using UnityEngine;
using UnityEditor;

namespace Alt3d
{
    [CustomEditor(typeof(Transform), true)]
    public class TransformEditor : Editor
    {
        public override void OnInspectorGUI()
        {
            var transform = target as Transform;
            if (!transform)
            {
                return;
            }

            EditorGUIUtility.labelWidth = 15f;

            Vector3 position;
            Vector3 rotation;
            Vector3 scale;
            bool isResetValid;

            EditorGUILayout.BeginHorizontal();
            {
                isResetValid = IsResetVectorValid(transform.localPosition, Vector3.zero);
                if (DrawButton("P", "Reset Position", isResetValid, 20f))
                {
                    Undo.RecordObject(transform, "Reset Position");
                    transform.localPosition = Vector3.zero;
                }
                position = DrawVector3(transform.localPosition);
            }
            EditorGUILayout.EndHorizontal();

            EditorGUILayout.BeginHorizontal();
            {
                isResetValid = IsResetVectorValid(transform.localEulerAngles, Vector3.zero);
                if (DrawButton("R", "Reset Rotation", isResetValid, 20f))
                {
                    Undo.RecordObject(transform, "Reset Rotation");
                    transform.localEulerAngles = Vector3.zero;
                }
                rotation = DrawVector3(transform.localEulerAngles);
            }
            EditorGUILayout.EndHorizontal();

            EditorGUILayout.BeginHorizontal();
            {
                isResetValid = IsResetVectorValid(transform.localScale, Vector3.one);
                if (DrawButton("S", "Reset Scale", isResetValid, 20f))
                {
                    Undo.RecordObject(transform, "Reset Scale");
                    transform.localScale = Vector3.one;
                }
                scale = DrawVector3(transform.localScale);
            }
            EditorGUILayout.EndHorizontal();

            if (GUI.changed)
            {
                Undo.RecordObject(transform, "Transform Change");
                transform.localPosition = ValidateVector(position);
                transform.localEulerAngles = ValidateVector(rotation);
                transform.localScale = ValidateVector(scale);
            }
        }

        private static bool DrawButton(string title, string tooltip, bool enabled, float width)
        {
            if (enabled)
            {
                return GUILayout.Button(new GUIContent(title, tooltip), GUILayout.Width(width));
            }

            var color = GUI.color;
            GUI.color = new Color(1f, 1f, 1f, 0.25f);
            GUILayout.Button(new GUIContent(title, tooltip), GUILayout.Width(width));
            GUI.color = color;
            return false;
        }

        private static Vector3 DrawVector3(Vector3 value)
        {
            var option = GUILayout.MinWidth(30f);
            value.x = EditorGUILayout.FloatField("X", value.x, option);
            value.y = EditorGUILayout.FloatField("Y", value.y, option);
            value.z = EditorGUILayout.FloatField("Z", value.z, option);
            return value;
        }

        private static bool IsResetVectorValid(Vector3 vector, Vector3 target)
        {
            return (vector.x != target.x || vector.y != target.y || vector.z != target.z);
        }

        private static Vector3 ValidateVector(Vector3 vector)
        {
            vector.x = float.IsNaN(vector.x) ? 0f : vector.x;
            vector.y = float.IsNaN(vector.y) ? 0f : vector.y;
            vector.z = float.IsNaN(vector.z) ? 0f : vector.z;
            return vector;
        }
    }
}