/// 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 {
  // Capture before any modal opens — the caller's element may be rebuilt.
  final bank = context.read<BankController>();
  final meta = context.read<TxMetaController>();
  final navigator = Navigator.of(context);

  TransactionFilterSelection? filter = initialFilter ?? existing?.filter;
  if (!skipFilterDialog || filter == null) {
    filter = await showTransactionFilterDialog(
      navigator.context,
      available: meta.allLabels,
      transactions: bank.transactions,
      initial: filter ?? const TransactionFilterSelection(labelIds: {}),
    );
    if (filter == null || !navigator.mounted) return null;
  }

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

  // Let the name dialog finish popping before presenting options.
  await WidgetsBinding.instance.endOfFrame;
  if (!navigator.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(navigator.context, draft);
}

Future<HomeFilterWidget?> _promptWidgetMetrics(
  BuildContext context,
  HomeFilterWidget draft,
) {
  var type = draft.type;
  var iconId = draft.iconId;
  var chartStyle = draft.chartStyle;
  var budgetCapMode = draft.budgetCapMode;
  var budgetFixedAmount = draft.budgetFixedAmount;
  var budgetAverageMonths = draft.budgetAverageMonths;
  var showIn = draft.showAmountIn;
  var showOut = draft.showAmountOut;
  var showCount = draft.showCount;
  var halfWidth = draft.halfWidth;
  final amountController = TextEditingController(
    text: budgetFixedAmount > 0
        ? (budgetFixedAmount == budgetFixedAmount.roundToDouble()
            ? budgetFixedAmount.toStringAsFixed(0)
            : budgetFixedAmount.toStringAsFixed(2))
        : '',
  );

