/****************************************************************************
 *                                                                          *
 ****************************************************************************/
 
    static char title[] = "dksort - Darklands Save Game Sorter";

/****************************************************************************
 *                                                                          *
 * Original Author (1992):                                                  *
 *  Steven J. Cotellesse  <stevec@ceba-tek.com>                             *
 * Modifications / Win32 adaptation (2000):                                 *
 *  Michael Petzold  <michael.petzold@e-technik.tu-chemnitz.de>             *
 *                                                                          *
 * Developed with Borland C++ 4.53, this code compiles equally well for     *
 * DOS 16-Bit and Win32 Console.                                            *
 *                                                                          *
 ****************************************************************************/

#include <stdio.h>                          /* printf */
#include <string.h>                         /* strcat, strcpy */
#include <stdlib.h>                         /* system, exit */

#include <dos.h>                            /* getdfree */
#include <dir.h>                            /* getcwd, etc.*/
#include <conio.h>                          /* getch */

static char version[] = "1.0";
static char game_dir[MAXPATH], save_dir[MAXPATH], save_dir_tmplt[MAXPATH];
static char file_names[200][13 + 1];
static long space_needed;
static unsigned short dte[200], tme[200];

/****************************************************************************/

static int load_file_name_list (const char *templt)
{
    int i;
    struct ffblk fb;

    space_needed = 0L;
    i = 0;

    if (findfirst (templt, &fb, 0) == 0) {
        strcpy (file_names[i], fb.ff_name);
        dte[i] = fb.ff_fdate;
        tme[i] = fb.ff_ftime;
        space_needed += fb.ff_fsize;
        ++i;
    }

    while (findnext (&fb) == 0 && i < 200) {
        strcpy (file_names[i], fb.ff_name);
        dte[i] = fb.ff_fdate;
        tme[i] = fb.ff_ftime;
        space_needed += fb.ff_fsize;
        ++i;
    }

    if (findnext (&fb) == 0) {
        printf ("More than 200 files found (%i) - "
                "only first 200 will be re-sorted\n", i);
    }

    return (i);
}

/****************************************************************************/

static int enough_disk_space (int num_files, long bytes_needed)
{
    struct dfree dt;
    double bytes_free;

    getdfree (0, &dt);                      /* 0: current drive */

    if (dt.df_sclus == (unsigned) -1) {     /* error condition */
        return (-1);
    }

    bytes_free = ((double) dt.df_avail *    /* free clusters */
                  (double) dt.df_sclus *    /* sectors per cluster */
                  (double) dt.df_bsec);     /* bytes per sector */

/*    printf ("(%.0f bytes free on current drive)\n", bytes_free); */

    if (dt.df_avail <= num_files ||         /* at least one cluster per file */
        bytes_free <= bytes_needed) {
        return (-1);
    }

    return (0);
}

/****************************************************************************/

static int copy_files_to_cwd (void)
{
    int rslt;
    char cmd[256];

    printf ("Copying files to current directory...\n");

    strcpy (cmd, "COPY ");
    strcat (cmd, save_dir);
    strcat (cmd, "DKSAVE*.??V > NUL");
    rslt = system (cmd);

    if (rslt != 0) {
        printf ("Unable to invoke command interpreter to copy files\n");
        printf ("(command: %s)\n", cmd);
    }

    return (rslt);
}

/****************************************************************************/

static void sort_files (int num_files)
{
    int i, j;
    unsigned short dd, tt;
    char tname[13 + 1];                     /* DL uses DOS names */

    printf ("Sorting files...\n");

    for (i = 0; i < (num_files + 1); i++) {
        for (j = (i + 1); j < num_files; j++) {
            if ((dte[j] > dte[i]) ||
                ((dte[j] == dte[i]) && (tme[j] > tme[i])) ||
                ((dte[j] == dte[i]) && (tme[j] == tme[i]) &&
                 (strcmp (file_names[j], file_names[i]) > 0 ))) {
                strcpy (tname, file_names[i]);
                strcpy (file_names[i], file_names[j]);
                strcpy (file_names[j], tname);
                dd = dte[i];
                dte[i] = dte[j];
                dte[j] = dd;
                tt = tme[i];
                tme[i] = tme[j];
                tme[j] = tt;
            }
        }
    }
}

