import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:tdesign_flutter/tdesign_flutter.dart';
import 'package:easy_refresh/easy_refresh.dart';
import '../../shared/widgets/nav_bar_config.dart';
import '../../core/theme/app_colors_extension.dart';
import '../../core/utils/date_utils.dart' as du;
import '../../core/utils/responsive.dart';
import '../../shared/widgets/list_card.dart';
import '../../shared/widgets/empty_state.dart';
import '../../shared/widgets/skeleton_list_card.dart';
import '../../shared/widgets/list_footer.dart';
import '../../core/i18n/app_localizations.dart';
import 'expense_list_controller.dart';
import 'expense_model.dart';
import 'expense_api.dart';


class ExpenseListPage extends ConsumerStatefulWidget {
  const ExpenseListPage({super.key});
  @override
  ConsumerState<ExpenseListPage> createState() => _ExpenseListPageState();
}

class _ExpenseListPageState extends ConsumerState<ExpenseListPage>
    with WidgetsBindingObserver {
  final _keywordCtrl = TextEditingController();
  final _startDateCtrl = TextEditingController();
  final _endDateCtrl = TextEditingController();
  late final EasyRefreshController _refreshCtrl;

  @override
  void initState() {
    super.initState();
    final now = DateTime.now();
    _startDateCtrl.text = '${now.year}-${now.month.toString().padLeft(2, '0')}-01';
    _endDateCtrl.text = '${now.year}-${now.month.toString().padLeft(2, '0')}-${_daysInMonth(now.year, now.month).toString().padLeft(2, '0')}';
    _refreshCtrl = EasyRefreshController();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      ref.read(expenseDateStartProvider.notifier).state = DateTime(now.year, now.month, 1);
      ref.read(expenseDateEndProvider.notifier).state = DateTime(now.year, now.month, _daysInMonth(now.year, now.month));
    });
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.resumed) {
      _keywordCtrl.clear();
      final now = DateTime.now();
      _startDateCtrl.text = '${now.year}-${now.month.toString().padLeft(2, '0')}-01';
      _endDateCtrl.text = '${now.year}-${now.month.toString().padLeft(2, '0')}-${_daysInMonth(now.year, now.month).toString().padLeft(2, '0')}';
      ref.read(expenseKeywordProvider.notifier).state = '';
      ref.read(expenseDateStartProvider.notifier).state = DateTime(now.year, now.month, 1);
      ref.read(expenseDateEndProvider.notifier).state = DateTime(now.year, now.month, _daysInMonth(now.year, now.month));
      ref.read(expenseRefreshProvider.notifier).state++;
    }
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    _keywordCtrl.dispose();
    _startDateCtrl.dispose();
    _endDateCtrl.dispose();
    _refreshCtrl.dispose();
    super.dispose();
  }

  void _pickDate(TextEditingController ctrl) {
    final l10n = AppLocalizations.of(context);
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final now = DateTime.now();
    TDPicker.showDatePicker(
      context, title: l10n.get('selectDate'), backgroundColor: colors.bgCard,
      useYear: true, useMonth: true, useDay: true,
      useHour: false, useMinute: false, useSecond: false, useWeekDay: false,
      dateStart: const [2020, 1, 1], dateEnd: [now.year + 1, 12, 31],
      initialDate: [now.year, now.month, now.day],
      onConfirm: (selected) {
        ctrl.text = '${selected['year']}-${selected['month'].toString().padLeft(2, '0')}-${selected['day'].toString().padLeft(2, '0')}';
        setState(() {});
        Navigator.of(context).pop();
      },
    );
  }

  int _daysInMonth(int year, int month) => DateTime(year, month + 1, 0).day;

  void _applyFilter() {
    ref.read(expenseKeywordProvider.notifier).state = _keywordCtrl.text.trim();
    ref.read(expenseDateStartProvider.notifier).state = _startDateCtrl.text.isNotEmpty ? DateTime.tryParse(_startDateCtrl.text) : null;
    ref.read(expenseDateEndProvider.notifier).state = _endDateCtrl.text.isNotEmpty ? DateTime.tryParse(_endDateCtrl.text) : null;
    _refreshCtrl.callRefresh();
  }

  Widget _dateChip(TextEditingController ctrl, String hint, TDThemeData tdTheme, AppColorsExtension colors) {
    final text = ctrl.text;
    return Container(
      height: 40, padding: const EdgeInsets.symmetric(horizontal: 16),
      decoration: BoxDecoration(color: colors.bgSecondaryContainer, borderRadius: BorderRadius.circular(20), border: Border.all(color: tdTheme.componentStrokeColor)),
      child: Row(children: [
        Icon(Icons.calendar_today, size: 16, color: colors.textSecondary), const SizedBox(width: 8),
        Expanded(child: Text(text.isNotEmpty ? text : hint, maxLines: 1, overflow: TextOverflow.ellipsis, style: TextStyle(fontSize: 14, color: text.isNotEmpty ? colors.textPrimary : colors.textSecondary))),
        if (text.isNotEmpty) GestureDetector(onTap: () { ctrl.clear(); setState(() {}); }, child: Icon(Icons.close, size: 18, color: colors.textSecondary)),
      ]),
    );
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final tdTheme = TDTheme.of(context);

