<?php
/**
 * Saqel Platform - High Performance Real-Time WebSocket Server (Workerman)
 * =========================================================================
 * Ports:
 *  - 4040 : Public WebSocket for Students, Teachers & Guardians
 *  - 4041 : Internal HTTP Event Dispatcher for PHP Backend
 */

use Workerman\Worker;
use Workerman\Connection\TcpConnection;

require_once __DIR__ . '/../app/bootstrap.php';
require_once __DIR__ . '/../app/Core/Security.php';
require_once __DIR__ . '/../app/Core/Database.php';

// 1. Initialize Public WebSocket Server
$wsPort = (int)(getenv('WS_PORT') ?: 4040);
$internalPort = (int)(getenv('WS_INTERNAL_PORT') ?: 4041);

$wsWorker = new Worker("websocket://0.0.0.0:{$wsPort}");
$wsWorker->count = 1; // Single process for unified in-memory connection registry

// Registry: [userId => [connectionId => TcpConnection]]
$userConnections = [];

// Registry: [connectionId => userId]
$connectionUserMap = [];

$wsWorker->onWorkerStart = function () use ($wsWorker, $internalPort, &$userConnections) {
    echo "====================================================\n";
    echo "  🚀 SAQEL REAL-TIME WORKERMAN SERVER STARTED       \n";
    echo "  📡 WebSocket: 0.0.0.0:{$GLOBALS['wsPort']}        \n";
    echo "  🔒 Internal HTTP: 0.0.0.0:{$internalPort}         \n";
    echo "====================================================\n";

    // Internal HTTP Event Listener (Receives pushes from PHP backend controllers)
    $innerHttp = new Worker("http://0.0.0.0:{$internalPort}");
    $innerHttp->onMessage = function ($connection, $request) use (&$userConnections) {
        $post = $request->post();
        $action = trim($post['action'] ?? '');
        $targetUserId = (int)($post['target_user_id'] ?? 0);
        $payload = $post['payload'] ?? [];

        if (is_string($payload)) {
            $payload = json_decode($payload, true) ?: $payload;
        }

        switch ($action) {
            case 'push_chat':
                if ($targetUserId && isset($userConnections[$targetUserId])) {
                    foreach ($userConnections[$targetUserId] as $conn) {
                        $conn->send(json_encode([
                            'event' => 'chat_message',
                            'data'  => $payload
                        ], JSON_UNESCAPED_UNICODE));
                    }
                    $connection->send(json_encode(['status' => 'delivered', 'recipients' => count($userConnections[$targetUserId])]));
                    return;
                }
                $connection->send(json_encode(['status' => 'offline']));
                break;

            case 'push_notification':
                if ($targetUserId && isset($userConnections[$targetUserId])) {
                    foreach ($userConnections[$targetUserId] as $conn) {
                        $conn->send(json_encode([
                            'event' => 'notification',
                            'data'  => $payload
                        ], JSON_UNESCAPED_UNICODE));
                    }
                    $connection->send(json_encode(['status' => 'delivered']));
                    return;
                }
                $connection->send(json_encode(['status' => 'offline']));
                break;

            case 'drm_force_logout':
                if ($targetUserId && isset($userConnections[$targetUserId])) {
                    foreach ($userConnections[$targetUserId] as $conn) {
                        $conn->send(json_encode([
                            'event' => 'drm_session_terminated',
                            'message' => 'تم تسجيل الدخول من جهاز آخر. تم إنهاء الجلسة لحماية محتواك.'
                        ], JSON_UNESCAPED_UNICODE));
                    }
                    $connection->send(json_encode(['status' => 'kicked']));
                    return;
                }
                $connection->send(json_encode(['status' => 'not_found']));
                break;

            case 'broadcast_course':
                $courseId = (int)($post['course_id'] ?? 0);
                // Broadcast to all active connections
                foreach ($userConnections as $uid => $conns) {
                    foreach ($conns as $conn) {
                        $conn->send(json_encode([
                            'event' => 'course_broadcast',
                            'course_id' => $courseId,
                            'data'  => $payload
                        ], JSON_UNESCAPED_UNICODE));
                    }
                }
                $connection->send(json_encode(['status' => 'broadcasted']));
                break;

            default:
                $connection->send(json_encode(['status' => 'unknown_action']));
                break;
        }
    };
    $innerHttp->listen();
};

$wsWorker->onConnect = function (TcpConnection $connection) {
    // Initial ping on connection
    $connection->send(json_encode([
        'event'   => 'connected',
        'message' => 'Connected to Saqel Real-time Network. Please authenticate with your JWT token.'
    ], JSON_UNESCAPED_UNICODE));
};

$wsWorker->onMessage = function (TcpConnection $connection, $data) use (&$userConnections, &$connectionUserMap) {
    $msg = json_decode($data, true);
    if (!is_array($msg)) {
        return;
    }

