Fibonacci-Lines-as-indicator-not-just-drawing-tool

CODE:
using WealthLab.Backtest;
using WealthLab.Core;
using WealthLab.Indicators;
using System.Drawing;
using System.Collections.Generic;

namespace WealthScript6 
{
   public class DivergenceExample2 : UserStrategyBase
   {
      PeakTroughCalculator _ptc;
      double[] levels = { 0.382, 0.5, 0.618 };
      
      //create indicators and other objects here, this is executed prior to the main trading loop
      public override void Initialize(BarHistory bars)
      {
         _ptc = new PeakTroughCalculator(bars, 5.0, PeakTroughReversalTypes.Percent);
         PlotStopsAndLimits(2);
      }

      //execute the strategy rules here, this is executed once for each bar in the backtest history
      public override void Execute(BarHistory bars, int idx)
      {
         if (!HasOpenPosition(bars, PositionType.Long))
         {
            PeakTrough pk = _ptc.GetPeak(idx);
            if (pk == null) return;
            PeakTrough prevT = _ptc.GetPrevTrough(pk);
            if (prevT == null) return;

            int b1 = pk.PeakTroughIndex, b2 = prevT.PeakTroughIndex;
            double p1 = bars.High[b1];
            
            DrawLine(b1, pk.Value, b2, prevT.Value, Color.Blue, 2);
            
            //Fibonacci Retracements 
            double dec = b1 - b2;

            for (int n = 0; n < levels.Length; n++)
            {
               double ret = p1 - dec * levels[n];
               int endBar = b1 +10 > idx ? idx : b1 +10;
               DrawLine(b1, ret, endBar, ret, Color.Blue, 2, LineStyles.Dotted);

               if (bars.Close[idx] > ret)
                  PlaceTrade(bars, TransactionType.Buy, OrderType.Limit, ret, levels[n].ToString("0.0##"));
            }

         }
         else
         {
            Position p = LastPosition;
            double tgt = p.EntryPrice * 1.10;   //10% gain
            double stop = p.EntryPrice * 0.95;  //-5% stop

            PlaceTrade(bars, TransactionType.Sell, OrderType.Stop, stop);
            PlaceTrade(bars, TransactionType.Sell, OrderType.Limit, tgt);
         }
      }
   }
}