// SPDX-License-Identifier: MIT
// Copyright (c) 2026 WickAtlas. MIT-licensed; provided "AS IS", without warranty.
// Version 1.0.0 | Released 2026-08-13 | Platform: MetaTrader 4 / MQL4 build 600+
// Defaults: RSI 14 on close; research levels 40, 50 and 60. Indicator only; no external access.
#property strict
#property copyright "WickAtlas"
#property link      "https://wickatlas.com/downloads"
#property version   "1.00"
#property description "RSI with 40, 50 and 60 research regime levels."
#property description "Regime levels are references, not order prompts."
#property indicator_separate_window
#property indicator_minimum 0
#property indicator_maximum 100
#property indicator_buffers 1
#property indicator_color1 clrMediumSeaGreen
#property indicator_level1 40.0
#property indicator_level2 50.0
#property indicator_level3 60.0
#property indicator_levelcolor clrSlateGray
#property indicator_levelstyle STYLE_DOT

input int                InpRSIPeriod    = 14;
input ENUM_APPLIED_PRICE InpAppliedPrice = PRICE_CLOSE;

double RSIBuffer[];

int OnInit()
{
   if(InpRSIPeriod<2)
      return(INIT_PARAMETERS_INCORRECT);

   if(!SetIndexBuffer(0,RSIBuffer))
      return(INIT_FAILED);
   ArraySetAsSeries(RSIBuffer,true);
   SetIndexStyle(0,DRAW_LINE,STYLE_SOLID,2,clrMediumSeaGreen);
   SetIndexLabel(0,"RSI");
   SetIndexEmptyValue(0,EMPTY_VALUE);
   SetIndexDrawBegin(0,InpRSIPeriod);
   IndicatorShortName("WickAtlas RSI Regime ("+IntegerToString(InpRSIPeriod)+")");
   IndicatorDigits(2);
   return(INIT_SUCCEEDED);
}

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[])
{
   if(rates_total<=InpRSIPeriod)
      return(0);

   int oldest=rates_total-InpRSIPeriod;
   int first=(prev_calculated==0 || prev_calculated>rates_total)
      ? oldest
      : MathMin(rates_total-prev_calculated+1,oldest);

   if(prev_calculated==0)
      ArrayInitialize(RSIBuffer,EMPTY_VALUE);

   for(int i=first;i>=0;i--)
   {
      ResetLastError();
      double rsiValue=iRSI(NULL,0,InpRSIPeriod,InpAppliedPrice,i);
      int rsiError=GetLastError();
      RSIBuffer[i]=(rsiError==0 && rsiValue!=EMPTY_VALUE) ? rsiValue : EMPTY_VALUE;
   }
   return(rates_total);
}