//+------------------------------------------------------------------+
//|                                     FixedRangeVolumeProfile.mq5 |
//|                             Copyright 2026, MetaQuotes Ltd.      |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2026, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"
#property indicator_chart_window
#property indicator_buffers 1
#property indicator_plots 1
#property indicator_color1 clrDarkGray, clrDimGray
#property indicator_label1 "Close Prices"


#include <Canvas\Canvas.mqh>
#include <ChartObjects\ChartObjectsLines.mqh>

//--- input parameters
input int      InpTicksPerBin      = 10;       // Ticks per bin
input int      InpValueAreaPercent = 70;       // Value Area Percentage
input int      InpWidthPercent     = 30;       // Width % of Chart

input string   InpSessionAsian     = "23:00-08:00"; // Asian Session
input color    InpColorAsian       = clrSkyBlue;    // Asian Color
input string   InpSessionLondon    = "07:00-16:30"; // London Session
input color    InpColorLondon      = clrLimeGreen;  // London Color
input string   InpSessionNY        = "12:00-21:30"; // NY Session
input color    InpColorNY          = clrOrange;     // NY Color

input color    InpColorPOC         = clrRed;      // POC Color

//--- global variables
CCanvas           m_canvas;
CChartObjectVLine m_line_start;
CChartObjectVLine m_line_end;
string            m_canvas_name = "FRVP_Canvas";
string            m_line_start_name = "FRVP_Start";
string            m_line_end_name = "FRVP_End";

datetime          m_last_start;
datetime          m_last_end;

struct BinData
  {
   double         price;
   long           volume;
   bool           is_va;
  };

struct SessionData
  {
   BinData        bins[];
   long           total_volume;
   double         poc_price;
   int            start_hour, start_min;
   int            end_hour, end_min;
   color          base_color;
  };

SessionData       m_sessions[3];

//+------------------------------------------------------------------+
//| Parse Session String                                             |
//+------------------------------------------------------------------+
void ParseSessions()
  {
   string sessions[3] = {InpSessionAsian, InpSessionLondon, InpSessionNY};
   color colors[3] = {InpColorAsian, InpColorLondon, InpColorNY};

   for(int i = 0; i < 3; i++)
     {
      string parts[];
      if(StringSplit(sessions[i], '-', parts) == 2)
        {
         string start_parts[];
         string end_parts[];
         if(StringSplit(parts[0], ':', start_parts) == 2 && StringSplit(parts[1], ':', end_parts) == 2)
           {
            m_sessions[i].start_hour = (int)StringToInteger(start_parts[0]);
            m_sessions[i].start_min  = (int)StringToInteger(start_parts[1]);
            m_sessions[i].end_hour   = (int)StringToInteger(end_parts[0]);
            m_sessions[i].end_min    = (int)StringToInteger(end_parts[1]);
           }
        }
      m_sessions[i].base_color = colors[i];
     }
  }

//+------------------------------------------------------------------+
//| Check if time is in session                                      |
//+------------------------------------------------------------------+
bool IsInSession(datetime t, int s_idx)
  {
   MqlDateTime dt;
   TimeToStruct(t, dt);
   int current_minutes = dt.hour * 60 + dt.min;
   int start_minutes = m_sessions[s_idx].start_hour * 60 + m_sessions[s_idx].start_min;
   int end_minutes = m_sessions[s_idx].end_hour * 60 + m_sessions[s_idx].end_min;

   if(start_minutes < end_minutes)
      return (current_minutes >= start_minutes && current_minutes < end_minutes);
   else // Overnight session
      return (current_minutes >= start_minutes || current_minutes < end_minutes);
  }

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
   ParseSessions();

//--- create lines
   if(!m_line_start.Create(0, m_line_start_name, 0, iTime(_Symbol, _Period, 100)))
      return(INIT_FAILED);
   m_line_start.Color(clrGray);
   m_line_start.Style(STYLE_DOT);
   m_line_start.Selectable(true);
   m_line_start.Selected(true);
   m_line_start.Tooltip("FRVP Start");

   if(!m_line_end.Create(0, m_line_end_name, 0, iTime(_Symbol, _Period, 0)))
      return(INIT_FAILED);
   m_line_end.Color(clrGray);
   m_line_end.Style(STYLE_DOT);
   m_line_end.Selectable(true);
   m_line_end.Selected(true);
   m_line_end.Tooltip("FRVP End");