    setNavBarTitle(context, ref, NavBarConfig(title: l10n.get('expenseList'), showBack: true, onBack: () => SystemNavigator.pop()));
    return Column(children: [
      Container(
        color: colors.bgCard,
        child: Column(mainAxisSize: MainAxisSize.min, children: [
          Padding(padding: const EdgeInsets.fromLTRB(12, 8, 12, 0), child: Row(children: [
            Expanded(child: GestureDetector(onTap: () => _pickDate(_startDateCtrl), child: _dateChip(_startDateCtrl, l10n.get('filterStartDate'), tdTheme, colors))),
            const SizedBox(width: 8), Text('—', style: TextStyle(fontSize: 14, color: colors.textSecondary)), const SizedBox(width: 8),
            Expanded(child: GestureDetector(onTap: () => _pickDate(_endDateCtrl), child: _dateChip(_endDateCtrl, l10n.get('filterEndDate'), tdTheme, colors))),
          ])),
          const SizedBox(height: 8),
          Padding(padding: const EdgeInsets.fromLTRB(12, 0, 12, 8), child: Row(children: [
            Expanded(
              child: Container(
                height: 40, padding: const EdgeInsets.symmetric(horizontal: 16),
                decoration: BoxDecoration(color: colors.bgSecondaryContainer, borderRadius: BorderRadius.circular(20), border: Border.all(color: tdTheme.componentStrokeColor)),
                child: Row(children: [
                  Expanded(child: TextField(controller: _keywordCtrl, style: TextStyle(fontSize: 14, color: colors.textPrimary), decoration: InputDecoration(hintText: l10n.get('searchExpense'), hintStyle: TextStyle(fontSize: 14, color: colors.textSecondary), border: InputBorder.none, isCollapsed: true), onChanged: (_) => setState(() {}))),
                  if (_keywordCtrl.text.isNotEmpty) GestureDetector(onTap: () { _keywordCtrl.clear(); setState(() {}); _applyFilter(); }, child: Icon(Icons.close, size: 18, color: colors.textSecondary)),
                ]),
              ),
            ),
            const SizedBox(width: 8),
            GestureDetector(
              onTap: () {
                final dir = ref.read(expenseSortDirProvider);
                ref.read(expenseSortDirProvider.notifier).state = dir == 'ASC' ? 'DESC' : 'ASC';
                _applyFilter();
              },
              child: Container(width: 40, height: 40, decoration: BoxDecoration(color: colors.primary, borderRadius: BorderRadius.circular(20)), child: Center(child: Icon(ref.watch(expenseSortDirProvider) == 'ASC' ? Icons.arrow_upward : Icons.arrow_downward, color: Colors.white, size: 20))),
            ),
            const SizedBox(width: 8),
            GestureDetector(onTap: _applyFilter, child: Container(width: 40, height: 40, decoration: BoxDecoration(color: colors.primary, borderRadius: BorderRadius.circular(20)), child: const Icon(Icons.search, color: Colors.white, size: 22))),
          ])),
        ]),
      ),
      Expanded(child: Container(color: colors.bgPage, child: _ExpenseListContent(refreshCtrl: _refreshCtrl))),
    ]);
  }
}

class _ExpenseListContent extends ConsumerWidget {
  final EasyRefreshController refreshCtrl;
  const _ExpenseListContent({required this.refreshCtrl});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final r = ResponsiveHelper.of(context);
    final itemsAsync = ref.watch(expenseMyListProvider(''));
    if (itemsAsync.isLoading && !itemsAsync.hasValue) return Center(child: ConstrainedBox(constraints: BoxConstraints(maxWidth: r.listMaxWidth), child: const SkeletonLoadingList()));
    return Center(child: ConstrainedBox(constraints: BoxConstraints(maxWidth: r.listMaxWidth), child: EasyRefresh(controller: refreshCtrl, header: TDRefreshHeader(), onRefresh: () async { ref.read(expenseRefreshProvider.notifier).state++; }, child: _buildContent(itemsAsync, context, ref))));
  }

  Widget _buildContent(AsyncValue<List<ExpenseModel>> itemsAsync, BuildContext context, WidgetRef ref) {
    final l10n = AppLocalizations.of(context);
    if (itemsAsync.isReloading) {
      final oldItems = itemsAsync.valueOrNull ?? [];
      if (oldItems.isEmpty) return ListView(children: [const SizedBox(height: 120), EmptyState(message: l10n.get('noExpenses'))]);
      return ListView.builder(padding: const EdgeInsets.fromLTRB(16, 16, 16, 24), itemCount: oldItems.length, itemBuilder: (_, i) {
        final item = oldItems[i];
        final applicant = item.deptName.isNotEmpty
            ? '${item.applicantName} · ${item.deptName}'
            : item.applicantName;
        final card = ListCard(cardNo: item.expenseNo, amount: '¥${item.totalAmount.toStringAsFixed(2)}', applicant: applicant, description: item.purpose, date: du.DateUtils.formatDate(item.expenseDate ?? item.createTime), onTap: () { context.push('/expense/detail/${item.expenseNo}'); });
        return Padding(padding: const EdgeInsets.only(bottom: 16), child: card);
      });
    }
    if (itemsAsync.hasError) return ListView(children: [const SizedBox(height: 120), EmptyState(message: l10n.get('loadFailed'))]);
    final items = itemsAsync.requireValue;
    if (items.isEmpty) return ListView(children: [const SizedBox(height: 120), EmptyState(message: l10n.get('noExpenses'))]);
    return ListView.builder(padding: const EdgeInsets.fromLTRB(16, 16, 16, 24), itemCount: items.length + 1, itemBuilder: (_, i) {
      if (i == items.length) return ListFooter(itemCount: items.length);
      final item = items[i];
      final applicant = item.deptName.isNotEmpty
          ? '${item.applicantName} · ${item.deptName}'
          : item.applicantName;
      final card = ListCard(cardNo: item.expenseNo, amount: '¥${item.totalAmount.toStringAsFixed(2)}', applicant: applicant, description: item.purpose, date: du.DateUtils.formatDate(item.expenseDate ?? item.createTime), onTap: () { context.push('/expense/detail/${item.expenseNo}'); });
      return Padding(padding: const EdgeInsets.only(bottom: 16), child: card);
    });
  }

}