#if UNITY_EDITOR
using UnityEditor;
using UnityEngine;
using System;
using System.Linq;
namespace KD.Destro2D.Editor {
[CustomPropertyDrawer(typeof(Destruction), true)]
public class Destro2DMenu : PropertyDrawer
{
    const float PAD = 2f;

    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {
        EditorGUI.BeginProperty(position, label, property);

        Rect header = new Rect(
            position.x,
            position.y,
            position.width,
            EditorGUIUtility.singleLineHeight
        );

        string title =
            property.managedReferenceValue == null
                ? "Select Destruction Type"
                : property.managedReferenceValue.GetType().Name;

        if (GUI.Button(header, title, EditorStyles.popup))
        {
            var menu = new GenericMenu();

            var types = TypeCache.GetTypesDerivedFrom<Destruction>()
                .Where(t => !t.IsAbstract && !t.IsGenericType);

            foreach (var type in types)
            {
                menu.AddItem(
                    new GUIContent(type.Name),
                    false,
                    () =>
                    {
                        property.managedReferenceValue = Activator.CreateInstance(type);
                        property.serializedObject.ApplyModifiedProperties();
                    }
                );
            }

            menu.ShowAsContext();
        }

        if (property.managedReferenceValue != null)
        {
            Rect body = new Rect(
                position.x,
                position.y + EditorGUIUtility.singleLineHeight + PAD,
                position.width,
                EditorGUI.GetPropertyHeight(property, true)
            );

            EditorGUI.indentLevel++;
            EditorGUI.PropertyField(body, property, GUIContent.none, true);
            EditorGUI.indentLevel--;
        }

        EditorGUI.EndProperty();
    }

    public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
    {
        if (property.managedReferenceValue == null)
            return EditorGUIUtility.singleLineHeight;

        return EditorGUIUtility.singleLineHeight +
               PAD +
               EditorGUI.GetPropertyHeight(property, true);
    }
}
}
#endif