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

namespace UtopiaCanteenSystem.Views;

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

    public AdminLoginView()
    {
        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 AdminLoginViewModel vm && !string.IsNullOrEmpty(vm.Password))
                PasswordBox.Password = vm.Password;

            TryLoadLogo();

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

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

        _vm = DataContext as AdminLoginViewModel;
        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(AdminLoginViewModel.Password), StringComparison.Ordinal))
            return;

        // Keep PasswordBox UI in sync when VM clears password after clicking Login.
        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 AdminLoginViewModel vm)
            vm.Password = PasswordBox.Password;
    }

    private void LogoImage_OnImageFailed(object sender, ExceptionRoutedEventArgs e)
    {
        // If assets/logo.png isn't present in output, fall back to text title.
        LogoImage.Visibility = Visibility.Collapsed;
        LogoFallbackText.Visibility = Visibility.Visible;
    }

    private void TryLoadLogo()
    {
        try
        {
            var uri = new Uri("pack://siteoforigin:,,,/assets/logo4.png", UriKind.Absolute);
            var bmp = new BitmapImage();
            bmp.BeginInit();
            bmp.UriSource = uri;
            bmp.CacheOption = BitmapCacheOption.OnLoad;
            bmp.EndInit();

            LogoImage.Source = bmp;
            LogoFallbackText.Visibility = Visibility.Collapsed;
            LogoImage.Visibility = Visibility.Visible;
        }
        catch
        {
            LogoImage.Visibility = Visibility.Collapsed;
            LogoFallbackText.Visibility = Visibility.Visible;
        }
    }

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

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