from flask import Blueprint, request, jsonify, redirect, make_response, current_app, g
from backend.auth import oauth
from backend.auth.middleware import require_auth
from backend.models import db, User
from datetime import datetime

bp = Blueprint('auth', __name__, url_prefix='/api/auth')


@bp.route('/login')
def login():
    """Redirect to Authelia login page"""
    redirect_uri = current_app.config['OIDC_REDIRECT_URI']
    return oauth.authelia.authorize_redirect(redirect_uri)


@bp.route('/callback')
def callback():
    """Handle OIDC callback from Authelia"""
    try:
        # Exchange authorization code for tokens
        token = oauth.authelia.authorize_access_token()

        # Parse ID token to get user info
        user_info = token.get('userinfo')
        if not user_info:
            user_info = oauth.authelia.parse_id_token(token)

        # Get or create user
        user = User.query.filter_by(authelia_sub=user_info['sub']).first()

        if not user:
            user = User(
                authelia_sub=user_info['sub'],
                email=user_info.get('email'),
                name=user_info.get('name'),
                preferred_username=user_info.get('preferred_username'),
                groups=user_info.get('groups', [])
            )
            db.session.add(user)
        else:
            user.email = user_info.get('email')
            user.name = user_info.get('name')
            user.preferred_username = user_info.get('preferred_username')
            user.groups = user_info.get('groups', [])
            user.last_login = datetime.utcnow()

        db.session.commit()

        # Redirect to frontend with tokens in URL fragment (SPA pattern)
        frontend_url = current_app.config.get('FRONTEND_URL', 'http://localhost:3000')

        # Create response with refresh token in HTTP-only cookie
        response = make_response(redirect(
            f"{frontend_url}/auth/callback#access_token={token['access_token']}"
            f"&id_token={token['id_token']}"
            f"&expires_in={token.get('expires_in', 900)}"
        ))

        # Set refresh token as HTTP-only cookie
        if token.get('refresh_token'):
            response.set_cookie(
                'refresh_token',
                value=token['refresh_token'],
                httponly=True,
                secure=current_app.config.get('SESSION_COOKIE_SECURE', False),
                samesite='Strict',
                max_age=7*24*60*60  # 7 days
            )

        return response

    except Exception as e:
        current_app.logger.error(f"OIDC callback error: {e}")
        frontend_url = current_app.config.get('FRONTEND_URL', 'http://localhost:3000')
        return redirect(f"{frontend_url}/login?error=auth_failed")


@bp.route('/refresh', methods=['POST'])
def refresh():
    """Refresh access token using refresh token"""
    refresh_token = request.cookies.get('refresh_token')

    if not refresh_token:
        return jsonify({'error': 'No refresh token'}), 401

    try:
        # Exchange refresh token for new access token
        new_token = oauth.authelia.fetch_access_token(
            grant_type='refresh_token',
            refresh_token=refresh_token
        )

        return jsonify({
            'access_token': new_token['access_token'],
            'expires_in': new_token.get('expires_in', 900)
        }), 200

    except Exception as e:
        current_app.logger.error(f"Token refresh failed: {e}")
        return jsonify({'error': 'Token refresh failed'}), 401


@bp.route('/logout', methods=['POST'])
def logout():
    """Logout user and revoke tokens"""
    # Clear refresh token cookie
    response = make_response(jsonify({'message': 'Logged out'}), 200)
    response.set_cookie('refresh_token', '', expires=0)

    # Return Authelia logout URL for frontend to redirect
    authelia_logout_url = f"{current_app.config['OIDC_ISSUER']}/logout"

    return jsonify({
        'message': 'Logged out',
        'logout_url': authelia_logout_url
    }), 200


@bp.route('/me')
@require_auth
def get_current_user():
    """Get current user info (requires auth)"""
    return jsonify(g.current_user.to_dict()), 200