/* Copyright (C) 2016 - IIT Bombay - FOSSEE

 This file must be used under the terms of the CeCILL.
 This source file is licensed as described in the file COPYING, which
 you should have received as part of this distribution.  The terms
 are also available at
 http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
 Author: Siddhesh Wani
 Organization: FOSSEE, IIT Bombay
 Email: toolbox@scilab.in
*/
#include <stdlib.h>
#include <string.h>
#include "matrixDivision.h" 
#include "lapack.h" 

void i16rdivma (	int16 * in1,		int lines1,	int columns1,
				int16 * in2,		int lines2,	int columns2,
				int16 * out){

	char cNorm	= 0;
	int iExit	= 0;

	/*temporary variables*/
	int iWork		= 0;
	int iInfo		= 0;
	int iMax		= 0;
	int16 dblRcond	= 0;

	int16 dblEps	= 0;
	int16 dblAnorm	= 0;

	int16 *pAf		= NULL;
	int16 *pAt		= NULL;
	int16 *pBt		= NULL;
	int16 *pDwork	= NULL;

	int *pRank	= NULL;
	int *pIpiv	= NULL;
	int *pJpvt	= NULL;
	int *pIwork	= NULL;

	iWork	= max(4 * columns2, max(min(lines2, columns2) + 3 * lines2 + 1, 2 * min(lines2, columns2) + lines1));


	/* Array allocations*/
	pAf			= (int16*)malloc(sizeof(int16) * (unsigned int)columns2 * (unsigned int)lines2);
	pAt			= (int16*)malloc(sizeof(int16) * (unsigned int)columns2 *(unsigned int) lines2);
	pBt			= (int16*)malloc(sizeof(int16) * (unsigned int)max(lines2,columns2) * (unsigned int)lines1);

	pRank		= (int*)malloc(sizeof(int));
	pIpiv		= (int*)malloc(sizeof(int) * (unsigned int)columns2);
	pJpvt		= (int*)malloc(sizeof(int) * (unsigned int)lines2);
	pIwork		= (int*)malloc(sizeof(int) * (unsigned int)columns2);


	cNorm		= '1';
	pDwork		= (int16*)malloc(sizeof(int16) * (unsigned int)iWork);
	dblEps		= getRelativeMachinePrecision() ;
	dblAnorm	= dlange_(&cNorm, &lines2, &columns1, in2, &lines2, pDwork);

	/*tranpose A and B*/

	dtransposea(in2, lines2, columns2, pAt);
	dtransposea(in1, lines1, columns2, pBt);

	if(lines2 == columns2)
	{
		cNorm		= 'F';
		dlacpy_(&cNorm, &columns2, &columns2, pAt, &columns2, pAf, &columns2);
		dgetrf_(&columns2, &columns2, pAf, &columns2, pIpiv, &iInfo);
		if(iInfo == 0)
		{
			cNorm = '1';
			dgecon_(&cNorm, &columns2, pAf, &columns2, &dblAnorm, &dblRcond, pDwork, pIwork, &iInfo);
			if(dblRcond > sqrt(dblEps))
			{
				cNorm	= 'N';
				dgetrs_(&cNorm, &columns2, &lines1, pAf, &columns2, pIpiv, pBt, &columns2, &iInfo);
				dtransposea(pBt, columns2, lines1, out);
				iExit = 1;
			}
		}

	}

	if(iExit == 0)
	{
		dblRcond = sqrt(dblEps);
		cNorm = 'F';
		iMax = max(lines2, columns2);
		memset(pJpvt, 0x00, (unsigned int)sizeof(int) * (unsigned int)lines2);
		dgelsy_(&columns2, &lines2, &lines1, pAt, &columns2, pBt, &iMax,
			pJpvt, &dblRcond, &pRank[0], pDwork, &iWork, &iInfo);

		if(iInfo == 0)
		{


		/*	TransposeRealMatrix(pBt, lines1, lines2, out, Max(lines1,columns1), lines2);*/

			/*Mega caca de la mort qui tue des ours a mains nues 
			mais je ne sais pas comment le rendre "beau" :(*/
			{
				int i,j,ij,ji;
				for(j = 0 ; j < lines2 ; j++)
				{
					for(i = 0 ; i < lines1 ; i++)
					{
						ij = i + j * lines1;
						ji = j + i * max(lines2, columns2);
						out[ij]	= pBt[ji];
					}
				}
			}
		}
	}

	free(pAf);
	free(pAt);
	free(pBt);
	free(pRank);
	free(pIpiv);
	free(pJpvt);
	free(pIwork);
	free(pDwork);

}