// app_updater.dart — App 内下载并安装更新(不再开浏览器)。
//
// 对照 jiu core/update/app_updater_io.dart,但补上了 jiu 没有的 Android 原生安装:
//   - Android:http 流式下 APK 到临时目录 → open_filex 拉起系统安装器
//              (open_filex 内部封装 FileProvider;manifest 需 REQUEST_INSTALL_PACKAGES)
//   - Windows:下 exe → Process.start(detached) 起安装 → exit(0) 让其覆盖
//   - macOS :下 zip → ditto 解压 → 分离 helper 等主进程退出后原子换 /Applications
//            里的 .app + open 重启(未开沙箱,admin 用户可写 /Applications → 全程无弹窗;
//            .app 属主非本人则 osascript 弹一次系统密码框提权;不可写/异常则回退访达定位手动拖)。
//            运行中的 sysext 从 /Library/SystemExtensions 跑,换 .app 不影响它——
//            与手动拖入同路径,新版启动照常走 OSSystemExtensionRequest。
//   - iOS   :不能 App 内装 → 外链(TestFlight/App Store)
// 进度用本地 ValueNotifier 驱动一个不可关闭的进度对话框;失败降级浏览器下载。
import 'dart:async';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:open_filex/open_filex.dart';
import 'package:path_provider/path_provider.dart';
import 'package:url_launcher/url_launcher.dart';

import '../../l10n/app_text.dart';
import '../../pangolin_theme.dart';
import '../../state/update_provider.dart';
import '../../widgets/pangolin_icons.dart';

/// 更新对话框「下载更新」入口:按平台 App 内下载并安装;iOS/无直链降级浏览器。
Future<void> startInAppUpdate(BuildContext context, AppText t, AppUpdateInfo info) async {
  final url = platformDownloadUrl(info.downloadUrls);
  if (url == null || url.isEmpty) return;

  // iOS 不允许 App 内安装 → 外链(download_urls['ios'] 应为 TestFlight/App Store)。
  if (Platform.isIOS) {
    await _openInBrowser(url);
    return;
  }

  final progress = ValueNotifier<double>(0);
  final installing = ValueNotifier<bool>(false);
  var dialogOpen = true;
  void closeDialog() {
    if (context.mounted && dialogOpen) {
      dialogOpen = false;
      Navigator.of(context, rootNavigator: true).pop();
    }
  }

  // 不可关闭的进度框。
  unawaited(showDialog<void>(
    context: context,
    barrierDismissible: false,
    builder: (_) => PopScope(
      canPop: false,
      child: _ProgressDialog(t: t, progress: progress, installing: installing),
    ),
  ));

  try {
    final savePath = await _savePath(url);
    await _download(url, savePath, (p) => progress.value = p);
    installing.value = true;
    await _install(savePath); // Win/macOS 可能在此 exit(0),不再返回
    closeDialog();
    if (Platform.isMacOS && context.mounted) {
      await _showInfo(context, t, t.lang.updateMacReveal);
    }
  } catch (_) {
    closeDialog();
    if (context.mounted) await _showFailed(context, t, url);
  } finally {
    progress.dispose();
    installing.dispose();
  }
}

/// 各平台下载文件的落盘路径。
Future<String> _savePath(String url) async {
  final tmp = await getTemporaryDirectory();
  if (Platform.isWindows) return '${tmp.path}${Platform.pathSeparator}pangolin-update-setup.exe';
  if (Platform.isMacOS) {
    // 下到「下载」目录便于用户在访达里操作;取不到则回退临时目录。
    final dl = await getDownloadsDirectory();
    final dir = dl ?? tmp;
    return '${dir.path}/pangolin-update.zip';
  }
  return '${tmp.path}/pangolin-update.apk'; // Android
}

/// http 流式下载 + 进度回调。失败抛异常(由调用方降级)。
Future<void> _download(String url, String savePath, void Function(double) onProgress) async {
  final client = http.Client();
  try {
    final req = http.Request('GET', Uri.parse(url));
    final resp = await client.send(req);
    if (resp.statusCode != 200) {
      throw HttpException('HTTP ${resp.statusCode}', uri: Uri.parse(url));
    }
    final total = resp.contentLength ?? 0;
    final file = File(savePath);
    final sink = file.openWrite();
    var received = 0;
    try {
      await for (final chunk in resp.stream) {
        received += chunk.length;
        sink.add(chunk);
        if (total > 0) onProgress(received / total);
      }
      await sink.flush();
    } finally {
      await sink.close();
    }
  } finally {
    client.close();
  }
}