  return showDialog<HomeFilterWidget>(
    context: context,
    useRootNavigator: true,
    builder: (context) {
      return StatefulBuilder(
        builder: (context, setState) {
          final theme = Theme.of(context);
          return AlertDialog(
            title: const Text('Widget options'),
            content: SizedBox(
              width: 360,
              child: SingleChildScrollView(
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    Text('Type', style: theme.textTheme.titleSmall),
                    const SizedBox(height: 8),
                    SegmentedButton<HomeWidgetType>(
                      segments: const [
                        ButtonSegment(
                          value: HomeWidgetType.stats,
                          label: Text('Stats'),
                          icon: Icon(Icons.analytics_outlined),
                        ),
                        ButtonSegment(
                          value: HomeWidgetType.budget,
                          label: Text('Budget'),
                          icon: Icon(Icons.savings_outlined),
                        ),
                      ],
                      selected: {type},
                      onSelectionChanged: (value) {
                        setState(() => type = value.first);
                      },
                    ),
                    const SizedBox(height: 16),
                    Text('Icon', style: theme.textTheme.titleSmall),
                    const SizedBox(height: 8),
                    Wrap(
                      spacing: 6,
                      runSpacing: 6,
                      children: [
                        for (final entry in HomeWidgetIcons.all)
                          ChoiceChip(
                            label: Icon(entry.$2, size: 18),
                            selected: iconId == entry.$1,
                            onSelected: (_) =>
                                setState(() => iconId = entry.$1),
                            tooltip: entry.$3,
                            visualDensity: VisualDensity.compact,
                            padding: const EdgeInsets.all(4),
                          ),
                      ],
                    ),
                    const SizedBox(height: 12),
                    SwitchListTile(
                      contentPadding: EdgeInsets.zero,
                      title: const Text('Half width'),
                      subtitle:
                          const Text('Share the row with another widget'),
                      value: halfWidth,
                      onChanged: (value) =>
                          setState(() => halfWidth = value),
                    ),
                    if (type == HomeWidgetType.stats) ...[
                      const Divider(),
                      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),
                      ),
                    ] else ...[
                      const Divider(),
                      Text('Budget cap', style: theme.textTheme.titleSmall),
                      const SizedBox(height: 8),
                      SegmentedButton<HomeBudgetCapMode>(
                        segments: const [
                          ButtonSegment(
                            value: HomeBudgetCapMode.fixed,
                            label: Text('Fixed'),
                          ),
                          ButtonSegment(
                            value: HomeBudgetCapMode.averageMonths,
                            label: Text('Average'),
                          ),
                        ],
                        selected: {budgetCapMode},
                        onSelectionChanged: (value) {
                          setState(() => budgetCapMode = value.first);
                        },
                      ),
                      const SizedBox(height: 12),
                      if (budgetCapMode == HomeBudgetCapMode.fixed)
                        TextField(
                          controller: amountController,
                          keyboardType: const TextInputType.numberWithOptions(
                            decimal: true,
                          ),
                          decoration: const InputDecoration(
                            labelText: 'Budget amount',
                            hintText: 'e.g. 500',
                            border: OutlineInputBorder(),
                            isDense: true,
                          ),
                        )
                      else
                        Row(
                          children: [
                            Expanded(
                              child: Text(
                                'Average |net| of last',
                                style: theme.textTheme.bodyMedium,
                              ),
                            ),
                            SizedBox(
                              width: 88,
                              child: DropdownButtonFormField<int>(
                                initialValue: budgetAverageMonths,
                                decoration: const InputDecoration(
                                  border: OutlineInputBorder(),
                                  isDense: true,
                                  suffixText: 'mo',
                                ),
                                items: [
                                  for (final n in const [1, 2, 3, 6, 12, 24])
                                    DropdownMenuItem(
                                      value: n,
                                      child: Text('$n'),
                                    ),
                                ],
                                onChanged: (value) {
                                  if (value == null) return;
                                  setState(
                                    () => budgetAverageMonths = value,
                                  );
                                },
                              ),
                            ),
                          ],
                        ),
                      const SizedBox(height: 16),
                      Text('Chart', style: theme.textTheme.titleSmall),
                      const SizedBox(height: 8),
                      SegmentedButton<HomeWidgetChartStyle>(
                        segments: const [
                          ButtonSegment(
                            value: HomeWidgetChartStyle.bar,
                            label: Text('Bar'),
                            icon: Icon(Icons.linear_scale),
                          ),
                          ButtonSegment(
                            value: HomeWidgetChartStyle.pie,
                            label: Text('Pie'),
                            icon: Icon(Icons.pie_chart_outline),
                          ),
                          ButtonSegment(
                            value: HomeWidgetChartStyle.ring,
                            label: Text('Ring'),
                            icon: Icon(Icons.donut_large),
                          ),
                        ],
                        selected: {chartStyle},
                        onSelectionChanged: (value) {
                          setState(() => chartStyle = value.first);
                        },
                      ),
                      const SizedBox(height: 8),
                      Text(
                        'Progress uses this month’s net (|in − out|) for the '
                        'filter toward the cap.',
                        style: theme.textTheme.bodySmall?.copyWith(
                          color: theme.colorScheme.onSurfaceVariant,
                        ),
                      ),
                    ],
                  ],
                ),
              ),
            ),
            actions: [
              TextButton(
                onPressed: () => Navigator.of(context).pop(),
                child: const Text('Cancel'),
              ),
              FilledButton(
                onPressed: () {
                  if (type == HomeWidgetType.stats &&
                      !showIn &&
                      !showOut &&
                      !showCount) {
                    return;
                  }
                  var fixed = budgetFixedAmount;
                  if (type == HomeWidgetType.budget &&
                      budgetCapMode == HomeBudgetCapMode.fixed) {
                    final parsed = double.tryParse(
                      amountController.text.trim().replaceAll(',', '.'),
                    );
                    if (parsed == null || parsed <= 0) return;
                    fixed = parsed;
                  }
                  Navigator.of(context).pop(
                    draft.copyWith(
                      type: type,
                      iconId: iconId,
                      chartStyle: chartStyle,
                      budgetCapMode: budgetCapMode,
                      budgetFixedAmount: fixed,
                      budgetAverageMonths: budgetAverageMonths,
                      showAmountIn: showIn,
                      showAmountOut: showOut,
                      showCount: showCount,
                      halfWidth: halfWidth,
                    ),
                  );
                },
                child: const Text('Save'),
              ),
            ],
          );
        },
      );
    },
  ).whenComplete(amountController.dispose);
}

