using System.Windows;
using System.Windows.Controls;
using CopaData.FileInspector.GUI.TilingPanels.Controls.DragAndDrop;
using CopaData.FileInspector.GUI.TilingPanels.Controls.DropArea;
using CopaData.FileInspector.GUI.TilingPanels.Models;
using CopaData.FileInspector.GUI.ViewModels;

namespace CopaData.FileInspector.GUI.TilingPanels.Controls;

/// <summary>
///   Control that represents the state of a <see cref="Models.TilingHost"/>,
///   with all the necessary interaction logic tied to it.
/// </summary>
public class TilingHostControl : DragAndDropControl
{
  public TilingHost? Host => DataContext as TilingHost;

  static TilingHostControl()
  {
    DefaultStyleKeyProperty.OverrideMetadata(
      typeof(TilingHostControl), 
      new FrameworkPropertyMetadata(typeof(TilingHostControl)));
  }

  protected override void OnElementDragOver(DragAndDropData data, UIElement targetElement)
  {
    SetValue(IsDragTargetPropertyKey, true);
  }

  protected override void OnElementDragLeave(UIElement targetElement)
  {
    SetValue(IsDragTargetPropertyKey, false);
  }

  protected override void OnElementDropped(DragAndDropData data, UIElement targetElement)
  {
    if (data.DataModel is not TilingFrame frame)
    {
         // not for us
         return;
    }

      DropDecision decision = (DropDecision)targetElement.GetValue(DropArea.DropArea.DropDecisionProperty);
      if (decision == DropDecision.Cancel)
         return;

      TilingDirection direction = (TilingDirection)decision; // simple cast suffices here
      if (direction == TilingDirection.None) {
         TilingHost.Insert(TilingManagerViewModel.GlobalRoot, Host!, frame);
      } else {
         TilingPanel.Attach(TilingManagerViewModel.GlobalRoot, Host!, frame, direction);
      }
  }

  #region Dependency Properties

  /// <inheritdoc cref="IsDragTarget" />
  private static readonly DependencyPropertyKey IsDragTargetPropertyKey =
    DependencyProperty.RegisterReadOnly(
        nameof(IsDragTarget),
        typeof(bool),
        typeof(TilingHostControl),
        new PropertyMetadata(false));

  /// <inheritdoc cref="IsDragTarget" />
  public static readonly DependencyProperty IsDragTargetProperty = IsDragTargetPropertyKey.DependencyProperty;

  /// <summary>
  ///   Whether this <see cref="TilingHostControl"/> is being a potential drop target at the moment.
  /// </summary>
  public bool IsDragTarget => (bool)GetValue(IsDragTargetProperty);

  #endregion
}