/// 下载后触发安装/打开。
Future<void> _install(String path) async {
  if (Platform.isAndroid) {
    await OpenFilex.open(path); // 系统安装器(open_filex 内封 FileProvider)
    return;
  }
  if (Platform.isWindows) {
    await Process.start(path, const [], mode: ProcessStartMode.detached);
    await Future<void>.delayed(const Duration(milliseconds: 400));
    exit(0); // 退出让安装器覆盖
  }
  if (Platform.isMacOS) {
    await _macInstall(path); // 成功则 exit(0) 不返回;回退则内部走访达定位后返回
  }
}

/// macOS 自动安装:解压 → 分离 helper 换 /Applications 的 .app + 重启。
/// 成功路径 exit(0)(不返回);不满足条件/失败则回退访达定位(现状半自动流程)后正常返回,
/// 由调用方提示手动拖入。
Future<void> _macInstall(String zipPath) async {
  final exe = Platform.resolvedExecutable; // …/pangolin_vpn.app/Contents/MacOS/pangolin_vpn
  const marker = '/Contents/MacOS/';
  final mi = exe.indexOf(marker);
  final appPath = mi > 0 ? exe.substring(0, mi) : ''; // …/pangolin_vpn.app
  // 仅当能定位到 .app bundle 才尝试自动装;异常布局(如无 bundle 运行)回退。
  if (appPath.isEmpty || !appPath.toLowerCase().endsWith('.app')) {
    await _macReveal(zipPath);
    return;
  }

  try {
    final tmp = await getTemporaryDirectory();
    final staging = '${tmp.path}/pangolin-update-${DateTime.now().millisecondsSinceEpoch}';
    final extractDir = '$staging/new';
    await Directory(extractDir).create(recursive: true);

    // ditto 解 PKZip(zip 由 --keepParent 打,顶层含 pangolin_vpn.app);失败即回退。
    final ex = await Process.run('/usr/bin/ditto', <String>['-x', '-k', zipPath, extractDir]);
    if (ex.exitCode != 0) {
      await _macReveal(zipPath);
      return;
    }
    final newApp = await _findDotApp(extractDir);
    if (newApp == null) {
      await _macReveal(zipPath);
      return;
    }

    // 写 helper、分离启动、退出让其换装重启。参数:PID/现.app/新.app/暂存/zip。
    final helper = '$staging/pangolin-update.sh';
    await File(helper).writeAsString(_macUpdateHelper);
    final chmod = await Process.run('/bin/chmod', <String>['+x', helper]);
    if (chmod.exitCode != 0) {
      // helper 跑不起来:清掉半截暂存(解压出的新 app + 不可执行的 helper),回退访达手动流程。
      try {
        await Directory(staging).delete(recursive: true);
      } catch (_) {}
      await _macReveal(zipPath);
      return;
    }
    await Process.start(
      '/bin/sh',
      <String>[helper, '$pid', appPath, newApp, staging, zipPath],
      mode: ProcessStartMode.detached,
    );
    await Future<void>.delayed(const Duration(milliseconds: 300));
    exit(0); // helper 等本进程退出后原子换 bundle + open 重启
  } catch (_) {
    await _macReveal(zipPath); // 任何意外 → 保底手动流程
  }
}

/// 回退:Archive Utility 解压 zip + 访达高亮(与旧版一致的半自动流程)。
Future<void> _macReveal(String zipPath) async {
  await Process.run('open', <String>[zipPath]); // 解压
  await Process.run('open', <String>['-R', zipPath]); // 访达定位
}

/// 在解压目录里找顶层 .app(ditto --keepParent 打的 zip 解出 pangolin_vpn.app)。
Future<String?> _findDotApp(String dir) async {
  final d = Directory(dir);
  if (!await d.exists()) return null;
  await for (final e in d.list(followLinks: false)) {
    if (e is Directory && e.path.toLowerCase().endsWith('.app')) return e.path;
  }
  return null;
}

/// macOS 自更新 helper 脚本(分离进程跑):等主 app 完全退出(超时+宽限后仍未退出则放弃,
/// 不硬动运行中的 bundle)→ codesign 验签新版(不过拒绝换装,Developer-ID 完整性闸)→
/// 原子换 bundle(失败必回滚并校验回滚是否真的成功,不假设 mv 一定成功;仍失败则 osascript
/// 提权,提权脚本自身具备「从 $BACKUP/$NEW_APP 自愈」逻辑,不假设 $APP 一定还在)→ 终检
/// $APP 确实存在才继续 → 清 quarantine → open 重启(检退出码,失败记日志尽力而为)。
/// 任何失败组合下都保证 /Applications 不会出现「app 消失、零提示」。
const String _macUpdateHelper = r'''#!/bin/sh
# Pangolin macOS 自更新 helper —— 由 app_updater.dart 生成、分离进程启动。
# 参数:PID(主app进程) APP(现.app) NEW_APP(解压出的新.app) STAGING(暂存目录) ZIP(下载的zip,清理用)
PID="$1"; APP="$2"; NEW_APP="$3"; STAGING="$4"; ZIP="$5"
exec >>"$STAGING/update.log" 2>&1
echo "[helper] start pid=$PID app=$APP new=$NEW_APP"

