import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:stomp_dart_client/stomp_dart_client.dart';

import 'config/app_config.dart';
import 'pages/webview_home_page.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  final config = await AppConfig.load();
  runApp(SwyxApp(config: config));
}

class SwyxApp extends StatelessWidget {
  const SwyxApp({super.key, required this.config});

  final AppConfig config;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Swyx App',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.indigo),
        useMaterial3: true,
      ),
      home: WebViewHomePage(config: config),
    );
  }
}

enum StompState { disconnected, connecting, connected, error }

class StompDemoPage extends StatefulWidget {
  const StompDemoPage({super.key, required this.config});

  final AppConfig config;

  @override
  State<StompDemoPage> createState() => _StompDemoPageState();
}

class _StompDemoPageState extends State<StompDemoPage> {
  late final TextEditingController _urlController =
      TextEditingController(text: widget.config.stompUrl);
  late final TextEditingController _topicController =
      TextEditingController(text: widget.config.defaultTopic);
  late final TextEditingController _destinationController =
      TextEditingController(text: widget.config.defaultDestination);
  late final TextEditingController _payloadController =
      TextEditingController(text: widget.config.defaultPayload);
  final ScrollController _logScroll = ScrollController();

  final List<_LogEntry> _log = [];
  final Map<String, void Function()> _subscriptions = {};
  StompClient? _client;
  StompState _state = StompState.disconnected;
  String? _lastError;

  @override
  void dispose() {
    _disconnect();
    _urlController.dispose();
    _topicController.dispose();
    _destinationController.dispose();
    _payloadController.dispose();
    _logScroll.dispose();
    super.dispose();
  }

  void _connect() {
    final url = _urlController.text.trim();
    if (url.isEmpty) return;
    setState(() {
      _state = StompState.connecting;
      _lastError = null;
    });
    final client = StompClient(
      config: StompConfig(
        url: url,
        onConnect: _onConnect,
        onWebSocketError: (dynamic e) {
          _appendLog(_LogEntry.error('ws error: $e'));
          setState(() {
            _state = StompState.error;
            _lastError = e.toString();
          });
        },
        onStompError: (StompFrame f) {
          _appendLog(_LogEntry.error(
              'stomp error: ${f.headers['message']} — ${f.body}'));
          setState(() => _state = StompState.error);
        },
        onDisconnect: (StompFrame f) {
          _appendLog(_LogEntry.system('disconnected'));
          if (mounted) setState(() => _state = StompState.disconnected);
        },
        onWebSocketDone: () {
          _appendLog(_LogEntry.system('websocket closed'));
          if (mounted && _state != StompState.error) {
            setState(() => _state = StompState.disconnected);
          }
        },
        reconnectDelay: widget.config.reconnectDelay,
      ),
    );
    client.activate();
    _client = client;
  }

  void _onConnect(StompFrame frame) {
    _appendLog(_LogEntry.system('STOMP connected (server=${frame.headers['server'] ?? '?'})'));
    if (mounted) setState(() => _state = StompState.connected);
  }

  Future<void> _disconnect() async {
    for (final unsub in _subscriptions.values) {
      unsub();
    }
    _subscriptions.clear();
    _client?.deactivate();
    _client = null;
    if (mounted) {
      setState(() => _state = StompState.disconnected);
    }
  }

  void _subscribe() {
    final client = _client;
    if (client == null || _state != StompState.connected) return;
    final topic = _topicController.text.trim();
    if (topic.isEmpty || _subscriptions.containsKey(topic)) return;
    final unsub = client.subscribe(
      destination: topic,
      callback: (StompFrame frame) {
        final body = frame.body ?? '';
        String pretty = body;
        try {
          pretty = const JsonEncoder.withIndent('  ').convert(jsonDecode(body));
        } catch (_) {}
        _appendLog(_LogEntry.incoming(topic, pretty));
      },
    );
    setState(() => _subscriptions[topic] = unsub);
    _appendLog(_LogEntry.system('subscribed to $topic'));
  }

