MQL5 Automated Trading Strategy: Hub Guide to All EA Types

//+------------------------------------------------------------------+
//|  MQL5 Automated Trading Hub — Dual MA Crossover EA               |
//|  Demonstrates the canonical OnInit / OnTick / OnDeinit pattern   |
//|  suitable as a starting template for any trend-following EA.      |
//|                                                                    |
//|  DISCLAIMER: For educational purposes only. Past performance       |
//|  does not guarantee future results. Always test on a demo account.|
//+------------------------------------------------------------------+
#property copyright "Pineify.app"
#property version   "1.00"
#property strict

//--- Input parameters
input int    FastMAPeriod   = 20;          // Fast MA period
input int    SlowMAPeriod   = 50;          // Slow MA period
input ENUM_MA_METHOD MAMethod = MODE_EMA;  // MA smoothing method
input double LotSize        = 0.10;        // Trade volume in lots
input int    StopLossPips   = 80;          // Stop-loss in pips
input int    TakeProfitPips = 160;         // Take-profit in pips
input int    MagicNumber    = 20240001;    // Unique EA identifier
input string TradeComment   = "HubEA";    // Order comment

//--- Global handles and state
int    g_fastHandle  = INVALID_HANDLE;
int    g_slowHandle  = INVALID_HANDLE;
double g_pipSize     = 0.0;
bool   g_tradeAllowed = false;

//+------------------------------------------------------------------+
//| Expert initialisation                                             |
//+------------------------------------------------------------------+
int OnInit()
  {
   //--- Validate periods
   if(FastMAPeriod >= SlowMAPeriod)
     {
      Print("ERROR: FastMAPeriod must be less than SlowMAPeriod.");
      return(INIT_PARAMETERS_INCORRECT);
     }

   //--- Create indicator handles
   g_fastHandle = iMA(_Symbol, PERIOD_CURRENT, FastMAPeriod, 0, MAMethod, PRICE_CLOSE);
   g_slowHandle = iMA(_Symbol, PERIOD_CURRENT, SlowMAPeriod, 0, MAMethod, PRICE_CLOSE);

   if(g_fastHandle == INVALID_HANDLE || g_slowHandle == INVALID_HANDLE)
     {
      Print("ERROR: Failed to create MA handles.");
      return(INIT_FAILED);
     }

   //--- Calculate pip size (handles 3/5-digit brokers)
   int digits = (int)SymbolInfoInteger(_Symbol, SYMBOL_DIGITS);
   g_pipSize  = (digits == 3 || digits == 5)
                ? SymbolInfoDouble(_Symbol, SYMBOL_POINT) * 10.0
                : SymbolInfoDouble(_Symbol, SYMBOL_POINT);

   g_tradeAllowed = true;
   Print("Hub EA initialised on ", _Symbol, " | FastMA=", FastMAPeriod, " SlowMA=", SlowMAPeriod);
   return(INIT_SUCCEEDED);
  }

//+------------------------------------------------------------------+
//| Expert tick handler                                               |
//+------------------------------------------------------------------+
void OnTick()
  {
   if(!g_tradeAllowed) return;

   //--- Only act on the close of a new bar to avoid multiple entries
   static datetime s_lastBarTime = 0;
   datetime currentBarTime = (datetime)SeriesInfoInteger(_Symbol, PERIOD_CURRENT, SERIES_LASTBAR_DATE);
   if(currentBarTime == s_lastBarTime) return;
   s_lastBarTime = currentBarTime;

   //--- Copy MA buffers (need 2 values to detect crossover)
   double fastMA[], slowMA[];
   ArraySetAsSeries(fastMA, true);
   ArraySetAsSeries(slowMA, true);

   if(CopyBuffer(g_fastHandle, 0, 0, 3, fastMA) < 3) return;
   if(CopyBuffer(g_slowHandle, 0, 0, 3, slowMA) < 3) return;

   //--- Detect crossover
   bool bullCross = (fastMA[1] > slowMA[1]) && (fastMA[2] <= slowMA[2]);
   bool bearCross = (fastMA[1] < slowMA[1]) && (fastMA[2] >= slowMA[2]);

   //--- Count existing positions for this EA
   int buyCount  = CountPositions(POSITION_TYPE_BUY);
   int sellCount = CountPositions(POSITION_TYPE_SELL);

   //--- Close opposite positions on crossover before opening new one
   if(bullCross && sellCount > 0)  CloseAllPositions(POSITION_TYPE_SELL);
   if(bearCross && buyCount  > 0)  CloseAllPositions(POSITION_TYPE_BUY);

