using UnityEngine;

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

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

      ///<summary>Random change interval between min (= x) and max (= y) in seconds (default: x = 10, y = 20).</summary>
      [Tooltip("Random change interval between min (= x) and max (= y) in seconds (default: x = 10, y = 20).")]
      public Vector2 ChangeInterval = new Vector2(10, 20);

      ///<summary>Minimum scale per axis (default: 0.1 for all axis).</summary>
      [Tooltip("Minimum rotation speed per axis (default: 5 for all axis).")] public Vector3 ScaleMin = new Vector3(0.1f, 0.1f, 0.1f);

      ///<summary>Maximum scale per axis (default: 0.1 for all axis).</summary>
      [Tooltip("Maximum scale per axis (default: 0.1 for all axis).")] public Vector3 ScaleMax = new Vector3(3, 3, 3);

      ///<summary>Uniform scaling for all axis (x-axis values will be used, default: true).</summary>
      [Tooltip("Uniform scaling for all axis (x-axis values will be used, default: true).")] public bool Uniform = true;

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

      private Transform tf;
      private Vector3 startScale;
      private Vector3 endScale;
      private float elapsedTime;
      private float changeTime;
      private float lerpTime;

      #endregion


      #region MonoBehaviour methods

      private void Start()
      {
         tf = transform;

         elapsedTime = changeTime = Random.Range(ChangeInterval.x, ChangeInterval.y);

         if (RandomScaleAtStart)
         {
            if (Uniform)
            {
               startScale.x = startScale.y = startScale.z = Random.Range(ScaleMin.x, Mathf.Abs(ScaleMax.x));
            }
            else
            {
               startScale.x = Random.Range(ScaleMin.x, Mathf.Abs(ScaleMax.x));
               startScale.y = Random.Range(ScaleMin.y, Mathf.Abs(ScaleMax.y));
               startScale.z = Random.Range(ScaleMin.z, Mathf.Abs(ScaleMax.z));
            }

            tf.localScale = startScale;
         }
         else
         {
            startScale = tf.localScale;
         }
      }

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

            if (elapsedTime > changeTime)
            {
               lerpTime = elapsedTime = 0f;

               if (Uniform)
               {
                  endScale.x = endScale.y = endScale.z = Random.Range(ScaleMin.x, Mathf.Abs(ScaleMax.x));
               }
               else
               {
                  endScale.x = Random.Range(ScaleMin.x, Mathf.Abs(ScaleMax.x));
                  endScale.y = Random.Range(ScaleMin.y, Mathf.Abs(ScaleMax.y));
                  endScale.z = Random.Range(ScaleMin.z, Mathf.Abs(ScaleMax.z));
               }

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

            tf.localScale = Vector3.Lerp(startScale, endScale, lerpTime);

            if (lerpTime < 1f)
            {
               lerpTime += Time.deltaTime / (changeTime - 0.1f);
            }
            else
            {
               startScale = tf.localScale;
            }
         }
      }

      #endregion
   }
}
// © 2015-2020 crosstales LLC (https://www.crosstales.com)