using UnityEngine;
using UnityEditor;
using Unity.Mathematics;
using System;
using System.Reflection;
using System.Collections;

namespace NanoBrain {
    [CustomPropertyDrawer(typeof(Neuron))]
    class NeuronDrawer : PropertyDrawer {
        public override void OnGUI(Rect position, SerializedProperty property, GUIContent label) {
            // Draw foldout + properties
            label = EditorGUI.BeginProperty(position, label, property);

            // Begin indent block
            int indent = EditorGUI.indentLevel;
            EditorGUI.indentLevel = 0;

            object instance = GetTargetObjectOfProperty(property);

            float lineHeight = EditorGUIUtility.singleLineHeight;
            Rect r = new(position.x, position.y, position.width, lineHeight);
            if (instance != null) {
                FieldInfo field = typeof(Neuron).GetField("_outputValue", BindingFlags.NonPublic | BindingFlags.Instance);
                if (field != null) {
                    float3 val = (float3)field.GetValue(instance);
                    EditorGUI.Vector3Field(r, $"Neuron: {label}", val);
                }
            }

            EditorGUI.indentLevel = indent;
            EditorGUI.EndProperty();
        }

        public override float GetPropertyHeight(SerializedProperty property, GUIContent label) {
            // height for 1 line
            return (EditorGUIUtility.singleLineHeight * 1) + (EditorGUIUtility.standardVerticalSpacing * 0);
        }

        public static object GetTargetObjectOfProperty(SerializedProperty prop) {
            var path = prop.propertyPath.Replace(".Array.data[", "[");
            object obj = prop.serializedObject.targetObject;
            var elements = path.Split('.');
            foreach (var element in elements) {
                if (element.Contains("[")) {
                    var elementName = element.Substring(0, element.IndexOf("["));
                    var index = Convert.ToInt32(element.Substring(element.IndexOf("[")).Replace("[", "").Replace("]", ""));
                    obj = GetValue_Imp(obj, elementName, index);
                }
                else {
                    obj = GetValue_Imp(obj, element);
                }
            }
            return obj;
        }

        static object GetValue_Imp(object source, string name) {
            if (source == null)
                return null;

            Type t = source.GetType();
            FieldInfo f = t.GetField(name, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
            if (f != null)
                return f.GetValue(source);
            PropertyInfo p = t.GetProperty(name, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
            return p?.GetValue(source, null);
        }
        static object GetValue_Imp(object source, string name, int index) {
            if (GetValue_Imp(source, name) is not IEnumerable enumerable)
                return null;
            IEnumerator en = enumerable.GetEnumerator();
            for (int i = 0; i <= index; i++) {
                if (!en.MoveNext())
                    return null;
            }
            return en.Current;
        }
    }
}