//+------------------------------------------------------------------+
//|                                                          RBase.mqh |
//|                                             Copyright 2026, Leo. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2026, Leo."
#property link      "https://www.mql5.com/en/users/nique_372"
#property strict

#ifndef SCALERBYLEO_SRC_SCALER_RSCALER_RBASE_MQH
#define SCALERBYLEO_SRC_SCALER_RSCALER_RBASE_MQH

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
#include "..\\ScalerBase.mqh"

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
namespace TSN
{
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
#define ROBUSTSCALER_PERCENTILE(vec, l, h, w) ((l == h) ? (vec[l]) : ((vec[l] * (1.0 - w)) + (vec[h] * w)))

//+------------------------------------------------------------------+
//|                    Robust Scaler Base                            |
//+------------------------------------------------------------------+
template<typename TFlt>
class RobustScalerBase : public ScalerBase
 {
protected:
  vector             m_medians, m_iqrs, m_iqrs_inv;
  virtual bool       OnLoad() { return true; }

  //---
  static __forceinline void MakeValues(const double rank, ulong &l, ulong &h, double &w);

public:
                     RobustScalerBase() : ScalerBase() { m_prefix_file = "_median_iqr.csv"; }

  //---
  bool               Save(string prefix_name, int extra_file_flags = FILE_COMMON);
  bool               LoadByFile(string prefix_name, int extra_file_flags = FILE_COMMON);
  bool               LoadByArr(const string &arr[]) override;

  //---
  bool               Fit(const matrix<TFlt> &X);
 };

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
template<typename TFlt>
static __forceinline void RobustScalerBase::MakeValues(const double rank, ulong &l, ulong &h, double &w)
 {
  l = (ulong)MathFloor(rank);
  h = (ulong)MathCeil(rank);
  w = rank - l;
 }

//+------------------------------------------------------------------+
//| Save / Load                                                      |
//+------------------------------------------------------------------+
template<typename TFlt>
bool RobustScalerBase::Save(string prefix_name, int extra_file_flags = FILE_COMMON)
 {
//---
  m_file_name_out = prefix_name + m_prefix_file;
  FileDelete(m_file_name_out);
  ResetLastError();

//---
  const int handle = FileOpen(m_file_name_out, FILE_WRITE | FILE_CSV | extra_file_flags);
  if(handle == INVALID_HANDLE)
   {
    m_last_err = SCALERBYLEO_ERR_FILE_OPEN;
    return false;
   }

//---
  FileWrite(handle, vector_to_string(m_iqrs));
  FileWrite(handle, vector_to_string(m_medians));
  FileWrite(handle, m_i_start);
  FileWrite(handle, m_i_count);

//---
  FileClose(handle);
  return true;
 }

//+------------------------------------------------------------------+
template<typename TFlt>
bool RobustScalerBase::LoadByFile(string prefix_name, int extra_file_flags = FILE_COMMON)
 {
//---
  m_file_name_out = prefix_name + m_prefix_file;

//---
  ResetLastError();
  const int handle = FileOpen(m_file_name_out, FILE_READ | FILE_CSV | extra_file_flags, "\n");
  if(handle == INVALID_HANDLE)
   {
    m_last_err = SCALERBYLEO_ERR_FILE_OPEN;
    return false;
   }

//---
  CStringFunc::ToVector<double, CStringConvert>(FileReadString(handle), m_iqrs, ',');
  CStringFunc::ToVector<double, CStringConvert>(FileReadString(handle), m_medians, ',');
  m_i_start = ulong(FileReadString(handle));
  m_i_count = long(FileReadString(handle));

//---
  m_iqrs_inv = 1.0 / m_iqrs;

//---
  FileClose(handle);
  return (m_loaded_scaler = OnLoad());
 }

//+------------------------------------------------------------------+
template<typename TFlt>
bool RobustScalerBase::LoadByArr(const string &arr[])
 {
  if(ArraySize(arr) < 4)
   {
    m_last_err = SCALERBYLEO_ERR_INVALID_DATA;
    return false;
   }

//---
  int p = 0;
  CStringFunc::ToVector<double, CStringConvert>(arr[p++], m_iqrs, ',');
  CStringFunc::ToVector<double, CStringConvert>(arr[p++], m_medians, ',');
  m_i_start = ulong(arr[p++]);
  m_i_count = long(arr[p++]);

//---
  m_iqrs_inv = 1.0 / m_iqrs;

//---
  return (m_loaded_scaler = OnLoad());
 }

//+------------------------------------------------------------------+
//| Fit                                                              |
//+------------------------------------------------------------------+
template<typename TFlt>
bool RobustScalerBase::Fit(const matrix<TFlt> &X)
 {
//---
  const ulong total_cols = X.Cols();
  const ulong rows = X.Rows();
  if(total_cols == 0 || rows == 0)
   {
    m_last_err = SCALERBYLEO_ERR_EMPTY_INPUT;
    return false;
   }
  if(m_i_start >= total_cols)
   {
    m_last_err = SCALERBYLEO_ERR_INVALID_RANGE;
    return false;
   }

//---
  const ulong fs = SCALERBYLEO_SIZE(total_cols);

//---
  m_medians.Resize(fs);
  m_iqrs.Resize(fs);
  m_iqrs_inv.Resize(fs);

//---
  const double rs_1 = double(rows - 1);

//--- make values
  ulong l50, h50;
  double w50;
  MakeValues(0.50 * rs_1, l50, h50, w50);

  ulong l25, h25;
  double w25;
  MakeValues(0.25 * rs_1, l25, h25, w25);

  ulong l75, h75;
  double w75;
  MakeValues(0.75 * rs_1, l75, h75, w75);

//--- iter
  for(ulong c = 0; c < fs; c++)
   {
    //---
    vector col = X.Col(m_i_start + c);
    col.Sort(SORT_ASCENDING);

    //---
    const double median_v = ROBUSTSCALER_PERCENTILE(col, l50, h50, w50);
    const double iqr_v = ROBUSTSCALER_PERCENTILE(col, l75, h75, w75) - ROBUSTSCALER_PERCENTILE(col, l25, h25, w25);

    //---
    if(fabs(iqr_v) < SCALER_BASE_MIN_VALUE)
     {
      m_last_err = SCALERBYLEO_ERR_DEGENERATE_SCALE;
      return false;
     }

    //---
    m_medians[c] = median_v;
    m_iqrs[c] = iqr_v;
    m_iqrs_inv[c] = 1.0 / iqr_v;
   }

//---
  return (m_loaded_scaler = OnLoad());
 }
}
#endif // SCALERBYLEO_SRC_SCALER_RSCALER_RBASE_MQH
//+------------------------------------------------------------------+