using UnityEngine;

namespace Crosstales.Common.Util
{
   /// <summary>Random color changer.</summary>
   public class RandomColor : MonoBehaviour
   {
      #region Variables

      ///<summary>Use intervals to change the color (default: true).</summary>
      [Tooltip("Use intervals to change the color (default: true).")] public bool UseInterval = true;

      ///<summary>Random change interval between min (= x) and max (= y) in seconds (default: x = 5, y = 10).</summary>
      [Tooltip("Random change interval between min (= x) and max (= y) in seconds (default: x = 5, y = 10).")]
      public Vector2 ChangeInterval = new Vector2(5, 10);

      ///<summary>Random hue range between min (= x) and max (= y) (default: x = 0, y = 1).</summary>
      [Tooltip("Random hue range between min (= x) and max (= y) (default: x = 0, y = 1).")] public Vector2 HueRange = new Vector2(0f, 1f);

      ///<summary>Random saturation range between min (= x) and max (= y) (default: x = 1, y = 1).</summary>
      [Tooltip("Random saturation range between min (= x) and max (= y) (default: x = 1, y = 1).")] public Vector2 SaturationRange = new Vector2(1f, 1f);

      ///<summary>Random value range between min (= x) and max (= y) (default: x = 1, y = 1).</summary>
      [Tooltip("Random value range between min (= x) and max (= y) (default: x = 1, y = 1).")] public Vector2 ValueRange = new Vector2(1f, 1f);

      ///<summary>Random alpha range between min (= x) and max (= y) (default: x = 1, y = 1).</summary>
      [Tooltip("Random alpha range between min (= x) and max (= y) (default: x = 1, y = 1).")] public Vector2 AlphaRange = new Vector2(1f, 1f);

      ///<summary>Use gray scale colors (default: false).</summary>
      [Tooltip("Use gray scale colors (default: false).")] public bool GrayScale;

      ///<summary>Modify the color of a material instead of the Renderer (default: not set, optional).</summary>
      [Tooltip("Modify the color of a material instead of the Renderer (default: not set, optional).")] public Material Material;

      ///<summary>Set the object to a random color at Start (default: false).</summary>
      [Tooltip("Set the object to a random color at Start (default: false).")] public bool RandomColorAtStart;

      private float _elapsedTime;
      private float _changeTime;
      private Renderer _currentRenderer;

      private Color32 _startColor;
      private Color32 _endColor;

      private float _lerpProgress;
      private bool _existsMaterial;

      private static readonly int COLOR_ID = Shader.PropertyToID("_Color");

      #endregion


      #region MonoBehaviour methods

      private void Start()
      {
         _existsMaterial = Material != null;

         _elapsedTime = _changeTime = Random.Range(ChangeInterval.x, ChangeInterval.y);

         if (RandomColorAtStart)
         {
            if (GrayScale)
            {
               float grayScale = Random.Range(HueRange.x, HueRange.y);
               _startColor = new Color(grayScale, grayScale, grayScale, Random.Range(AlphaRange.x, AlphaRange.y));
            }
            else
            {
               _startColor = Random.ColorHSV(HueRange.x, HueRange.y, SaturationRange.x, SaturationRange.y, ValueRange.x, ValueRange.y, AlphaRange.x, AlphaRange.y);
            }

            if (_existsMaterial)
            {
               Material.SetColor(COLOR_ID, _startColor);
            }
            else
            {
               _currentRenderer = GetComponent<Renderer>();
               _currentRenderer.material.color = _startColor;
            }
         }
         else
         {
            if (_existsMaterial)
            {
               _startColor = Material.GetColor(COLOR_ID);
            }
            else
            {
               _currentRenderer = GetComponent<Renderer>();
               _startColor = _currentRenderer.material.color;
            }
         }
      }

      private void Update()
      {
         if (UseInterval)
         {
            _elapsedTime += Time.deltaTime;

            if (_elapsedTime > _changeTime)
            {
               _lerpProgress = _elapsedTime = 0f;

               if (GrayScale)
               {
                  float grayScale = Random.Range(HueRange.x, HueRange.y);
                  _endColor = new Color(grayScale, grayScale, grayScale, Random.Range(AlphaRange.x, AlphaRange.y));
               }
               else
               {
                  _endColor = Random.ColorHSV(HueRange.x, HueRange.y, SaturationRange.x, SaturationRange.y, ValueRange.x, ValueRange.y, AlphaRange.x, AlphaRange.y);
               }

               _changeTime = Random.Range(ChangeInterval.x, ChangeInterval.y);
            }

            if (_existsMaterial)
            {
               Material.SetColor(COLOR_ID, Color.Lerp(_startColor, _endColor, _lerpProgress));
            }
            else
            {
               _currentRenderer.material.color = Color.Lerp(_startColor, _endColor, _lerpProgress);
            }

            if (_lerpProgress < 1f)
            {
               _lerpProgress += Time.deltaTime / (_changeTime - 0.1f);
            }
            else
            {
               _startColor = _existsMaterial ? Material.GetColor(COLOR_ID) : _currentRenderer.material.color;
            }
         }
      }

      #endregion
   }
}
// © 2015-2023 crosstales LLC (https://www.crosstales.com)