// "First non-garbage strategy" (NGS)

sclass NGSStrategy extends G22CandleBasedStrategy {
  settable double minDistance = 0.4; // input.float(0.4, minval=0, step=0.02)
  settable int period1 = 100; // the "slow" MA
  settable int period2 = 5;   // the fast MA (for opening)
  settable double maMinMove = 0.07; // MA trend threshold
  settable double stopLoss = 2;
  settable double trailStart = 1;
  settable double trailPullback = 0.3;
  settable bool doLongs = true;
  settable bool doShorts = true;
  settable bool unblockAfterCrossingBand;
  settable bool unblockAfterTouchingBand = true;
  
  // per-run fields

  settable bool blockLong;
  settable bool blockShort;
  settable double maMove;
  
  void reset :: after {
    resetFields(this, "blockShort blockLong maMove");
  }

  void unblockLong {
    if (blockLong) {
      log("Long unblock");
      blockLong(false);
    }
  }

  void unblockShort {
    if (blockShort) {
      log("Short unblock");
      blockShort(false);
    }
  }
  
  bool maRising() { ret maMove >= maMinMove; }
  bool maFalling() { ret maMove <= -maMinMove; }
  
  double upperBand() { ret ma1*(1+minDistance/100); }
  double lowerBand() { ret ma1*(1-minDistance/100); }

    ma1 = ta.sma(close, period1)
    ma2 = ta.sma(close, period2) 

    maMove((ma1/ma1[1]-1)*100);

    longCondition(doLongs && ma2 > upperBand && maRising);
    shortCondition(doShorts & ma2 < lowerBand && maFalling);

    if (ma2 > ma1)
      unblockShort();

    if (ma2 < ma1)
      unblockLong();

    double drift = drift();
    
    if (drift <= 0 && longCondition && !blockLong) {
      openLong();
      blockLong(true);
    }

    if (drift >= 0 && shortCondition && !blockShort) {
      openShort();
      blockShort(true);
    }

    if (drift > 0 && close < lowerBand) {
      closeAllPositions("Below band");
      if (unblockAfterCrossingBand)
        unblockLong();
    }

    if (drift < 0 && close > upperBand) {
      closeAllPositions("Above band");
      if (unblockAfterCrossingBand)
        unblockShort();
    }

    if (unblockAfterTouchingBand && close < upperBand)
      unblockLong();
    
    if (unblockAfterTouchingBand && close > lowerBand)
      unblockShort();
  }
}