import 'dart:async';
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)),
        scaffoldBackgroundColor: const Color(0xFFF8FAFC),
        useMaterial3: true,
      ),
      home: const InputSyncPage(),
    );
  }
}

enum SendButtonState { idle, sending, success }

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

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

class _InputSyncPageState extends State<InputSyncPage>
    with SingleTickerProviderStateMixin {
  static const _hostKey = 'server_host';
  static const _portKey = 'server_port';
  static const _historyKey = 'send_history';
  static const _clearAfterSendKey = 'clear_after_send';
  static const _appendEnterKey = 'append_enter';
  static const _maxHistoryItems = 10;

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

  late final AnimationController statusPulseController;
  WebSocketChannel? channel;
  StreamSubscription<dynamic>? channelSubscription;
  List<String> sendHistory = [];
  SendButtonState sendButtonState = SendButtonState.idle;
  bool appendEnter = false;
  bool clearAfterSend = false;
  bool connected = false;
  bool headerExpanded = true;
  bool inputFocused = false;

  @override
  void initState() {
    super.initState();
    statusPulseController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 1300),
      lowerBound: 0.55,
      upperBound: 1,
    )..repeat(reverse: true);
    inputController.addListener(_handleDraftChanged);
    inputFocusNode.addListener(_handleFocusChanged);
    _loadSavedState();
  }

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

  Future<void> _loadSavedState() async {
    final prefs = await SharedPreferences.getInstance();
    if (!mounted) {
      return;
    }

    setState(() {
      hostController.text = prefs.getString(_hostKey) ?? '';
      portController.text = prefs.getString(_portKey) ?? '8181';
      clearAfterSend = prefs.getBool(_clearAfterSendKey) ?? false;
      appendEnter = prefs.getBool(_appendEnterKey) ?? false;
      sendHistory = prefs.getStringList(_historyKey) ?? [];
    });
  }

  void _handleDraftChanged() {
    setState(() {});
  }

  void _handleFocusChanged() {
    setState(() {
      inputFocused = inputFocusNode.hasFocus;
    });
  }

  Future<void> _connect() async {
    final host = hostController.text.trim();
    final port = portController.text.trim();
    if (host.isEmpty || port.isEmpty) {
      _showToast('请先填写 Windows IP 和端口');
      setState(() {
        headerExpanded = true;
      });
      return;
    }

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

    await channelSubscription?.cancel();
    await channel?.sink.close();

    try {
      final nextChannel = WebSocketChannel.connect(
        Uri.parse('ws://$host:$port'),
      );
      channel = nextChannel;
      channelSubscription = nextChannel.stream.listen(
        (_) {},
        onError: (_) => _markDisconnected(expandHeader: true, message: '连接已断开'),
        onDone: () => _markDisconnected(expandHeader: true, message: '连接已断开'),
      );

      setState(() {
        connected = true;
        headerExpanded = false;
      });
      _showToast('成功连接到 Windows 桌面端');
      inputFocusNode.requestFocus();
    } catch (_) {
      _markDisconnected(expandHeader: true, message: '连接失败，请检查地址');
    }
  }

  Future<void> _disconnect() async {
    await channelSubscription?.cancel();
    await channel?.sink.close();
    _markDisconnected(expandHeader: true, message: '已断开连接');
  }

  void _markDisconnected({required bool expandHeader, String? message}) {
    if (!mounted) {
      return;
    }

    channel = null;
    channelSubscription = null;
    setState(() {
      connected = false;
      headerExpanded = expandHeader;
      sendButtonState = SendButtonState.idle;
    });

    if (message != null) {
      _showToast(message);
    }
  }

  Future<void> _sendCurrentText() async {
    if (!_canSend) {
      return;
    }

    final channel = this.channel;
    final draft = inputController.text;
    final textToSend = appendEnter ? '$draft\n' : draft;

    if (channel == null) {
      _markDisconnected(expandHeader: true, message: '未连接到桌面端');
      return;
    }

    setState(() {
      sendButtonState = SendButtonState.sending;
    });

    try {
      channel.sink.add(
        jsonEncode({'action': 'replaceAll', 'text': textToSend}),
      );
      await _saveHistory(draft);

      if (clearAfterSend) {
        inputController.clear();
      }

      if (!mounted) {
        return;
      }

      setState(() {
        sendButtonState = SendButtonState.success;
      });
      await Future<void>.delayed(const Duration(milliseconds: 1500));
      if (mounted) {
        setState(() {
          sendButtonState = SendButtonState.idle;
        });
        inputFocusNode.requestFocus();
      }
    } catch (_) {
      _markDisconnected(expandHeader: true, message: '发送失败，连接已断开');
    }
  }

