import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_inappwebview/flutter_inappwebview.dart';

import 'avatar_bridge.dart';
import 'control_panel_sheet.dart';
import 'voice_chat/voice_chat_controller.dart';
import 'voice_chat/voice_chat_sheet.dart';

int _serverPort = 8080;

/// 探测端口是否可用 —— InAppLocalhostServer.start() 在端口被占时会死等不抛异常，
/// 所以必须先用 ServerSocket 试探一下能不能 bind。
Future<bool> _isPortFree(int port) async {
  try {
    final s = await ServerSocket.bind('127.0.0.1', port);
    await s.close();
    return true;
  } catch (_) {
    return false;
  }
}

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  // 同机多端（macOS + iOS sim 共享 localhost）端口可能冲突，循环找一个空闲端口
  for (var port = 8080; port < 8090; port++) {
    if (await _isPortFree(port)) {
      await InAppLocalhostServer(
        documentRoot: 'assets/web',
        port: port,
      ).start();
      _serverPort = port;
      debugPrint('[server] listening on localhost:$port');
      break;
    } else {
      debugPrint('[server] port $port busy, trying next');
    }
  }
  runApp(const AvatarApp());
}

class AvatarApp extends StatelessWidget {
  const AvatarApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Avatar PoC',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        useMaterial3: true,
        brightness: Brightness.dark,
        scaffoldBackgroundColor: const Color(0xFF1A1A1F),
        colorScheme: const ColorScheme.dark(
          primary: Color(0xFF4488DD),
          surface: Color(0xFF222228),
        ),
      ),
      home: const AvatarHomePage(),
    );
  }
}

class AvatarHomePage extends StatefulWidget {
  const AvatarHomePage({super.key});

  @override
  State<AvatarHomePage> createState() => _AvatarHomePageState();
}

class _AvatarHomePageState extends State<AvatarHomePage> with WidgetsBindingObserver {
  AvatarBridge? _bridge;
  bool _ready = false;
  VoiceChatController? _voiceController;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    _voiceController?.dispose();
    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    final controller = _voiceController;
    if (controller == null) return;
    if (state == AppLifecycleState.resumed) {
      // 回到前台：重新建立会话
      controller.startSession();
    } else if (state == AppLifecycleState.paused) {
      controller.stopSession();
    }
  }

  void _ensureVoiceSessionStarted() {
    if (_bridge == null) return;
    _voiceController ??= VoiceChatController(bridge: _bridge!);
    _voiceController!.startSession();
  }

  Widget _buildVoiceFab() {
    // 第一次进入页面时立刻启动会话；同时监听 controller 让 FAB 颜色实时反映状态
    _ensureVoiceSessionStarted();
    return ListenableBuilder(
      listenable: _voiceController!,
      builder: (context, _) {
        final c = _voiceController!;
        final (label, bg) = c.connected
            ? ('语音对话 · 已连接', const Color(0xFF1E9F4D))  // 绿色
            : c.connecting
                ? ('语音对话 · 连接中', const Color(0xFFD08F2C))  // 黄色
                : ('语音对话 · 未连接', const Color(0xFF6B6B73)); // 灰色
        return FloatingActionButton.extended(
          heroTag: 'voice',
          onPressed: () {
            // 单击只展开抽屉看消息/日志；会话本身在后台一直跑
            showModalBottomSheet(
              context: context,
              isScrollControlled: true,
              backgroundColor: Colors.transparent,
              builder: (_) => VoiceChatSheet(controller: c),
            );
          },
          icon: Icon(c.connected ? Icons.graphic_eq : Icons.sync_problem),
          label: Text(label),
          backgroundColor: bg,
          foregroundColor: Colors.white,
        );
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Stack(
          children: [
            InAppWebView(
              initialUrlRequest: URLRequest(
                url: WebUri('http://localhost:$_serverPort/index.html'),
              ),
              initialSettings: InAppWebViewSettings(
                javaScriptEnabled: true,
                transparentBackground: false,
                allowsInlineMediaPlayback: true,
                mediaPlaybackRequiresUserGesture: false,
                // macOS / iOS：允许 localhost 加载
                allowsBackForwardNavigationGestures: false,
              ),
              onWebViewCreated: (controller) {
                _bridge = AvatarBridge(controller);
              },
              onLoadStop: (controller, _) async {
                // 隐藏 H5 内置调试面板（Flutter 接管控制权）
                await controller.evaluateJavascript(source: '''
                  const p = document.getElementById('debug-panel');
                  if (p) p.style.display = 'none';
                ''');
                // 等 avatar 全局对象注册完成
                await _bridge?.waitReady();
                if (mounted) setState(() => _ready = true);
              },
              onConsoleMessage: (_, msg) {
                debugPrint('[webview] ${msg.message}');
              },
            ),
            if (!_ready)
              const Center(
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    CircularProgressIndicator(),
                    SizedBox(height: 12),
                    Text('Loading Live2D...'),
                  ],
                ),
              ),
          ],
        ),
      ),
      floatingActionButton: _ready
          ? Column(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.end,
              children: [
                _buildVoiceFab(),
                const SizedBox(height: 12),
                FloatingActionButton.extended(
                  heroTag: 'panel',
                  onPressed: () {
                    if (_bridge == null) return;
                    showModalBottomSheet(
                      context: context,
                      isScrollControlled: true,
                      backgroundColor: Colors.transparent,
                      builder: (_) => ControlPanelSheet(bridge: _bridge!),
                    );
                  },
                  icon: const Icon(Icons.tune),
                  label: const Text('控制面板'),
                  backgroundColor: const Color(0xFF2766B6),
                  foregroundColor: Colors.white,
                ),
              ],
            )
          : null,
    );
  }
}