#if HAVE_SLATE

using System;

using UnityEngine;

using Slate;
using Slate.ActionClips;

using Framework.Support;

namespace Framework.Cinematics {

  /// <summary>Changes the alpha value of a standard shader based material</summary>
  [Category("Material")]
  [Description("Change the transparency level of a standard shader based material")]
  public class SetMaterialAlphaAction : ActorActionClip {

    /// <summary>Opacity level that will be assigned to the material</summary>
    public float Opacity = 0.5f;

    /// <summary>Summary of what this action does</summary>
    public override string info {
      get { return "Material Alpha\n" + this.Opacity.ToString("0.0"); }
    }

    /// <summary>Called before the event is played back for the first time</summary>
    protected override void OnEnter() {
      this.materials = MaterialHelper.GetMeshMaterials(actor);

      int materialCount = this.materials.Length;

      this.previousAlpha = new float[materialCount];
      for(int index = 0; index < materialCount; ++index) {
        previousAlpha[index] = this.materials[index].color.a;
      }

      for(int index = 0; index < materialCount; ++index) {
        Color color = this.materials[index].color;
        color.a = previousAlpha[index] * this.Opacity;
        this.materials[index].color = color;
      }
    }

    /// <summary>Called when the action's effects should be reversed</summary>
    /// <remarks>
    ///   Called either after the event has been scrubbed/played in reverse
    ///   or when the stop button is hit after the event was played.
    /// </remarks>
    protected override void OnReverse() {
      int materialCount = this.materials.Length;

      for(int index = 0; index < materialCount; ++index) {
        Color color = this.materials[index].color;
        color.a = this.previousAlpha[index];
        this.materials[index].color = color;
      }
    }

    /// <summary>All materials in whom the opacity level will be changed</summary>
    private Material[] materials;
    /// <summary>Opacity levels the materials had before the action</summary>
    private float[] previousAlpha;

  }

} // namespace Framework.Cinematics

#endif // HAVE_SLATE