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

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

/// 系统日志页（TabBar：系统日志 / 审计日志 / JST调用日志）。
class LogPage extends ConsumerStatefulWidget {
  const LogPage({super.key});

  @override
  ConsumerState<LogPage> createState() => _LogPageState();
}

class _LogPageState extends ConsumerState<LogPage>
    with SingleTickerProviderStateMixin {
  late TabController _tabController;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 3, vsync: this);
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        automaticallyImplyLeading: false,
        title: const Text('系统日志'),
        bottom: TabBar(
          controller: _tabController,
          tabs: const [
            Tab(text: '系统日志'),
            Tab(text: '审计日志'),
            Tab(text: 'JST调用日志'),
          ],
        ),
      ),
      body: TabBarView(
        controller: _tabController,
        children: const [
          _LogTab(title: '系统日志', logType: _LogType.system),
          _LogTab(title: '审计日志', logType: _LogType.audit),
          _LogTab(title: 'JST调用日志', logType: _LogType.jst),
        ],
      ),
    );
  }
}

/// 日志类型枚举。
enum _LogType { system, audit, jst }

/// 日志列表 Tab。
class _LogTab extends StatefulWidget {
  const _LogTab({
    required this.title,
    required this.logType,
  });

  final String title;
  final _LogType logType;

  @override
  State<_LogTab> createState() => _LogTabState();
}

class _LogTabState extends State<_LogTab>
    with AutomaticKeepAliveClientMixin {
  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
  bool get wantKeepAlive => true;

  @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<List<SysLog>> _fetch({int page = 1, int limit = 20}) {
    switch (widget.logType) {
      case _LogType.system:
        return _service.getLogList(page: page, limit: limit);
      case _LogType.audit:
        return _service.getAuditLogList(page: page, limit: limit);
      case _LogType.jst:
        return _service.getApiJstCallLogList(page: page, limit: limit);
    }
  }

  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 _fetch(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) {
    super.build(context);

    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 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: [
                  Row(
                    children: [
                      Expanded(
                        child: Text(
                          log.operation.isEmpty
                              ? '（无操作描述）'
                              : log.operation,
                          style: Theme.of(context).textTheme.titleSmall,
                        ),
                      ),
                      Text(
                        '${log.time}ms',
                        style: Theme.of(context).textTheme.bodySmall,
                      ),
                    ],
                  ),
                  const SizedBox(height: 4),
                  Text('用户：${log.username}'),
                  const SizedBox(height: 2),
                  Text(
                    '方法：${log.method}',
                    style: Theme.of(context).textTheme.bodySmall,
                    maxLines: 2,
                    overflow: TextOverflow.ellipsis,
                  ),
                  const SizedBox(height: 2),
                  Text('IP：${log.ip}'),
                  const SizedBox(height: 2),
                  Text(
                    '时间：${_formatDate(log.createDate)}',
                    style: Theme.of(context).textTheme.bodySmall,
                  ),
                ],
              ),
            ),
          );
        },
      ),
    );
  }
}