/// Manage Home filter widgets: display, metrics, add/remove.
library;

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

import '../models/home_filter_widget.dart';
import '../models/transaction_meta.dart';
import '../providers/bank_provider.dart';
import '../providers/preferences_provider.dart';
import '../providers/tx_meta_provider.dart';
import '../widgets/label_filter_dialog.dart';
import '../widgets/overview_favourites_sheet.dart' show promptFavouriteName;

Future<void> showHomeWidgetsSheet(BuildContext context) {
  return showModalBottomSheet<void>(
    context: context,
    isScrollControlled: true,
    showDragHandle: true,
    builder: (context) {
      return Padding(
        padding: EdgeInsets.only(
          bottom: MediaQuery.viewInsetsOf(context).bottom,
        ),
        child: const _HomeWidgetsSheet(),
      );
    },
  );
}

Future<HomeFilterWidget?> composeHomeFilterWidget(
  BuildContext context, {
  TransactionFilterSelection? initialFilter,
  HomeFilterWidget? existing,
  bool skipFilterDialog = false,
}) async {
  TransactionFilterSelection? filter = initialFilter ?? existing?.filter;
  if (!skipFilterDialog || filter == null) {
    final bank = context.read<BankController>();
    final meta = context.read<TxMetaController>();
    filter = await showTransactionFilterDialog(
      context,
      available: meta.allLabels,
      transactions: bank.transactions,
      initial: filter ?? const TransactionFilterSelection(labelIds: {}),
    );
    if (filter == null || !context.mounted) return null;
  }

  final name = await promptFavouriteName(
    context,
    initial: existing?.name ?? '',
    title: existing == null ? 'Name this widget' : 'Rename widget',
  );
  if (name == null || !context.mounted) return null;

  await Future<void>.delayed(Duration.zero);
  if (!context.mounted) return null;

  final draft = existing == null
      ? HomeFilterWidget.fromFilter(name: name, filter: filter)
      : existing.copyWith(
          name: name,
          labelIds: filter.labelIds.toList(growable: false),
          flow: filter.flow,
          amountRange: filter.amountRange,
          query: filter.query,
          monthOnly: filter.monthOnly,
        );

  return _promptWidgetMetrics(context, draft);
}

Future<HomeFilterWidget?> _promptWidgetMetrics(
  BuildContext context,
  HomeFilterWidget draft,
) {
  var showIn = draft.showAmountIn;
  var showOut = draft.showAmountOut;
  var showCount = draft.showCount;

  return showDialog<HomeFilterWidget>(
    context: context,
    useRootNavigator: true,
    builder: (context) {
      return StatefulBuilder(
        builder: (context, setState) {
          return AlertDialog(
            title: const Text('Widget metrics'),
            content: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                CheckboxListTile(
                  contentPadding: EdgeInsets.zero,
                  title: const Text('Amount in'),
                  value: showIn,
                  onChanged: (value) =>
                      setState(() => showIn = value ?? false),
                ),
                CheckboxListTile(
                  contentPadding: EdgeInsets.zero,
                  title: const Text('Amount out'),
                  value: showOut,
                  onChanged: (value) =>
                      setState(() => showOut = value ?? false),
                ),
                CheckboxListTile(
                  contentPadding: EdgeInsets.zero,
                  title: const Text('Number of transactions'),
                  value: showCount,
                  onChanged: (value) =>
                      setState(() => showCount = value ?? false),
                ),
              ],
            ),
            actions: [
              TextButton(
                onPressed: () => Navigator.of(context).pop(),
                child: const Text('Cancel'),
              ),
              FilledButton(
                onPressed: () {
                  if (!showIn && !showOut && !showCount) return;
                  Navigator.of(context).pop(
                    draft.copyWith(
                      showAmountIn: showIn,
                      showAmountOut: showOut,
                      showCount: showCount,
                    ),
                  );
                },
                child: const Text('Save'),
              ),
            ],
          );
        },
      );
    },
  );
}

class _HomeWidgetsSheet extends StatelessWidget {
  const _HomeWidgetsSheet();

  @override
  Widget build(BuildContext context) {
    final prefs = context.watch<PreferencesController>();
    final theme = Theme.of(context);
    final widgets = prefs.homeFilterWidgets;

    return SafeArea(
      child: ConstrainedBox(
        constraints: BoxConstraints(
          maxHeight: MediaQuery.sizeOf(context).height * 0.72,
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Padding(
              padding: const EdgeInsets.fromLTRB(20, 4, 20, 8),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text('Home widgets', style: theme.textTheme.titleLarge),
                  const SizedBox(height: 4),
                  Text(
                    'Pin saved transaction filters on Home. Check Display to '
                    'show a widget; edit metrics or remove anytime.',
                    style: theme.textTheme.bodyMedium?.copyWith(
                      color: theme.colorScheme.onSurfaceVariant,
                    ),
                  ),
                ],
              ),
            ),
            Padding(
              padding: const EdgeInsets.fromLTRB(16, 0, 16, 8),
              child: OutlinedButton.icon(
                onPressed: () async {
                  final created = await composeHomeFilterWidget(context);
                  if (created == null || !context.mounted) return;
                  await prefs.addHomeFilterWidget(created);
                },
                icon: const Icon(Icons.add),
                label: const Text('Add filter widget'),
              ),
            ),
            const Divider(height: 1),
            Expanded(
              child: widgets.isEmpty
                  ? Center(
                      child: Padding(
                        padding: const EdgeInsets.all(24),
                        child: Text(
                          'No widgets yet. Add a filter, or save one from '
                          'Transactions.',
                          textAlign: TextAlign.center,
                          style: theme.textTheme.bodyMedium?.copyWith(
                            color: theme.colorScheme.onSurfaceVariant,
                          ),
                        ),
                      ),
                    )
                  : ListView.separated(
                      padding: const EdgeInsets.fromLTRB(8, 8, 8, 24),
                      itemCount: widgets.length,
                      separatorBuilder: (_, _) => const Divider(height: 1),
                      itemBuilder: (context, index) {
                        final widgetItem = widgets[index];
                        return CheckboxListTile(
                          value: widgetItem.display,
                          onChanged: (value) {
                            if (value == null) return;
                            prefs.setHomeFilterWidgetDisplay(
                              widgetItem.id,
                              value,
                            );
                          },
                          secondary: IconButton(
                            tooltip: 'Edit',
                            onPressed: () async {
                              final updated = await composeHomeFilterWidget(
                                context,
                                existing: widgetItem,
                              );
                              if (updated == null || !context.mounted) return;
                              await prefs.updateHomeFilterWidget(updated);
                            },
                            icon: const Icon(Icons.edit_outlined),
                          ),
                          title: Text(widgetItem.name),
                          subtitle: Text(
                            '${_subtitle(widgetItem)}\n'
                            'Display on Home',
                          ),
                          isThreeLine: true,
                          controlAffinity: ListTileControlAffinity.leading,
                        );
                      },
                    ),
            ),
          ],
        ),
      ),
    );
  }

  static String _subtitle(HomeFilterWidget w) {
    final parts = <String>[
      if (w.monthOnly) 'This month',
      if (w.flow != TxFlowFilter.all) w.flow.name,
      if (w.labelIds.isNotEmpty) '${w.labelIds.length} labels',
      if (w.query.trim().isNotEmpty) '“${w.query.trim()}”',
      if (w.showAmountIn) 'In',
      if (w.showAmountOut) 'Out',
      if (w.showCount) 'Count',
    ];
    return parts.isEmpty ? 'All transactions' : parts.join(' · ');
  }
}