/* TA-LIB Copyright (c) 1999-2025, Mario Fortier
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
*   notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
*   notice, this list of conditions and the following disclaimer in
*   the documentation and/or other materials provided with the
*   distribution.
*
* - Neither name of author nor the names of its contributors
*   may be used to endorse or promote products derived from this
*   software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/* AUTO-GENERATED by ta_codegen — DO NOT EDIT.
* Source of truth: ta_codegen/input/<name>/  (regenerate: cd ta_codegen/generator && cargo run -- generate)
*/

#include <string.h>
#include <math.h>
#include "ta_func.h"
#include "ta_utility.h"
#include "ta_memory.h"
#include "ta_func_unguarded.h"

/* List of contributors:
 *
 *  Initial  Name/description
 *  -------------------------------------------------------------------
 *  MF       Mario Fortier
 *
 *
 * Change history:
 *
 *  MMDDYY BY   Description
 *  -------------------------------------------------------------------
 *  112400 MF   Template creation.
 *  052603 MF   Adapt code to compile with .NET Managed C++
 */

TA_LIB_API int TA_WMA_Lookback( int optInTimePeriod )
{
   if( (int)optInTimePeriod == (int)0x80000000 )
      optInTimePeriod = 30;
   else if( (int)optInTimePeriod < 1 || (int)optInTimePeriod > 100000 )
      return -1;
   return optInTimePeriod - 1;
}

TA_LIB_API TA_RetCode TA_WMA( int    startIdx,
                              int    endIdx,
                              const double inReal[],
                              int optInTimePeriod,
                              int          *outBegIdx,
                              int          *outNBElement,
                              double        outReal[] )
{
   int inIdx;
   int outIdx;
   int i;
   int trailingIdx;
   int divider;
   double periodSum;
   double periodSub;
   double tempReal;
   double trailingValue;
   int lookbackTotal;

   if( startIdx < 0 )
      return TA_OUT_OF_RANGE_START_INDEX;
   if( (endIdx < 0) || (endIdx < startIdx) )
      return TA_OUT_OF_RANGE_END_INDEX;

   if( !inReal )
      return TA_BAD_PARAM;
   if( (int)optInTimePeriod == (int)0x80000000 )
      optInTimePeriod = 30;
   else if( (int)optInTimePeriod < 1 || (int)optInTimePeriod > 100000 )
      return TA_BAD_PARAM;
   if( !outReal )
      return TA_BAD_PARAM;

