//+------------------------------------------------------------------+
//| ForexTrendBot.mq5                                                |
//| Simple EMA 20/50 crossover EA - DEMO ACCOUNTS ONLY               |
//| Educational example; not a guarantee of profit.                  |
//+------------------------------------------------------------------+
#property strict
#property version   "1.00"
#property description "EMA 20/50 trend-following example. Demo accounts only."

#include <Trade/Trade.mqh>

input double InpLots             = 0.01;   // Fixed lot size
input int    InpFastEMA          = 20;     // Fast EMA period
input int    InpSlowEMA          = 50;     // Slow EMA period
input int    InpStopLossPoints   = 300;    // Stop loss in points
input int    InpTakeProfitPoints = 600;    // Take profit in points
input int    InpMaxSpreadPoints  = 25;     // Maximum spread in points
input ulong  InpMagicNumber      = 205020; // EA identifier

CTrade trade;
int fastHandle = INVALID_HANDLE;
int slowHandle = INVALID_HANDLE;
datetime lastBarTime = 0;

//+------------------------------------------------------------------+
int OnInit()
{
   // This EA intentionally refuses to run on non-demo accounts.
   if((ENUM_ACCOUNT_TRADE_MODE)AccountInfoInteger(ACCOUNT_TRADE_MODE)
      != ACCOUNT_TRADE_MODE_DEMO)
   {
      Print("ForexTrendBot is DEMO-ONLY. Initialization blocked.");
      return(INIT_FAILED);
   }

   if(InpLots <= 0 || InpFastEMA <= 0 || InpSlowEMA <= 0 ||
      InpFastEMA >= InpSlowEMA || InpStopLossPoints <= 0 ||
      InpTakeProfitPoints <= 0 || InpMaxSpreadPoints < 0)
   {
      Print("Invalid input settings.");
      return(INIT_PARAMETERS_INCORRECT);
   }

   fastHandle = iMA(_Symbol, PERIOD_M15, InpFastEMA, 0, MODE_EMA, PRICE_CLOSE);
   slowHandle = iMA(_Symbol, PERIOD_M15, InpSlowEMA, 0, MODE_EMA, PRICE_CLOSE);

   if(fastHandle == INVALID_HANDLE || slowHandle == INVALID_HANDLE)
   {
      Print("Could not create EMA indicator handles. Error: ", GetLastError());
      return(INIT_FAILED);
   }

   trade.SetExpertMagicNumber(InpMagicNumber);
   trade.SetTypeFillingBySymbol(_Symbol);
   Print("ForexTrendBot initialized on demo account. Signal timeframe: M15.");
   return(INIT_SUCCEEDED);
}

//+------------------------------------------------------------------+
void OnDeinit(const int reason)
{
   if(fastHandle != INVALID_HANDLE)
      IndicatorRelease(fastHandle);
   if(slowHandle != INVALID_HANDLE)
      IndicatorRelease(slowHandle);
}

//+------------------------------------------------------------------+
void OnTick()
{
   if((ENUM_ACCOUNT_TRADE_MODE)AccountInfoInteger(ACCOUNT_TRADE_MODE)
      != ACCOUNT_TRADE_MODE_DEMO)
      return;

   if(!IsNewBar())
      return;

   if(HasOurPosition())
      return;

   MqlTick tick;
   if(!SymbolInfoTick(_Symbol, tick))
      return;

   double point = SymbolInfoDouble(_Symbol, SYMBOL_POINT);
   if(point <= 0)
      return;

   double spreadPoints = (tick.ask - tick.bid) / point;
   if(spreadPoints > InpMaxSpreadPoints)
   {
      Print("Spread too high; skipping this bar. Spread points: ", spreadPoints);
      return;
   }

   // Dynamic series arrays: index 0=current bar, 1=last closed, 2=previous.
   double fast[], slow[];
   ArrayResize(fast, 3);
   ArrayResize(slow, 3);
   ArraySetAsSeries(fast, true);
   ArraySetAsSeries(slow, true);

   if(CopyBuffer(fastHandle, 0, 0, 3, fast) < 3 ||
      CopyBuffer(slowHandle, 0, 0, 3, slow) < 3)
   {
      Print("Not enough EMA data yet.");
      return;
   }

   bool bullishCross = (fast[2] <= slow[2] && fast[1] > slow[1]);
   bool bearishCross = (fast[2] >= slow[2] && fast[1] < slow[1]);

   int digits = (int)SymbolInfoInteger(_Symbol, SYMBOL_DIGITS);
   double sl = 0.0, tp = 0.0;

   if(bullishCross)
   {
      sl = NormalizeDouble(tick.ask - InpStopLossPoints * point, digits);
      tp = NormalizeDouble(tick.ask + InpTakeProfitPoints * point, digits);

      if(!trade.Buy(InpLots, _Symbol, 0.0, sl, tp, "EMA20/50 demo buy"))
         Print("Buy failed. Retcode: ", trade.ResultRetcode(), " - ",
               trade.ResultRetcodeDescription());
      else
         Print("Demo BUY submitted. SL=", sl, " TP=", tp);
   }
   else if(bearishCross)
   {
      sl = NormalizeDouble(tick.bid + InpStopLossPoints * point, digits);
      tp = NormalizeDouble(tick.bid - InpTakeProfitPoints * point, digits);

      if(!trade.Sell(InpLots, _Symbol, 0.0, sl, tp, "EMA20/50 demo sell"))
         Print("Sell failed. Retcode: ", trade.ResultRetcode(), " - ",
               trade.ResultRetcodeDescription());
      else
         Print("Demo SELL submitted. SL=", sl, " TP=", tp);
   }
}

//+------------------------------------------------------------------+
bool IsNewBar()
{
   datetime currentBar = iTime(_Symbol, PERIOD_M15, 0);
   if(currentBar == 0 || currentBar == lastBarTime)
      return false;

   lastBarTime = currentBar;
   return true;
}

//+------------------------------------------------------------------+
bool HasOurPosition()
{
   for(int i = PositionsTotal() - 1; i >= 0; i--)
   {
      ulong ticket = PositionGetTicket(i);
      if(ticket == 0)
         continue;

      if(PositionGetString(POSITION_SYMBOL) == _Symbol &&
         (ulong)PositionGetInteger(POSITION_MAGIC) == InpMagicNumber)
         return true;
   }
   return false;
}
//+------------------------------------------------------------------+