//+------------------------------------------------------------------+
//|                                    aroon-trend-ea.mq4             |
//|  An Aroon crossover EA: trades Aroon Up/Aroon Down crosses (custom|
//|  calculated, no built-in Aroon function) only when the crossing   |
//|  line is already above AroonThreshold, with ATR-based Stop        |
//|  Loss/Take Profit and risk-based position sizing. One position    |
//|  at a time.                                                       |
//|  EDUCATIONAL — test on a demo account first. Past performance     |
//|  does not guarantee future results. This is not financial advice.|
//|  Source: web-forex (educational, free to use and modify)          |
//+------------------------------------------------------------------+
#property copyright "web-forex"
#property strict

extern string ___Strategy___       = "--- Aroon Trend Strategy ---";
extern int    AroonPeriod          = 14;
extern double AroonThreshold       = 70.0;

extern string ___RiskManagement___ = "--- Risk Management ---";
extern int    ATRPeriod            = 14;
extern double ATRMultiplier        = 2.0;
extern double RiskRewardRatio      = 2.0;
extern bool   UseFixedLot          = false;
extern double FixedLotSize         = 0.01;
extern double RiskPercent          = 1.0;

extern string ___Filters___        = "--- Filters ---";
extern int    MaxSpreadPoints      = 30;

extern string ___General___        = "--- General ---";
extern int    MagicNumber          = 20260814;
extern bool   EnableTrading        = true;

datetime lastBarTime = 0;

int OnInit()
{
   return(INIT_SUCCEEDED);
}

void OnTick()
{
   if (!EnableTrading)
      return;

   if (Time[0] == lastBarTime)
      return; // only evaluate once per new bar
   lastBarTime = Time[0];

   if (CountOpenPositions() > 0)
      return; // one position at a time

   double spreadPoints = MarketInfo(Symbol(), MODE_SPREAD);
   if (spreadPoints > MaxSpreadPoints)
      return; // spread too wide right now, skip this bar

   double upLast, downLast, upPrev, downPrev;
   CalculateAroon(1, upLast, downLast);
   CalculateAroon(2, upPrev, downPrev);

   double atr = iATR(NULL, 0, ATRPeriod, 1);

   bool bullishCross = (upPrev <= downPrev && upLast > downLast && upLast >= AroonThreshold);
   bool bearishCross = (upPrev >= downPrev && upLast < downLast && downLast >= AroonThreshold);

   if (bullishCross)
      OpenTrade(OP_BUY, atr);
   else if (bearishCross)
      OpenTrade(OP_SELL, atr);
}

void CalculateAroon(int shift, double &up, double &down)
{
   int highestIdx = 0, lowestIdx = 0;
   double highest = High[shift];
   double lowest  = Low[shift];

   for (int j = 1; j <= AroonPeriod; j++)
   {
      int idx = shift + j;
      if (High[idx] > highest) { highest = High[idx]; highestIdx = j; }
      if (Low[idx] < lowest)   { lowest  = Low[idx];  lowestIdx  = j; }
   }

   up   = ((AroonPeriod - highestIdx) / (double)AroonPeriod) * 100.0;
   down = ((AroonPeriod - lowestIdx) / (double)AroonPeriod) * 100.0;
}

int CountOpenPositions()
{
   int count = 0;
   for (int i = 0; i < OrdersTotal(); i++)
   {
      if (OrderSelect(i, SELECT_BY_POS, MODE_TRADES))
      {
         if (OrderSymbol() == Symbol() && OrderMagicNumber() == MagicNumber)
            count++;
      }
   }
   return(count);
}

void OpenTrade(int type, double atr)
{
   double slDistance = atr * ATRMultiplier;
   double tpDistance = slDistance * RiskRewardRatio;
   double lots       = CalculateLotSize(slDistance);
   double price, sl, tp;

   if (type == OP_BUY)
   {
      price = Ask;
      sl = price - slDistance;
      tp = price + tpDistance;
   }
   else
   {
      price = Bid;
      sl = price + slDistance;
      tp = price - tpDistance;
   }

   int ticket = OrderSend(Symbol(), type, lots, price, 3, sl, tp, "Aroon Trend EA", MagicNumber, 0,
                          type == OP_BUY ? clrDodgerBlue : clrOrangeRed);
   if (ticket < 0)
      Print("Aroon Trend EA: OrderSend failed, error ", GetLastError());
}

double CalculateLotSize(double slDistance)
{
   if (UseFixedLot || slDistance <= 0)
      return(NormalizeLotSize(FixedLotSize));

   double riskAmount = AccountBalance() * (RiskPercent / 100.0);
   double tickValue   = MarketInfo(Symbol(), MODE_TICKVALUE);
   double tickSize    = MarketInfo(Symbol(), MODE_TICKSIZE);
   if (tickSize <= 0 || tickValue <= 0)
      return(NormalizeLotSize(FixedLotSize));

   double slTicks = slDistance / tickSize;
   double lots    = riskAmount / (slTicks * tickValue);

   return(NormalizeLotSize(lots));
}

double NormalizeLotSize(double lots)
{
   double minLot  = MarketInfo(Symbol(), MODE_MINLOT);
   double maxLot  = MarketInfo(Symbol(), MODE_MAXLOT);
   double lotStep = MarketInfo(Symbol(), MODE_LOTSTEP);
   if (lotStep <= 0)
      return(minLot);

   lots = MathFloor(lots / lotStep) * lotStep;
   if (lots < minLot)
      lots = minLot;
   if (lots > maxLot)
      lots = maxLot;
   return(lots);
}