import 'package:flutter/material.dart';

import '../../core/app_state.dart';
import '../../core/app_theme.dart';
import '../../core/sync/sync_coordinator.dart';
import '../../core/sync/sync_models.dart';
import '../../widgets/app_widgets.dart';

/// 跨平台同步设置底部面板
class SyncSettingsSheet extends StatefulWidget {
  const SyncSettingsSheet({super.key, required this.state});

  final AppState state;

  static Future<void> show(BuildContext context, AppState state) {
    return showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      showDragHandle: true,
      builder: (context) => Padding(
        padding: EdgeInsets.only(
          bottom: MediaQuery.of(context).viewInsets.bottom,
        ),
        child: SafeArea(
          child: SyncSettingsSheet(state: state),
        ),
      ),
    );
  }

  @override
  State<SyncSettingsSheet> createState() => _SyncSettingsSheetState();
}

class _SyncSettingsSheetState extends State<SyncSettingsSheet> {
  final _coordinator = SyncCoordinator.instance;
  late final TextEditingController _serverController;
  final _userController = TextEditingController();
  final _passwordController = TextEditingController();

  bool _isRegisterMode = false;
  bool _testingConnection = false;
  String? _testMessage;
  bool? _testOk;

  @override
  void initState() {
    super.initState();
    _serverController = TextEditingController(text: _coordinator.serverUrl);
  }

  @override
  void dispose() {
    _serverController.dispose();
    _userController.dispose();
    _passwordController.dispose();
    super.dispose();
  }

  Future<void> _handleTestConnection() async {
    setState(() {
      _testingConnection = true;
      _testMessage = null;
      _testOk = null;
    });
    final ok = await _coordinator.testConnection(_serverController.text);
    if (!mounted) return;
    setState(() {
      _testingConnection = false;
      _testOk = ok;
      _testMessage = ok ? '服务器连接正常' : '无法连接到服务器，请检查地址或网络';
    });
  }

  Future<void> _handleAuth() async {
    final server = _serverController.text.trim();
    final user = _userController.text.trim();
    final pwd = _passwordController.text;

    if (server.isEmpty || user.isEmpty || pwd.isEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('请填写完整的服务器地址、账号和密码')),
      );
      return;
    }

    final success = _isRegisterMode
        ? await _coordinator.register(
            serverUrl: server,
            username: user,
            password: pwd,
          )
        : await _coordinator.login(
            serverUrl: server,
            username: user,
            password: pwd,
          );

    if (!mounted) return;
    if (success) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(_isRegisterMode ? '注册并登录成功！' : '登录成功！'),
          backgroundColor: AppColors.green,
        ),
      );
      // 登录成功后自动执行一次同步
      await _coordinator.syncNow(widget.state);
    }
  }

  Future<void> _handleSyncNow() async {
    final ok = await _coordinator.syncNow(widget.state);
    if (!mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(ok ? '同步完成，进度已合并。' : '同步失败：${_coordinator.errorMessage}'),
        backgroundColor: ok ? AppColors.green : Colors.redAccent,
      ),
    );
  }

  String _formatTime(DateTime? time) {
    if (time == null) return '从未同步';
    final local = time.toLocal();
    final now = DateTime.now();
    final diff = now.difference(local);
    if (diff.inSeconds < 60) return '刚刚';
    if (diff.inMinutes < 60) return '${diff.inMinutes} 分钟前';
    if (diff.inHours < 24) return '${diff.inHours} 小时前';
    return '${local.year}-${local.month.toString().padLeft(2, '0')}-${local.day.toString().padLeft(2, '0')} ${local.hour.toString().padLeft(2, '0')}:${local.minute.toString().padLeft(2, '0')}';
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _coordinator,
      builder: (context, _) {
        final isLoggedIn = _coordinator.isLoggedIn;

        return SingleChildScrollView(
          padding: const EdgeInsets.fromLTRB(16, 8, 16, 24),
          child: SpacedColumn(
                        children: [
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                  Text(
                    '云同步与多端备份',
                    style: Theme.of(context).textTheme.titleLarge,
                  ),
                  if (isLoggedIn)
                    Container(
                      padding: const EdgeInsets.symmetric(
                        horizontal: 8,
                        vertical: 3,
                      ),
                      decoration: BoxDecoration(
                        color: _coordinator.state == SyncState.syncing
                            ? AppColors.warm
                            : _coordinator.state == SyncState.error
                                ? Colors.red.shade50
                                : AppColors.softGreen,
                        borderRadius: BorderRadius.circular(12),
                      ),
                      child: Row(
                        mainAxisSize: MainAxisSize.min,
                        children: [
                          Icon(
                            _coordinator.state == SyncState.syncing
                                ? Icons.sync
                                : _coordinator.state == SyncState.error
                                    ? Icons.error_outline
                                    : Icons.cloud_done_outlined,
                            size: 14,
                            color: _coordinator.state == SyncState.syncing
                                ? AppColors.warmInk
                                : _coordinator.state == SyncState.error
                                    ? Colors.redAccent
                                    : AppColors.green,
                          ),
                          const SizedBox(width: 4),
                          Text(
                            _coordinator.state == SyncState.syncing
                                ? '同步中'
                                : _coordinator.state == SyncState.error
                                    ? '同步异常'
                                    : '已连接',
                            style: TextStyle(
                              fontSize: 12,
                              color: _coordinator.state == SyncState.syncing
                                  ? AppColors.warmInk
                                  : _coordinator.state == SyncState.error
                                      ? Colors.redAccent
                                      : AppColors.green,
                              fontWeight: FontWeight.w600,
                            ),
                          ),
                        ],
                      ),
                    ),
                ],
              ),
              Text(
                '本地优先架构：无网络时不影响学习，联网后自动双向合并学习进度与复习掌握度。',
                style: TextStyle(fontSize: 13, color: AppColors.muted),
              ),
              const SizedBox(height: 8),