   //--- Open new position if none exists in signal direction
   if(bullCross && buyCount == 0)
      OpenPosition(ORDER_TYPE_BUY);
   else if(bearCross && sellCount == 0)
      OpenPosition(ORDER_TYPE_SELL);
  }

//+------------------------------------------------------------------+
//| Expert deinitialization                                           |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
   if(g_fastHandle != INVALID_HANDLE) IndicatorRelease(g_fastHandle);
   if(g_slowHandle != INVALID_HANDLE) IndicatorRelease(g_slowHandle);
   g_tradeAllowed = false;
   PrintFormat("Hub EA removed. Reason code: %d", reason);
  }

//+------------------------------------------------------------------+
//| Open a buy or sell position with SL/TP                           |
//+------------------------------------------------------------------+
void OpenPosition(ENUM_ORDER_TYPE orderType)
  {
   MqlTradeRequest request = {};
   MqlTradeResult  result  = {};

   double ask = SymbolInfoDouble(_Symbol, SYMBOL_ASK);
   double bid = SymbolInfoDouble(_Symbol, SYMBOL_BID);
   double sl, tp;

   if(orderType == ORDER_TYPE_BUY)
     {
      sl = NormalizeDouble(ask - StopLossPips   * g_pipSize, _Digits);
      tp = NormalizeDouble(ask + TakeProfitPips * g_pipSize, _Digits);
      request.price = ask;
     }
   else
     {
      sl = NormalizeDouble(bid + StopLossPips   * g_pipSize, _Digits);
      tp = NormalizeDouble(bid - TakeProfitPips * g_pipSize, _Digits);
      request.price = bid;
     }

   request.action    = TRADE_ACTION_DEAL;
   request.symbol    = _Symbol;
   request.volume    = LotSize;
   request.type      = orderType;
   request.sl        = sl;
   request.tp        = tp;
   request.magic     = MagicNumber;
   request.comment   = TradeComment;
   request.type_filling = ORDER_FILLING_IOC;

   if(!OrderSend(request, result))
      PrintFormat("OrderSend failed. Error: %d | Retcode: %d", GetLastError(), result.retcode);
   else
      PrintFormat("Position opened: %s | Ticket: %d | Price: %.5f | SL: %.5f | TP: %.5f",
                  EnumToString(orderType), result.order, result.price, sl, tp);
  }

//+------------------------------------------------------------------+
//| Count open positions by direction for this EA                     |
//+------------------------------------------------------------------+
int CountPositions(ENUM_POSITION_TYPE posType)
  {
   int count = 0;
   for(int i = PositionsTotal() - 1; i >= 0; i--)
     {
      ulong ticket = PositionGetTicket(i);
      if(ticket == 0) continue;
      if(PositionGetString(POSITION_SYMBOL)           != _Symbol)    continue;
      if((long)PositionGetInteger(POSITION_MAGIC)     != MagicNumber) continue;
      if((ENUM_POSITION_TYPE)PositionGetInteger(POSITION_TYPE) == posType)
         count++;
     }
   return count;
  }

//+------------------------------------------------------------------+
//| Close all positions of a given direction for this EA             |
//+------------------------------------------------------------------+
void CloseAllPositions(ENUM_POSITION_TYPE posType)
  {
   for(int i = PositionsTotal() - 1; i >= 0; i--)
     {
      ulong ticket = PositionGetTicket(i);
      if(ticket == 0) continue;
      if(PositionGetString(POSITION_SYMBOL)           != _Symbol)    continue;
      if((long)PositionGetInteger(POSITION_MAGIC)     != MagicNumber) continue;
      if((ENUM_POSITION_TYPE)PositionGetInteger(POSITION_TYPE) != posType) continue;

      MqlTradeRequest request = {};
      MqlTradeResult  result  = {};
      request.action = TRADE_ACTION_DEAL;
      request.symbol = _Symbol;
      request.volume = PositionGetDouble(POSITION_VOLUME);
      request.type   = (posType == POSITION_TYPE_BUY) ? ORDER_TYPE_SELL : ORDER_TYPE_BUY;
      request.price  = (posType == POSITION_TYPE_BUY)
                       ? SymbolInfoDouble(_Symbol, SYMBOL_BID)
                       : SymbolInfoDouble(_Symbol, SYMBOL_ASK);
      request.position      = ticket;
      request.magic         = MagicNumber;
      request.comment       = TradeComment + "_close";
      request.type_filling  = ORDER_FILLING_IOC;

      if(!OrderSend(request, result))
         PrintFormat("Close failed for ticket %d. Error: %d", ticket, GetLastError());
     }
  }
//+------------------------------------------------------------------+