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

import '../../l10n/app_localizations.dart';
import '../../l10n/app_localizations_helpers.dart';
import '../../models/app_error.dart';
import '../../models/bar_tab.dart';
import '../../services/pin_lock_service.dart';
import '../../viewmodels/admin_pin_view_model.dart';
import '../../viewmodels/bar_screen_view_model.dart';
import 'duplicate_tab_name_dialog.dart';

Future<void> showEditTabDialog(BuildContext context, BarTab tab) async {
  final l10n = AppLocalizations.of(context);

  final name = await showDialog<String>(
    context: context,
    builder: (_) => _EditTabDialog(initialName: tab.customerName),
  );

  final trimmed = name?.trim() ?? '';
  if (trimmed.isEmpty || trimmed == tab.customerName || !context.mounted) {
    return;
  }

  final viewModel = context.read<BarScreenViewModel>();
  if (viewModel.hasOpenTabNamed(trimmed, exceptTabId: tab.id) &&
      !await confirmDuplicateTabName(context, trimmed)) {
    return;
  }

  try {
    await viewModel.renameTab(tab.id, trimmed);
  } catch (_) {
    if (!context.mounted) return;
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(l10n.couldNotRenameTab)));
  }
}

class _EditTabDialog extends StatefulWidget {
  final String initialName;

  const _EditTabDialog({required this.initialName});

  @override
  State<_EditTabDialog> createState() => _EditTabDialogState();
}

class _EditTabDialogState extends State<_EditTabDialog> {
  late final TextEditingController _controller;

  @override
  void initState() {
    super.initState();
    _controller = TextEditingController(text: widget.initialName);
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);

    return AlertDialog(
      title: Text(l10n.editTab),
      content: TextField(
        controller: _controller,
        autofocus: true,
        textInputAction: TextInputAction.done,
        decoration: InputDecoration(labelText: l10n.customerGroupName),
        onSubmitted: (value) {
          Navigator.of(context).pop(value);
        },
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.of(context).pop(),
          child: Text(l10n.cancel),
        ),
        FilledButton(
          onPressed: () => Navigator.of(context).pop(_controller.text),
          child: Text(l10n.confirm),
        ),
      ],
    );
  }
}

/// Deleting a tab with drinks on it leaves no trace in history, so it needs
/// the admin PIN when one is set.
Future<void> confirmDeleteTab(BuildContext context, BarTab tab) async {
  final l10n = AppLocalizations.of(context);
  final adminPinViewModel = context.read<AdminPinViewModel>();
  final needsAdminPin = tab.items.isNotEmpty && adminPinViewModel.isPinSet;

  final result = await showDialog<_DeleteTabResult>(
    context: context,
    builder: (_) => _DeleteTabDialog(
      description: tab.items.isEmpty
          ? l10n.deleteTabDescription
          : l10n.deleteTabWithItemsDescription,
      needsAdminPin: needsAdminPin,
    ),
  );

  if (result == null || !context.mounted) return;

  if (needsAdminPin) {
    final error = await _verifyAdminPin(adminPinViewModel, result.pin);
    if (error != null) {
      if (!context.mounted) return;
      ScaffoldMessenger.of(
        context,
      ).showSnackBar(SnackBar(content: Text(l10n.errorText(error))));
      return;
    }
  }

  if (!context.mounted) return;

  try {
    await context.read<BarScreenViewModel>().deleteTab(tab.id);
  } catch (_) {
    if (!context.mounted) return;
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(l10n.couldNotDeleteTab)));
  }
}

Future<AppError?> _verifyAdminPin(
  AdminPinViewModel adminPinViewModel,
  String pin,
) async {
  try {
    final matches = await adminPinViewModel.adminPinService.verifyPin(pin);
    return matches ? null : AppError.incorrectPin;
  } on PinLockedOutException {
    return AppError.tooManyPinAttempts;
  } catch (_) {
    return AppError.verifyPin;
  }
}

class _DeleteTabResult {
  final String pin;

  const _DeleteTabResult(this.pin);
}

class _DeleteTabDialog extends StatefulWidget {
  final String description;
  final bool needsAdminPin;

  const _DeleteTabDialog({
    required this.description,
    required this.needsAdminPin,
  });

  @override
  State<_DeleteTabDialog> createState() => _DeleteTabDialogState();
}

class _DeleteTabDialogState extends State<_DeleteTabDialog> {
  final _pinController = TextEditingController();

  @override
  void dispose() {
    _pinController.dispose();
    super.dispose();
  }

  void _confirm() {
    Navigator.of(context).pop(_DeleteTabResult(_pinController.text));
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);

    return AlertDialog(
      title: Text(l10n.deleteTab),
      content: SizedBox(
        width: 360,
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(widget.description),
            if (widget.needsAdminPin) ...[
              const SizedBox(height: 16),
              TextField(
                controller: _pinController,
                autofocus: true,
                obscureText: true,
                keyboardType: TextInputType.number,
                maxLength: 4,
                decoration: InputDecoration(labelText: l10n.adminPin),
                onSubmitted: (_) => _confirm(),
              ),
            ],
          ],
        ),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.of(context).pop(),
          child: Text(l10n.cancel),
        ),
        FilledButton(
          onPressed: _confirm,
          style: FilledButton.styleFrom(
            backgroundColor: Theme.of(context).colorScheme.error,
          ),
          child: Text(l10n.delete),
        ),
      ],
    );
  }
}