BACKUP="${APP}.pangolin-old"

# 放弃自动换装:访达定位新版供用户手动拖,保留现场(STAGING/BACKUP)便于排查/手动恢复。
fallback_reveal() {
  echo "[helper] fallback: $1"
  /usr/bin/open -R "$NEW_APP" 2>/dev/null
}

# 1. 等主 app 完全退出(最多 ~30s;超时再给 5s 宽限;仍未退出则放弃,不硬动运行中的 bundle)
i=0
while kill -0 "$PID" 2>/dev/null; do
  sleep 0.3; i=$((i+1))
  [ "$i" -gt 100 ] && break
done
if kill -0 "$PID" 2>/dev/null; then
  echo "[helper] wait timeout at ~30s, grace +5s"
  sleep 5
  if kill -0 "$PID" 2>/dev/null; then
    fallback_reveal "app still running after grace period, refusing to touch bundle"
    exit 1
  fi
fi
sleep 0.5

# 2. 签名验签闸:换装前必须验证新版签名完整(Developer-ID 分发完整性),不过拒绝换装
if ! /usr/bin/codesign --verify --deep --strict "$NEW_APP" 2>/dev/null; then
  fallback_reveal "codesign verify failed on new app, refusing swap"
  exit 1
fi

# 3. 静默换装(无提权):自愈式 swap —— 若 $APP 因上次失败缺失但 $BACKUP 还在,先自愈复原再换;
#    换装失败一律回滚,并校验回滚是否真的成功(不假设 mv 一定成功)。
#    返回码:0=成功 1=失败但 $APP 完好(未动/已回滚) 2=$APP 缺失且无 $BACKUP 可自愈 3=回滚也失败($APP 缺失,严重)
swap_plain() {
  if [ ! -d "$APP" ] && [ -d "$BACKUP" ]; then
    /bin/mv "$BACKUP" "$APP" 2>/dev/null
  fi
  if [ ! -d "$APP" ]; then
    return 2
  fi
  /bin/rm -rf "$BACKUP" 2>/dev/null
  /bin/mv "$APP" "$BACKUP" 2>/dev/null || return 1
  if /bin/mv "$NEW_APP" "$APP" 2>/dev/null; then
    /bin/rm -rf "$BACKUP" 2>/dev/null
    return 0
  fi
  /bin/mv "$BACKUP" "$APP" 2>/dev/null
  if [ -d "$APP" ]; then
    return 1
  fi
  return 3
}

swap_plain
rc=$?
if [ "$rc" -eq 0 ]; then
  echo "[helper] swap_plain ok"
else
  echo "[helper] swap_plain failed (rc=$rc) -> osascript 提权自愈"
  # 4. 提权兜底:ROOT_SH 自身自愈,不假设 $APP 一定存在——
  #    优先从 $BACKUP 复原、再正常 swap;$APP/$BACKUP 都没了则以 $NEW_APP 直接就位兜底。
  ROOT_SH="$STAGING/swap-root.sh"
  {
    echo '#!/bin/sh'
    echo "APP=\"$APP\""
    echo "NEW_APP=\"$NEW_APP\""
    echo "BACKUP=\"$BACKUP\""
    echo 'if [ ! -d "$APP" ] && [ -d "$BACKUP" ]; then /bin/mv "$BACKUP" "$APP"; fi'
    echo 'if [ ! -d "$APP" ] && [ -d "$NEW_APP" ]; then'
    echo '  /bin/mv "$NEW_APP" "$APP" || exit 1'
    echo '  exit 0'
    echo 'fi'
    echo 'if [ ! -d "$APP" ]; then exit 1; fi'
    echo '/bin/rm -rf "$BACKUP"'
    echo '/bin/mv "$APP" "$BACKUP" || exit 1'
    echo '/bin/mv "$NEW_APP" "$APP" || { /bin/mv "$BACKUP" "$APP" 2>/dev/null; exit 1; }'
    echo '/bin/rm -rf "$BACKUP"'
    echo 'exit 0'
  } > "$ROOT_SH"
  if ! /bin/chmod +x "$ROOT_SH"; then
    fallback_reveal "chmod ROOT_SH failed"
    exit 1
  fi
  if ! /usr/bin/osascript -e "do shell script \"/bin/sh '$ROOT_SH'\" with administrator privileges"; then
    echo "[helper] osascript failed/canceled -> 回退访达定位"
    fallback_reveal "osascript failed or canceled"
    exit 1
  fi
fi

