using System.Collections;
using UnityEngine;

namespace Crosstales.UI
{
   /// <summary>Controls a UI group (hint).</summary>
   public class UIHint : MonoBehaviour
   {
      #region Variables

      /// <summary>Group to fade.</summary>
      [Tooltip("Group to fade.")] public CanvasGroup Group;

      /// <summary>Delay in seconds before fading (default: 2).</summary>
      [Tooltip("Delay in seconds before fading (default: 2).")] public float Delay = 2f;

      /// <summary>Fade time in seconds (default: 2).</summary>
      [Tooltip("Fade time in seconds (default: 2).")] public float FadeTime = 2f;

      /// <summary>Disable UI element after the fade (default: true).</summary>
      [Tooltip("Disable UI element after the fade (default: true).")] public bool Disable = true;

      /// <summary>Fade at Start (default: true).</summary>
      [Tooltip("Fade at Start (default: true).")] public bool FadeAtStart = true;

      #endregion


      #region MonoBehaviour methods

      private void Start()
      {
         if (FadeAtStart)
            FadeDown();
      }

      #endregion


      #region Public methods

      public void FadeUp()
      {
         StartCoroutine(lerpAlphaUp(0f, 1f, FadeTime, Delay, Group));
      }

      public void FadeDown()
      {
         StartCoroutine(lerpAlphaDown(1f, 0f, FadeTime, Delay, Group));
      }

      #endregion


      #region Private methods

      private IEnumerator lerpAlphaDown(float startAlphaValue, float endAlphaValue, float time, float delay, Component gameObjectToFade)
      {
         gameObjectToFade.gameObject.SetActive(true);

         Group.alpha = Mathf.Clamp01(startAlphaValue);
         endAlphaValue = Mathf.Clamp01(endAlphaValue);

         if (delay > 0)
            yield return new WaitForSeconds(delay);

         while (Group.alpha >= endAlphaValue + 0.01f)
         {
            Group.alpha -= (1f - endAlphaValue) / time * Time.deltaTime;
            yield return null;
         }

         gameObjectToFade.gameObject.SetActive(!Disable);
      }

      private IEnumerator lerpAlphaUp(float startAlphaValue, float endAlphaValue, float time, float delay, Component gameObjectToFade)
      {
         if (gameObjectToFade != null)
         {
            gameObjectToFade.gameObject.SetActive(true);

            Group.alpha = Mathf.Clamp01(startAlphaValue);
            endAlphaValue = Mathf.Clamp01(endAlphaValue);

            if (delay > 0)
               yield return new WaitForSeconds(delay);

            while (Group.alpha <= endAlphaValue - 0.01f)
            {
               Group.alpha += endAlphaValue / time * Time.deltaTime;
               yield return null;
            }

            gameObjectToFade.gameObject.SetActive(!Disable);
         }
      }

      #endregion
   }
}
// © 2018-2023 crosstales LLC (https://www.crosstales.com)