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

import '../../../models/schedule.dart';
import '../../../models/sys_log.dart';
import '../../../services/api_client.dart';
import '../../../services/sys_service.dart';

/// 定时任务管理页。
class SchedulePage extends ConsumerStatefulWidget {
  const SchedulePage({super.key});

  @override
  ConsumerState<SchedulePage> createState() => _SchedulePageState();
}

class _SchedulePageState extends ConsumerState<SchedulePage> {
  final SystemService _service = SystemService();

  final List<Schedule> _items = [];
  bool _loading = false;
  int _page = 1;
  bool _hasMore = true;
  String? _error;

  final ScrollController _scrollController = ScrollController();
  final int _limit = 20;

  @override
  void initState() {
    super.initState();
    _scrollController.addListener(_onScroll);
    _loadData();
  }

  @override
  void dispose() {
    _scrollController.removeListener(_onScroll);
    _scrollController.dispose();
    super.dispose();
  }

  void _onScroll() {
    if (_scrollController.position.pixels >=
        _scrollController.position.maxScrollExtent - 200) {
      _loadMore();
    }
  }

  Future<void> _loadData({bool reset = false}) async {
    if (_loading) return;
    if (reset) {
      _page = 1;
      _hasMore = true;
      _items.clear();
    }
    setState(() {
      _loading = true;
      _error = null;
    });
    try {
      final list = await _service.getScheduleList(page: _page, limit: _limit);
      _items.addAll(list);
      _hasMore = list.length >= _limit;
    } on ApiException catch (e) {
      _error = e.message;
    } catch (e) {
      _error = e.toString();
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  Future<void> _loadMore() async {
    if (_loading || !_hasMore) return;
    _page++;
    await _loadData();
  }

  Future<void> _refresh() async {
    await _loadData(reset: true);
  }

  Future<void> _showForm({Schedule? schedule}) async {
    final result = await showModalBottomSheet<Map<String, dynamic>>(
      context: context,
      isScrollControlled: true,
      builder: (context) => _ScheduleForm(schedule: schedule),
    );

    if (result == null) return;

    try {
      await _service.saveSchedule(result);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('保存成功')),
        );
        _refresh();
      }
    } on ApiException catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(e.message)),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('保存失败：$e')),
        );
      }
    }
  }

  Future<void> _deleteSchedule(Schedule schedule) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('确认删除'),
        content: Text('确定要删除任务「${schedule.beanName}.${schedule.methodName}」吗？'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: const Text('取消'),
          ),
          FilledButton(
            onPressed: () => Navigator.pop(context, true),
            child: const Text('删除'),
          ),
        ],
      ),
    );

    if (confirmed != true) return;

    try {
      await _service.deleteSchedule([int.tryParse(schedule.jobId) ?? 0]);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('删除成功')),
        );
        _refresh();
      }
    } on ApiException catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(e.message)),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('删除失败：$e')),
        );
      }
    }
  }

  Future<void> _pauseSchedule(Schedule schedule) async {
    try {
      await _service.pauseSchedule(schedule.jobId);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('任务已暂停')),
        );
        _refresh();
      }
    } on ApiException catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(e.message)),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('暂停失败：$e')),
        );
      }
    }
  }

  Future<void> _resumeSchedule(Schedule schedule) async {
    try {
      await _service.resumeSchedule(schedule.jobId);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('任务已恢复')),
        );
        _refresh();
      }
    } on ApiException catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(e.message)),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('恢复失败：$e')),
        );
      }
    }
  }

  Future<void> _runSchedule(Schedule schedule) async {
    try {
      await _service.runSchedule(schedule.jobId);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('任务已触发执行')),
        );
      }
    } on ApiException catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(e.message)),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('执行失败：$e')),
        );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(automaticallyImplyLeading: false, title: const Text('定时任务')),
      body: _buildBody(),
      floatingActionButton: FloatingActionButton(
        onPressed: () => _showForm(),
        child: const Icon(Icons.add),
      ),
    );
  }

