/*

   igraph library.

   Copyright (C) 2024  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>

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

    igraph_t graph;

    igraph_vector_int_t edges;

    igraph_set_warning_handler(igraph_warning_handler_ignore);

    if (Size % 2 == 0 || Size > 512+1 || Size < 1) {

        return 0;

    }

    igraph_vector_int_init(&edges, Size-1);

    for (size_t i=0; i < Size-1; ++i) {

        VECTOR(edges)[i] = Data[i+1];

    }

    /* Undirected */

    if (igraph_create(&graph, &edges, Data[0], IGRAPH_UNDIRECTED) == IGRAPH_SUCCESS) {

        igraph_bool_t has_multi, has_loop, is_simple, is_complete, is_bipartite;

        igraph_bool_t is_connected, is_acyclic, is_tree, is_biconnected, is_chordal;

        igraph_bool_t has_eulerian_path, has_eulerian_cycle;

        igraph_int_t vcount, ecount;

        igraph_real_t r;

        /* Tip for reading the assertions below:

         * "A implies B" is equivalent to "!A || B".

         */

        vcount = igraph_vcount(&graph);

        ecount = igraph_ecount(&graph);

        igraph_has_multiple(&graph, &has_multi);

        igraph_has_loop(&graph, &has_loop);

        igraph_invalidate_cache(&graph);

        igraph_is_simple(&graph, &is_simple, IGRAPH_DIRECTED);

        igraph_invalidate_cache(&graph);

        IGRAPH_ASSERT((has_loop || has_multi) == !is_simple);

        igraph_is_complete(&graph, &is_complete);

        igraph_invalidate_cache(&graph);

        IGRAPH_ASSERT(!is_complete || ecount >= vcount*(vcount-1) / 2); /* valid for undirected */

        igraph_is_bipartite(&graph, &is_bipartite, NULL);

        igraph_invalidate_cache(&graph);

        IGRAPH_ASSERT(!is_complete || !is_bipartite || vcount <= 2);

        igraph_is_connected(&graph, &is_connected, IGRAPH_WEAK);

        igraph_invalidate_cache(&graph);

        IGRAPH_ASSERT(!is_complete || is_connected || vcount == 0);

        IGRAPH_ASSERT(!is_connected || ecount >= vcount - 1);

        igraph_is_acyclic(&graph, &is_acyclic);

        igraph_invalidate_cache(&graph);

        IGRAPH_ASSERT(!is_complete || !is_acyclic || vcount <= 2);

        igraph_is_tree(&graph, &is_tree, NULL, IGRAPH_ALL);

        igraph_invalidate_cache(&graph);

        IGRAPH_ASSERT(!(is_connected && is_acyclic) || is_tree);

        igraph_is_eulerian(&graph, &has_eulerian_path, &has_eulerian_cycle);

        igraph_invalidate_cache(&graph);

        IGRAPH_ASSERT(!has_eulerian_cycle || has_eulerian_path);

        igraph_is_biconnected(&graph, &is_biconnected);

        igraph_invalidate_cache(&graph);

        IGRAPH_ASSERT(!is_biconnected || is_connected);

        igraph_is_chordal(&graph, NULL, NULL, &is_chordal, NULL, NULL);

        igraph_invalidate_cache(&graph);

        igraph_density(&graph, NULL, &r, false);

        IGRAPH_ASSERT(!is_complete || r >= 1 || vcount <= 1);

        igraph_density(&graph, NULL, &r, true);

        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.

}