import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:web_socket_channel/web_socket_channel.dart';

void main() {
  runApp(const WirelessTextSyncerApp());
}

class WirelessTextSyncerApp extends StatelessWidget {
  const WirelessTextSyncerApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'WirelessTextSyncer',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: const Color(0xFF2563EB)),
        useMaterial3: true,
      ),
      home: const InputSyncPage(),
    );
  }
}

class InputSyncPage extends StatefulWidget {
  const InputSyncPage({super.key});

  @override
  State<InputSyncPage> createState() => _InputSyncPageState();
}

class _InputSyncPageState extends State<InputSyncPage> {
  static const _hostKey = 'server_host';
  static const _portKey = 'server_port';

  final hostController = TextEditingController();
  final portController = TextEditingController(text: '8181');
  final inputController = TextEditingController();
  final inputFocusNode = FocusNode();

  WebSocketChannel? channel;
  String lastText = '';
  bool connected = false;

  @override
  void initState() {
    super.initState();
    _loadSavedConnection();
    inputController.addListener(_syncTextChange);
  }

  @override
  void dispose() {
    channel?.sink.close();
    hostController.dispose();
    portController.dispose();
    inputController.dispose();
    inputFocusNode.dispose();
    super.dispose();
  }

  Future<void> _loadSavedConnection() async {
    final prefs = await SharedPreferences.getInstance();
    hostController.text = prefs.getString(_hostKey) ?? '';
    portController.text = prefs.getString(_portKey) ?? '8181';
  }

  Future<void> _connect() async {
    final host = hostController.text.trim();
    final port = portController.text.trim();
    if (host.isEmpty || port.isEmpty) {
      return;
    }

    final prefs = await SharedPreferences.getInstance();
    await prefs.setString(_hostKey, host);
    await prefs.setString(_portKey, port);

    channel?.sink.close();
    channel = WebSocketChannel.connect(Uri.parse('ws://$host:$port'));

    setState(() {
      connected = true;
    });
    inputFocusNode.requestFocus();
  }

  void _disconnect() {
    channel?.sink.close();
    channel = null;
    setState(() {
      connected = false;
    });
  }

  void _syncTextChange() {
    final currentText = inputController.text;
    if (!connected || channel == null || currentText == lastText) {
      lastText = currentText;
      return;
    }

    if (currentText.length > lastText.length &&
        currentText.startsWith(lastText)) {
      _send('insertText', text: currentText.substring(lastText.length));
    } else if (lastText.length == currentText.length + 1 &&
        lastText.startsWith(currentText)) {
      _send('backspace');
    } else {
      _send('insertText', text: currentText);
    }

    lastText = currentText;
  }

  void _send(String action, {String? text}) {
    channel?.sink.add(jsonEncode({'action': action, 'text': ?text}));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Column(
          children: [
            Padding(
              padding: const EdgeInsets.all(12),
              child: Row(
                children: [
                  Expanded(
                    flex: 3,
                    child: TextField(
                      controller: hostController,
                      decoration: const InputDecoration(
                        labelText: 'Windows IP',
                        border: OutlineInputBorder(),
                        isDense: true,
                      ),
                      keyboardType: TextInputType.number,
                    ),
                  ),
                  const SizedBox(width: 8),
                  Expanded(
                    child: TextField(
                      controller: portController,
                      decoration: const InputDecoration(
                        labelText: 'Port',
                        border: OutlineInputBorder(),
                        isDense: true,
                      ),
                      keyboardType: TextInputType.number,
                    ),
                  ),
                  const SizedBox(width: 8),
                  IconButton.filledTonal(
                    tooltip: connected ? 'Disconnect' : 'Connect',
                    onPressed: connected ? _disconnect : _connect,
                    icon: Icon(connected ? Icons.link_off : Icons.link),
                  ),
                ],
              ),
            ),
            Expanded(
              child: TextField(
                controller: inputController,
                focusNode: inputFocusNode,
                autofocus: true,
                expands: true,
                maxLines: null,
                minLines: null,
                textAlignVertical: TextAlignVertical.top,
                decoration: const InputDecoration(
                  border: InputBorder.none,
                  contentPadding: EdgeInsets.all(16),
                  hintText: 'Type here',
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}