  Widget _buildBody() {
    if (_error != null && _items.isEmpty) {
      return Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(_error!),
            const SizedBox(height: 8),
            FilledButton.tonal(
              onPressed: _refresh,
              child: const Text('重试'),
            ),
          ],
        ),
      );
    }

    if (_items.isEmpty && !_loading) {
      return const Center(child: Text('暂无数据'));
    }

    return RefreshIndicator(
      onRefresh: _refresh,
      child: ListView.builder(
        controller: _scrollController,
        physics: const AlwaysScrollableScrollPhysics(),
        itemCount: _items.length + 1,
        itemBuilder: (context, index) {
          if (index == _items.length) {
            if (_loading) {
              return const Padding(
                padding: EdgeInsets.all(16),
                child: Center(child: CircularProgressIndicator()),
              );
            }
            if (!_hasMore) {
              return const Padding(
                padding: EdgeInsets.all(16),
                child: Center(child: Text('没有更多数据')),
              );
            }
            return const SizedBox.shrink();
          }
          final schedule = _items[index];
          return Card(
            margin: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
            child: ListTile(
              title: Text('${schedule.beanName}.${schedule.methodName}'),
              subtitle: Text(
                'Cron：${schedule.cronExpression}  |  ${schedule.status == 0 ? '正常' : '暂停'}'
                '${schedule.remark.isNotEmpty ? "\n${schedule.remark}" : ""}',
              ),
              trailing: PopupMenuButton<String>(
                onSelected: (value) {
                  switch (value) {
                    case 'edit':
                      _showForm(schedule: schedule);
                      break;
                    case 'delete':
                      _deleteSchedule(schedule);
                      break;
                    case 'pause':
                      _pauseSchedule(schedule);
                      break;
                    case 'resume':
                      _resumeSchedule(schedule);
                      break;
                    case 'run':
                      _runSchedule(schedule);
                      break;
                    case 'log':
                      _showScheduleLog(schedule);
                      break;
                  }
                },
                itemBuilder: (context) => [
                  const PopupMenuItem(value: 'edit', child: Text('编辑')),
                  const PopupMenuItem(value: 'delete', child: Text('删除')),
                  const PopupMenuItem(value: 'pause', child: Text('暂停')),
                  const PopupMenuItem(value: 'resume', child: Text('恢复')),
                  const PopupMenuItem(value: 'run', child: Text('立即运行')),
                  const PopupMenuItem(value: 'log', child: Text('日志')),
                ],
              ),
            ),
          );
        },
      ),
    );
  }

  void _showScheduleLog(Schedule schedule) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => _ScheduleLogPage(jobId: schedule.jobId),
      ),
    );
  }
}

/// 定时任务日志页。
class _ScheduleLogPage extends StatefulWidget {
  const _ScheduleLogPage({required this.jobId});

  final String jobId;

  @override
  State<_ScheduleLogPage> createState() => _ScheduleLogPageState();
}

class _ScheduleLogPageState extends State<_ScheduleLogPage> {
  final SystemService _service = SystemService();

  final List<SysLog> _items = [];
  bool _loading = false;
  int _page = 1;
  bool _hasMore = true;
  String? _error;

  final ScrollController _scrollController = ScrollController();
  final int _limit = 20;

  @override
  void initState() {
    super.initState();
    _scrollController.addListener(_onScroll);
    _loadData();
  }

  @override
  void dispose() {
    _scrollController.removeListener(_onScroll);
    _scrollController.dispose();
    super.dispose();
  }

  void _onScroll() {
    if (_scrollController.position.pixels >=
        _scrollController.position.maxScrollExtent - 200) {
      _loadMore();
    }
  }

  Future<void> _loadData({bool reset = false}) async {
    if (_loading) return;
    if (reset) {
      _page = 1;
      _hasMore = true;
      _items.clear();
    }
    setState(() {
      _loading = true;
      _error = null;
    });
    try {
      final list =
          await _service.getScheduleLogList(page: _page, limit: _limit);
      _items.addAll(list);
      _hasMore = list.length >= _limit;
    } on ApiException catch (e) {
      _error = e.message;
    } catch (e) {
      _error = e.toString();
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  Future<void> _loadMore() async {
    if (_loading || !_hasMore) return;
    _page++;
    await _loadData();
  }

  Future<void> _refresh() async {
    await _loadData(reset: true);
  }

  String _formatDate(DateTime? dt) {
    if (dt == null) return '';
    return '${dt.year}-${dt.month.toString().padLeft(2, '0')}-'
        '${dt.day.toString().padLeft(2, '0')} '
        '${dt.hour.toString().padLeft(2, '0')}:'
        '${dt.minute.toString().padLeft(2, '0')}:'
        '${dt.second.toString().padLeft(2, '0')}';
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(automaticallyImplyLeading: false, title: const Text('任务日志')),
      body: _buildBody(),
    );
  }