   lookbackTotal = optInTimePeriod - 1;
   /* Move up the start index if there is not
    * enough initial data.
    */
   if( startIdx < lookbackTotal )
   {
      startIdx = lookbackTotal;
   }
   /* Make sure there is still something to evaluate. */
   if( startIdx > endIdx )
   {
      *outBegIdx= 0;
      *outNBElement= 0;
      return TA_SUCCESS;
   }
   /* To make the rest more efficient, handle exception
    * case where the user is asking for a period of '1'.
    * In that case outputs equals inputs for the requested
    * range.
    */
   if( optInTimePeriod == 1 )
   {
      *outBegIdx= startIdx;
      *outNBElement= endIdx - startIdx + 1;
      memmove(outReal,&inReal[startIdx],(int)*outNBElement * sizeof(double));
      return TA_SUCCESS;
   }
   /* Calculate the divider (always an integer value).
    * By induction: 1+2+3+4+'n' = n(n+1)/2
    * '>>1' is usually faster than '/2' for unsigned.
    */
   divider = optInTimePeriod * (optInTimePeriod + 1) >> 1;
   /* The algo used here use a very basic property of
    * multiplication/addition: (x*2) = x+x
    *
    * As an example, a 3 period weighted can be
    * interpreted in two way:
    *  (x1*1)+(x2*2)+(x3*3)
    *      OR
    *  x1+x2+x2+x3+x3+x3 (this is the periodSum)
    *
    * When you move forward in the time serie
    * you can quickly adjust the periodSum for the
    * period by substracting:
    *   x1+x2+x3 (This is the periodSub)
    * Making the new periodSum equals to:
    *   x2+x3+x3
    *
    * You can then add the new price bar
    * which is x4+x4+x4 giving:
    *   x2+x3+x3+x4+x4+x4
    *
    * At this point one iteration is completed and you can
    * see that we are back to the step 1 of this example.
    *
    * Why making it so un-intuitive? The number of memory
    * access and floating point operations are kept to a
    * minimum with this algo.
    */
   outIdx = 0;
   trailingIdx = startIdx - lookbackTotal;
   /* Evaluate the initial periodSum/periodSub and trailingValue. */
   periodSub = (double)0.0;
   periodSum = periodSub;
   inIdx = trailingIdx;
   i = 1;
   while( inIdx < startIdx )
   {
      tempReal = inReal[inIdx++];
      periodSub += tempReal;
      periodSum += tempReal * i;
      i += 1;
   }
   trailingValue = 0.0;
   /* Tight loop for the requested range. */
   while( inIdx <= endIdx )
   {
      /* Add the current price bar to the sum
       * who are carried through the iterations.
       */
      tempReal = inReal[inIdx++];
      periodSub += tempReal;
      periodSub -= trailingValue;
      periodSum += tempReal * optInTimePeriod;
      /* Save the trailing value for being substract at
       * the next iteration.
       * (must be saved here just in case outReal and
       *  inReal are the same buffer).
       */
      trailingValue = inReal[trailingIdx++];
      /* Calculate the WMA for this price bar. */
      outReal[outIdx++] = periodSum / divider;
      /* Prepare the periodSum for the next iteration. */
      periodSum -= periodSub;
   }
   /* Set output limits. */
   *outNBElement= outIdx;
   *outBegIdx= startIdx;
   return TA_SUCCESS;
}

TA_LIB_API TA_RetCode TA_WMA_Unguarded( int    startIdx,
                                        int    endIdx,
                                        const double inReal[],
                                        int optInTimePeriod,
                                        int          *outBegIdx,
                                        int          *outNBElement,
                                        double        outReal[] )
{
   int inIdx;
   int outIdx;
   int i;
   int trailingIdx;
   int divider;
   double periodSum;
   double periodSub;
   double tempReal;
   double trailingValue;
   int lookbackTotal;

   lookbackTotal = optInTimePeriod - 1;
   if( startIdx < lookbackTotal )
   {
      startIdx = lookbackTotal;
   }
   if( startIdx > endIdx )
   {
      *outBegIdx= 0;
      *outNBElement= 0;
      return TA_SUCCESS;
   }
   if( optInTimePeriod == 1 )
   {
      *outBegIdx= startIdx;
      *outNBElement= endIdx - startIdx + 1;
      memmove(outReal,&inReal[startIdx],(int)*outNBElement * sizeof(double));
      return TA_SUCCESS;
   }
   divider = optInTimePeriod * (optInTimePeriod + 1) >> 1;
   outIdx = 0;
   trailingIdx = startIdx - lookbackTotal;
   periodSub = (double)0.0;
   periodSum = periodSub;
   inIdx = trailingIdx;
   i = 1;
   while( inIdx < startIdx )
   {
      tempReal = inReal[inIdx++];
      periodSub += tempReal;
      periodSum += tempReal * i;
      i += 1;
   }
   trailingValue = 0.0;
   while( inIdx <= endIdx )
   {
      tempReal = inReal[inIdx++];
      periodSub += tempReal;
      periodSub -= trailingValue;
      periodSum += tempReal * optInTimePeriod;
      trailingValue = inReal[trailingIdx++];
      outReal[outIdx++] = periodSum / divider;
      periodSum -= periodSub;
   }
   *outNBElement= outIdx;
   *outBegIdx= startIdx;
   return TA_SUCCESS;
}

