import 'dart:typed_data';

import 'package:flutter/material.dart';

import '../models.dart';
import '../services/api_service.dart';
import '../services/auth_service.dart';
import '../services/update_service.dart';
import '../widgets/server_card.dart';
import 'server_detail_screen.dart';
import 'settings_screen.dart';

class ServersScreen extends StatefulWidget {
  const ServersScreen({
    super.key,
    required this.auth,
    required this.api,
    required this.onLoggedOut,
  });
  final AuthService auth;
  final ApiService api;
  final VoidCallback onLoggedOut;

  @override
  State<ServersScreen> createState() => _ServersScreenState();
}

class _ServersScreenState extends State<ServersScreen> {
  List<GameServer>? _servers;
  String? _error;
  final _busy = <String>{};
  final _imgCache = <String, Uint8List?>{};

  Future<Uint8List?> _image(GameServer s) async {
    if (!s.hasImage) return null;
    if (_imgCache.containsKey(s.id)) return _imgCache[s.id];
    final b = await widget.api.imageBytes(s.id).catchError((_) => null);
    _imgCache[s.id] = b;
    return b;
  }

  @override
  void initState() {
    super.initState();
    _refresh();
    _checkUpdate();
  }

  Future<void> _refresh() async {
    try {
      final servers = await widget.api.servers();
      if (mounted) setState(() {
        _servers = servers;
        _error = null;
        _imgCache.clear(); // recharge les images (elles ont pu changer)
      });
    } on UnauthorizedException {
      await widget.auth.logout();
      widget.onLoggedOut();
    } catch (e) {
      if (mounted) setState(() => _error = '$e');
    }
  }

  Future<void> _toggle(GameServer s) async {
    setState(() => _busy.add(s.id));
    try {
      s.isUp ? await widget.api.stop(s.id) : await widget.api.start(s.id);
      await Future.delayed(const Duration(seconds: 2));
      await _refresh();
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('$e')));
      }
    } finally {
      if (mounted) setState(() => _busy.remove(s.id));
    }
  }

  Future<void> _checkUpdate() async {
    final info = await UpdateService(widget.api.baseUrl).check();
    if (info == null || !mounted) return;
    final go = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: Text('Mise à jour ${info.version}'),
        content: Text(info.notes.isEmpty ? 'Une nouvelle version est disponible.' : info.notes),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('Plus tard')),
          FilledButton(onPressed: () => Navigator.pop(ctx, true), child: const Text('Installer')),
        ],
      ),
    );
    if (go != true || !mounted) return;

    final progress = ValueNotifier<double?>(0);
    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (_) => AlertDialog(
        title: const Text('Téléchargement…'),
        content: ValueListenableBuilder<double?>(
          valueListenable: progress,
          builder: (_, p, __) => Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              LinearProgressIndicator(value: p),
              const SizedBox(height: 10),
              Text(p == null ? '' : '${(p * 100).round()} %'),
            ],
          ),
        ),
      ),
    );

    final ok = await UpdateService(widget.api.baseUrl)
        .apply(info, onProgress: (p) => progress.value = p);
    if (mounted) Navigator.of(context, rootNavigator: true).pop(); // ferme la progression
    if (mounted && !ok) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Mise à jour impossible.')),
      );
    }
  }

  Future<void> _openDetail(GameServer s) async {
    await Navigator.push(context,
        MaterialPageRoute(builder: (_) => ServerDetailScreen(server: s, api: widget.api)));
    _refresh();
  }

  Future<void> _openSettings() async {
    await Navigator.push(context,
        MaterialPageRoute(builder: (_) => SettingsScreen(api: widget.api)));
    _refresh();
  }

  Future<void> _logout() async {
    await widget.auth.logout();
    widget.onLoggedOut();
  }

  @override
  Widget build(BuildContext context) {
    return DefaultTabController(
      length: 2,
      child: Scaffold(
        appBar: AppBar(
          title: const Text('Serveurs'),
          actions: [
            IconButton(onPressed: _openSettings, icon: const Icon(Icons.settings_outlined)),
            IconButton(onPressed: _logout, icon: const Icon(Icons.logout)),
          ],
          bottom: const TabBar(
            tabs: [
              Tab(icon: Icon(Icons.public), text: 'Production'),
              Tab(icon: Icon(Icons.science_outlined), text: 'Preprod'),
            ],
          ),
        ),
        body: _buildBody(),
      ),
    );
  }

  Widget _buildBody() {
    if (_error != null && _servers == null) {
      return ListView(children: [
        const SizedBox(height: 120),
        Icon(Icons.cloud_off, size: 60, color: Theme.of(context).colorScheme.outline),
        const SizedBox(height: 12),
        Center(child: Text('Connexion à l\'API impossible.\n$_error', textAlign: TextAlign.center)),
        const SizedBox(height: 12),
        Center(child: FilledButton(onPressed: _refresh, child: const Text('Réessayer'))),
      ]);
    }
    if (_servers == null) {
      return const Center(child: CircularProgressIndicator());
    }

    final prod = _servers!.where((s) => !s.isPreprod).toList();
    final preprod = _servers!.where((s) => s.isPreprod).toList();

    return TabBarView(
      children: [_envList(prod), _envList(preprod)],
    );
  }

  Widget _envList(List<GameServer> list) {
    return RefreshIndicator(
      onRefresh: _refresh,
      child: list.isEmpty
          ? ListView(children: const [
              SizedBox(height: 120),
              Center(child: Text('Aucun serveur dans cet environnement.')),
            ])
          : ListView(
              padding: const EdgeInsets.fromLTRB(16, 12, 16, 24),
              children: list.map(_card).toList(),
            ),
    );
  }

  Widget _card(GameServer s) => Padding(
        padding: const EdgeInsets.only(bottom: 14),
        child: FutureBuilder<Uint8List?>(
          future: _image(s),
          builder: (_, snap) => ServerCard(
            server: s,
            iconUrl: '',
            imageBytes: snap.data,
            busy: _busy.contains(s.id),
            onToggle: () => _toggle(s),
            onTap: () => _openDetail(s),
          ),
        ),
      );
}