//+------------------------------------------------------------------+
//|   XAUUSD EMA20 Reversal Scalper                                  |
//+------------------------------------------------------------------+
input int      EMA_Period = 20;
input double   TakeProfitPips = 40;
input double   StopLossPips  = 20;
input double   LotSize = 0.1;
input ENUM_TIMEFRAMES TimeFrame = PERIOD_M5;

//--- Helper to get EMA
double GetEMA(int shift) {
    return iMA(NULL, TimeFrame, EMA_Period, 0, MODE_EMA, PRICE_CLOSE, shift);
}

//--- Helper to calculate pips for XAUUSD (usually point = 0.01)
double PipValue() { return 0.10; }

//--- Check for simple reversal (bullish/bearish engulfing as sample)
bool IsReversal(int shift) {
    double open1 = iOpen(NULL, TimeFrame, shift+1);
    double close1 = iClose(NULL, TimeFrame, shift+1);
    double open0 = iOpen(NULL, TimeFrame, shift);
    double close0 = iClose(NULL, TimeFrame, shift);

    // Bullish engulfing
    if (close1 < open1 && close0 > open0 && close0 > open1 && open0 < close1)
        return(true);

    // Bearish engulfing
    if (close1 > open1 && close0 < open0 && close0 < open1 && open0 > close1)
        return(true);

    return(false);
}

//+------------------------------------------------------------------+
//|   Main trading loop                                              |
//+------------------------------------------------------------------+
void OnTick() {
    // Only on new candles
    static datetime lastCandle;
    datetime currentCandle = iTime(NULL, TimeFrame, 0);
    if (lastCandle == currentCandle) return;
    lastCandle = currentCandle;

    double ema = GetEMA(1);
    double price = iClose(NULL, TimeFrame, 1);

    // Price touch EMA
    if (MathAbs(price - ema) <= PipValue()) {
        if (IsReversal(1)) {
            // Detect reversal direction
            bool bullish = iClose(NULL, TimeFrame, 1) > iOpen(NULL, TimeFrame, 1);
            bool bearish = iClose(NULL, TimeFrame, 1) < iOpen(NULL, TimeFrame, 1);

            double sl, tp;
            if (bullish) {
                sl = price - StopLossPips * PipValue();
                tp = price + TakeProfitPips * PipValue();
                // Place Buy trade
                trade.Buy(LotSize, NULL, price, sl, tp, NULL);
            } else if (bearish) {
                sl = price + StopLossPips * PipValue();
                tp = price - TakeProfitPips * PipValue();
                // Place Sell trade
                trade.Sell(LotSize, NULL, price, sl, tp, NULL);
            }
        }
    }
}