using System;
using Godot;


namespace Rokojori
{  
  [Tool]
  [GlobalClass ]
  public partial class TweenPosition:SequenceAction
  {
    [Export]
    public Node3D target;

    [Export]
    public Node3D endPosition;

    [Export]
    public Vector3 endOffset;

    [Export]
    public TweenType tweenType = new TweenTimeCurve();


    [Export]
    public bool cacheEndPositionOnStart = true;

    [Export]
    public TimeLine timeLine;


    protected override void _OnTrigger()
    {
      if ( target == null )
      {
        return;
      }

      var tl = TimeLineManager.Ensure( timeLine );

      var start = tl.position;

      var fromPosition = target.GlobalPosition;
      var toPosition = endOffset; 

      if ( endPosition != null )
      {
        toPosition += endPosition.GlobalPosition;
      }
      
      var sequenceID = DispatchStart(); 

      var tweenType = this.tweenType;

      if ( tweenType == null )
      {
        tweenType = TweenTimeCurve.defaultCurve;
      }      

      TimeLineManager.ScheduleSpanIn( tl, 0, tweenType.GetTweenDuration(), 
        ( span, type )=>
        {         
          var timeNow = tl.position;
          var elapsed = timeNow - start;

          var state = tweenType.GetTweenPhaseForPhase( span.phase );

          if ( ! cacheEndPositionOnStart )
          {
            toPosition = endOffset; 

            if ( endPosition != null )
            {
              toPosition += endPosition.GlobalPosition;
            }
          }

          var lerpedPosition = fromPosition.Lerp( toPosition, state );

          target.GlobalPosition = lerpedPosition;
         
          if ( type == TimeLineSpanUpdateType.End )
          {          
            DispatchEnd( sequenceID );
          }
        }
      );
    }

  }
}