  Future<void> _saveHistory(String text) async {
    final trimmed = text.trim();
    if (trimmed.isEmpty) {
      return;
    }

    final nextHistory = [
      text,
      ...sendHistory.where((item) => item != text),
    ].take(_maxHistoryItems).toList();
    final prefs = await SharedPreferences.getInstance();
    await prefs.setStringList(_historyKey, nextHistory);

    if (mounted) {
      setState(() {
        sendHistory = nextHistory;
      });
    }
  }

  Future<void> _setClearAfterSend(bool value) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_clearAfterSendKey, value);
    setState(() {
      clearAfterSend = value;
    });
  }

  Future<void> _setAppendEnter(bool value) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_appendEnterKey, value);
    setState(() {
      appendEnter = value;
    });
  }

  void _restoreHistory(String text) {
    inputController.text = text;
    inputController.selection = TextSelection.collapsed(offset: text.length);
    Navigator.of(context).pop();
    _showToast('已从历史记录恢复');
    inputFocusNode.requestFocus();
  }

  void _showHistorySheet() {
    showModalBottomSheet<void>(
      context: context,
      showDragHandle: true,
      isScrollControlled: true,
      backgroundColor: Theme.of(context).colorScheme.surface,
      builder: (context) {
        return SafeArea(
          child: SizedBox(
            height: MediaQuery.of(context).size.height * 0.58,
            child: Column(
              children: [
                Padding(
                  padding: const EdgeInsets.fromLTRB(20, 0, 12, 10),
                  child: Row(
                    children: [
                      const Expanded(
                        child: Text(
                          '发送历史',
                          style: TextStyle(
                            fontSize: 18,
                            fontWeight: FontWeight.w700,
                          ),
                        ),
                      ),
                      IconButton(
                        tooltip: '关闭',
                        onPressed: () => Navigator.of(context).pop(),
                        icon: const Icon(Icons.close),
                      ),
                    ],
                  ),
                ),
                Expanded(
                  child: sendHistory.isEmpty
                      ? const _HistoryEmptyState()
                      : ListView.separated(
                          padding: const EdgeInsets.fromLTRB(16, 0, 16, 20),
                          itemBuilder: (context, index) {
                            final item = sendHistory[index];
                            return ListTile(
                              minVerticalPadding: 12,
                              shape: RoundedRectangleBorder(
                                borderRadius: BorderRadius.circular(8),
                              ),
                              tileColor: const Color(0xFFF8FAFC),
                              title: Text(
                                item,
                                maxLines: 3,
                                overflow: TextOverflow.ellipsis,
                              ),
                              subtitle: Text('${item.length} 字符'),
                              onTap: () => _restoreHistory(item),
                            );
                          },
                          separatorBuilder: (_, _) => const SizedBox(height: 8),
                          itemCount: sendHistory.length,
                        ),
                ),
              ],
            ),
          ),
        );
      },
    );
  }

  void _showToast(String message) {
    if (!mounted) {
      return;
    }

    ScaffoldMessenger.of(context)
      ..hideCurrentSnackBar()
      ..showSnackBar(
        SnackBar(
          behavior: SnackBarBehavior.floating,
          content: Text(message),
          duration: const Duration(milliseconds: 1600),
        ),
      );
  }

  bool get _canSend {
    return connected &&
        inputController.text.isNotEmpty &&
        sendButtonState != SendButtonState.sending;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      resizeToAvoidBottomInset: true,
      body: SafeArea(
        child: Column(
          children: [
            _buildHeader(context),
            Expanded(child: _buildDraftBoard(context)),
            _buildFooter(context),
          ],
        ),
      ),
    );
  }

  Widget _buildHeader(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;
    final statusText = connected
        ? '已连接: ${hostController.text.trim()}:${portController.text.trim()}'
        : '未连接 (点击配置)';

