/*
   igraph library.
   Copyright (C) 2008-2012  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>
#include "test_utilities.h"

int check_projection(const igraph_t *graph,
                     const igraph_vector_bool_t *types,
                     const igraph_t *proj1,
                     const igraph_t *proj2) {
    igraph_int_t vcount1, ecount1, vcount2, ecount2;
    igraph_bipartite_projection_size(graph, types, &vcount1, &ecount1,
                                     &vcount2, &ecount2);
    if (proj1 && igraph_vcount(proj1) != vcount1) {
        exit(10);
    }
    if (proj1 && igraph_ecount(proj1) != ecount1) {
        exit(11);
    }
    if (proj2 && igraph_vcount(proj2) != vcount2) {
        exit(12);
    }
    if (proj2 && igraph_ecount(proj2) != ecount2) {
        exit(13);
    }
    return 0;
}

int main(void) {

    igraph_t g, p1, p2, full, ring;
    igraph_vector_bool_t types;
    igraph_bool_t iso;
    igraph_int_t i, m2 = 0, w, f, t;
    igraph_vector_int_t mult1, mult2;

    /*******************************************************/
    /* Full bipartite graph -> full graphs                 */
    /*******************************************************/

    igraph_vector_bool_init(&types, 0);
    igraph_full_bipartite(&g, &types, 5, 3, /*directed=*/ 0,
                          /*mode=*/ IGRAPH_ALL);

    /* Get both projections */
    igraph_bipartite_projection(&g, &types, &p1, &p2, 0, 0, /*probe1=*/ -1);
    check_projection(&g, &types, &p1, &p2);

    /* Check first projection */
    igraph_full(&full, igraph_vcount(&p1), /*directed=*/0, /*loops=*/0);
    igraph_isomorphic_bliss(&p1, &full, 0, 0, &iso, 0, 0,
                            IGRAPH_BLISS_FM, 0, 0);
    if (!iso) {
        return 1;
    }
    igraph_destroy(&full);

    /* Check second projection */
    igraph_full(&full, igraph_vcount(&p2), /*directed=*/0, /*loops=*/0);
    igraph_isomorphic_bliss(&p2, &full, 0, 0, &iso, 0, 0,
                            IGRAPH_BLISS_FM, 0, 0);
    if (!iso) {
        return 2;
    }
    igraph_destroy(&full);

    igraph_destroy(&p1);
    igraph_destroy(&p2);
    igraph_destroy(&g);
    igraph_vector_bool_destroy(&types);

    /*******************************************************/
    /* More sophisticated test                             */
    /*******************************************************/

    igraph_ring(&g, 100, /*directed=*/ 1, /*mutual=*/ 1,
                /*circular=*/ 1);
    igraph_vector_bool_init(&types, igraph_vcount(&g));
    for (i = 0; i < igraph_vector_bool_size(&types); i++) {
        VECTOR(types)[i] = i % 2 ? 0 : 1;
    }

    /* Get both projections */
    igraph_bipartite_projection(&g, &types, &p1, &p2, 0, 0, /*probe1=*/ -1);
    check_projection(&g, &types, &p1, &p2);

    /* Check first projection */
    igraph_ring(&ring, igraph_vcount(&g) / 2, /*directed=*/ 0,
                /*mutual=*/ 0, /*circular=*/ 1);
    igraph_isomorphic_bliss(&p1, &ring, 0, 0, &iso, 0, 0,
                            IGRAPH_BLISS_FM, 0, 0);
    if (!iso) {
        return 1;
    }

    /* Check second projection */
    igraph_isomorphic_bliss(&p2, &ring, 0, 0, &iso, 0, 0,
                            IGRAPH_BLISS_FM, 0, 0);
    if (!iso) {
        return 2;
    }
    igraph_destroy(&ring);

    igraph_destroy(&p1);
    igraph_destroy(&p2);
    igraph_destroy(&g);
    igraph_vector_bool_destroy(&types);

    /*******************************************************/
    /* Multiplicity test                                   */
    /*******************************************************/

    igraph_small(&g, 10, IGRAPH_UNDIRECTED,
                 0, 8, 1, 8, 2, 8, 3, 8, 4, 8, 4, 9, 5, 9, 6, 9, 7, 9, 0, 9,
                 -1);
    igraph_vector_bool_init(&types, igraph_vcount(&g));
    igraph_vector_bool_fill(&types, true);
    VECTOR(types)[8] = VECTOR(types)[9] = 0;

    igraph_vector_int_init(&mult1, 0);
    igraph_vector_int_init(&mult2, 0);
    igraph_bipartite_projection(&g, &types, &p1, &p2, &mult1, &mult2,
                                /*probe=*/ -1);
    check_projection(&g, &types, &p1, &p2);

    if (igraph_vector_int_size(&mult1) != igraph_ecount(&p1)) {
        return 21;
    }
    if (igraph_vector_int_size(&mult2) != igraph_ecount(&p2)) {
        return 22;
    }
    if (VECTOR(mult1)[0] != 2) {
        return 23;
    }
    for (i = 0; i < igraph_vector_int_size(&mult2); i++) {
        if (VECTOR(mult2)[i] != 1 && VECTOR(mult2)[i] != 2) {
            return 24;
        }
        if (VECTOR(mult2)[i] == 2) {
            m2++;
            w = i;
        }
    }
    if (m2 != 1) {
        return 25;
    }
    f = IGRAPH_FROM(&p2, w);
    t = IGRAPH_TO(&p2, w);
    if (fmin(f, t) != 0 || fmax(f, t) != 4) {
        return 26;
    }

    igraph_vector_int_destroy(&mult1);
    igraph_vector_int_destroy(&mult2);
    igraph_destroy(&p1);
    igraph_destroy(&p2);
    igraph_destroy(&g);
    igraph_vector_bool_destroy(&types);

    VERIFY_FINALLY_STACK();
    return 0;
}