    $event = $msg['event'] ?? '';
    $payload = $msg['data'] ?? [];

    switch ($event) {
        // 1. Authenticate WebSocket Connection via JWT
        case 'auth':
            $token = trim((string)($payload['token'] ?? ''));
            if (empty($token)) {
                $connection->send(json_encode(['event' => 'auth_error', 'message' => 'Token required']));
                return;
            }

            try {
                $decoded = \App\Core\Security::decodeJwt($token);
                if (!$decoded || empty($decoded['user_id'])) {
                    $connection->send(json_encode(['event' => 'auth_error', 'message' => 'Invalid or expired token']));
                    return;
                }

                $userId = (int)$decoded['user_id'];
                $role   = (string)($decoded['role'] ?? 'student');

                $userConnections[$userId][$connection->id] = $connection;
                $connectionUserMap[$connection->id] = $userId;

                $connection->send(json_encode([
                    'event'   => 'authenticated',
                    'user_id' => $userId,
                    'role'    => $role,
                    'message' => 'Authenticated successfully. Real-time stream active.'
                ], JSON_UNESCAPED_UNICODE));

                echo "✅ [WS Auth] User #{$userId} ({$role}) connected (Connection ID: {$connection->id})\n";

            } catch (\Exception $e) {
                $connection->send(json_encode(['event' => 'auth_error', 'message' => $e->getMessage()]));
            }
            break;

        // 2. Direct Chat Message (Student <-> Teacher)
        case 'chat_send':
            $senderId = $connectionUserMap[$connection->id] ?? null;
            if (!$senderId) {
                $connection->send(json_encode(['event' => 'error', 'message' => 'Unauthorized']));
                return;
            }

            $receiverId  = (int)($payload['receiver_id'] ?? 0);
            $messageText = trim((string)($payload['message'] ?? ''));
            $messageType = (string)($payload['message_type'] ?? 'text');
            $mediaUrl    = !empty($payload['media_url']) ? trim((string)$payload['media_url']) : null;
            $courseId    = !empty($payload['course_id']) ? (int)$payload['course_id'] : null;

            if (!$receiverId || empty($messageText)) {
                $connection->send(json_encode(['event' => 'error', 'message' => 'receiver_id and message required']));
                return;
            }

            // Save to MySQL
            $uuid = sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
                mt_rand(0, 0xffff), mt_rand(0, 0xffff),
                mt_rand(0, 0xffff),
                mt_rand(0, 0x0fff) | 0x4000,
                mt_rand(0, 0x3fff) | 0x8000,
                mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
            );

            try {
                $msgId = \App\Core\Database::insert(
                    "INSERT INTO chat_messages (uuid, sender_id, receiver_id, course_id, message, message_type, media_url, is_read) 
                     VALUES (?, ?, ?, ?, ?, ?, ?, 0)",
                    [$uuid, $senderId, $receiverId, $courseId, $messageText, $messageType, $mediaUrl]
                );

                $msgData = [
                    'id'           => $msgId,
                    'uuid'         => $uuid,
                    'sender_id'    => $senderId,
                    'receiver_id'  => $receiverId,
                    'course_id'    => $courseId,
                    'message'      => $messageText,
                    'message_type' => $messageType,
                    'media_url'    => $mediaUrl,
                    'is_read'      => false,
                    'created_at'   => date('Y-m-d H:i:s')
                ];

                // Echo back to sender with confirmed ID
                $connection->send(json_encode([
                    'event' => 'chat_sent',
                    'data'  => array_merge($msgData, ['is_mine' => true])
                ], JSON_UNESCAPED_UNICODE));

                // Dispatch to receiver if online
                if (isset($userConnections[$receiverId])) {
                    foreach ($userConnections[$receiverId] as $recConn) {
                        $recConn->send(json_encode([
                            'event' => 'chat_message',
                            'data'  => array_merge($msgData, ['is_mine' => false])
                        ], JSON_UNESCAPED_UNICODE));
                    }
                }

            } catch (\Exception $e) {
                $connection->send(json_encode(['event' => 'error', 'message' => 'DB insert failed: ' . $e->getMessage()]));
            }
            break;

        // 3. Typing Indicator
        case 'typing':
            $senderId = $connectionUserMap[$connection->id] ?? null;
            $receiverId = (int)($payload['receiver_id'] ?? 0);
            if ($senderId && $receiverId && isset($userConnections[$receiverId])) {
                foreach ($userConnections[$receiverId] as $recConn) {
                    $recConn->send(json_encode([
                        'event'     => 'user_typing',
                        'sender_id' => $senderId,
                        'is_typing' => (bool)($payload['is_typing'] ?? true)
                    ]));
                }
            }
            break;

        // 4. Heartbeat
        case 'ping':
            $connection->send(json_encode(['event' => 'pong', 'timestamp' => time()]));
            break;
    }
};

$wsWorker->onClose = function (TcpConnection $connection) use (&$userConnections, &$connectionUserMap) {
    if (isset($connectionUserMap[$connection->id])) {
        $userId = $connectionUserMap[$connection->id];
        unset($userConnections[$userId][$connection->id]);
        if (empty($userConnections[$userId])) {
            unset($userConnections[$userId]);
        }
        unset($connectionUserMap[$connection->id]);
        echo "🔌 [WS Disconnect] User #{$userId} disconnected (Connection ID: {$connection->id})\n";
    }
};

Worker::runAll();