/////////////////////////////////////////////////////////////////
//
// SaherElm IT Center Volume Indicator
// -------------------------------------------------------------
// this indicator provides Volume ...
//
// Maintainer:
// ------------
// Hadi Khazaee Asl (hadi_khazaee_asl@yahoo.com)
//
////////////////////////////////////////////////////////////////
//
// Global Properties ...
#property copyright "Copyright 2023, SaherElm IT Center"
#property link "https://saherelm.ir"
#property version "1.00"
#property description "SaherElm Volume Indicator"
#property strict

//
// START Inputs ...
//
input int length = 11; // Length 
//
// END Inputs ...
//

//
// START Global Definitions: Variables, Properties and etc ...
//
//
// Includes our shared library ...
#include "../Libraries/x-saherelm.lib.mq4"

//
#property indicator_separate_window

//
// we have 2 buffer in this indicator ...
#property indicator_buffers 3

//
// also we have 2 line for draw on this indicator ...
#property indicator_plots   3

//
// Buy Volume ...
#property indicator_width1 1
#property indicator_color1 clrGreen
#property indicator_type1 DRAW_HISTOGRAM
#property indicator_style1 STYLE_DOT

//
// Sell Volume ...
#property indicator_width2 1
#property indicator_type2 DRAW_LINE
#property indicator_color2 clrRed
#property indicator_style2 STYLE_DOT

//
// Diff ...
#property indicator_width3 1
#property indicator_type3 DRAW_HISTOGRAM
#property indicator_color3 clrYellow
#property indicator_style3 STYLE_SOLID

//
//#property indicator_minimum 0
//#property indicator_maximum 1

//
// set color of horizontal levels ...
#property indicator_levelcolor clrGray

//
// set style of horizontal levels ...
#property indicator_levelstyle STYLE_DOT

//
// Declare Buffers ...
#define buyVolumeBufferIndex 0
#define sellVolumeBufferIndex 1
#define diffBufferIndex 2

//
double buyVolumeBuffer[];
double sellVolumeBuffer[];
double diffBuffer[];

//
// here we specify logging enabled or not ...
bool enableLogging = true;

//
// this is a Tag which attached to our Logger ...
string logTag = "XS_VOLUME";
//
// END Global Definitions: Variables, Properties and etc ...
//

//
// Start Event Handlers ...
//
//
// Initialization ...
int OnInit() {
    //
    // Initialize what we want ...
    
    //
    // Validating Input Parameters ...
    if (length < 0) {
        return INIT_PARAMETERS_INCORRECT;
    }

    //
    // set descriptions of horizontal levels ...
    SetLevelValue(0, 0.0);
    IndicatorSetString(INDICATOR_LEVELTEXT,0,"");

    //
    // Buy Volume Buffer ...
    SetIndexBuffer(buyVolumeBufferIndex, buyVolumeBuffer);
    SetIndexLabel(buyVolumeBufferIndex, "Buy Volume");

    //
    // Sell Volume Buffer ...
    SetIndexBuffer(sellVolumeBufferIndex, sellVolumeBuffer);
    SetIndexLabel(sellVolumeBufferIndex, "Sell Volume");

    //
    // Diff Buffer ...
    SetIndexBuffer(diffBufferIndex, diffBuffer);
    SetIndexLabel(diffBufferIndex, "Diff");
    
    //
    return(INIT_SUCCEEDED);
}

//
// Do Calculation ...
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[]
) {
    //
    // this counts Available Bars ...
    int limit;

    //
    // because in some cases we may have more than one input for 
    // calculation and we must prevent any calculation
    // untill we pass the biggest input length, here we get max Input length
    // and then wait until pass it ...
    int maxLength = MathMax(0, length);

    //
    // input variable, we return 0 means nothing passed ...
    if (rates_total < maxLength) {
      return 0;
    }
    
    //
    // found which candles calculated before ...
    limit = (prev_calculated == 0) ? rates_total - maxLength - 1 : rates_total - prev_calculated + 1;

    //
    // this is the main loop of calculations, for each bar index ...
    for (int i = limit - 1; i >= 0; i--) {
        //
        // Start Calculation here ...
        // i is bar_index ... 

        //
        CalculateBuffers(
            open,
            close,
            high,
            low,
            i
        );
    }

    //
    return rates_total;
}

//
// De Initialization ...
void OnDeinit(const int reason) {
}
//
// END Event Handlers ...
//

//
// START Functions ...
//
//
void CalculateBuffers(
    const double &open[],
    const double &close[],
    const double &high[],
    const double &low[],
    const int &bar_index
) {
    //
    long volume = iVolume(
        _Symbol,
        _Period,
        bar_index
    );

    //
    double buyVolume = 0.0;
    double sellVolume = 0.0;

    //
    // Up ...
    if (close[bar_index] > open[bar_index]) {
        //
        double cuenta = (high[bar_index] - low[bar_index]) * 10000;
        double cuenta1 = volume - cuenta;

        //
        buyVolume = ((volume - cuenta) / 2) + cuenta;
        
        //
        buyVolumeBuffer[bar_index] = buyVolume;
        sellVolumeBuffer[bar_index] = volume - buyVolume;
    } else 
    //
    // Down ...
    if (close[bar_index] < open[bar_index]) {
        //
        double cuenta1 = (high[bar_index] - low[bar_index]) * 10000;
        double cuenta = volume - cuenta1;

        //
        sellVolume = ((volume - cuenta1) / 2) + cuenta1;

        //
        sellVolumeBuffer[bar_index] = sellVolume;
        buyVolumeBuffer[bar_index] = volume - sellVolume;
    } else 
    //
    // Neutral ...
    if (close[bar_index] == open[bar_index]) {
        //
        double cuenta = (volume / 2) * 1.0;

        //
        sellVolumeBuffer[bar_index] = cuenta;
        buyVolumeBuffer[bar_index] = volume - cuenta;
    }

    //
    diffBuffer[bar_index] = MathAbs(buyVolumeBuffer[bar_index]) - MathAbs(sellVolumeBuffer[bar_index]);
}
//
// END Functions ...
//