using SHADE;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SHADE_Scripting.UI
{
  public class SceneFadeInOut : Script
  {
    //[Tooltip("If true, the panel fadeUI fades in (increasing alpha). If false, no fading. Mutually exclusive with fadeIn")]
    private bool fadeIn;

    //[Tooltip("If true, the panel fadeUI fades out (decreasing alpha). If false, no fading. Mutually exclusive with fadeIn")]
    private bool fadeOut;

    [Tooltip("The initial alpha value of the UI that is faded. Between 0 and 1 inclusive.")]
    public float alphaValue;

    [SerializeField]
    private float fadeInTime;

    [SerializeField]
    private float fadeOutTime;

    private Renderable fadeR;

    public static SceneFadeInOut Instance { get; private set; }

    protected override void awake()
    {
      if (Instance != null && Instance != this)
        RemoveScript<SceneFadeInOut>();
      else
        Instance = this;

      fadeR = GameObject.GetComponent<Renderable>();
      fadeR.Material.SetProperty<float>("data.alpha", alphaValue);
      GameObject.Parent.SetActive(false);
      //alphaValue = fadeR.Material.GetProperty<float>("data.alpha");
    }

    protected override void start()
    {
    }

    protected override void update()
    {
      if (fadeR != null)
      {
        if (fadeIn) //fading in
        {
          fadeOut = false;
          if (fadeInTime == 0.0f)
          {
            alphaValue = 1.0f;
          }
          else
          {
            alphaValue += (1.0f / fadeInTime) * Time.DeltaTimeF;
          }
          if (alphaValue >= 1.0f)
          {
            alphaValue = 1.0f;
            //GameObject.Parent.SetActive(false);
          }
        }

        if (fadeOut) //fading out
        {
          fadeIn = false;
          if (fadeOutTime == 0.0f)
          {
            alphaValue = 0.0f;
            
          }
          else
          {
            alphaValue -= (1.0f / fadeOutTime) * Time.DeltaTimeF;
          }
          if (alphaValue <= 0.0f)
          { 
            alphaValue = 0.0f;
            //This line is to be added so that (because the fade in and out item is usually the front-most UI element)
            //the fade in and out UI element does not block functionality of other UI elements
            GameObject.Parent.SetActive(false);
          }
        }

        fadeR.Material.SetProperty<float>("data.alpha", alphaValue);
      }
    }
    
    protected override void onDestroy()
    {
      if (Instance == this)
        Instance = null;
    }

    public void CallFadeIn()
    {
      fadeIn = true;
      fadeOut = false;
      GameObject.Parent.SetActive(true);
    }

    public void CallFadeOut()
    {
      fadeOut = true;
      fadeIn = false;
      GameObject.Parent.SetActive(true);
    }

    public void CallFadeStop()
    {
      fadeOut = false;
      fadeIn = false;
      GameObject.Parent.SetActive(false);
    }

    public bool FadeOutFinished()
    {
      return (alphaValue <= 0.0f);
    }

    public bool FadeInFinished()
    {
      return (alphaValue >= 1.0f);
    }
  }
}