  Widget _buildBody() {
    if (_error != null && _items.isEmpty) {
      return Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(_error!),
            const SizedBox(height: 8),
            FilledButton.tonal(
              onPressed: _refresh,
              child: const Text('重试'),
            ),
          ],
        ),
      );
    }

    if (_items.isEmpty && !_loading) {
      return const Center(child: Text('暂无日志'));
    }

    return RefreshIndicator(
      onRefresh: _refresh,
      child: ListView.builder(
        controller: _scrollController,
        physics: const AlwaysScrollableScrollPhysics(),
        itemCount: _items.length + 1,
        itemBuilder: (context, index) {
          if (index == _items.length) {
            if (_loading) {
              return const Padding(
                padding: EdgeInsets.all(16),
                child: Center(child: CircularProgressIndicator()),
              );
            }
            if (!_hasMore) {
              return const Padding(
                padding: EdgeInsets.all(16),
                child: Center(child: Text('没有更多数据')),
              );
            }
            return const SizedBox.shrink();
          }
          final log = _items[index];
          return Card(
            margin: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
            child: Padding(
              padding: const EdgeInsets.all(12),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    log.operation.isEmpty ? '（无操作描述）' : log.operation,
                    style: Theme.of(context).textTheme.titleSmall,
                  ),
                  const SizedBox(height: 4),
                  Text('用户：${log.username}'),
                  const SizedBox(height: 2),
                  Text(
                    '方法：${log.method}',
                    style: Theme.of(context).textTheme.bodySmall,
                    maxLines: 2,
                    overflow: TextOverflow.ellipsis,
                  ),
                  const SizedBox(height: 2),
                  Text('耗时：${log.time}ms'),
                  const SizedBox(height: 2),
                  Text(
                    '时间：${_formatDate(log.createDate)}',
                    style: Theme.of(context).textTheme.bodySmall,
                  ),
                ],
              ),
            ),
          );
        },
      ),
    );
  }
}

/// 定时任务表单。
class _ScheduleForm extends StatefulWidget {
  const _ScheduleForm({this.schedule});

  final Schedule? schedule;

  @override
  State<_ScheduleForm> createState() => _ScheduleFormState();
}

class _ScheduleFormState extends State<_ScheduleForm> {
  final _formKey = GlobalKey<FormState>();
  late final TextEditingController _beanName;
  late final TextEditingController _methodName;
  late final TextEditingController _params;
  late final TextEditingController _cronExpression;
  late final TextEditingController _remark;

  @override
  void initState() {
    super.initState();
    final s = widget.schedule;
    _beanName = TextEditingController(text: s?.beanName ?? '');
    _methodName = TextEditingController(text: s?.methodName ?? '');
    _params = TextEditingController(text: s?.params ?? '');
    _cronExpression = TextEditingController(text: s?.cronExpression ?? '');
    _remark = TextEditingController(text: s?.remark ?? '');
  }

  @override
  void dispose() {
    _beanName.dispose();
    _methodName.dispose();
    _params.dispose();
    _cronExpression.dispose();
    _remark.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final isEdit = widget.schedule != null;
    return SingleChildScrollView(
      padding: EdgeInsets.only(
        bottom: MediaQuery.of(context).viewInsets.bottom,
      ),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Form(
          key: _formKey,
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Text(isEdit ? '编辑任务' : '新增任务',
                  style: Theme.of(context).textTheme.titleMedium),
              const SizedBox(height: 16),
              TextFormField(
                controller: _beanName,
                decoration: const InputDecoration(labelText: 'Bean名称'),
                validator: (v) =>
                    (v == null || v.trim().isEmpty) ? '请输入Bean名称' : null,
              ),
              TextFormField(
                controller: _methodName,
                decoration: const InputDecoration(labelText: '方法名称'),
                validator: (v) =>
                    (v == null || v.trim().isEmpty) ? '请输入方法名称' : null,
              ),
              TextFormField(
                controller: _params,
                decoration: const InputDecoration(labelText: '参数'),
              ),
              TextFormField(
                controller: _cronExpression,
                decoration: const InputDecoration(labelText: 'Cron表达式'),
                validator: (v) =>
                    (v == null || v.trim().isEmpty) ? '请输入Cron表达式' : null,
              ),
              TextFormField(
                controller: _remark,
                decoration: const InputDecoration(labelText: '备注'),
              ),
              const SizedBox(height: 16),
              FilledButton(
                onPressed: () {
                  if (_formKey.currentState?.validate() != true) return;
                  final data = <String, dynamic>{
                    if (isEdit) 'jobId': widget.schedule!.jobId,
                    'beanName': _beanName.text.trim(),
                    'methodName': _methodName.text.trim(),
                    'params': _params.text.trim(),
                    'cronExpression': _cronExpression.text.trim(),
                    'remark': _remark.text.trim(),
                  };
                  Navigator.pop(context, data);
                },
                child: const Text('保存'),
              ),
            ],
          ),
        ),
      ),
    );
  }
}