using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Threading;
using UtopiaCanteenSystem.ViewModels;

namespace UtopiaCanteenSystem.Views;

/// <summary>
/// Minimal code-behind for PasswordBox + initial focus.
/// </summary>
public partial class AdminSettingsAuthView : UserControl
{
    private AdminSettingsAuthViewModel? _vm;

    public AdminSettingsAuthView()
    {
        InitializeComponent();
        Loaded += OnLoaded;
        DataContextChanged += OnDataContextChanged;
    }

    private void OnLoaded(object sender, RoutedEventArgs e)
    {
        Dispatcher.BeginInvoke(() =>
        {
            // If VM has a remembered password, prefill the PasswordBox (it's not bindable).
            if (DataContext is AdminSettingsAuthViewModel vm && !string.IsNullOrEmpty(vm.Password))
                PasswordBox.Password = vm.Password;

            UsernameTextBox.Focus();
            UsernameTextBox.SelectAll();
        }, DispatcherPriority.Input);
    }

    private void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
    {
        if (_vm != null)
            _vm.PropertyChanged -= VmOnPropertyChanged;

        _vm = DataContext as AdminSettingsAuthViewModel;
        if (_vm != null)
            _vm.PropertyChanged += VmOnPropertyChanged;

        // Sync PasswordBox from VM when navigating here (supports remembered creds).
        if (_vm != null)
            PasswordBox.Password = _vm.Password ?? string.Empty;
    }

    private void VmOnPropertyChanged(object? sender, PropertyChangedEventArgs e)
    {
        if (!string.Equals(e.PropertyName, nameof(AdminSettingsAuthViewModel.Password), StringComparison.Ordinal))
            return;

        if (_vm != null && string.IsNullOrEmpty(_vm.Password) && !string.IsNullOrEmpty(PasswordBox.Password))
            PasswordBox.Password = string.Empty;
    }

    private void PasswordBox_OnPasswordChanged(object sender, RoutedEventArgs e)
    {
        if (DataContext is AdminSettingsAuthViewModel vm)
            vm.Password = PasswordBox.Password;
    }

    private void Confirm_OnKeyDown(object sender, KeyEventArgs e)
    {
        if (e.Key != Key.Enter)
            return;

        if (DataContext is AdminSettingsAuthViewModel vm && vm.ConfirmCommand.CanExecute(null))
        {
            vm.ConfirmCommand.Execute(null);
            e.Handled = true;
        }
    }
}