TA_RetCode TA_S_WMA( int    startIdx,
                     int    endIdx,
                     const float inReal[],
                     int optInTimePeriod,
                     int          *outBegIdx,
                     int          *outNBElement,
                     double        outReal[] )
{
   int inIdx;
   int outIdx;
   int i;
   int trailingIdx;
   int divider;
   double periodSum;
   double periodSub;
   double tempReal;
   double trailingValue;
   int lookbackTotal;

   if( startIdx < 0 )
      return TA_OUT_OF_RANGE_START_INDEX;
   if( (endIdx < 0) || (endIdx < startIdx) )
      return TA_OUT_OF_RANGE_END_INDEX;

   if( !inReal )
      return TA_BAD_PARAM;
   if( (int)optInTimePeriod == (int)0x80000000 )
      optInTimePeriod = 30;
   else if( (int)optInTimePeriod < 1 || (int)optInTimePeriod > 100000 )
      return TA_BAD_PARAM;
   if( !outReal )
      return TA_BAD_PARAM;

   lookbackTotal = optInTimePeriod - 1;
   if( startIdx < lookbackTotal )
   {
      startIdx = lookbackTotal;
   }
   if( startIdx > endIdx )
   {
      *outBegIdx= 0;
      *outNBElement= 0;
      return TA_SUCCESS;
   }
   if( optInTimePeriod == 1 )
   {
      *outBegIdx= startIdx;
      *outNBElement= endIdx - startIdx + 1;
      memmove(outReal,&inReal[startIdx],(int)*outNBElement * sizeof(double));
      return TA_SUCCESS;
   }
   divider = optInTimePeriod * (optInTimePeriod + 1) >> 1;
   outIdx = 0;
   trailingIdx = startIdx - lookbackTotal;
   periodSub = (double)0.0;
   periodSum = periodSub;
   inIdx = trailingIdx;
   i = 1;
   while( inIdx < startIdx )
   {
      tempReal = inReal[inIdx++];
      periodSub += tempReal;
      periodSum += tempReal * i;
      i += 1;
   }
   trailingValue = 0.0;
   while( inIdx <= endIdx )
   {
      tempReal = inReal[inIdx++];
      periodSub += tempReal;
      periodSub -= trailingValue;
      periodSum += tempReal * optInTimePeriod;
      trailingValue = inReal[trailingIdx++];
      outReal[outIdx++] = periodSum / divider;
      periodSum -= periodSub;
   }
   *outNBElement= outIdx;
   *outBegIdx= startIdx;
   return TA_SUCCESS;
}

TA_RetCode TA_S_WMA_Unguarded( int    startIdx,
                               int    endIdx,
                               const float inReal[],
                               int optInTimePeriod,
                               int          *outBegIdx,
                               int          *outNBElement,
                               double        outReal[] )
{
   int inIdx;
   int outIdx;
   int i;
   int trailingIdx;
   int divider;
   double periodSum;
   double periodSub;
   double tempReal;
   double trailingValue;
   int lookbackTotal;

   lookbackTotal = optInTimePeriod - 1;
   if( startIdx < lookbackTotal )
   {
      startIdx = lookbackTotal;
   }
   if( startIdx > endIdx )
   {
      *outBegIdx= 0;
      *outNBElement= 0;
      return TA_SUCCESS;
   }
   if( optInTimePeriod == 1 )
   {
      *outBegIdx= startIdx;
      *outNBElement= endIdx - startIdx + 1;
      memmove(outReal,&inReal[startIdx],(int)*outNBElement * sizeof(double));
      return TA_SUCCESS;
   }
   divider = optInTimePeriod * (optInTimePeriod + 1) >> 1;
   outIdx = 0;
   trailingIdx = startIdx - lookbackTotal;
   periodSub = (double)0.0;
   periodSum = periodSub;
   inIdx = trailingIdx;
   i = 1;
   while( inIdx < startIdx )
   {
      tempReal = inReal[inIdx++];
      periodSub += tempReal;
      periodSum += tempReal * i;
      i += 1;
   }
   trailingValue = 0.0;
   while( inIdx <= endIdx )
   {
      tempReal = inReal[inIdx++];
      periodSub += tempReal;
      periodSub -= trailingValue;
      periodSum += tempReal * optInTimePeriod;
      trailingValue = inReal[trailingIdx++];
      outReal[outIdx++] = periodSum / divider;
      periodSum -= periodSub;
   }
   *outNBElement= outIdx;
   *outBegIdx= startIdx;
   return TA_SUCCESS;
}