    return Material(
      color: colorScheme.surface,
      elevation: 1,
      child: AnimatedSize(
        duration: const Duration(milliseconds: 260),
        curve: Curves.easeOutCubic,
        child: Padding(
          padding: const EdgeInsets.fromLTRB(12, 8, 12, 10),
          child: Column(
            children: [
              InkWell(
                borderRadius: BorderRadius.circular(8),
                onTap: () {
                  setState(() {
                    headerExpanded = !headerExpanded;
                  });
                },
                child: SizedBox(
                  height: 44,
                  child: Row(
                    children: [
                      _ConnectionIndicator(
                        connected: connected,
                        animation: statusPulseController,
                      ),
                      const SizedBox(width: 10),
                      Expanded(
                        child: Text(
                          statusText,
                          overflow: TextOverflow.ellipsis,
                          style: TextStyle(
                            color: connected
                                ? const Color(0xFF166534)
                                : colorScheme.error,
                            fontWeight: FontWeight.w600,
                          ),
                        ),
                      ),
                      Icon(
                        headerExpanded
                            ? Icons.keyboard_arrow_up
                            : Icons.keyboard_arrow_down,
                      ),
                    ],
                  ),
                ),
              ),
              AnimatedCrossFade(
                firstChild: const SizedBox.shrink(),
                secondChild: Padding(
                  padding: const EdgeInsets.only(top: 8),
                  child: Row(
                    children: [
                      Expanded(
                        flex: 7,
                        child: TextField(
                          controller: hostController,
                          decoration: const InputDecoration(
                            labelText: 'IP 地址',
                            border: OutlineInputBorder(),
                            isDense: true,
                          ),
                          keyboardType: TextInputType.url,
                        ),
                      ),
                      const SizedBox(width: 8),
                      Expanded(
                        flex: 3,
                        child: TextField(
                          controller: portController,
                          decoration: const InputDecoration(
                            labelText: '端口',
                            border: OutlineInputBorder(),
                            isDense: true,
                          ),
                          keyboardType: TextInputType.number,
                        ),
                      ),
                      const SizedBox(width: 8),
                      IconButton.filledTonal(
                        tooltip: connected ? '断开连接' : '连接',
                        style: IconButton.styleFrom(
                          minimumSize: const Size(48, 48),
                          foregroundColor: connected
                              ? colorScheme.error
                              : colorScheme.primary,
                        ),
                        onPressed: connected ? _disconnect : _connect,
                        icon: Icon(connected ? Icons.link_off : Icons.link),
                      ),
                    ],
                  ),
                ),
                crossFadeState: headerExpanded
                    ? CrossFadeState.showSecond
                    : CrossFadeState.showFirst,
                duration: const Duration(milliseconds: 260),
                sizeCurve: Curves.easeOutCubic,
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildDraftBoard(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;

    return Padding(
      padding: const EdgeInsets.fromLTRB(12, 12, 12, 8),
      child: Column(
        children: [
          SizedBox(
            height: 44,
            child: Row(
              children: [
                Text(
                  '草稿板',
                  style: TextStyle(
                    color: colorScheme.onSurfaceVariant,
                    fontWeight: FontWeight.w600,
                  ),
                ),
                const Spacer(),
                IconButton(
                  tooltip: '历史记录',
                  onPressed: _showHistorySheet,
                  icon: const Icon(Icons.history),
                ),
                AnimatedSwitcher(
                  duration: const Duration(milliseconds: 180),
                  child: inputController.text.isEmpty
                      ? const SizedBox(width: 48, height: 48)
                      : IconButton(
                          key: const ValueKey('clear-draft'),
                          tooltip: '清空',
                          onPressed: inputController.clear,
                          icon: const Icon(Icons.delete_outline),
                        ),
                ),
              ],
            ),
          ),
          Expanded(
            child: AnimatedContainer(
              duration: const Duration(milliseconds: 180),
              curve: Curves.easeOut,
              decoration: BoxDecoration(
                color: colorScheme.surface,
                borderRadius: BorderRadius.circular(8),
                border: Border.all(
                  color: inputFocused
                      ? colorScheme.primary
                      : const Color(0xFFE2E8F0),
                  width: inputFocused ? 2 : 1,
                ),
              ),
              child: Stack(
                children: [
                  TextField(
                    controller: inputController,
                    focusNode: inputFocusNode,
                    autofocus: true,
                    expands: true,
                    maxLines: null,
                    minLines: null,
                    textAlignVertical: TextAlignVertical.top,
                    decoration: const InputDecoration(
                      border: InputBorder.none,
                      contentPadding: EdgeInsets.fromLTRB(16, 16, 16, 42),
                      hintText: '点击输入或语音录入... 发送后草稿会保留，方便随时修改',
                    ),
                    keyboardType: TextInputType.multiline,
                  ),
                  Positioned(
                    right: 14,
                    bottom: 10,
                    child: Text(
                      '${inputController.text.length} 字符',
                      style: TextStyle(
                        color: colorScheme.onSurfaceVariant.withValues(
                          alpha: 0.72,
                        ),
                        fontSize: 12,
                      ),
                    ),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildFooter(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;

