mql5/Experts/_Architecture/Market/TimeHelpers.mqh

//+------------------------------------------------------------------+
//|                                                  TimeHelpers.mqh |
//|                                  Copyright 2025, MetaQuotes Ltd. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2025, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"

#include "../Configs/SymbolConfig.mqh"

//+------------------------------------------------------------------+
//|                                                    TimePrice.mqh |
//+------------------------------------------------------------------+

struct TimePrice
  {
   int               i;
   datetime          x;
   double            y;
   //+------------------------------------------------------------------+
   //|                                                                  |
   //+------------------------------------------------------------------+

   void              Reset()
     {
      x = 0;
      y = 0.0;
     }
   //+------------------------------------------------------------------+
   //|                                                                  |
   //+------------------------------------------------------------------+

   void              Set(datetime timeValue, double priceValue)
     {

      x = timeValue;
      y = priceValue;
     }
   //+------------------------------------------------------------------+
   //|                                                                  |
   //+------------------------------------------------------------------+

   void              Set(int index, datetime timeValue, double priceValue)
     {
      i = index;
      x = timeValue;
      y = priceValue;
     }
   //+------------------------------------------------------------------+
   //|                                                                  |
   //+------------------------------------------------------------------+

   void              Set(TimePrice &tp)
     {
      Set(tp.i, tp.x, tp.y);
     }

   bool              Ok()
     {
      return x > 0 && y > 0.0;
     }
   //+------------------------------------------------------------------+
   //|                                                                  |
   //+------------------------------------------------------------------+

   TimePrice         CenterCoord(TimePrice &p2)
     {
      if(!Ok() && !p2.Ok())
        {

         return p2;
        }

      if(!Ok())
         return p2;

      if(!p2.Ok())
         return *this;

      TimePrice tp;

      datetime tx = x + (p2.x - x) / 2;
      double py   = (y + p2.y) / 2.0;

      tp.Set(tx, py);

      return tp;
     }

   string            ToString()
     {
      return "Time: " + TimeToString(x) + " | Price: " + DoubleToString(y);
     }

   //+------------------------------------------------------------------+
   //|                                                                  |
   //+------------------------------------------------------------------+
   TimePrice         Min(TimePrice &p2)
     {
      TimePrice tp;

      if(y <= p2.y)
         tp.Set(i, x, y);
      else
         tp.Set(p2.i, p2.x, p2.y);

      return tp;
     }

   //+------------------------------------------------------------------+
   //|                                                                  |
   //+------------------------------------------------------------------+
   TimePrice         Max(TimePrice &p2)
     {
      TimePrice tp;

      if(y >= p2.y)
         tp.Set(i, x, y);
      else
         tp.Set(p2.i, p2.x, p2.y);

      return tp;
     }

   TimePrice         MaxT(TimePrice &p2)
     {
      TimePrice tp;

      if(x >= p2.x)
         tp.Set(i, x, y);
      else
         tp.Set(p2.i, p2.x, p2.y);

      return tp;
     }
  };


//+------------------------------------------------------------------+

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
class TimeHelpers
  {
private:
   datetime          SubtractDays(datetime time, int days);
public:
                     TimeHelpers() {}
                    ~TimeHelpers() {}

   datetime          PreviousDayStart(datetime currentTime);
   datetime          PreviousWeekStart(datetime currentTime, int weekOffset = 1);
   datetime          FirstOfPreviousMonths(datetime currentTime, int monthsBack = 1);
   // Inside class TimeHelpers, add:
   datetime          NextRelaunchTime(datetime currentTime, ENUM_TIME_FETCH_TYPE fetchType, int count);
  };
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
datetime TimeHelpers:: SubtractDays(datetime time, int days)
  {
   MqlDateTime dt;
   TimeToStruct(time, dt);

   dt.day -= days;

   while(dt.day <= 0)
     {
      dt.mon--;
      if(dt.mon <= 0)
        {
         dt.mon = 12;
         dt.year--;
        }
      // Get days in the previous month
      MqlDateTime lastDay;
      lastDay.year  = dt.year;
      lastDay.mon   = dt.mon;
      lastDay.day   = 1;
      lastDay.hour  = 0;
      lastDay.min   = 1;
      lastDay.sec   = 0;

      datetime firstOfMonth = StructToTime(lastDay);
      datetime lastOfPrevMonth = firstOfMonth - 1;