/****************************************************************************/

static void delete_save_files (void)
{
    int rslt;
    char cmd[256];

    printf ("Deleting original save game files...\n");

    strcpy (cmd, "DEL ");
    strcat (cmd, save_dir);
    strcat (cmd, "DKSAVE*.??V > NUL");
    rslt = system (cmd);

    if (rslt != 0) {
        printf ("Unable to invoke command interpreter to remove files\n");
        printf ("(command: %s)\n", cmd);
    }
}

/****************************************************************************/

static int copy_from_to (const char *file_name,
                         const char *from_dir,
                         const char *to_dir)
{
    int rslt;
    char cmd[256];

    strcpy (cmd, "COPY ");
    strcat (cmd, from_dir);
    strcat (cmd, file_name);
    strcat (cmd, " ");
    strcat (cmd, to_dir);
    strcat (cmd, file_name);
    strcat (cmd, " > NUL");

    rslt = system (cmd);

    if (rslt != 0) {
        printf ("Unable to invoke command interpreter to copy files\n");
        printf ("(command: %s)\n", cmd);
    }

    return (rslt);
}

/****************************************************************************/

static int copy_files_to_savedir (int num_files)
{
    int i, rslt;

    i = 0;
    rslt = 0;

    printf ("Copying save game files to saves directory...\n");

    while ((rslt == 0) && (i < num_files)) {
        rslt = copy_from_to (file_names[i], game_dir, save_dir);
        ++i;
    }

    return (rslt);
}

/****************************************************************************/

static void delete_temp_files (void)
{
    int rslt;
    char cmd[256];

    printf ("Deleting temporary files...\n");

    strcpy (cmd, "DEL ");
    strcat (cmd, game_dir);
    strcat (cmd, "DKSAVE*.??V > NUL");
    rslt = system (cmd);

    if (rslt != 0) {
        printf ("Unable to invoke command interpreter to remove files\n");
        printf ("(command: %s)\n", cmd);
    }
}

/****************************************************************************/

static void wait_to_exit (void)
{
    printf ("Press any key to exit...\n");
    (void) getch ();
}

/****************************************************************************/

static void error_exit (void)
{
    printf ("Files not re-sorted\n");
    wait_to_exit ();
    exit (1);
}

/****************************************************************************/

int main (void)
{
    int num_files;

    printf ("%s ", title);
    printf ("V%s\n\n", version);

    if (getcwd (game_dir, MAXPATH) == NULL) {
        printf ("Could not allocate CWD buffer\n");
        error_exit ();
    }

    if (game_dir[3] != '\0')               /* Root dir already has trailing \ */
        strcat (game_dir, "\\");
    strcpy (save_dir, game_dir);
    strcat (save_dir, "SAVES\\");
    strcpy (save_dir_tmplt, save_dir);
    strcat (save_dir_tmplt, "DKSAVE*.??V");

    num_files = load_file_name_list (save_dir_tmplt);

    if (num_files == 0) {
        printf ("No save game files found in directory %s\n", save_dir);
        printf ("(%s)\n", save_dir_tmplt);
        error_exit ();
    }

    if (enough_disk_space (num_files, space_needed + 2048) != 0) {
        printf ("Not enough disk space to re-sort. "
                "(%ld bytes are needed)\n", space_needed + 2048);
        error_exit ();
    }

    if (copy_files_to_cwd () != 0) {
        error_exit ();
    }

    sort_files (num_files);

    delete_save_files ();

    if (copy_files_to_savedir (num_files) != 0) {
        error_exit ();
    }

    delete_temp_files ();

    printf ("Files sorted!\n");
    wait_to_exit ();

    return (0);
}

/****************************************************************************/