import 'dart:async';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:path/path.dart' as p;

import '../app/app_controller.dart';
import '../core/dlna.dart';
import '../core/file_ops.dart' show formatSize;
import '../core/reader_sources.dart';
import '../l10n/tr.dart';
import 'player_page.dart';
import 'reader_page.dart' show openReader;
import 'theme.dart';

/// X-plore 비교 5-2 (사용자 결정 10/21 "DLNA 보기만"): 같은 Wi-Fi 의 미디어 서버 보기 · 재생 (서버 · 올리기 · 지우기 없음)
Future<void> openDlna(BuildContext context, AppController c) =>
    Navigator.of(context).push(MaterialPageRoute<void>(builder: (_) => DlnaPage(c: c)));

class DlnaPage extends StatefulWidget {
  final AppController c;

  /// 시험: 찾기 · 읽기를 바꿔 끼움
  final Future<List<DlnaServer>> Function()? discover;
  final Future<DlnaResult> Function(DlnaServer s, String id, int start)? browse;
  const DlnaPage({super.key, required this.c, this.discover, this.browse});

  @override
  State<DlnaPage> createState() => _DlnaPageState();
}

/// [dlnaBrowse] 의 결과 (시험에서 만들 수 있게)
typedef DlnaResult = ({List<DlnaEntry> entries, int total});

class _DlnaPageState extends State<DlnaPage> {
  List<DlnaServer>? _servers;
  bool _finding = false;
  DlnaServer? _server;

  /// 들어간 폴더들 (id, 이름) - 맨 앞은 뿌리
  final _path = <(String, String)>[];
  List<DlnaEntry> _entries = const [];
  int _total = 0;
  bool _loading = false;
  String? _error;

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

  Future<void> _find() async {
    setState(() {
      _finding = true;
      _error = null;
    });
    try {
      final list = await (widget.discover ?? discoverDlna)();
      if (mounted) setState(() => _servers = list);
    } catch (e) {
      if (mounted) setState(() => _error = trf('찾지 못했습니다: {0}', [e]));
    } finally {
      if (mounted) setState(() => _finding = false);
    }
  }

  Future<DlnaResult> _browse(DlnaServer s, String id, int start) async {
    if (widget.browse != null) return widget.browse!(s, id, start);
    final page = await dlnaBrowse(s, objectId: id, start: start);
    return (entries: page.entries, total: page.total);
  }

  Future<void> _open(DlnaServer s, String id, String name, {bool push = true}) async {
    setState(() {
      _server = s;
      if (push) _path.add((id, name));
      _entries = const [];
      _loading = true;
      _error = null;
    });
    try {
      final r = await _browse(s, id, 0);
      if (!mounted) return;
      setState(() {
        _entries = r.entries;
        _total = r.total;
      });
    } catch (e) {
      if (mounted) setState(() => _error = trf('서버에서 목록을 읽지 못했습니다: {0}', [e]));
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  Future<void> _more() async {
    final s = _server!;
    setState(() => _loading = true);
    try {
      final r = await _browse(s, _path.last.$1, _entries.length);
      if (mounted) setState(() => _entries = [..._entries, ...r.entries]);
    } catch (e) {
      if (mounted) setState(() => _error = trf('서버에서 목록을 읽지 못했습니다: {0}', [e]));
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  void _up() {
    if (_path.length > 1) {
      _path.removeLast();
      unawaited(_open(_server!, _path.last.$1, _path.last.$2, push: false));
    } else {
      setState(() {
        _server = null;
        _path.clear();
        _entries = const [];
      });
    }
  }

  Future<void> _tap(DlnaEntry e) async {
    if (e.isContainer) return _open(_server!, e.id, e.title);
    final url = e.url;
    if (url == null) {
      _snack(tr('이 항목은 같은 망 밖의 주소라 열지 않습니다'));
      return;
    }
    switch (e.kind) {
      case 'video' || 'audio':
        // 같은 폴더의 같은 종류를 차례대로 (다음 화로 넘어가게)
        final list = [for (final x in _entries) if (!x.isContainer && x.url != null && x.kind == e.kind) x];
        final create = widget.c.services.createMediaPlayer;
        if (create == null) return;
        await Navigator.of(context).push(MaterialPageRoute<void>(
            builder: (_) => PlayerPage(c: widget.c, player: create(), files: [for (final x in list) x.url!], start: list.indexOf(e))));
      case 'image':
        await _viewImage(e);
      default:
        _snack(tr('볼 수 없는 종류입니다'));
    }
  }

