/* Y2K fix for 3.0j nethack on UNIXPC; reading of topten records will go
 * wrong otherwise.  logfile has the same format, but is write-only.
 * structure comment and locking stolen from nethack's src/topten.c.
 */

#include <stdio.h>
#include <errno.h>
extern int errno;
#include <sys/stat.h>

#define NHDIR "/usr/games/lib/nethackdir"

/* struct toptenentry {
        struct toptenentry *tt_next;
        long int points;		10
        int level,maxlvl,hp,maxhp;	4*5
        int uid;			5
        char plchar;			1
        char sex;			1
        char name[NAMSZ+1];		10
        char death[DTHSZ+1];		60
        char date[7];			6
					10 separators
					----
					123
    }

    920128 102 1 1 10 25 240 PF wizard,quit	1992
    1191110 107 1 1 3 13 114 HM test,quit	2019
    120 124 102 6 6 -1 40 1838 HM demo,killed by a soldier ant	2020
*/


int
main()
{
	char *recfile = "record";
	char *reclock = "record_lock";
	char *recfile2 = "record2";
	FILE *rfile, *rfile2;
	char line[128];
	int sleepct = 100;

	chdir(NHDIR);

	/* lock record file like nethack, just in case we end up with serial
	 * terminals or something */
	while (link(recfile, reclock) == -1) {
		perror(reclock);
		if (!sleepct--) {
			puts("I give up.  Sorry.");
			puts("Perhaps there is an old record_lock around?");
			return(1);
		}
		printf("Waiting for access to record file. (%d)\n",
			sleepct);
		fflush(stdout);
		sleep(1);
	}

	if (!(rfile = fopen(recfile,"r"))) {
		puts("Cannot open record file!");
		unlink(reclock);
		return(1);
	}
	if (!(rfile2 = fopen(recfile2,"w"))) {
		puts("Cannot open record2 file!");
		unlink(reclock);
		return(1);
	}
	if (chmod(recfile2,0644) != 0) {
		puts("Cannot chmod record2!");
		unlink(reclock);
		return(1);
	}

	while (fgets(line,128,rfile)) {
		if (line[6] == ' ') {
			fputs(line, rfile2);
		} else if (line[7] == ' ') {
			/* nethack filled month and day when not shifted */
			if (line[3] == ' ') line[3] = '0';
			if (line[5] == ' ') line[5] = '0';
			fputs(line+1, rfile2);
		} else {
			printf("Unexpected line format '%s'\n", line);
			unlink(reclock);
			return(1);
		}
	}

	if (unlink(recfile) != 0) {
		puts("Cannot unlink record!");
		unlink(reclock);
		return(1);
	}
	if (link(recfile2,recfile) != 0) {
		puts("Cannot link record2!");
		unlink(reclock);
		return(1);
	}
	if (unlink(recfile2) != 0) {
		puts("Cannot unlink record!");
		unlink(reclock);
		return(1);
	}

	fclose(rfile);
	fclose(rfile2);
	unlink(reclock);
	return(0);
}