#include <stdio.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <libgen.h>
#include "options.h"

Options options = { .progname = NULL, .datadir = DATADIR, .styleSheetName = "html5" };

char*
datadir(const char* progname) {
    struct stat sb;
    char* progname_copy = strdup(progname);
    const char* progdir = dirname(progname_copy);
    char* local_datadir = NULL;
    char result[PATH_MAX];
    int l = strlen(progdir) + 9;

    if (stat(DATADIR, &sb) == 0) {
        if (S_ISDIR(sb.st_mode)) {
            free(progname_copy);
            return strdup(DATADIR);
        }
    }

    local_datadir = malloc(l);
    snprintf(local_datadir, l, "%s/../data", progdir);
    realpath(local_datadir, result);
    free(local_datadir);
    free(progname_copy);
    if (stat(result, &sb) == 0) {
        if (S_ISDIR(sb.st_mode)) {
            return strdup(result);
        }
    }

    return NULL;
}

static void usage(const char* progname) {
    fprintf(stderr, "Usage: %s [-h] FILE\n"
            "\n"
            "    -h             Display help message\n"
            "    -s STYLESHEET  Apply stylesheet (default \"html5\")\n"
            "\n"
            "    FILE         sermon file to scan (\"-\" for stdin)\n", progname);
}

void InitOptions(int argc, const char* argv[]) {
    int i = 0;
    options.progname = argv[0];
    options.datadir = datadir(options.progname);
    while (++i < argc) {
        if (strcmp(argv[i], "-h") == 0) { usage(options.progname); exit(0); }
        else if (strcmp(argv[i], "-") == 0) {
            options.inputFileName = argv[i];
        } else if (strcmp(argv[i], "-s") == 0) {
            options.styleSheetName = argv[++i];
        } else if (strncmp(argv[i], "-s", 2) == 0) {
            options.styleSheetName = argv[i] + 2;
        } else if (argv[i][0] == '-') {
            fprintf(stderr, "Unknown option: %s\n", argv[i]);
        } else {
            options.inputFileName = argv[i];
        }
    }

    /* input filename required */
    if (!options.inputFileName) {
        usage(options.progname);
        exit(1);
    }
}

char*
OptionsDataFile(const char* fname) {
    char result[PATH_MAX], *t = malloc(strlen(options.datadir) + strlen(fname) + 2);
    snprintf(t, PATH_MAX, "%s/%s", options.datadir, fname);
    realpath(t, result);
    free(t);
    return strdup(result);
}

void FreeOptions() {
    free(options.datadir);
}