import 'dart:async';

import 'print/backend.dart';
import 'print/mock_backend.dart';
import 'server/http_server.dart';
import 'server/print_queue.dart';
import 'utils/file_log.dart';

/// 启动参数：--mock 模拟打印；--port=NNN / --port NNN 指定监听端口（默认 38200-38202 顺延）。
class AgentOptions {
  AgentOptions({this.mock = false, this.port});

  final bool mock;
  final int? port;

  factory AgentOptions.parse(List<String> args) {
    var mock = false;
    int? port;
    for (var i = 0; i < args.length; i++) {
      final arg = args[i];
      if (arg == '--mock') {
        mock = true;
      } else if (arg.startsWith('--port=')) {
        port = int.tryParse(arg.substring('--port='.length));
      } else if ((arg == '--port' || arg == '-p') && i + 1 < args.length) {
        port = int.tryParse(args[++i]);
      }
    }
    return AgentOptions(mock: mock, port: port);
  }
}

/// 运行日志环形缓冲（GUI 展示用），同时打到 stdout。
class AgentLog {
  final lines = <String>[];
  final _controller = StreamController<String>.broadcast();

  Stream<String> get stream => _controller.stream;

  void write(String line) {
    final stamped = '${DateTime.now().toIso8601String().substring(11, 19)} $line';
    lines.add(stamped);
    if (lines.length > 500) {
      lines.removeRange(0, lines.length - 500);
    }
    // ignore: avoid_print
    print(stamped);
    FileLog.write(line); // 文件持久化（供现场排查，用户可取回分析）
    _controller.add(stamped);
  }

  void dispose() => _controller.close();
}

/// 助手核心：组合打印后端、任务队列与 HTTP 服务（Flutter 窗口与 headless 入口共用）。
class Agent {
  Agent(this.options) : log = AgentLog();

  final AgentOptions options;
  final AgentLog log;

  late final PrintQueue queue;
  late final PrintBackend backend;
  late final AgentHttpServer server;
  int? port;

  Future<int> start() async {
    final backendName = osBackendName();
    backend = options.mock ? MockBackend(onLog: log.write) : createOsBackend(onLog: log.write);
    queue = PrintQueue(backend, onLog: log.write);
    server = AgentHttpServer(
      queue: queue,
      backend: backend,
      mock: options.mock,
      manifestBackendName: backendName,
    );
    final ports = options.port == null ? const [38200, 38201, 38202] : <int>[options.port!];
    port = await server.start(candidatePorts: ports);
    log.write('资安信插件助手已启动 http://127.0.0.1:$port'
        '（后端=$backendName，mock=${options.mock}，agent=desktop-plugin）');
    return port!;
  }

  bool _stopped = false;

  /// 幂等停止：托盘退出与窗口销毁可能先后各调一次。
  Future<void> stop() async {
    if (_stopped) return;
    _stopped = true;
    await server.stop();
    queue.dispose();
    log.dispose();
  }
}