import 'package:flutter/material.dart';
import 'package:miaoji_zhang/shared/api/api_client.dart';
import 'package:miaoji_zhang/shared/api/business_api.dart';
import 'package:miaoji_zhang/shared/services/current_ledger_store.dart';
import 'package:miaoji_zhang/shared/services/transaction_events.dart';
import 'package:miaoji_zhang/shared/theme/app_theme.dart';
import 'package:miaoji_zhang/shared/widgets/category_icon.dart';
import 'package:miaoji_zhang/shared/widgets/app_controls.dart';
import 'package:miaoji_zhang/shared/widgets/backend_status_icon.dart';

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

  @override
  State<RecycleBinPage> createState() => _RecycleBinPageState();
}

class _RecycleBinPageState extends State<RecycleBinPage> {
  List<TxItem> _items = const [];
  bool _loading = true;
  int _loadRevision = 0;

  @override
  void initState() {
    super.initState();
    _load();
  }

  Future<void> _load() async {
    final revision = ++_loadRevision;
    setState(() => _loading = true);
    try {
      await CurrentLedgerStore.instance.loadCached();
      final cached = TxApi.recycleBinLocal();
      if (mounted && revision == _loadRevision) {
        setState(() {
          _items = cached;
          _loading = false;
        });
      }
      final remote = await TxApi.recycleBinRemote();
      if (mounted && revision == _loadRevision) {
        setState(() => _items = remote);
      }
    } catch (error) {
      if (mounted && revision == _loadRevision && _loading) {
        setState(() => _loading = false);
        _showError(error);
      }
    } finally {
      if (mounted && revision == _loadRevision && _loading) {
        setState(() => _loading = false);
      }
    }
  }

  Future<void> _restore(TxItem item) async {
    try {
      await TxApi.restore(item.id);
      TransactionEvents.notifyChanged();
      await _load();
    } catch (error) {
      if (mounted) _showError(error);
    }
  }

  Future<void> _permanentDelete(TxItem item) async {
    if (ApiClient.availability.value != BackendAvailability.online) return;
    final confirmed = await _confirm('永久删除', '永久删除后无法恢复，聊天中的账单卡片会显示为已删除。');
    if (!confirmed) return;
    try {
      await TxApi.permanentlyDelete(item.id);
      await _load();
    } catch (error) {
      if (mounted) _showError(error);
    }
  }

  Future<void> _clear() async {
    if (_items.isEmpty ||
        ApiClient.availability.value != BackendAvailability.online) {
      return;
    }
    final confirmed = await _confirm('清空回收站', '将永久删除当前账本回收站中的全部账单，无法恢复。');
    if (!confirmed) return;
    try {
      await TxApi.clearRecycleBin();
      await _load();
    } catch (error) {
      if (mounted) _showError(error);
    }
  }

  Future<bool> _confirm(String title, String message) => showJzConfirmSheet(
    context,
    title: title,
    message: message,
    confirmLabel: '永久删除',
    destructive: true,
  );

  Future<void> _showActions(TxItem item) async {
    final online = ApiClient.availability.value == BackendAvailability.online;
    final action = await showJzOptionSheet<String>(
      context,
      title: item.note ?? item.categoryName,
      options: [
        const JzOption(value: 'restore', label: '恢复账单'),
        if (online)
          const JzOption(value: 'delete', label: '永久删除', subtitle: '删除后无法恢复'),
      ],
    );
    if (action == 'restore') await _restore(item);
    if (action == 'delete') await _permanentDelete(item);
  }

  void _showError(Object error) {
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(apiErrorMessage(error))));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('${CurrentLedgerStore.instance.currentName} · 回收站'),
        actions: [
          BackendStatusIcon(onRetry: _load),
          ValueListenableBuilder<BackendAvailability>(
            valueListenable: ApiClient.availability,
            builder: (context, availability, _) => TextButton(
              onPressed:
                  _items.isEmpty || availability != BackendAvailability.online
                  ? null
                  : _clear,
              child: Text('清空'),
            ),
          ),
        ],
      ),
      body: _loading
          ? Center(
              child: CircularProgressIndicator(
                color: AppTheme.primary,
                strokeWidth: 2,
              ),
            )
          : _items.isEmpty
          ? Center(
              child: Text(
                '回收站暂无账单\n删除的账单会保留 30 天',
                textAlign: TextAlign.center,
                style: TextStyle(color: context.jz.text3, height: 1.6),
              ),
            )
          : ListView.builder(
              padding: const EdgeInsets.all(16),
              itemCount: _items.length,
              itemBuilder: (context, index) {
                final item = _items[index];
                return Card(
                  child: ListTile(
                    leading: CategoryIconBox(
                      iconKey: item.categoryIcon,
                      colorKey: item.categoryColor,
                    ),
                    title: Text(item.note ?? item.categoryName),
                    subtitle: Text(
                      '${item.occurredAt.year}-${item.occurredAt.month.toString().padLeft(2, '0')}-${item.occurredAt.day.toString().padLeft(2, '0')}',
                    ),
                    trailing: IconButton(
                      tooltip: '账单操作',
                      onPressed: () => _showActions(item),
                      icon: Icon(Icons.more_horiz_rounded),
                    ),
                  ),
                );
              },
            ),
    );
  }
}