# 5. 终检:/Applications 里必须有可用的 app 才继续,否则宁可停手也不再往下动(不清 quarantine、不 open)
if [ ! -d "$APP" ]; then
  fallback_reveal "final check: app still missing after all recovery attempts"
  exit 1
fi

# 6. 清 quarantine(已公证+staple,防御性)+ open 重启新版;open 失败(Gatekeeper/TCC 拦截)记日志,尽力而为
/usr/bin/xattr -dr com.apple.quarantine "$APP" 2>/dev/null
if /usr/bin/open "$APP"; then
  echo "[helper] relaunched"
else
  echo "[helper] open \"$APP\" failed, app updated on disk but not launched (Gatekeeper/TCC?); user needs to open manually"
fi

# 7. 清理(仅在换装成功、$APP 确认可用后才清;失败路径保留现场供排查)
/bin/rm -f "$ZIP" 2>/dev/null
/bin/rm -rf "$STAGING/new" 2>/dev/null
exit 0
''';

Future<void> _openInBrowser(String url) async {
  final uri = Uri.parse(url);
  if (await canLaunchUrl(uri)) {
    await launchUrl(uri, mode: LaunchMode.externalApplication);
  }
}

Future<void> _showInfo(BuildContext context, AppText t, String msg) {
  final c = context.pangolin;
  return showDialog<void>(
    context: context,
    builder: (ctx) => AlertDialog(
      backgroundColor: c.surface,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(PangolinRadius.xl)),
      content: Text(msg, style: PangolinText.sm.copyWith(color: c.fg2, height: 1.5)),
      actions: [
        TextButton(
          onPressed: () => Navigator.of(ctx).pop(),
          child: Text('OK', style: PangolinText.sm.copyWith(color: c.accent, fontWeight: FontWeight.w700)),
        ),
      ],
    ),
  );
}

Future<void> _showFailed(BuildContext context, AppText t, String url) {
  final c = context.pangolin;
  return showDialog<void>(
    context: context,
    builder: (ctx) => AlertDialog(
      backgroundColor: c.surface,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(PangolinRadius.xl)),
      content: Text(t.lang.updateDownloadFailed, style: PangolinText.sm.copyWith(color: c.fg2, height: 1.5)),
      actions: [
        TextButton(
          onPressed: () => Navigator.of(ctx).pop(),
          child: Text(t.lang.updateCancelBtn, style: PangolinText.sm.copyWith(color: c.fg2, fontWeight: FontWeight.w600)),
        ),
        TextButton(
          onPressed: () async {
            Navigator.of(ctx).pop();
            await _openInBrowser(url);
          },
          child: Text(t.lang.updateOpenBrowser, style: PangolinText.sm.copyWith(color: c.accent, fontWeight: FontWeight.w700)),
        ),
      ],
    ),
  );
}

class _ProgressDialog extends StatelessWidget {
  const _ProgressDialog({required this.t, required this.progress, required this.installing});
  final AppText t;
  final ValueNotifier<double> progress;
  final ValueNotifier<bool> installing;

  @override
  Widget build(BuildContext context) {
    final c = context.pangolin;
    return AlertDialog(
      backgroundColor: c.surface,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(PangolinRadius.xl)),
      title: Row(children: [
        Container(
          width: 34,
          height: 34,
          decoration: BoxDecoration(color: c.accentSubtle, shape: BoxShape.circle),
          child: Icon(PangolinIcons.zap, size: 18, color: c.accent),
        ),
        const SizedBox(width: 12),
        Expanded(
          child: Text(t.updateDownload,
              style: PangolinText.body.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
        ),
      ]),
      content: ValueListenableBuilder<bool>(
        valueListenable: installing,
        builder: (_, inst, __) => ValueListenableBuilder<double>(
          valueListenable: progress,
          builder: (_, p, __) => Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              ClipRRect(
                borderRadius: BorderRadius.circular(PangolinRadius.full),
                child: LinearProgressIndicator(
                  value: inst || p <= 0 ? null : p,
                  minHeight: 6,
                  backgroundColor: c.bgSubtle,
                  valueColor: AlwaysStoppedAnimation<Color>(c.accent),
                ),
              ),
              const SizedBox(height: 12),
              Text(
                inst ? t.lang.updateInstalling : t.lang.updateDownloadingPercent((p * 100).clamp(0, 100).round()),
                style: PangolinText.sm.copyWith(color: c.fg2),
              ),
            ],
          ),
        ),
      ),
    );
  }
}