/* *
 * Copyright (c) 2013, James S. Plank and Kevin Greenan
 * All rights reserved.
 *
 * Jerasure - A C/C++ Library for a Variety of Reed-Solomon and RAID-6 Erasure
 * Coding Techniques
 *
 * Revision 2.0: Galois Field backend now links to GF-Complete
 *
 * 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 the name of the University of Tennessee 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 COPYRIGHT
 * HOLDER 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.
 */

    
/*
	revised by S. Simmerman
	2/25/08  
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "jerasure.h"

#define talloc(type, num) (type *) malloc(sizeof(type)*(num))

usage(char *s)
{
  fprintf(stderr, "usage: jerasure_06 k m w packetsize\n");
  fprintf(stderr, "Does a simple Cauchy Reed-Solomon coding example in GF(2^w).\n");
  fprintf(stderr, "       \n");
  fprintf(stderr, "       k+m must be < 2^w.  Packetsize must be a multiple of sizeof(long)\n");
  fprintf(stderr, "       It sets up a Cauchy distribution matrix and encodes k devices of w*packetsize bytes.\n");
  fprintf(stderr, "       After that, it decodes device 0 by using jerasure_make_decoding_bitmatrix()\n");
  fprintf(stderr, "       and jerasure_bitmatrix_dotprod().\n");
  fprintf(stderr, "       \n");
  fprintf(stderr, "This demonstrates: jerasure_bitmatrix_encode()\n");
  fprintf(stderr, "                   jerasure_bitmatrix_decode()\n");
  fprintf(stderr, "                   jerasure_print_bitmatrix()\n");
  fprintf(stderr, "                   jerasure_make_decoding_bitmatrix()\n");
  fprintf(stderr, "                   jerasure_bitmatrix_dotprod()\n");
  if (s != NULL) fprintf(stderr, "\n%s\n\n", s);
  exit(1);
}

static void print_data_and_coding(int k, int m, int w, int psize, 
		char **data, char **coding) 
{
	int i, j, x, n, sp;
	long l;

	if(k > m) n = k;
	else n = m;
	sp = psize * 2 + (psize/4) + 12;

	printf("%-*sCoding\n", sp, "Data");
	for(i = 0; i < n; i++) {
		for (j = 0; j < w; j++) {
			if(i < k) {

				if(j==0) printf("D%-2d p%-2d:", i,j);
				else printf("    p%-2d:", j);
				for(x = 0; x < psize; x +=4) {
					memcpy(&l, data[i]+j*psize+x, sizeof(long));
					printf(" %08lx", l);
				}
				printf("    ");
			}
			else printf("%*s", sp, "");
			if(i < m) {
				if(j==0) printf("C%-2d p%-2d:", i,j);
				else printf("    p%-2d:", j);
				for(x = 0; x < psize; x +=4) {
					memcpy(&l, coding[i]+j*psize+x, sizeof(long));
					printf(" %08lx", l);
				}
			}
			printf("\n");
		}
	}

    printf("\n");
}

int main(int argc, char **argv)
{
  long l;
  int k, w, i, j, m, psize, x;
  int *matrix, *bitmatrix;
  char **data, **coding;
  int *erasures, *erased;
  int *decoding_matrix, *dm_ids;
  
  if (argc != 5) usage(NULL);
  if (sscanf(argv[1], "%d", &k) == 0 || k <= 0) usage("Bad k");
  if (sscanf(argv[2], "%d", &m) == 0 || m <= 0) usage("Bad m");
  if (sscanf(argv[3], "%d", &w) == 0 || w <= 0 || w > 32) usage("Bad w");
  if (w < 30 && (k+m) > (1 << w)) usage("k + m is too big");
  if (sscanf(argv[4], "%d", &psize) == 0 || psize <= 0) usage("Bad packetsize");
  if(psize%sizeof(long) != 0) usage("Packetsize must be multiple of sizeof(long)");

  matrix = talloc(int, m*k);
  for (i = 0; i < m; i++) {
    for (j = 0; j < k; j++) {
      matrix[i*k+j] = galois_single_divide(1, i ^ (m + j), w);
    }
  }
  bitmatrix = jerasure_matrix_to_bitmatrix(k, m, w, matrix);

  printf("Last (m * w) rows of the Binary Distribution Matrix:\n\n");
  jerasure_print_bitmatrix(bitmatrix, w*m, w*k, w);
  printf("\n");

  srand48(0);
  data = talloc(char *, k);
  for (i = 0; i < k; i++) {
    data[i] = talloc(char, psize*w);
    for (j = 0; j < w; j++) {
		for(x = 0; x < psize; x += 4) {
			l = lrand48();
			memcpy(data[i]+j*psize+x, &l, sizeof(long));
		}

    }
  }

  coding = talloc(char *, m);
  for (i = 0; i < m; i++) {
    coding[i] = talloc(char, psize*w);
  }

  jerasure_bitmatrix_encode(k, m, w, bitmatrix, data, coding, w*psize, psize);
  
  printf("Encoding Complete:\n\n");
  print_data_and_coding(k, m, w, psize, data, coding);

  erasures = talloc(int, (m+1));
  erased = talloc(int, (k+m));
  for (i = 0; i < m+k; i++) erased[i] = 0;
  for (i = 0; i < m; ) {
    erasures[i] = lrand48()%(k+m);
    if (erased[erasures[i]] == 0) {
      erased[erasures[i]] = 1;
      bzero((erasures[i] < k) ? data[erasures[i]] : coding[erasures[i]-k], psize*w);
      i++;
    }
  }
  erasures[i] = -1;

  printf("Erased %d random devices:\n\n", m);
  print_data_and_coding(k, m, w, psize, data, coding);
  
  i = jerasure_bitmatrix_decode(k, m, w, bitmatrix, 0, erasures, data, coding, 
		  w*psize, psize);

  printf("State of the system after decoding:\n\n");
  print_data_and_coding(k, m, w, psize, data, coding);
  
  decoding_matrix = talloc(int, k*k*w*w);
  dm_ids = talloc(int, k);

  for (i = 0; i < m; i++) erased[i] = 1;
  for (; i < k+m; i++) erased[i] = 0;

  jerasure_make_decoding_bitmatrix(k, m, w, bitmatrix, erased, decoding_matrix, dm_ids);

  printf("Suppose we erase the first %d devices.  Here is the decoding matrix:\n\n", m);
  jerasure_print_bitmatrix(decoding_matrix, k*w, k*w, w);
  printf("\n");
  printf("And dm_ids:\n\n");
  jerasure_print_matrix(dm_ids, 1, k, w);

  //memcpy(&l, data[0], sizeof(long));
  //printf("\nThe value of device #%d, word 0 is: %lx\n", 0, l);
  bzero(data[0], w*psize);
  jerasure_bitmatrix_dotprod(k, w, decoding_matrix, dm_ids, 0, data, coding, w*psize, psize);

  printf("\nAfter calling jerasure_matrix_dotprod, we calculate the value of device #0, packet 0 to be:\n");
	printf("\nD0  p0 :");
	for(i = 0; i < psize; i +=sizeof(long)) {
		memcpy(&l, data[0]+i, sizeof(long));
		printf(" %08lx", l);
	}
	printf("\n\n");
  //memcpy(&l, data[0], sizeof(long));

  return 0;
}