// 入力パラメータ
input double ATR_Multiplier = 1.5;    // ATR乗数係数
input int    ATR_Period = 7;          // ATR期間

// グローバル変数




//+------------------------------------------------------------------+
//| Expert deinitialization function                                 |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
   // インジケーターハンドルの解放
}

//+------------------------------------------------------------------+
//| Expert tick function                                             |
//+------------------------------------------------------------------+
void OnTick()
  {
   // ポジションがあるか確認
   bool hasPosition = false;
   for(int i = OrdersTotal()-1; i >= 0; i--)
     {
      if(OrderSelect(i, SELECT_BY_POS, MODE_TRADES))
         if(OrderSymbol() == Symbol())
           {
            hasPosition = true;
            TrailStop(OrderTicket(), OrderType());
           }
     }
  }

//+------------------------------------------------------------------+
//| トレーリングストップを実行                                       |
//+------------------------------------------------------------------+
void TrailStop(int ticket, int orderType)
  {
   if(!OrderSelect(ticket, SELECT_BY_TICKET))
      return;
   
   double atr = iATR(NULL, 0, ATR_Period,1);
   double newStop = 0;
   double currentStop = OrderStopLoss();
   
   if(orderType == OP_BUY)
     {
      newStop = Bid - (atr * ATR_Multiplier);
      newStop = NormalizeDouble(newStop, Digits);
      
      // 現在のストップロスより有利な場合のみ更新
      if(newStop > currentStop || currentStop == 0)
         ModifyStopLoss(ticket, newStop);
     }
   else if(orderType == OP_SELL)
     {
      newStop = Ask + (atr * ATR_Multiplier);
      newStop = NormalizeDouble(newStop, Digits);
      
      // 現在のストップロスより有利な場合のみ更新
      if(newStop < currentStop || currentStop == 0)
         ModifyStopLoss(ticket, newStop);
     }
  }

//+------------------------------------------------------------------+
//| ストップロスを変更                                               |
//+------------------------------------------------------------------+
void ModifyStopLoss(int ticket, double newStop)
  {
   if(OrderModify(ticket, OrderOpenPrice(), newStop, OrderTakeProfit(), 0, clrRed))
      Print("Stop loss updated to ", newStop);
   else
      Print("OrderModify failed with error #", GetLastError());
  }
//+------------------------------------------------------------------+