/* -*- mode: C -*-  */
/* 
   IGraph library.
   Copyright (C) 2009-2012  Gabor Csardi <csardi.gabor@gmail.com>
   334 Harvard street, Cambridge, MA 02139 USA
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 
   02110-1301 USA

*/

#include <igraph.h>
#include <stdlib.h>

int check(const igraph_vector_t *v1, const igraph_vector_t *v2, int code) {
  igraph_vector_t v;
  long int i, n=igraph_vector_size(v1);
  igraph_real_t m;

  igraph_vector_copy(&v, v1);
  igraph_vector_sub(&v, v2);
  
  for (i=0; i<n; i++) {
    VECTOR(v)[i] = fabs(VECTOR(v)[i]);
  }
  
  if ( (m=igraph_vector_max(&v)) > 0.01) { 
    printf("Difference: %g\n", m);
    exit(code); 
  }

  igraph_vector_destroy(&v);

  return 0;
}

int main() {
  
  igraph_t g;
  igraph_vector_t bet, bet2, weights, edges;
  igraph_vector_t bbet, bbet2;
  
  igraph_real_t nontriv[] = { 0, 19, 0, 16, 0, 20, 1, 19, 2, 5, 3, 7, 3, 8, 
			      4, 15, 4, 11, 5, 8, 5, 19, 6, 7, 6, 10, 6, 8, 
			      6, 9, 7, 20, 9, 10, 9, 20, 10, 19, 
			      11, 12, 11, 20, 12, 15, 13, 15, 
			      14, 18, 14, 16, 14, 17, 15, 16, 17, 18 };
  
  igraph_real_t nontriv_weights[] = { 0.5249, 1, 0.1934, 0.6274, 0.5249, 
				      0.0029, 0.3831, 0.05, 0.6274, 0.3831, 
				      0.5249, 0.0587, 0.0579, 0.0562, 0.0562, 
				      0.1934, 0.6274, 0.6274, 0.6274, 0.0418, 
				      0.6274, 0.3511, 0.3511, 0.1486, 1, 1, 
				      0.0711, 0.2409 };

  igraph_real_t nontriv_res[] = { 20, 0, 0, 0, 0, 19, 80, 85, 32, 0, 10, 
				  75, 70, 0, 36, 81, 60, 0, 19, 19, 86 };

  /*******************************************************/

  igraph_barabasi_game(/* graph= */    &g,
		       /* n= */        1000,
		       /* power= */    1,
		       /* m= */        3,
		       /* outseq= */   0,
		       /* outpref= */  0,
		       /* A= */        1,
		       /* directed= */ 0, 
		       /* algo= */     IGRAPH_BARABASI_BAG,
		       /* start_from= */ 0);
  
  igraph_simplify(&g, /* multiple= */ 1, /* loops= */ 1, /*edge_comb=*/ 0);
  
  igraph_vector_init(&bet, 0);
  igraph_vector_init(&bbet, 0);
  
  igraph_betweenness_estimate(/* graph=     */ &g,
			      /* res=       */ &bet,
			      /* vids=      */ igraph_vss_all(),
			      /* directed = */ 0,
			      /* cutoff=    */ 2,
			      /* weights=   */ 0, 
			      /* nobigint=  */ 1);

  igraph_betweenness_estimate(/* graph=     */ &g,
			      /* res=       */ &bbet,
			      /* vids=      */ igraph_vss_all(),
			      /* directed = */ 0,
			      /* cutoff=    */ 2,
			      /* weights=   */ 0, 
			      /* nobigint=  */ 0);  

  check(&bet, &bbet, 10);

  igraph_vector_destroy(&bet);
  igraph_vector_destroy(&bbet);
  igraph_destroy(&g);

  /*******************************************************/

  igraph_tree(&g, 20000, 10, IGRAPH_TREE_UNDIRECTED);
  
  igraph_vector_init(&bet, 0);
  igraph_vector_init(&bbet, 0);
  
  igraph_betweenness_estimate(/* graph=     */ &g,
			      /* res=       */ &bet,
			      /* vids=      */ igraph_vss_all(),
			      /* directed = */ 0,
			      /* cutoff=    */ 3,
			      /* weights=   */ 0, 
			      /* nobigint=  */ 1);

  igraph_betweenness_estimate(/* graph=     */ &g,
			      /* res=       */ &bbet,
			      /* vids=      */ igraph_vss_all(),
			      /* directed = */ 0,
			      /* cutoff=    */ 3,
			      /* weights=   */ 0, 
			      /* nobigint=  */ 0);

  check(&bet, &bbet, 20);

  igraph_vector_init(&bet2, 0);
  igraph_vector_init(&bbet2, 0);
  igraph_vector_init(&weights, igraph_ecount(&g));
  igraph_vector_fill(&weights, 1.0);
  
  igraph_betweenness_estimate(/* graph=     */ &g,
			      /* res=       */ &bet2,
			      /* vids=      */ igraph_vss_all(),
			      /* directed = */ 0,
			      /* cutoff=    */ 3,
			      /* weights=   */ &weights, 
			      /* nobigint=  */ 1);

  igraph_betweenness_estimate(/* graph=     */ &g,
			      /* res=       */ &bbet2,
			      /* vids=      */ igraph_vss_all(),
			      /* directed = */ 0,
			      /* cutoff=    */ 3,
			      /* weights=   */ &weights, 
			      /* nobigint=  */ 0);

  if (!igraph_vector_all_e(&bet, &bet2)) {
    return 1;
  }

/*   if (!igraph_vector_all_e(&bbet, &bbet2)) { */
/*     return 2; */
/*   } */

  check(&bet, &bbet, 30);
  check(&bet2, &bbet2, 40);

  igraph_vector_destroy(&bet);
  igraph_vector_destroy(&bet2);
  igraph_vector_destroy(&bbet);
  igraph_vector_destroy(&bbet2);
  igraph_vector_destroy(&weights);
  igraph_destroy(&g);

  /* Non-trivial weighted graph */
  igraph_vector_view(&edges, nontriv, sizeof(nontriv)/sizeof(igraph_real_t));
  igraph_create(&g, &edges, 0, /* directed= */ 0);
  igraph_vector_view(&weights, nontriv_weights, 
		     sizeof(nontriv_weights)/sizeof(igraph_real_t));
  igraph_vector_init(&bet, 0);
  igraph_vector_init(&bbet, 0);

  igraph_betweenness(/*graph=*/ &g, /*res=*/ &bet, /*vids=*/ igraph_vss_all(), 
		     /*directed=*/0, /*weights=*/ &weights, /*nobigint=*/ 1);

  igraph_betweenness(/*graph=*/ &g, /*res=*/ &bbet, /*vids=*/ igraph_vss_all(), 
		     /*directed=*/0, /*weights=*/ &weights, /*nobigint=*/ 0);

  igraph_vector_view(&bet2, nontriv_res, 
		     sizeof(nontriv_res)/sizeof(igraph_real_t));

  if (!igraph_vector_all_e(&bet, &bet2)) {
    return 2;
  }

  check(&bet, &bbet, 50);
  
  igraph_vector_destroy(&bet);
  igraph_vector_destroy(&bbet);
  igraph_destroy(&g);

  if (IGRAPH_FINALLY_STACK_SIZE() != 0) return 3;

  return 0;
}