/******************************************************************************
 * Copyright (C) Ultraleap, Inc. 2011-2021.                                   *
 *                                                                            *
 * Use subject to the terms of the Apache License 2.0 available at            *
 * http://www.apache.org/licenses/LICENSE-2.0, or another agreement           *
 * between Ultraleap and you, your company or other organization.             *
 ******************************************************************************/

using System;
using System.Collections.Generic;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

namespace Leap.Unity.Attributes
{
    using Query;

    public class EnumFlags : CombinablePropertyAttribute, IFullPropertyDrawer
    {

        public EnumFlags() { }

#if UNITY_EDITOR
        private string[] _enumNames;
        private int[] _enumValues;

        public void DrawProperty(Rect rect, SerializedProperty property, GUIContent label)
        {
            if (_enumNames == null)
            {
                string[] names = (string[])Enum.GetNames(fieldInfo.FieldType);
                int[] values = (int[])Enum.GetValues(fieldInfo.FieldType);

                int count = values.Query().Count(v => v != 0);
                _enumNames = new string[count];
                _enumValues = new int[count];

                int index = 0;
                for (int i = 0; i < names.Length; i++)
                {
                    if (values[i] == 0) continue;

                    _enumNames[index] = names[i];
                    _enumValues[index] = values[i];
                    index++;
                }
            }

            int convertedMask = 0;
            for (int i = 0; i < _enumValues.Length; i++)
            {
                if ((property.intValue & _enumValues[i]) != 0)
                {
                    convertedMask |= (1 << i);
                }
            }

            int resultMask = EditorGUI.MaskField(rect, label, convertedMask, _enumNames);

            int propertyMask = 0;
            {
                int index = 0;
                while (resultMask != 0 && index < _enumValues.Length)
                {
                    if ((resultMask & 1) != 0)
                    {
                        propertyMask |= _enumValues[index];
                    }

                    index++;
                    resultMask = resultMask >> 1;
                }
            }

            property.intValue = propertyMask;
        }

        public override IEnumerable<SerializedPropertyType> SupportedTypes
        {
            get
            {
                yield return SerializedPropertyType.Enum;
            }
        }
#endif
    }
}