/* -*- mode: C -*-  */
/* 
   IGraph library.
   Copyright (C) 2010-2012  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>

void prepare_weights_vector(igraph_vector_t* weights, const igraph_t* graph) {
  int i, n = igraph_ecount(graph);
  igraph_vector_resize(weights, n);
  for (i = 0; i < n; i++) {
    VECTOR(*weights)[i] = i % 5;
  }
}

int main() {
  igraph_t graph;

  igraph_vector_t v;
  igraph_real_t edges[] = { 0, 1, 0, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 8,
			    0,10, 0,11, 0,12, 0,13, 0,17, 0,19, 0,21, 0,31,
			    1, 2, 1, 3, 1, 7, 1,13, 1,17, 1,19, 1,21, 1,30,
			    2, 3, 2, 7, 2,27, 2,28, 2,32, 2, 9, 2, 8, 2,13,
			    3, 7, 3,12, 3,13, 4, 6, 4,10, 5, 6, 5,10, 5,16,
			    6,16, 8,30, 8,32, 8,33, 9,33,13,33,14,32,14,33,
			    15,32,15,33,18,32,18,33,19,33,20,32,20,33,
			    22,32,22,33,23,25,23,27,23,32,23,33,23,29,
			    24,25,24,27,24,31,25,31,26,29,26,33,27,33,
			    28,31,28,33,29,32,29,33,30,32,30,33,31,32,31,33,
			    32,33
  };

  igraph_vector_t membership;
  igraph_vector_t weights;
  igraph_real_t modularity;
  igraph_bool_t simple;
  int retval;

  igraph_vector_view(&v, edges, sizeof(edges)/sizeof(double));
  igraph_create(&graph, &v, 0, IGRAPH_UNDIRECTED);

  igraph_vector_init(&weights, 0);

  igraph_is_simple(&graph, &simple);
  if (!simple) { return 1; }

  igraph_vector_init(&membership, 0);

  igraph_set_error_handler(&igraph_error_handler_printignore);

  /* Zachary karate club, unweighted */
  retval = igraph_community_optimal_modularity(&graph, &modularity,
					       &membership, 0);
  if (retval == IGRAPH_UNIMPLEMENTED) { return 77; }
  if (fabs(modularity - 0.4197896) > 0.0000001) { return 2; }
  /* Zachary karate club, weighted */
  prepare_weights_vector(&weights, &graph);
  igraph_community_optimal_modularity(&graph, &modularity,
				      &membership, &weights);
  if (fabs(modularity - 0.5115767) > 0.0000001) { return 4; }
  igraph_destroy(&graph);

  /* simple graph with loop edges, unweighted */
  igraph_small(&graph, 6, IGRAPH_UNDIRECTED,
          0,1,1,2,2,3,3,4,4,5,5,0,0,0,2,2,-1);
  igraph_community_optimal_modularity(&graph, &modularity,
				      &membership, 0);
  if (fabs(modularity - 0.28125) > 0.00001) { return 3; }
  /* simple graph with loop edges, weighted */
  prepare_weights_vector(&weights, &graph);
  igraph_community_optimal_modularity(&graph, &modularity,
				      &membership, &weights);
  if (fabs(modularity - 0.36686) > 0.00001) { return 5; }
  igraph_destroy(&graph);

  igraph_vector_destroy(&membership);
  igraph_vector_destroy(&weights);

  return 0;
}