  void _unsubscribe(String topic) {
    final unsub = _subscriptions.remove(topic);
    unsub?.call();
    setState(() {});
    _appendLog(_LogEntry.system('unsubscribed $topic'));
  }

  void _send() {
    final client = _client;
    if (client == null || _state != StompState.connected) return;
    final destination = _destinationController.text.trim();
    final payload = _payloadController.text.trim();
    if (destination.isEmpty || payload.isEmpty) return;
    try {
      jsonDecode(payload);
    } catch (e) {
      _appendLog(_LogEntry.error('not valid JSON: $e'));
      return;
    }
    client.send(
      destination: destination,
      body: payload,
      headers: {'content-type': 'application/json'},
    );
    _appendLog(_LogEntry.outgoing(destination, payload));
  }

  void _appendLog(_LogEntry entry) {
    setState(() => _log.add(entry));
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (_logScroll.hasClients) {
        _logScroll.animateTo(
          _logScroll.position.maxScrollExtent,
          duration: const Duration(milliseconds: 200),
          curve: Curves.easeOut,
        );
      }
    });
  }

  Color _statusColor() {
    switch (_state) {
      case StompState.connected:
        return Colors.green;
      case StompState.connecting:
        return Colors.orange;
      case StompState.error:
        return Colors.red;
      case StompState.disconnected:
        return Colors.grey;
    }
  }

  String _statusLabel() {
    switch (_state) {
      case StompState.connected:
        return 'verbunden';
      case StompState.connecting:
        return 'verbinde…';
      case StompState.error:
        return 'Fehler';
      case StompState.disconnected:
        return 'getrennt';
    }
  }

  @override
  Widget build(BuildContext context) {
    final isConnected = _state == StompState.connected;
    return Scaffold(
      appBar: AppBar(
        title: const Text('Swyx – STOMP'),
        actions: [
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 12),
            child: Row(children: [
              Icon(Icons.circle, size: 12, color: _statusColor()),
              const SizedBox(width: 6),
              Text(_statusLabel()),
            ]),
          ),
        ],
      ),
      body: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Row(children: [
              Expanded(
                child: TextField(
                  controller: _urlController,
                  enabled: !isConnected && _state != StompState.connecting,
                  decoration: const InputDecoration(
                    labelText: 'STOMP URL',
                    border: OutlineInputBorder(),
                  ),
                ),
              ),
              const SizedBox(width: 8),
              FilledButton.icon(
                onPressed: isConnected ? _disconnect : _connect,
                icon: Icon(isConnected ? Icons.link_off : Icons.link),
                label: Text(isConnected ? 'Trennen' : 'Verbinden'),
              ),
            ]),
            if (_lastError != null) ...[
              const SizedBox(height: 8),
              Text(_lastError!,
                  style: const TextStyle(color: Colors.red, fontSize: 12)),
            ],
            const SizedBox(height: 16),
            _sectionTitle('Abonnements'),
            Row(children: [
              Expanded(
                child: TextField(
                  controller: _topicController,
                  decoration: const InputDecoration(
                    labelText: 'Topic',
                    border: OutlineInputBorder(),
                    isDense: true,
                  ),
                ),
              ),
              const SizedBox(width: 8),
              FilledButton.tonalIcon(
                onPressed: isConnected ? _subscribe : null,
                icon: const Icon(Icons.add),
                label: const Text('Subscribe'),
              ),
            ]),
            const SizedBox(height: 8),
            Wrap(
              spacing: 6,
              runSpacing: 4,
              children: [
                for (final t in widget.config.topicPresets)
                  ActionChip(
                    label: Text(t, style: const TextStyle(fontSize: 11)),
                    onPressed: () => _topicController.text = t,
                  ),
              ],
            ),
            const SizedBox(height: 8),
            if (_subscriptions.isNotEmpty)
              Wrap(
                spacing: 6,
                runSpacing: 4,
                children: [
                  for (final t in _subscriptions.keys)
                    InputChip(
                      label: Text(t, style: const TextStyle(fontSize: 11)),
                      onDeleted: () => _unsubscribe(t),
                    ),
                ],
              ),
            const SizedBox(height: 16),
            Expanded(
              child: Container(
                padding: const EdgeInsets.all(8),
                decoration: BoxDecoration(
                  color: Theme.of(context).colorScheme.surfaceContainerHighest,
                  borderRadius: BorderRadius.circular(8),
                ),
                child: ListView.builder(
                  controller: _logScroll,
                  itemCount: _log.length,
                  itemBuilder: (context, i) => _LogTile(entry: _log[i]),
                ),
              ),
            ),
            const SizedBox(height: 12),
            _sectionTitle('Senden'),
            TextField(
              controller: _destinationController,
              decoration: const InputDecoration(
                labelText: 'Destination (z.B. /app/ping)',
                border: OutlineInputBorder(),
                isDense: true,
              ),
            ),
            const SizedBox(height: 8),
            TextField(
              controller: _payloadController,
              minLines: 2,
              maxLines: 5,
              style: const TextStyle(fontFamily: 'monospace'),
              decoration: const InputDecoration(
                labelText: 'JSON Payload',
                border: OutlineInputBorder(),
              ),
            ),
            const SizedBox(height: 8),
            Row(children: [
              FilledButton.icon(
                onPressed: isConnected ? _send : null,
                icon: const Icon(Icons.send),
                label: const Text('Senden'),
              ),
              const SizedBox(width: 8),
              TextButton.icon(
                onPressed: () => setState(_log.clear),
                icon: const Icon(Icons.clear_all),
                label: const Text('Log leeren'),
              ),
            ]),
          ],
        ),
      ),
    );
  }