    return Material(
      color: colorScheme.surface,
      elevation: 4,
      child: Padding(
        padding: const EdgeInsets.fromLTRB(12, 10, 12, 12),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Row(
              children: [
                Expanded(
                  child: _FooterToggle(
                    label: '发送后清空',
                    value: clearAfterSend,
                    onChanged: _setClearAfterSend,
                  ),
                ),
                const SizedBox(width: 8),
                Expanded(
                  child: _FooterToggle(
                    label: '追加回车',
                    value: appendEnter,
                    onChanged: _setAppendEnter,
                  ),
                ),
              ],
            ),
            const SizedBox(height: 10),
            SizedBox(
              width: double.infinity,
              height: 52,
              child: FilledButton.icon(
                onPressed: _canSend ? _sendCurrentText : null,
                style: FilledButton.styleFrom(
                  backgroundColor: sendButtonState == SendButtonState.success
                      ? const Color(0xFF16A34A)
                      : null,
                  disabledBackgroundColor: const Color(0xFFE2E8F0),
                  disabledForegroundColor: const Color(0xFF64748B),
                ),
                icon: _buildSendButtonIcon(),
                label: Text(
                  _sendButtonText,
                  style: const TextStyle(fontWeight: FontWeight.w700),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildSendButtonIcon() {
    return switch (sendButtonState) {
      SendButtonState.sending => const SizedBox(
        width: 18,
        height: 18,
        child: CircularProgressIndicator(strokeWidth: 2),
      ),
      SendButtonState.success => const Icon(Icons.check),
      SendButtonState.idle => const Icon(Icons.send),
    };
  }

  String get _sendButtonText {
    return switch (sendButtonState) {
      SendButtonState.sending => '发送中...',
      SendButtonState.success => '发送成功',
      SendButtonState.idle => '发送到电脑',
    };
  }
}

class _ConnectionIndicator extends StatelessWidget {
  const _ConnectionIndicator({
    required this.connected,
    required this.animation,
  });

  final bool connected;
  final Animation<double> animation;

  @override
  Widget build(BuildContext context) {
    if (!connected) {
      return const _StatusDot(color: Color(0xFFDC2626), scale: 1);
    }

    return AnimatedBuilder(
      animation: animation,
      builder: (context, child) {
        return _StatusDot(
          color: const Color(0xFF16A34A),
          scale: animation.value,
        );
      },
    );
  }
}

class _StatusDot extends StatelessWidget {
  const _StatusDot({required this.color, required this.scale});

  final Color color;
  final double scale;

  @override
  Widget build(BuildContext context) {
    return Transform.scale(
      scale: scale,
      child: Container(
        width: 12,
        height: 12,
        decoration: BoxDecoration(
          color: color,
          shape: BoxShape.circle,
          boxShadow: [
            BoxShadow(
              color: color.withValues(alpha: 0.24),
              blurRadius: 8,
              spreadRadius: 2,
            ),
          ],
        ),
      ),
    );
  }
}

class _FooterToggle extends StatelessWidget {
  const _FooterToggle({
    required this.label,
    required this.value,
    required this.onChanged,
  });

  final String label;
  final bool value;
  final ValueChanged<bool> onChanged;

  @override
  Widget build(BuildContext context) {
    return InkWell(
      borderRadius: BorderRadius.circular(8),
      onTap: () => onChanged(!value),
      child: Container(
        constraints: const BoxConstraints(minHeight: 44),
        padding: const EdgeInsets.only(left: 10),
        decoration: BoxDecoration(
          borderRadius: BorderRadius.circular(8),
          border: Border.all(color: const Color(0xFFE2E8F0)),
        ),
        child: Row(
          children: [
            Expanded(
              child: Text(
                label,
                overflow: TextOverflow.ellipsis,
                style: const TextStyle(fontWeight: FontWeight.w600),
              ),
            ),
            Switch.adaptive(value: value, onChanged: onChanged),
          ],
        ),
      ),
    );
  }
}

class _HistoryEmptyState extends StatelessWidget {
  const _HistoryEmptyState();

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(
            Icons.history_toggle_off,
            size: 56,
            color: colorScheme.onSurfaceVariant.withValues(alpha: 0.45),
          ),
          const SizedBox(height: 12),
          Text('暂无发送记录', style: TextStyle(color: colorScheme.onSurfaceVariant)),
        ],
      ),
    );
  }
}