/*

   IGraph library.

   Copyright (C) 2021-2022  The igraph development team

   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 <cstdlib>

inline void check_err(int err) {

    if (err)

        abort();

}

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {

    igraph_t graph;

    igraph_vector_int_t edges;

    igraph_set_error_handler(igraph_error_handler_ignore);

    igraph_set_warning_handler(igraph_warning_handler_ignore);

    if (Size % 2 == 1 || Size > 65280) {

        return 0;

    }

    check_err(igraph_vector_int_init(&edges, Size));

    for (size_t i=0; i < Size; ++i) {

        VECTOR(edges)[i] = Data[i];

    }

    if (! igraph_create(&graph, &edges, 0, IGRAPH_DIRECTED)) {

        igraph_integer_t conn;

        /* Enable connectivity checks in order to try to force the fuzzer

         * to find connected graphs. Disconnected graphs result in low coverage. */

        check_err(igraph_edge_connectivity(&graph, &conn, 1));

        check_err(igraph_to_undirected(&graph, IGRAPH_TO_UNDIRECTED_COLLAPSE, nullptr));

        check_err(igraph_edge_connectivity(&graph, &conn, 1));

        igraph_destroy(&graph);

    }

    igraph_vector_int_destroy(&edges);

    IGRAPH_ASSERT(IGRAPH_FINALLY_STACK_EMPTY);

    return 0;  // Non-zero return values are reserved for future use.

}