/* LIBDGL -- a Directed Graph Library implementation
 * Copyright (C) 2002 Roberto Micarelli
 *
 * 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
 */

/*
 * Source best viewed with tabstop=4
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <time.h>
#include <errno.h>
#include <math.h>

#include "../type.h"
#include "../graph.h"

#include "opt.h"

static int _clipper(dglGraph_s *pgraphIn, dglGraph_s *pgraphOut,
                    dglSpanClipInput_s *pArgIn, dglSpanClipOutput_s *pArgOut,
                    void *pvArg)
{
    return 0;
}

int main(int argc, char **argv)
{
    dglGraph_s graph;

#define MY_MAX_COMPONENTS 1024
    dglGraph_s agraphComponents[MY_MAX_COMPONENTS];
    int nret, fd, i, cComponents;
    char szGraphOutFilename[1024];

    /* program options
     */
    char *pszGraph;
    char *pszGraphOut;

    GNO_BEGIN /* short   long                default     variable        help */
        GNO_OPTION("g", "graph", NULL, &pszGraph, "Input Graph file")
        GNO_OPTION("o", "graphout", NULL, &pszGraphOut, "Output Graph file")
    GNO_END
    if (GNO_PARSE(argc, argv) < 0) {
        return 1;
    }
    /*
     * options parsed
     */

    if (pszGraph == NULL || pszGraphOut == NULL) {
        GNO_HELP("components usage");
        return 1;
    }

    printf("Graph read:\n");
    if ((fd = open(pszGraph, O_RDONLY)) < 0) {
        perror("open");
        return 1;
    }
    nret = dglRead(&graph, fd);
    if (nret < 0) {
        fprintf(stderr, "dglRead error: %s\n", dglStrerror(&graph));
        return 1;
    }
    close(fd);
    printf("Done.\n");

    printf("Graph depth components spanning:\n");
    cComponents = dglDepthComponents(&graph, agraphComponents,
                                     MY_MAX_COMPONENTS, _clipper, NULL);
    if (cComponents < 0) {
        fprintf(stderr, "dglDepthSpanning error: %s\n", dglStrerror(&graph));
        return 1;
    }
    printf("Done.\n");

    printf("Connected Component(s) Found: %d\n", cComponents);

    for (i = 0; i < cComponents; i++) {
        printf("Component %d of %d: ", i + 1, cComponents);
        fflush(stdout);

        printf("[flatten...");
        fflush(stdout);
        nret = dglFlatten(&agraphComponents[i]);
        printf("done] ");
        fflush(stdout);

        if (dglGet_EdgeCount(&agraphComponents[i]) > 0) {
            if (pszGraphOut) {
                snprintf(szGraphOutFilename, sizeof(szGraphOutFilename),
                         "%s-component-%d", pszGraphOut, i);
                printf("[write <%s>...", szGraphOutFilename);
                fflush(stdout);
                if ((fd = open(szGraphOutFilename, O_WRONLY | O_CREAT | O_TRUNC,
                               0666)) < 0) {
                    perror("open");
                    return 1;
                }
                dglWrite(&agraphComponents[i], fd);
                if (nret < 0) {
                    fprintf(stderr, "dglWrite error: %s\n",
                            dglStrerror(&graph));
                    return 1;
                }
                close(fd);
                printf("done] ");
                fflush(stdout);
            }
        }
        else {
            printf("component is empty. No output produced.\n");
        }

        printf("[release...");
        dglRelease(&agraphComponents[i]);
        printf("done]\n");
    }

    dglRelease(&graph);
    return 0;
}
