import 'dart:async';

import 'package:device_plugin_interface/device_plugin_interface.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:get/get.dart';

import '../../../core/theme/app_palette.dart';
import '../../../data/services/background_launch_consent.dart';
import '../../../devices/device_hub.dart';
import '../../../devices/device_vendors.dart';
import '../../../routes/app_routes.dart';
import '../../main_tab/controllers/main_tab_controller.dart';

/// EaiRec 录音支架（AI手机支架）的扫描 / 连接页——走 [DeviceHub] 里的支架插件。
class HolderScanView extends StatefulWidget {
  const HolderScanView({super.key});

  @override
  State<HolderScanView> createState() => _HolderScanViewState();
}

class _HolderScanViewState extends State<HolderScanView> {
  DevicePlugin get _plugin => DeviceHub.to.plugin(DeviceVendors.holder)!;
  final RxList<DiscoveredDevice> _scanned = <DiscoveredDevice>[].obs;
  final RxBool _isScanning = false.obs;
  StreamSubscription<DevicePluginEvent>? _sub;
  bool _connecting = false;

  @override
  void initState() {
    super.initState();
    _sub = _plugin.eventStream.listen((e) {
      switch (e.type) {
        case DevicePluginEventType.scanStarted:
          _isScanning.value = true;
          break;
        case DevicePluginEventType.scanStopped:
          _isScanning.value = false;
          break;
        case DevicePluginEventType.deviceDiscovered:
          final d = e.discovered;
          if (d == null || d.id.isEmpty) break;
          // 按地址去重累积：原生是「每扫到一个就单独上报一次」
          final i = _scanned.indexWhere((x) => x.id == d.id);
          if (i >= 0) {
            _scanned[i] = d;
          } else {
            _scanned.add(d);
          }
          break;
        default:
          break;
      }
    });
    // 进页面自动开扫
    WidgetsBinding.instance.addPostFrameCallback((_) => _startScan());
  }

  Future<void> _startScan() async {
    _scanned.clear();
    if (!await _plugin.ensureReady()) {
      Get.snackbar('tip'.tr, 'holderPairHint'.tr,
          snackPosition: SnackPosition.TOP);
      return;
    }
    await _plugin.startScan();
  }

  @override
  void dispose() {
    _sub?.cancel();
    _plugin.stopScan();
    super.dispose();
  }

  Future<void> _connect(DiscoveredDevice d) async {
    if (_connecting) return;
    // Android 上 SDK 的 connect() 本身就是向系统注册后台扫连（设备靠近就唤醒
    // 本应用），属于自启动行为，必须先向用户明示并取得同意。
    if (!await BackgroundLaunchConsent.ensure(userInitiated: true)) {
      Get.snackbar(
          'autoConnectRequired'.tr,
          BackgroundLaunchConsent.declined
              ? 'autoConnectReenableHint'.tr
              : 'autoConnectRequiredDesc'.tr,
          snackPosition: SnackPosition.TOP);
      return;
    }
    setState(() => _connecting = true);
    bool ok = false;
    try {
      await _plugin.connect(d.id);
      ok = true;
    } on DeviceException catch (e) {
      debugPrint('holder connect failed: ${e.code} ${e.message}');
    } catch (e) {
      debugPrint('holder connect failed: $e');
    }
    if (!mounted) return;
    setState(() => _connecting = false);
    if (ok) {
      Get.snackbar('连接成功', '${d.name} 已连接',
          snackPosition: SnackPosition.TOP,
          duration: const Duration(seconds: 2));
      Get.offAllNamed(Routes.home);
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (Get.isRegistered<MainTabController>()) {
          MainTabController.to.showDeviceAfterConnect();
        }
      });
    } else {
      Get.snackbar('连接失败', 'holderRetryHint'.tr,
          snackPosition: SnackPosition.TOP);
    }
  }

  @override
  Widget build(BuildContext context) {
    final bool isDark = Theme.of(context).brightness == Brightness.dark;
    return Scaffold(
      backgroundColor: AppPalette.background(isDark),
      appBar: AppBar(
        backgroundColor: AppPalette.background(isDark),
        elevation: 0,
        title: Text('holderAddTitle'.tr),
        actions: [
          Obx(() => _isScanning.value
              ? Padding(
                  padding: EdgeInsets.only(right: 16.w),
                  child: Center(
                    child: SizedBox(
                      width: 18.w,
                      height: 18.w,
                      child: const CircularProgressIndicator(strokeWidth: 2),
                    ),
                  ),
                )
              : IconButton(
                  icon: const Icon(Icons.refresh),
                  onPressed: _startScan,
                )),
        ],
      ),
      body: _connecting
          ? Center(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  const CircularProgressIndicator(),
                  const SizedBox(height: 16),
                  Text('holderConnecting'.tr),
                ],
              ),
            )
          : Obx(() {
              final list = _scanned;
              if (list.isEmpty) {
                return Center(
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      Icon(Icons.bluetooth_searching,
                          size: 56.sp, color: AppPalette.brand300),
                      SizedBox(height: 12.h),
                      Text(
                        _isScanning.value
                            ? 'holderSearching'.tr
                            : 'holderNotFound'.tr,
                        style: TextStyle(
                            fontSize: 15.sp,
                            color: AppPalette.textSecondary(isDark)),
                      ),
                      SizedBox(height: 6.h),
                      Text(
                        'holderPairHint'.tr,
                        style: TextStyle(
                            fontSize: 12.sp, color: AppPalette.textHint(isDark)),
                      ),
                    ],
                  ),
                );
              }
              return ListView.separated(
                padding: EdgeInsets.symmetric(horizontal: 16.w, vertical: 16.h),
                itemCount: list.length,
                separatorBuilder: (_, __) => SizedBox(height: 12.h),
                itemBuilder: (context, i) {
                  final d = list[i];
                  return GestureDetector(
                    behavior: HitTestBehavior.opaque,
                    onTap: () => _connect(d),
                    child: Container(
                      padding: EdgeInsets.all(14.w),
                      decoration: BoxDecoration(
                        color: AppPalette.surface(isDark),
                        borderRadius: BorderRadius.circular(14.r),
                        border: Border.all(color: AppPalette.border(isDark)),
                      ),
                      child: Row(
                        children: [
                          Icon(Icons.stay_current_portrait,
                              size: 26.sp, color: AppPalette.accent),
                          SizedBox(width: 12.w),
                          Expanded(
                            child: Column(
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                Text(
                                  d.name.isEmpty ? 'bleUnknownDevice'.tr : d.name,
                                  style: TextStyle(
                                    fontSize: 15.sp,
                                    fontWeight: FontWeight.w600,
                                    color: AppPalette.textPrimary(isDark),
                                  ),
                                ),
                                SizedBox(height: 2.h),
                                Text(
                                  d.id,
                                  style: TextStyle(
                                    fontSize: 11.sp,
                                    color: AppPalette.textHint(isDark),
                                  ),
                                ),
                              ],
                            ),
                          ),
                          Text('连接',
                              style: TextStyle(
                                  fontSize: 13.sp,
                                  fontWeight: FontWeight.w600,
                                  color: AppPalette.accent)),
                        ],
                      ),
                    ),
                  );
                },
              );
            }),
    );
  }
}