///////////////////////////////////////////////////////
// 
// SaherElm IT Center Momentum Oscillator
// ---------------------------------------------
// saherelm implementation of above oscillator ...
//
// 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 Momentum Oscillator"
#property strict

//
// START Inputs ...
//
input int length = 7; // Market Length
//
// END Inputs ...
//

//
// START Global Definitions: Variables, Properties and etc ...
//
//
#property indicator_separate_window

//
#property indicator_buffers    1

//
#property indicator_level1     0.0
#property indicator_level2     100.0
#property indicator_levelcolor clrSilver
#property indicator_levelstyle STYLE_DOT

//
// MOMENTUM ...
#property indicator_width1 1
#property indicator_color1 clrLightBlue
#property indicator_type1 DRAW_LINE
#property indicator_style1 STYLE_SOLID

//
// Declare Buffers ...
#define momentumBufferIndex 0

double momentumBuffer[];
//
// 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;
    }

    //
    IndicatorBuffers(1);

    //
    SetIndexBuffer(momentumBufferIndex, momentumBuffer);
    SetIndexLabel(momentumBufferIndex, "Momentum");
    SetIndexDrawBegin(momentumBufferIndex, length);

    //
    // initialization done ...
    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 ... 
        
        //
        // Calculate Long TP ...
        CalculateBuffers(
            i,
            close
        );
    }

    //
    return rates_total;
}
//
// END Event Handlers ...
// 

//
// START Functions ...
//
void CalculateBuffers(
    const int bar_index,
    const double &close[]
) {
    //
    // Calculate Buffers ...
    double momentum = close[bar_index] * 100 / close[bar_index + length];

    //
    momentumBuffer[bar_index] = momentum;
}
//
// END Functions ...
//