CheckMargin

ÿþ#property copyright           "Mokara"

#property link                "https://www.mql5.com/en/users/mokara"

#property description         "Check Margin"

#property version             "1.0"

#property script_show_inputs  true



enum ORDER

{

   BUY,

   SELL

};



input string symbol = "";  //Symbol Name

input double volume = 0.1; //Volume

input ORDER order = BUY;   //Order Type



//required margin to open {or} with {vol} lots for {sym}

double RequiredMargin(string sym, double vol, ORDER or)

{

   string currencyAccount, currencyBase, currencyQuote, symTemp;

   double symbolContract, symbolBid, symbolAsk;

   int accountLeverage;

   bool symbolType;

   currencyAccount = AccountInfoString(ACCOUNT_CURRENCY);

   currencyBase = SymbolInfoString(sym, SYMBOL_CURRENCY_BASE);

   currencyQuote = SymbolInfoString(sym, SYMBOL_CURRENCY_PROFIT);

   symbolContract = SymbolInfoDouble(sym, SYMBOL_TRADE_CONTRACT_SIZE);

   symbolBid = SymbolInfoDouble(sym, SYMBOL_BID);

   symbolAsk = SymbolInfoDouble(sym, SYMBOL_ASK);

   accountLeverage = AccountInfoInteger(ACCOUNT_LEVERAGE);   

   

   if(currencyAccount == currencyBase)

   {

      return(vol * symbolContract / accountLeverage);

   }

   else if(currencyAccount == currencyQuote)

   {

      return((or==BUY?symbolAsk:symbolBid)*vol*symbolContract/accountLeverage);

   }

   else

   {      

      if(SymbolExist(currencyBase+currencyAccount, symbolType))

      {

         symTemp = currencyBase+currencyAccount;

         if(!SymbolInfoInteger(symTemp, SYMBOL_SELECT)) SymbolSelect(symTemp, true);

         Sleep(100);

         symbolBid = SymbolInfoDouble(symTemp, SYMBOL_BID);

         symbolAsk = SymbolInfoDouble(symTemp, SYMBOL_ASK);

         return((or==BUY?symbolAsk:symbolBid)*vol*symbolContract/accountLeverage); 

      }

      else if(SymbolExist(currencyAccount+currencyBase, symbolType))

      {

         symTemp = currencyAccount+currencyBase;

         if(!SymbolInfoInteger(symTemp, SYMBOL_SELECT)) SymbolSelect(symTemp, true);

         Sleep(100);

         symbolBid = SymbolInfoDouble(symTemp, SYMBOL_BID);

         symbolAsk = SymbolInfoDouble(symTemp, SYMBOL_ASK);

         return((1/(or==BUY?symbolAsk:symbolBid))*vol*symbolContract/accountLeverage); 

      }

      else

      {

         MessageBox("Unable to calculate required margin.", "ERROR", MB_ICONERROR|MB_OK);

         return(0);

      }

   }

}



//check if symbol exists or not, list on marketwatch if not

bool CheckSymbol(string sym)

{

   bool type;

   if(!SymbolExist(sym, type))

   {

      return(false);

   }

   else

   {

      if(!SymbolInfoInteger(sym, SYMBOL_SELECT)) SymbolSelect(sym, true);

      Sleep(100);

   }

   return(true);

}



//is {vol} a valid volume value for {sym}

bool CheckVolume(string sym, double vol)

{

   if(!CheckSymbol(sym))

   {

      MessageBox(sym + " doesn't exists.", "ERROR", MB_ICONERROR|MB_OK);

      return(false);

   }

   double volMin = SymbolInfoDouble(_Symbol, SYMBOL_VOLUME_MIN);

   double volMax = SymbolInfoDouble(_Symbol, SYMBOL_VOLUME_MAX);

   double volStep = SymbolInfoDouble(_Symbol, SYMBOL_VOLUME_STEP);

   int ratio = (int)MathRound(vol / volStep);

   if(vol < volMin) 

   {

      MessageBox("Minimum volume is " + volMin + ".", "ERROR", MB_ICONERROR|MB_OK);

      return(false);

   }

   else if(vol > volMax) 

   {

      MessageBox("Maximum volume is " + volMax + ".", "ERROR", MB_ICONERROR|MB_OK);

      return(false);

   }

   else if(MathAbs(ratio * volStep - vol) > 0.0000001) 

   {

      MessageBox("Invalid volume. Nearest is " + ratio * volStep + ".", "ERROR", MB_ICONERROR|MB_OK);

      return(false);

   }

   else return(true);

}



//maximum volume that can be traded if required margin {mar} for one lot of {sym} is known.

double GetMaxVol(string sym, double mar)

{

   double marginFree = AccountInfoDouble(ACCOUNT_MARGIN_FREE);

   double volStep = SymbolInfoDouble(sym, SYMBOL_VOLUME_STEP);

   double volOut = MathFloor((marginFree/mar)/volStep)*volStep;

   if(volOut < SymbolInfoDouble(sym, SYMBOL_VOLUME_MIN)) volOut = 0;

   if(volOut > SymbolInfoDouble(sym, SYMBOL_VOLUME_MAX)) volOut = SymbolInfoDouble(sym, SYMBOL_VOLUME_MAX);

   return(volOut);

}



void OnStart()

{

   double mar;

   string msg = "";

   string symbolName = symbol;

   

   if(!CheckSymbol(symbolName))

   {      

      symbolName = _Symbol;

   }

   if(!CheckVolume(symbolName, volume))

   {

      return;

   }   

   

   //Custom Function

   //mar = RequiredMargin(symbolName, volume, order);

   

   //Built-In Function

   if(!OrderCalcMargin((order == BUY)?ORDER_TYPE_BUY:ORDER_TYPE_SELL, symbolName, volume, (order == BUY)?SymbolInfoDouble(symbolName, SYMBOL_ASK):SymbolInfoDouble(symbolName, SYMBOL_BID), mar))

   {

      Alert("ERROR: margin cannot be calculated.");

      return;

   }

   

   msg += "Free Margin: " + AccountInfoDouble(ACCOUNT_MARGIN_FREE) + " " + AccountInfoString(ACCOUNT_CURRENCY) + "\n";

   msg += "Required Margin to " + EnumToString(order) + " " + DoubleToString(volume, 2) + " Lots: " + DoubleToString(mar, 2) + " " + AccountInfoString(ACCOUNT_CURRENCY) + "\n";

   msg += "Maximum Lots Available to " + EnumToString(order) + ": " + DoubleToString(GetMaxVol(symbolName, mar/volume), 2) + "\n";  

   

   MessageBox(msg, "Check Margin (" + symbolName + ")", MB_ICONINFORMATION|MB_OK);

}