      TimeToStruct(lastOfPrevMonth, lastDay);
      dt.day += lastDay.day;   // add days of previous month
     }

   dt.hour = 0;
   dt.min  = 0;
   dt.sec  = 0;

   return StructToTime(dt);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
datetime TimeHelpers:: PreviousDayStart(datetime currentTime)
  {
   return SubtractDays(currentTime, 1);
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
datetime TimeHelpers::PreviousWeekStart(datetime currentTime, int weekOffset = 1)
  {
   MqlDateTime dt;
   TimeToStruct(currentTime, dt);

   int dow = dt.day_of_week;          // 0=Sunday, 1=Monday, ..., 6=Saturday
   int offsetToMonday;

   if(dow == 0)
      offsetToMonday = 6;   // Sunday -> go back 6 days to Monday
   else
      offsetToMonday = dow - 1; // Monday=0, Tuesday=1, ...

// total days to subtract: offset to Monday of current week + 7 * weekOffset
   int totalDays = offsetToMonday + 7 * weekOffset;

   return SubtractDays(currentTime, totalDays);
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
datetime TimeHelpers::FirstOfPreviousMonths(datetime currentTime, int monthsBack)
  {
   MqlDateTime dt;
   TimeToStruct(currentTime, dt);
// 1. Go to the first day of the current month (00:00)
   datetime firstCurrent = SubtractDays(currentTime, dt.day - 1);

// 2. Subtract monthsBack months by subtracting full months day by day
   for(int i = 0; i < monthsBack; i++)
     {
      // Get the last day of the previous month = firstCurrent - 1 second
      datetime lastPrev = firstCurrent - 1;
      TimeToStruct(lastPrev, dt);

      int daysInPrevMonth = dt.day;   // day-of-month gives days count
      firstCurrent = SubtractDays(firstCurrent, daysInPrevMonth);
     }

   return firstCurrent; // already at 00:00
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
datetime TimeHelpers::NextRelaunchTime(
   datetime currentTime,
   ENUM_TIME_FETCH_TYPE fetchType,
   int count)
  {
   MqlDateTime dt;
   TimeToStruct(currentTime, dt);

// Prevent invalid values
   if(count < 1)
      count = 1;

   dt.hour = 0;
   dt.min  = 0;
   dt.sec  = 0;

   datetime baseTime = StructToTime(dt);

   switch(fetchType)
     {
      //============================================================
      // PREVIOUS DAY
      // count = 1 → tomorrow
      // count = 2 → 2 days from today
      // count = 3 → 3 days from today
      //============================================================
      case FETCH_PREVIOUS_DAY:
        {
         return baseTime + (count * 86400);
        }

      //============================================================
      // PREVIOUS WEEK
      // count = 1 → next Monday
      // count = 2 → Monday after next
      // count = 3 → 3 Mondays from now
      //============================================================
      case FETCH_PREVIOUS_WEEK:
        {
         int dow = dt.day_of_week == 0 ? 7 : dt.day_of_week;

         // Days until next Monday
         int daysUntilMonday = 8 - dow;

         // Additional complete weeks
         int additionalWeeks = (count - 1) * 7;

         return baseTime
                + (daysUntilMonday + additionalWeeks) * 86400;
        }

      //============================================================
      // FIRST PREVIOUS MONTH
      // count = 1 → first day of next month
      // count = 2 → first day two months from now
      // count = 3 → first day three months from now
      //============================================================
      case FETCH_FIRST_PREVIOUS_MONTH:
        {
         dt.day = 1;

         dt.mon += count;

         while(dt.mon > 12)
           {
            dt.mon -= 12;
            dt.year++;
           }

         return StructToTime(dt);
        }

      //============================================================
      default:
         return 0;
     }
  }
//+------------------------------------------------------------------+