              if (isLoggedIn) ...[
                // Logged In State
                SectionCard(
                  child: Column(
                                        children: [
                      Row(
                        children: [
                          CircleAvatar(
                            radius: 18,
                            backgroundColor: AppColors.softGreen,
                            child: Icon(Icons.person, color: AppColors.green),
                          ),
                          const SizedBox(width: 12),
                          Expanded(
                            child: Column(
                                                            children: [
                                Text(
                                  _coordinator.username ?? '同步用户',
                                  style: const TextStyle(
                                    fontWeight: FontWeight.w600,
                                    fontSize: 15,
                                  ),
                                ),
                                Text(
                                  _coordinator.serverUrl,
                                  style: TextStyle(
                                    fontSize: 12,
                                    color: AppColors.muted,
                                  ),
                                ),
                              ],
                            ),
                          ),
                          TextButton(
                            onPressed: () => _coordinator.logout(),
                            child: const Text('退出登录'),
                          ),
                        ],
                      ),
                      const Divider(height: 24),
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
                        children: [
                          const Text('上次同步：'),
                          Text(
                            _formatTime(_coordinator.lastSyncTime),
                            style: const TextStyle(fontWeight: FontWeight.w500),
                          ),
                        ],
                      ),
                    ],
                  ),
                ),
                SwitchListTile(
                  contentPadding: EdgeInsets.zero,
                  title: const Text('自动后台同步'),
                  subtitle: const Text('在关卡完成与复习提交后自动静默同步'),
                  value: _coordinator.autoSyncEnabled,
                  activeThumbColor: AppColors.green,
                  onChanged: (val) => _coordinator.setAutoSyncEnabled(val),
                ),
                if (_coordinator.errorMessage != null)
                  SectionCard(
                    tint: Colors.red.shade50,
                    child: Row(
                      children: [
                        const Icon(Icons.error_outline, color: Colors.redAccent),
                        const SizedBox(width: 10),
                        Expanded(
                          child: Text(
                            '同步失败：${_coordinator.errorMessage}',
                            style: const TextStyle(
                              color: Colors.redAccent,
                              fontSize: 13,
                            ),
                          ),
                        ),
                      ],
                    ),
                  ),
                const SizedBox(height: 8),
                PrimaryButton(
                  label: _coordinator.state == SyncState.syncing
                      ? '正在同步...'
                      : '立即同步 (双向合并)',
                  icon: Icons.sync,
                  onPressed: _coordinator.state == SyncState.syncing
                      ? null
                      : _handleSyncNow,
                ),
              ] else ...[
                // Not Logged In State (Login / Register Form)
                Row(
                  children: [
                    Expanded(
                      child: ChoiceChip(
                        label: const Center(child: Text('登录已有账号')),
                        selected: !_isRegisterMode,
                        onSelected: (val) =>
                            setState(() => _isRegisterMode = false),
                      ),
                    ),
                    const SizedBox(width: 12),
                    Expanded(
                      child: ChoiceChip(
                        label: const Center(child: Text('注册新账号')),
                        selected: _isRegisterMode,
                        onSelected: (val) =>
                            setState(() => _isRegisterMode = true),
                      ),
                    ),
                  ],
                ),
                const SizedBox(height: 8),
                TextField(
                  controller: _serverController,
                  keyboardType: TextInputType.url,
                  decoration: InputDecoration(
                    labelText: '自建同步服务器地址',
                    hintText: 'https://syncenglish.slcydia.fun',
                    border: const OutlineInputBorder(),
                    suffixIcon: IconButton(
                      tooltip: '测试连通性',
                      icon: _testingConnection
                          ? const SizedBox(
                              width: 18,
                              height: 18,
                              child: CircularProgressIndicator(strokeWidth: 2),
                            )
                          : const Icon(Icons.network_check),
                      onPressed: _testingConnection ? null : _handleTestConnection,
                    ),
                  ),
                ),
                if (_testMessage != null)
                  Text(
                    _testMessage!,
                    style: TextStyle(
                      fontSize: 12,
                      color: _testOk == true ? AppColors.green : Colors.redAccent,
                    ),
                  ),
                TextField(
                  controller: _userController,
                  decoration: const InputDecoration(
                    labelText: '用户名',
                    border: OutlineInputBorder(),
                  ),
                ),
                TextField(
                  controller: _passwordController,
                  obscureText: true,
                  decoration: const InputDecoration(
                    labelText: '密码',
                    border: OutlineInputBorder(),
                  ),
                ),
                if (_coordinator.errorMessage != null)
                  SectionCard(
                    tint: Colors.red.shade50,
                    child: Text(
                      _coordinator.errorMessage!,
                      style: const TextStyle(
                        color: Colors.redAccent,
                        fontSize: 13,
                      ),
                    ),
                  ),
                PrimaryButton(
                  label: _coordinator.state == SyncState.syncing
                      ? '处理中...'
                      : (_isRegisterMode ? '注册账号并开启同步' : '登录并同步进度'),
                  onPressed: _coordinator.state == SyncState.syncing
                      ? null
                      : _handleAuth,
                ),
              ],
            ],
          ),
        );
      },
    );
  }
}