//--- initialize canvas
   if(!m_canvas.CreateBitmapLabel(m_canvas_name, 0, 0, (int)ChartGetInteger(0, CHART_WIDTH_IN_PIXELS), (int)ChartGetInteger(0, CHART_HEIGHT_IN_PIXELS), COLOR_FORMAT_ARGB_NORMALIZE))
      return(INIT_FAILED);
   
   m_canvas.Erase(0);
   m_canvas.Update();

   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function                       |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
   m_line_start.Delete();
   m_line_end.Delete();
   m_canvas.Destroy();
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {
   datetime t_start = m_line_start.Time(0);
   datetime t_end = m_line_end.Time(0);

   if(t_start != m_last_start || t_end != m_last_end)
     {
      CalculateProfile(t_start, t_end);
      RenderProfile();
      m_last_start = t_start;
      m_last_end = t_end;
     }

   return(rates_total);
  }
//+------------------------------------------------------------------+
//| ChartEvent function                                              |
//+------------------------------------------------------------------+
void OnChartEvent(const int id,
                  const long &lparam,
                  const double &dparam,
                  const string &sparam)
  {
   if(id == CHARTEVENT_OBJECT_DRAG || id == CHARTEVENT_CHART_CHANGE)
     {
      datetime t_start = m_line_start.Time(0);
      datetime t_end = m_line_end.Time(0);

      if(t_start != m_last_start || t_end != m_last_end || id == CHARTEVENT_CHART_CHANGE)
        {
         CalculateProfile(t_start, t_end);
         RenderProfile();
         m_last_start = t_start;
         m_last_end = t_end;
        }
     }
  }
//+------------------------------------------------------------------+
//| Calculate Volume Profile                                         |
//+------------------------------------------------------------------+
void CalculateProfile(datetime t1, datetime t2)
  {
   datetime start_time = (t1 < t2) ? t1 : t2;
   datetime end_time = (t1 < t2) ? t2 : t1;

   int start_bar = iBarShift(_Symbol, _Period, start_time);
   int end_bar = iBarShift(_Symbol, _Period, end_time);

   if(start_bar < 0 || end_bar < 0) return;

   //--- Find price range
   double min_price = 0, max_price = 0;
   for(int i = end_bar; i <= start_bar; i++)
     {
      double h = iHigh(_Symbol, _Period, i);
      double l = iLow(_Symbol, _Period, i);
      if(i == end_bar) { min_price = l; max_price = h; }
      else { if(l < min_price) min_price = l; if(h > max_price) max_price = h; }
     }

   double tick_size = SymbolInfoDouble(_Symbol, SYMBOL_TRADE_TICK_SIZE);
   double bin_size = tick_size * InpTicksPerBin;
   
   if(bin_size <= 0) return;

   int bin_count = (int)((max_price - min_price) / bin_size) + 1;

   for(int s = 0; s < 3; s++)
     {
      ArrayResize(m_sessions[s].bins, bin_count);
      for(int i = 0; i < bin_count; i++)
        {
         m_sessions[s].bins[i].price = min_price + i * bin_size;
         m_sessions[s].bins[i].volume = 0;
         m_sessions[s].bins[i].is_va = false;
        }
      m_sessions[s].total_volume = 0;
     }

   for(int i = end_bar; i <= start_bar; i++)
     {
      datetime bar_time = iTime(_Symbol, _Period, i);
      double h = iHigh(_Symbol, _Period, i);
      double l = iLow(_Symbol, _Period, i);
      long vol = iTickVolume(_Symbol, _Period, i);
      
      int h_idx = (int)((h - min_price) / bin_size);
      int l_idx = (int)((l - min_price) / bin_size);
      
      if(h_idx >= bin_count) h_idx = bin_count - 1;
      if(l_idx < 0) l_idx = 0;
      
      int bins_covered = h_idx - l_idx + 1;
      long vol_per_bin = vol / bins_covered;
      
      for(int s = 0; s < 3; s++)
        {
         if(IsInSession(bar_time, s))
           {
            for(int j = l_idx; j <= h_idx; j++)
              {
               m_sessions[s].bins[j].volume += vol_per_bin;
               m_sessions[s].total_volume += vol_per_bin;
              }
           }
        }
     }