  /// 그림은 임시로 받아서 보기 화면으로 (50MB 까지)
  Future<void> _viewImage(DlnaEntry e) async {
    try {
      final dir = Directory(p.join(await widget.c.services.storage.tempDirectory(), 'jj_dlna'));
      await dir.create(recursive: true);
      final ext = switch (e.mime) { 'image/png' => '.png', 'image/gif' => '.gif', 'image/webp' => '.webp', _ => '.jpg' };
      final out = File(p.join(dir.path, 'view$ext'));
      final client = HttpClient()..connectionTimeout = const Duration(seconds: 5);
      try {
        final res = await (await client.getUrl(Uri.parse(e.url!))).close();
        if (res.statusCode >= 300) throw HttpException('HTTP ${res.statusCode}');
        final sink = out.openWrite();
        var n = 0;
        await for (final chunk in res) {
          n += chunk.length;
          if (n > 50 * 1024 * 1024) throw const HttpException('too big');
          sink.add(chunk);
        }
        await sink.close();
      } finally {
        client.close(force: true);
      }
      if (!mounted) return;
      await openReader(context, widget.c, ImageFilesSource([out.path], tempDir: dir.path, title: e.title));
    } catch (err) {
      _snack(trf('열 수 없습니다: {0}', [err]));
    }
  }

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

  IconData _icon(DlnaEntry e) => e.isContainer
      ? Icons.folder
      : switch (e.kind) { 'video' => Icons.movie_outlined, 'audio' => Icons.audiotrack_outlined, 'image' => Icons.image_outlined, _ => Icons.insert_drive_file_outlined };

  String _d(Duration d) => [if (d.inHours > 0) '${d.inHours}', (d.inMinutes % 60).toString().padLeft(d.inHours > 0 ? 2 : 1, '0'), (d.inSeconds % 60).toString().padLeft(2, '0')].join(':');

  @override
  Widget build(BuildContext context) {
    final s = _server;
    return PopScope(
      canPop: s == null,
      onPopInvokedWithResult: (didPop, _) {
        if (!didPop) _up();
      },
      child: Scaffold(
        appBar: AppBar(
          title: Text(s == null ? tr('미디어 서버 (DLNA)') : [s.name, ..._path.skip(1).map((x) => x.$2)].join(' / '),
              maxLines: 1, overflow: TextOverflow.ellipsis),
          leading: s == null ? null : IconButton(tooltip: tr('뒤로'), icon: const Icon(Icons.arrow_back), onPressed: _up),
          actions: [
            if (s == null)
              IconButton(tooltip: tr('다시 찾기'), icon: const Icon(Icons.refresh), onPressed: _finding ? null : _find),
          ],
        ),
        body: Column(crossAxisAlignment: CrossAxisAlignment.stretch, children: [
          Padding(
            padding: const EdgeInsets.fromLTRB(16, 8, 16, 4),
            child: Text(tr('보기만 합니다 - 같은 Wi-Fi · 유선 망의 미디어 서버만 찾고, 올리기 · 지우기는 없습니다'),
                style: TextStyle(fontSize: 12, color: JjColors.textDim)),
          ),
          if (_error != null) Padding(padding: const EdgeInsets.all(16), child: Text(_error!, style: TextStyle(color: JjColors.danger))),
          if (s == null) Expanded(child: _serverList()) else Expanded(child: _entryList()),
        ]),
      ),
    );
  }

  Widget _serverList() {
    final list = _servers;
    if (_finding && (list == null || list.isEmpty)) {
      return Center(
        child: Column(mainAxisSize: MainAxisSize.min, children: [
          const CircularProgressIndicator(),
          const SizedBox(height: 12),
          Text(tr('같은 망의 미디어 서버를 찾는 중 …')),
        ]),
      );
    }
    if (list == null || list.isEmpty) {
      return Center(
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: Text(tr('미디어 서버를 찾지 못했습니다. Wi-Fi · 유선에 연결돼 있는지, 서버 (NAS 의 미디어 서버 등) 가 켜져 있는지 확인하세요'),
              textAlign: TextAlign.center),
        ),
      );
    }
    return ListView(children: [
      for (final x in list)
        ListTile(
          leading: const Icon(Icons.dns_outlined),
          title: Text(x.name),
          subtitle: Text(x.host, style: TextStyle(color: JjColors.textDim)),
          onTap: () => _open(x, '0', x.name),
        ),
    ]);
  }

  Widget _entryList() {
    if (_loading && _entries.isEmpty) return const Center(child: CircularProgressIndicator());
    if (!_loading && _entries.isEmpty && _error == null) return Center(child: Text(tr('비어 있음')));
    return ListView.builder(
      itemCount: _entries.length + (_entries.length < _total ? 1 : 0),
      itemBuilder: (_, i) {
        if (i == _entries.length) {
          return Padding(
            padding: const EdgeInsets.all(8),
            child: OutlinedButton(onPressed: _loading ? null : _more, child: Text(trf('더 보기 ({0} / {1})', [_entries.length, _total]))),
          );
        }
        final e = _entries[i];
        return ListTile(
          dense: true,
          leading: Icon(_icon(e), color: e.isContainer ? JjColors.amber : JjColors.textDim),
          title: Text(e.title, maxLines: 1, overflow: TextOverflow.ellipsis),
          subtitle: e.isContainer
              ? (e.childCount == null ? null : Text(trf('{0}개', [e.childCount!])))
              : Text([if (e.size != null) formatSize(e.size!), if (e.duration != null) _d(e.duration!), if (e.url == null) tr('열 수 없음')].join(' · ')),
          onTap: () => _tap(e),
        );
      },
    );
  }
}