  Widget _sectionTitle(String text) => Padding(
        padding: const EdgeInsets.only(bottom: 6),
        child: Text(text,
            style: Theme.of(context).textTheme.titleSmall?.copyWith(
                  color: Theme.of(context).colorScheme.primary,
                )),
      );
}

enum _LogKind { incoming, outgoing, system, error }

class _LogEntry {
  final DateTime timestamp;
  final _LogKind kind;
  final String destination;
  final String text;

  _LogEntry(this.kind, this.destination, this.text)
      : timestamp = DateTime.now();

  factory _LogEntry.incoming(String dest, String s) =>
      _LogEntry(_LogKind.incoming, dest, s);
  factory _LogEntry.outgoing(String dest, String s) =>
      _LogEntry(_LogKind.outgoing, dest, s);
  factory _LogEntry.system(String s) => _LogEntry(_LogKind.system, '', s);
  factory _LogEntry.error(String s) => _LogEntry(_LogKind.error, '', s);
}

class _LogTile extends StatelessWidget {
  const _LogTile({required this.entry});

  final _LogEntry entry;

  @override
  Widget build(BuildContext context) {
    final (icon, color, prefix) = switch (entry.kind) {
      _LogKind.incoming => (Icons.arrow_downward, Colors.green, '<-'),
      _LogKind.outgoing => (Icons.arrow_upward, Colors.blue, '->'),
      _LogKind.system => (Icons.info_outline, Colors.grey, '*'),
      _LogKind.error => (Icons.error_outline, Colors.red, '!'),
    };
    final time = entry.timestamp.toIso8601String().substring(11, 19);
    final header = entry.destination.isEmpty
        ? '$time $prefix '
        : '$time $prefix ${entry.destination} ';
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Icon(icon, size: 16, color: color),
          const SizedBox(width: 8),
          Text(header,
              style: TextStyle(
                  fontFamily: 'monospace', color: color, fontSize: 12)),
          Expanded(
            child: SelectableText(
              entry.text,
              style: const TextStyle(fontFamily: 'monospace', fontSize: 12),
            ),
          ),
        ],
      ),
    );
  }
}