using System;
using Module.Inspector.Editor.Utilities;
using UnityEditor;
using UnityEngine;

namespace Module.Inspector.Editor
{
    [CustomPropertyDrawer(typeof(IntToEnum))]
    internal sealed class DrawerIntToEnum : DrawerPropertyDrawer
    {
        private GUIContent[] names;
        private int[] values;
        
        public override bool Draw(Rect position, DrawerPropertyAttribute attribute, SerializedProperty property, GUIContent label, EditorPropertyUtility.Result result)
        {
            if (property.propertyType != SerializedPropertyType.Integer)
                return false;
            
            var att = (IntToEnum)attribute;
            FetchLayerNames(att);
                
            EditorGUI.BeginChangeCheck();
            EditorGUI.BeginProperty(position, label, property);
            {
                int index = Array.IndexOf(values, property.intValue);
                int newIndex = EditorGUI.Popup(position, label, index, names);

                if (newIndex != -1 && index != newIndex)
                    property.intValue = values[newIndex];
            }
            EditorGUI.EndProperty();
            bool changed = EditorGUI.EndChangeCheck();

            if (changed)
                property.serializedObject.ApplyModifiedProperties();
            
            return true;
        }
        
        public override string GetErrorMessage(SerializedProperty property)
        {
            return "Only supports integers";
        }

        private void FetchLayerNames(IntToEnum attribute)
        {
            if (names != null)
                return;

            Type type = attribute.GetValidType();
            string[] arrNames = Enum.GetNames(type);
            Array arrValues = Enum.GetValues(type);
            
            names = new GUIContent[arrNames.Length];
            values = new int[arrValues.Length];

            for (var i = 0; i < names.Length; i++)
            {
                names[i] = new GUIContent(arrNames[i]);
                values[i] = Convert.ToInt32(arrValues.GetValue(i));
            }
        }
    }
}