xianyan/docs/toolsapi/scripts/qrcode_ws_relay.dart

/// ============================================================
/// 闲言APP — 二维码登录WebSocket中继服务器
/// 创建时间: 2026-06-02
/// 更新时间: 2026-06-02
/// 作用: WebSocket中继服务器，推送二维码状态变更给订阅客户端
/// 上次更新: 初始创建，基于shelf_web_socket
///
/// 部署方式:
///   dart run qrcode_ws_relay.dart --port 9444
///
/// 架构:
///   1. 客户端连接 ws://host:9444 并发送 {"type":"qrcode_subscribe","code":"xxx"}
///   2. PHP后端在qrcodeConfirm/qrcodeCancel时调用 POST /notify
///   3. 中继服务器将状态变更推送给订阅了对应code的客户端
/// ============================================================

import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:shelf/shelf.dart' as shelf;
import 'package:shelf/shelf_io.dart' as shelf_io;
import 'package:shelf_router/shelf_router.dart';
import 'package:shelf_web_socket/shelf_web_socket.dart';

final _subscribers = <String, List<WebSocketChannel>>{};
final _codeToChannels = <String, List<WebSocketChannel>>{};

void main(List<String> args) async {
  final port = int.tryParse(args.isNotEmpty ? args.first : '9444') ?? 9444;

  final router = Router();

  router.get('/ws', webSocketHandler((WebSocketChannel ws) {
    String? subscribedCode;

    ws.stream.listen(
      (data) {
        try {
          final json = jsonDecode(data as String) as Map<String, dynamic>;
          final type = json['type'] as String? ?? '';

          if (type == 'qrcode_subscribe') {
            final code = json['code'] as String? ?? '';
            if (code.isNotEmpty) {
              subscribedCode = code;
              _codeToChannels.putIfAbsent(code, () => []).add(ws);
              print('[subscribe] code=$code total=${_codeToChannels[code]?.length}');
              ws.sink.add(jsonEncode({
                'type': 'qrcode_subscribed',
                'code': code,
              }));
            }
          } else if (type == 'qrcode_unsubscribe') {
            final code = json['code'] as String? ?? '';
            if (code.isNotEmpty) {
              _codeToChannels[code]?.remove(ws);
              if (_codeToChannels[code]?.isEmpty ?? false) {
                _codeToChannels.remove(code);
              }
              subscribedCode = null;
              print('[unsubscribe] code=$code');
            }
          } else if (type == 'ping') {
            ws.sink.add(jsonEncode({'type': 'pong'}));
          }
        } catch (e) {
          print('[error] parse failed: $e');
        }
      },
      onDone: () {
        if (subscribedCode != null) {
          _codeToChannels[subscribedCode]?.remove(ws);
          if (_codeToChannels[subscribedCode]?.isEmpty ?? false) {
            _codeToChannels.remove(subscribedCode);
          }
          print('[disconnect] code=$subscribedCode');
        }
      },
      onError: (e) {
        print('[error] $e');
        if (subscribedCode != null) {
          _codeToChannels[subscribedCode]?.remove(ws);
        }
      },
    );
  }));

  router.post('/notify', (shelf.Request request) async {
    try {
      final body = await request.readAsString();
      final json = jsonDecode(body) as Map<String, dynamic>;
      final code = json['code'] as String? ?? '';
      final status = json['status'] as String? ?? '';
      final token = json['token'] as String?;

      if (code.isEmpty || status.isEmpty) {
        return shelf.Response(400, body: jsonEncode({'error': 'code and status required'}));
      }

      final channels = _codeToChannels[code];
      if (channels == null || channels.isEmpty) {
        return shelf.Response.ok(jsonEncode({'sent': 0, 'message': 'no subscribers'}));
      }

      final message = jsonEncode({
        'type': 'qrcode_status_update',
        'code': code,
        'status': status,
        if (token != null) 'token': token,
        'ts': DateTime.now().millisecondsSinceEpoch,
      });

      var sent = 0;
      final toRemove = <WebSocketChannel>[];
      for (final ch in channels) {
        try {
          ch.sink.add(message);
          sent++;
        } catch (e) {
          toRemove.add(ch);
        }
      }
      for (final ch in toRemove) {
        channels.remove(ch);
      }

      print('[notify] code=$code status=$status sent=$sent');
      return shelf.Response.ok(jsonEncode({'sent': sent}));
    } catch (e) {
      return shelf.Response(500, body: jsonEncode({'error': e.toString()}));
    }
  });

  router.get('/stats', (shelf.Request request) {
    final stats = <String, int>{};
    for (final entry in _codeToChannels.entries) {
      stats[entry.key] = entry.value.length;
    }
    return shelf.Response.ok(jsonEncode({
      'total_codes': _codeToChannels.length,
      'subscribers': stats,
    }));
  });

  final handler = const shelf.Pipeline()
      .addMiddleware(shelf.logRequests())
      .addHandler(router.call);

  final server = await shelf_io.serve(handler, InternetAddress.anyIPv4, port);
  print('🚀 QR Code WebSocket Relay running on ws://0.0.0.0:$port/ws');
  print('📡 Notify endpoint: POST http://0.0.0.0:$port/notify');
  print('📊 Stats endpoint: GET http://0.0.0.0:$port/stats');
}

// WebSocketChannel stub for standalone server
// When running as standalone, import web_socket_channel directly
class WebSocketChannel {
  final Stream<dynamic> stream;
  final WebSocketSink sink;
  WebSocketChannel(this.stream, this.sink);
}

class WebSocketSink {
  final Function(String) _add;
  final Function() _close;
  WebSocketSink(this._add, this._close);
  void add(String data) => _add(data);
  void close() => _close();
}