   //--- Calculate POC and VA for each session
   for(int s = 0; s < 3; s++)
     {
      if(m_sessions[s].total_volume <= 0) continue;

      long max_vol = -1;
      int poc_idx = 0;
      for(int i = 0; i < bin_count; i++)
        {
         if(m_sessions[s].bins[i].volume > max_vol)
           {
            max_vol = m_sessions[s].bins[i].volume;
            poc_idx = i;
           }
        }
      m_sessions[s].poc_price = m_sessions[s].bins[poc_idx].price + bin_size / 2.0;

      long target_va_vol = (long)(m_sessions[s].total_volume * (InpValueAreaPercent / 100.0));
      long current_va_vol = m_sessions[s].bins[poc_idx].volume;
      m_sessions[s].bins[poc_idx].is_va = true;

      int up_idx = poc_idx + 1;
      int dn_idx = poc_idx - 1;

      while(current_va_vol < target_va_vol && (up_idx < bin_count || dn_idx >= 0))
        {
         long up_vol = (up_idx < bin_count) ? m_sessions[s].bins[up_idx].volume : -1;
         long dn_vol = (dn_idx >= 0) ? m_sessions[s].bins[dn_idx].volume : -1;

         if(up_vol >= dn_vol && up_vol != -1)
           {
            current_va_vol += up_vol;
            m_sessions[s].bins[up_idx].is_va = true;
            up_idx++;
           }
         else if(dn_vol != -1)
           {
            current_va_vol += dn_vol;
            m_sessions[s].bins[dn_idx].is_va = true;
            dn_idx--;
           }
         else break;
        }
     }
  }
//+------------------------------------------------------------------+
//| Render Volume Profile                                            |
//+------------------------------------------------------------------+
void RenderProfile()
  {
   int width = (int)ChartGetInteger(0, CHART_WIDTH_IN_PIXELS);
   int height = (int)ChartGetInteger(0, CHART_HEIGHT_IN_PIXELS);

   if(width != m_canvas.Width() || height != m_canvas.Height())
     {
      m_canvas.Resize(width, height);
     }

   m_canvas.Erase(0);

   int bin_count = ArraySize(m_sessions[0].bins);
   if(bin_count == 0) { m_canvas.Update(); return; }

   long global_max_vol = 0;
   for(int i = 0; i < bin_count; i++)
     {
      long total_bin_vol = 0;
      for(int s = 0; s < 3; s++) total_bin_vol += m_sessions[s].bins[i].volume;
      if(total_bin_vol > global_max_vol) global_max_vol = total_bin_vol;
     }

   if(global_max_vol <= 0) { m_canvas.Update(); return; }

   int max_draw_width = (int)(width * (InpWidthPercent / 100.0));
   
   int x_right = width - 1;
   
   double tick_size = SymbolInfoDouble(_Symbol, SYMBOL_TRADE_TICK_SIZE);
   double bin_height_price = tick_size * InpTicksPerBin;

   for(int i = 0; i < bin_count; i++)
     {
      double p_top = m_sessions[0].bins[i].price + bin_height_price;
      double p_bot = m_sessions[0].bins[i].price;
      int y_top = PriceToY(p_top);
      int y_bot = PriceToY(p_bot);

      int current_x = x_right;
      
      for(int s = 0; s < 3; s++)
        {
         if(m_sessions[s].bins[i].volume <= 0) continue;

         int segment_w = (int)((double)m_sessions[s].bins[i].volume / global_max_vol * max_draw_width);
         if(segment_w <= 0) continue;

         uint base_clr_rgb = COLOR2RGB(m_sessions[s].base_color);
         uint clr = ARGB(m_sessions[s].bins[i].is_va ? 180 : 80, (base_clr_rgb>>16)&0xFF, (base_clr_rgb>>8)&0xFF, base_clr_rgb&0xFF);
         
         m_canvas.FillRectangle(current_x - segment_w, y_top, current_x, y_bot, clr);
         current_x -= segment_w;
        }
     }

   //--- Draw POCs
   for(int s = 0; s < 3; s++)
     {
      if(m_sessions[s].total_volume <= 0) continue;
      int y_poc = PriceToY(m_sessions[s].poc_price);
      uint poc_rgb = COLOR2RGB(m_sessions[s].base_color); // Use session color for its POC
      uint poc_clr = ARGB(255, (poc_rgb>>16)&0xFF, (poc_rgb>>8)&0xFF, poc_rgb&0xFF);
      m_canvas.LineHorizontal(x_right - max_draw_width, x_right, y_poc, poc_clr);
     }

   m_canvas.Update();
  }

//+------------------------------------------------------------------+
//| Helper to convert price to Y coordinate                          |
//+------------------------------------------------------------------+
int PriceToY(double price)
  {
   double chart_min = ChartGetDouble(0, CHART_PRICE_MIN);
   double chart_max = ChartGetDouble(0, CHART_PRICE_MAX);
   int height = (int)ChartGetInteger(0, CHART_HEIGHT_IN_PIXELS);
   
   if(chart_max == chart_min) return 0;
   return (int)((chart_max - price) / (chart_max - chart_min) * height);
  }

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