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 layout', style: theme.textTheme.titleLarge),
                  const SizedBox(height: 4),
                  Text(
                    'Choose which built-in sections and filter widgets appear '
                    'on Home. Check Display to show an item.',
                    style: theme.textTheme.bodyMedium?.copyWith(
                      color: theme.colorScheme.onSurfaceVariant,
                    ),
                  ),
                ],
              ),
            ),
            Padding(
              padding: const EdgeInsets.fromLTRB(8, 0, 8, 0),
              child: Column(
                children: [
                  CheckboxListTile(
                    value: prefs.homeBuiltInSections.showTransactions,
                    onChanged: (value) {
                      if (value == null) return;
                      prefs.setHomeShowTransactions(value);
                    },
                    title: const Text('Transactions'),
                    subtitle: const Text('Total transaction count'),
                    controlAffinity: ListTileControlAffinity.leading,
                  ),
                  CheckboxListTile(
                    value: prefs.homeBuiltInSections.showCategorized,
                    onChanged: (value) {
                      if (value == null) return;
                      prefs.setHomeShowCategorized(value);
                    },
                    title: const Text('Categorized'),
                    subtitle: const Text('Labeled transaction count'),
                    controlAffinity: ListTileControlAffinity.leading,
                  ),
                  CheckboxListTile(
                    value: prefs.homeBuiltInSections.showRecent,
                    onChanged: (value) {
                      if (value == null) return;
                      prefs.setHomeShowRecent(value);
                    },
                    title: const Text('Recent transactions'),
                    subtitle: const Text('Latest activity list'),
                    controlAffinity: ListTileControlAffinity.leading,
                  ),
                ],
              ),
            ),
            const Divider(height: 1),
            Padding(
              padding: const EdgeInsets.fromLTRB(16, 8, 16, 8),
              child: OutlinedButton.icon(
                onPressed: () async {
                  final preferences = context.read<PreferencesController>();
                  final created = await composeHomeFilterWidget(context);
                  if (created == null) return;
                  await preferences.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 filter widgets yet. Add one here, or save a '
                          'filter 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: PopupMenuButton<String>(
                            tooltip: 'Widget actions',
                            onSelected: (value) async {
                              if (value == 'edit') {
                                final preferences =
                                    context.read<PreferencesController>();
                                final updated =
                                    await composeHomeFilterWidget(
                                  context,
                                  existing: widgetItem,
                                );
                                if (updated == null) return;
                                await preferences
                                    .updateHomeFilterWidget(updated);
                              } else if (value == 'delete') {
                                await prefs
                                    .removeHomeFilterWidget(widgetItem.id);
                              }
                            },
                            itemBuilder: (context) => const [
                              PopupMenuItem(
                                value: 'edit',
                                child: Text('Edit'),
                              ),
                              PopupMenuItem(
                                value: 'delete',
                                child: Text('Delete'),
                              ),
                            ],
                          ),
                          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>[
      w.type == HomeWidgetType.budget ? 'Budget' : 'Stats',
      if (w.type == HomeWidgetType.budget)
        w.budgetCapMode == HomeBudgetCapMode.fixed
            ? 'Fixed'
            : 'Avg ${w.budgetAverageMonths}mo',
      if (w.type == HomeWidgetType.budget) w.chartStyle.name,
      if (w.monthOnly) 'This month',
      if (w.flow != TxFlowFilter.all) w.flow.name,
      if (w.labelIds.isNotEmpty) '${w.labelIds.length} labels',
      if (w.query.trim().isNotEmpty) '“${w.query.trim()}”',
      if (w.type == HomeWidgetType.stats && w.showAmountIn) 'In',
      if (w.type == HomeWidgetType.stats && w.showAmountOut) 'Out',
      if (w.type == HomeWidgetType.stats && w.showCount) 'Count',
      if (w.halfWidth) 'Half',
    ];
    return parts.join(' · ');
  }
}