/// 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';

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

  // Name is edited inside Widget options (no separate rename dialog).
  await WidgetsBinding.instance.endOfFrame;
  if (!navigator.mounted) return null;
  return _promptWidgetMetrics(navigator.context, draft);
}

Future<HomeFilterWidget?> _promptWidgetMetrics(
  BuildContext context,
  HomeFilterWidget draft,
) {
  return showDialog<HomeFilterWidget>(
    context: context,
    useRootNavigator: true,
    builder: (context) => _WidgetOptionsDialog(draft: draft),
  );
}

class _WidgetOptionsDialog extends StatefulWidget {
  const _WidgetOptionsDialog({required this.draft});

  final HomeFilterWidget draft;

  @override
  State<_WidgetOptionsDialog> createState() => _WidgetOptionsDialogState();
}

class _WidgetOptionsDialogState extends State<_WidgetOptionsDialog> {
  late HomeWidgetType _type;
  late String _iconId;
  late HomeWidgetChartStyle _chartStyle;
  late HomeBudgetCapMode _budgetCapMode;
  late int _budgetAverageMonths;
  late bool _showIn;
  late bool _showOut;
  late bool _showCount;
  late bool _halfWidth;
  late final TextEditingController _nameController;
  late final TextEditingController _amountController;

  @override
  void initState() {
    super.initState();
    final draft = widget.draft;
    _type = draft.type;
    _iconId = draft.iconId;
    _chartStyle = draft.chartStyle;
    _budgetCapMode = draft.budgetCapMode;
    _budgetAverageMonths = draft.budgetAverageMonths;
    _showIn = draft.showAmountIn;
    _showOut = draft.showAmountOut;
    _showCount = draft.showCount;
    _halfWidth = draft.halfWidth;
    _nameController = TextEditingController(text: draft.name);
    final fixed = draft.budgetFixedAmount;
    _amountController = TextEditingController(
      text: fixed > 0
          ? (fixed == fixed.roundToDouble()
              ? fixed.toStringAsFixed(0)
              : fixed.toStringAsFixed(2))
          : '',
    );
  }

  @override
  void dispose() {
    _nameController.dispose();
    _amountController.dispose();
    super.dispose();
  }

  void _save() {
    final name = _nameController.text.trim();
    if (name.isEmpty) return;
    if (_type == HomeWidgetType.stats && !_showIn && !_showOut && !_showCount) {
      return;
    }
    var fixed = widget.draft.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(
      widget.draft.copyWith(
        name: name,
        type: _type,
        iconId: _iconId,
        chartStyle: _chartStyle,
        budgetCapMode: _budgetCapMode,
        budgetFixedAmount: fixed,
        budgetAverageMonths: _budgetAverageMonths,
        showAmountIn: _showIn,
        showAmountOut: _showOut,
        showCount: _showCount,
        halfWidth: _halfWidth,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return AlertDialog(
      title: const Text('Widget options'),
      content: SizedBox(
        width: double.maxFinite,
        child: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              TextField(
                controller: _nameController,
                textCapitalization: TextCapitalization.sentences,
                decoration: const InputDecoration(
                  labelText: 'Name',
                  border: OutlineInputBorder(),
                  isDense: true,
                ),
              ),
              const SizedBox(height: 16),
              Text('Type', style: theme.textTheme.titleSmall),
              const SizedBox(height: 8),
              SegmentedButton<HomeWidgetType>(
                showSelectedIcon: false,
                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('Spent'),
                  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>(
                  showSelectedIcon: false,
                  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
                  DropdownButtonFormField<int>(
                    key: ValueKey(_budgetAverageMonths),
                    initialValue: _budgetAverageMonths,
                    isExpanded: true,
                    decoration: const InputDecoration(
                      labelText: 'Average of last N months',
                      border: OutlineInputBorder(),
                      isDense: true,
                    ),
                    items: [
                      for (final n in const [1, 2, 3, 6, 12, 24])
                        DropdownMenuItem(
                          value: n,
                          child: Text('$n months'),
                        ),
                    ],
                    onChanged: (value) {
                      if (value == null) return;
                      setState(() => _budgetAverageMonths = value);
                    },
                  ),
                const SizedBox(height: 16),
                Text('Chart', style: theme.textTheme.titleSmall),
                const SizedBox(height: 8),
                Wrap(
                  spacing: 8,
                  children: [
                    for (final entry in const [
                      (HomeWidgetChartStyle.bar, Icons.linear_scale, 'Bar'),
                      (
                        HomeWidgetChartStyle.pie,
                        Icons.pie_chart_outline,
                        'Pie'
                      ),
                      (HomeWidgetChartStyle.ring, Icons.donut_large, 'Ring'),
                    ])
                      ChoiceChip(
                        avatar: Icon(entry.$2, size: 18),
                        label: Text(entry.$3),
                        selected: _chartStyle == entry.$1,
                        onSelected: (_) =>
                            setState(() => _chartStyle = entry.$1),
                      ),
                  ],
                ),
                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: _save,
          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 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) 'Spent',
      if (w.type == HomeWidgetType.stats && w.showCount) 'Count',
      if (w.halfWidth) 'Half',
    ];
    return parts.join(' · ');
  }
}