception as e:
            logger.error(f"Error fetching user info: {e}")
            return None

    def create_or_update_user(self, user_info: Dict) -> Optional[Dict]:
        """
        Create or update user from SSO login.

        Args:
            user_info: User information from Microsoft Graph

        Returns:
            User dictionary or None if failed
        """
        try:
            email = user_info.get('mail') or user_info.get('userPrincipalName')
            username = email.split('@')[0] if email else user_info.get('displayName', 'unknown')
            full_name = user_info.get('displayName')

            # Check if user exists
            user = db.get_user_by_username(username)

            if not user:
                # Create new user
                user_id = db.create_user(
                    username=username,
                    email=email,
                    full_name=full_name,
                    auth_method='sso'
                )

                if user_id:
                    user = db.get_user_by_id(user_id)
                    logger.info(f"Created new SSO user: {username}")
                else:
                    logger.error(f"Failed to create SSO user: {username}")
                    return None
            else:
                logger.info(f"Existing SSO user logged in: {username}")

            return user

        except Exception as e:
            logger.error(f"Error creating/updating SSO user: {e}")
            return None


# Initialize Microsoft SSO
sso = MicrosoftSSO()


def is_sso_enabled() -> bool:
    """Check if Microsoft SSO is enabled and configured."""
    return sso.enabled


def get_sso_instance() -> MicrosoftSSO:
    """Get Microsoft SSO instance."""
    return sso