//+------------------------------------------------------------------+
//|                            SmartLotCalculatorExample.mq5          |
//|          Example script for the Smart Lot Calculator library     |
//+------------------------------------------------------------------+
#property script_show_inputs
#property version   "1.00"
#property description "Calculates a recommended volume without opening trades."

#include "../Include/SmartLotCalculator.mqh"

// Symbol left empty means the current chart symbol.
input string          InpSymbol            = "";
input ENUM_ORDER_TYPE InpOrderType         = ORDER_TYPE_BUY;
input double          InpRiskPercent       = 1.0;
input ENUM_RISK_BASE  InpRiskBase          = RISK_BASE_EQUITY;
input int             InpStopLossPoints    = 500;

//+------------------------------------------------------------------+
//| Script start                                                     |
//+------------------------------------------------------------------+
void OnStart()
{
   string symbol = InpSymbol;

   if(symbol == "")
      symbol = _Symbol;

   if(InpStopLossPoints <= 0)
   {
      Print("Error: Stop Loss points must be greater than zero.");
      return;
   }

   if(!SymbolSelect(symbol, true))
   {
      Print("Error: could not select symbol ", symbol, ".");
      return;
   }

   MqlTick tick;

   if(!SymbolInfoTick(symbol, tick))
   {
      Print(
         "Error: could not obtain current prices for ",
         symbol,
         ". MetaTrader error code: ",
         GetLastError()
      );

      return;
   }

   double point = SymbolInfoDouble(symbol, SYMBOL_POINT);

   if(point <= 0.0)
   {
      Print("Error: invalid point size for ", symbol, ".");
      return;
   }

   double entry_price = 0.0;
   double stop_price  = 0.0;

   if(InpOrderType == ORDER_TYPE_BUY)
   {
      entry_price = tick.ask;
      stop_price  = entry_price - (InpStopLossPoints * point);
   }
   else if(InpOrderType == ORDER_TYPE_SELL)
   {
      entry_price = tick.bid;
      stop_price  = entry_price + (InpStopLossPoints * point);
   }
   else
   {
      Print("Error: select ORDER_TYPE_BUY or ORDER_TYPE_SELL.");
      return;
   }

   int price_digits = (int)SymbolInfoInteger(symbol, SYMBOL_DIGITS);

   entry_price = NormalizeDouble(entry_price, price_digits);
   stop_price  = NormalizeDouble(stop_price, price_digits);

   string error = "";

   double recommended_volume =
      CSmartLotCalculator::CalculateByRiskPercent(
         symbol,
         InpOrderType,
         entry_price,
         stop_price,
         InpRiskPercent,
         InpRiskBase,
         error
      );

   if(recommended_volume <= 0.0)
   {
      Print("Calculation failed: ", error);
      return;
   }

   double potential_loss =
      CSmartLotCalculator::CalculatePotentialLoss(
         symbol,
         InpOrderType,
         recommended_volume,
         entry_price,
         stop_price,
         error
      );

   if(potential_loss <= 0.0)
   {
      Print("Loss verification failed: ", error);
      return;
   }

   string direction =
      InpOrderType == ORDER_TYPE_BUY ? "BUY" : "SELL";

   Print("--------------------------------------------------");
   Print("SMART LOT CALCULATOR RESULT");
   Print("Symbol: ", symbol);
   Print("Direction: ", direction);
   Print("Entry price: ", DoubleToString(entry_price, price_digits));
   Print("Stop Loss: ", DoubleToString(stop_price, price_digits));
   Print("Stop distance: ", InpStopLossPoints, " points");
   Print("Selected risk: ", DoubleToString(InpRiskPercent, 2), "%");
   Print(
      "Recommended volume: ",
      DoubleToString(recommended_volume, 8),
      " lots"
   );
   Print(
      "Estimated loss at Stop Loss: ",
      DoubleToString(potential_loss, 2),
      " ",
      AccountInfoString(ACCOUNT_CURRENCY)
   );
   Print("No trade was opened.");
   Print("--------------------------------------------------");
}