import 'dart:async';
import 'dart:typed_data';

import 'package:flutter/material.dart';

import '../core/app_manager.dart';
import '../core/file_ops.dart' show formatSize;
import '../core/vfs.dart' show vDisplay;
import '../l10n/tr.dart';
import 'theme.dart';
import 'jj_title_bar.dart';

/// X-plore 비교 5-2 앱 관리자 (사용자 결정 10/21, Android): 실행할 수 있는 앱 목록 - 이름 · 판 · 크기 · 설치일,
/// [APK 백업] (Download/JJ_MKVMaker/apk) · [앱 정보] (시스템 화면) · [지우기] (시스템 지우기 창)
Future<void> openAppManager(BuildContext context, {AppManagerBackend? backend}) => Navigator.of(context)
    .push(MaterialPageRoute<void>(builder: (_) => AppManagerPage(backend: backend ?? AndroidAppManager())));

class AppManagerPage extends StatefulWidget {
  final AppManagerBackend backend;
  const AppManagerPage({super.key, required this.backend});

  @override
  State<AppManagerPage> createState() => _AppManagerPageState();
}

class _AppManagerPageState extends State<AppManagerPage> {
  List<InstalledApp>? _apps;
  String? _error;
  String _sort = 'name';
  String _filter = '';
  final _icons = <String, Future<Uint8List?>>{};

  @override
  void initState() {
    super.initState();
    unawaited(_load());
  }

  Future<void> _load() async {
    try {
      final l = await widget.backend.list();
      if (mounted) setState(() => _apps = l);
    } catch (e) {
      if (mounted) setState(() => _error = trf('앱 목록을 읽지 못했습니다: {0}', [e]));
    }
  }

  List<InstalledApp> get _shown {
    final f = _filter.toLowerCase();
    final l = [for (final a in _apps ?? const <InstalledApp>[]) if (f.isEmpty || a.label.toLowerCase().contains(f) || a.package.contains(f)) a];
    switch (_sort) {
      case 'size':
        l.sort((a, b) => b.size.compareTo(a.size));
      case 'installed':
        l.sort((a, b) => b.installed.compareTo(a.installed));
      default:
        l.sort((a, b) => a.label.toLowerCase().compareTo(b.label.toLowerCase()));
    }
    return l;
  }

  void _snack(String t) => ScaffoldMessenger.maybeOf(context)?.showSnackBar(SnackBar(content: Text(t)));

  String _day(DateTime d) => '${d.year}-${d.month.toString().padLeft(2, '0')}-${d.day.toString().padLeft(2, '0')}';

  Future<void> _backup(InstalledApp a) async {
    try {
      final out = await backupApk(a, await widget.backend.backupDir());
      _snack(a.splits > 0
          ? trf('APK 를 저장했습니다: {0} - 나눠진 앱 (조각 {1}개) 이라 이 파일 하나로는 설치되지 않을 수 있습니다', [vDisplay(out), a.splits])
          : trf('APK 를 저장했습니다: {0}', [vDisplay(out)]));
    } catch (e) {
      _snack(trf('APK 를 저장하지 못했습니다: {0}', [e]));
    }
  }

  Future<void> _menu(InstalledApp a) async {
    final w = await showModalBottomSheet<String>(
      context: context,
      builder: (ctx) => SafeArea(
        child: Column(mainAxisSize: MainAxisSize.min, children: [
          ListTile(title: Text(a.label), subtitle: Text(a.package)),
          ListTile(leading: const Icon(Icons.save_alt), title: Text(tr('APK 백업')), onTap: () => Navigator.pop(ctx, 'backup')),
          ListTile(leading: const Icon(Icons.info_outline), title: Text(tr('앱 정보 (시스템 화면)')), onTap: () => Navigator.pop(ctx, 'details')),
          if (!a.system)
            ListTile(
                leading: Icon(Icons.delete_outline, color: JjColors.danger),
                title: Text(tr('지우기 (시스템 창에서 확인)')),
                onTap: () => Navigator.pop(ctx, 'uninstall')),
        ]),
      ),
    );
    switch (w) {
      case 'backup':
        await _backup(a);
      case 'details':
        await widget.backend.details(a.package);
      case 'uninstall':
        await widget.backend.uninstall(a.package);
    }
  }

  @override
  Widget build(BuildContext context) {
    final apps = _apps;
    return Scaffold(
      appBar: jjTitleBar(
        context,
        title: tr('앱 관리자'),
        actions: [IconButton(tooltip: tr('새로 고침'), icon: const Icon(Icons.refresh), onPressed: _load)],
      ),
      body: Column(crossAxisAlignment: CrossAxisAlignment.stretch, children: [
        Padding(
          padding: const EdgeInsets.fromLTRB(16, 8, 16, 0),
          child: Text(tr('보이는 앱만 나옵니다 (모든 앱 목록 권한은 쓰지 않음)'), style: TextStyle(fontSize: 12, color: JjColors.textDim)),
        ),
        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 12),
          child: Row(children: [
            Expanded(
              child: TextField(
                decoration: InputDecoration(isDense: true, prefixIcon: const Icon(Icons.search, size: 18), hintText: tr('이름으로 찾기')),
                onChanged: (v) => setState(() => _filter = v.trim()),
              ),
            ),
            const SizedBox(width: 8),
            DropdownButton<String>(
              value: _sort,
              items: [
                DropdownMenuItem(value: 'name', child: Text(tr('이름'))),
                DropdownMenuItem(value: 'size', child: Text(tr('크기'))),
                DropdownMenuItem(value: 'installed', child: Text(tr('설치일'))),
              ],
              onChanged: (v) => setState(() => _sort = v!),
            ),
          ]),
        ),
        if (_error != null) Padding(padding: const EdgeInsets.all(16), child: Text(_error!, style: TextStyle(color: JjColors.danger))),
        if (apps == null && _error == null) const Expanded(child: Center(child: CircularProgressIndicator())),
        if (apps != null)
          Expanded(
            child: ListView.builder(
              itemCount: _shown.length,
              itemBuilder: (_, i) {
                final a = _shown[i];
                return ListTile(
                  leading: SizedBox(
                    width: 40,
                    height: 40,
                    child: FutureBuilder<Uint8List?>(
                      future: _icons[a.package] ??= widget.backend.icon(a.package).catchError((_) => null),
                      builder: (_, s) => s.data == null ? const Icon(Icons.android) : Image.memory(s.data!, width: 40, height: 40),
                    ),
                  ),
                  title: Text(a.label, maxLines: 1, overflow: TextOverflow.ellipsis),
                  subtitle: Text([if (a.version.isNotEmpty) a.version, formatSize(a.size), trf('설치 {0}', [_day(a.installed)])].join(' · '),
                      maxLines: 1, overflow: TextOverflow.ellipsis),
                  trailing: IconButton(tooltip: tr('더 보기'), icon: const Icon(Icons.more_vert), onPressed: () => _menu(a)),
                  onTap: () => _menu(a),
                );
              },
            ),
          ),
      ]),
    );
  }
}