/*
 *  Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
 *  Copyright (C) 2008-2008 - INRIA - Allan SIMON
 *
 *  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
 *
 */
#include <stdlib.h>
#include <string.h>
#include "matrixDivision.h" 
#include "lapack.h" 

void drdivma (	double * in1,		int lines1,	int columns1,
				double * in2,		int lines2,	int columns2,
				double * out){

	char cNorm	= 0;
	int iExit	= 0;

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

	double dblEps	= 0;
	double dblAnorm	= 0;

	double *pAf		= NULL;
	double *pAt		= NULL;
	double *pBt		= NULL;
	double *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			= (double*)malloc(sizeof(double) * (unsigned int)columns2 * (unsigned int)lines2);
	pAt			= (double*)malloc(sizeof(double) * (unsigned int)columns2 *(unsigned int) lines2);
	pBt			= (double*)malloc(sizeof(double) * (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		= (double*)malloc(sizeof(double) * (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);

}