Rewrite accounting of play time

Replace daychange() and gettimeleft() by update_timeused_login(),
update_timeused() and enforce_minimum_session_time().  The new
code doesn't assume the day is always 24 hours long which can
occur when transitioning into or out of DST and such.  Logging
in after more a multiple of 128 days now resets nat_timeused
properly.

Fix nat_timeused calculation on midnight rollover to include
the time since midnight.

struct natstr member nat_dayno and struct player member timeleft
are now unused, remove them.

src/lib/common/nsc.c

@@ -563,7 +563,6 @@ struct castr cou_ca[] = {
      EF_BAD, NSC_DEITY | NSC_EXTRA},
     {"yorg", fldoff(nat_yorg), NSC_YCOORD, 0, NULL,
      EF_BAD, NSC_DEITY | NSC_EXTRA},
-    {"dayno", fldoff(nat_dayno), NSC_CHAR, 0, NULL, EF_BAD, 0},
     {"update", fldoff(nat_update), NSC_CHAR, 0, NULL, EF_BAD, 0},
     {"tgms", fldoff(nat_tgms), NSC_USHORT, 0, NULL, EF_BAD, 0},
     {"ann", fldoff(nat_ann), NSC_USHORT, 0, NULL, EF_BAD, 0},

src/lib/player/empdis.c

@@ -213,33 +213,58 @@ gamedown(void)
     return 1;
 }
 
+static int
+seconds_since_midnight(time_t time)
+{
+    struct tm *tm = localtime(&time);
+    time_t midnight;
+
+    tm->tm_hour = 0;
+    tm->tm_min = 0;
+    tm->tm_sec = 0;
+    tm->tm_isdst = -1;
+    midnight = mktime(tm);
+
+    return(time - midnight);
+}
+
 void
-daychange(time_t now)
+update_timeused_login(time_t now)
 {
-    struct natstr *natp;
-    struct tm *tm;
+    struct natstr *natp = getnatp(player->cnum);
+    time_t midnight_secs = seconds_since_midnight(player->lasttime);
 
-    natp = getnatp(player->cnum);
-    tm = localtime(&now);
-    if ((tm->tm_yday % 128) != natp->nat_dayno) {
-	natp->nat_dayno = tm->tm_yday % 128;
+    if (now - natp->nat_last_logout > midnight_secs) {
 	natp->nat_timeused = 0;
+	putnat(natp);
     }
+    player->lasttime = now;
 }
 
-int
-gettimeleft(time_t now, int mpd)
+void
+update_timeused(time_t now)
 {
-    struct tm *tm;
-    int nsecleft;
-    struct natstr *natp;
-    int n;
+    struct natstr *natp = getnatp(player->cnum);
+    time_t midnight_secs = seconds_since_midnight(now);
+    time_t dt = now - player->lasttime;
 
-    tm = localtime(&now);
-    natp = getnatp(player->cnum);
-    nsecleft = mpd * 60 - natp->nat_timeused;
-    n = 60 * 60 * 24 - (tm->tm_sec + tm->tm_min * 60 + tm->tm_hour * 3600);
-    if (n < nsecleft)
-	nsecleft = n;
-    return nsecleft;
+    if (dt > midnight_secs)
+        natp->nat_timeused = midnight_secs;
+    else
+        natp->nat_timeused += dt;
+    player->lasttime = now;
+    putnat(natp);
+}
+
+void
+enforce_minimum_session_time(void)
+{
+   struct natstr *natp = getnatp(player->cnum);
+
+    time_t dt = natp->nat_last_logout - natp->nat_last_login;
+    if (dt > seconds_since_midnight(natp->nat_last_logout))
+	dt = seconds_since_midnight(natp->nat_last_logout);
+    if (dt < 15)
+	natp->nat_timeused += 15 - dt;
+    putnat(natp);
 }

src/lib/player/player.c

@@ -60,13 +60,12 @@ void
 player_main(struct player *p)
 {
     struct natstr *natp;
-    int secs;
     char buf[128];
 
     p->state = PS_PLAYING;
     player = p;
-    time(&player->lasttime);
     time(&player->curup);
+    update_timeused_login(player->curup);
     show_motd();
     if (init_nats() < 0) {
 	pr("Server confused, try again later\n");
@@ -78,8 +77,8 @@ player_main(struct player *p)
 	if (natp->nat_stat != STAT_GOD)
 	    return;
     }
-    daychange(player->curup);
-    if ((player->timeleft = gettimeleft(player->curup, m_m_p_d)) <= 0) {
+    if (natp->nat_stat == STAT_ACTIVE &&
+	natp->nat_timeused > m_m_p_d * 60) {
 	pr("Time exceeded today\n");
 	return;
     }
@@ -118,14 +117,10 @@ player_main(struct player *p)
     }
     /* #*# I put the following line in to prevent server crash -KHS */
     natp = getnatp(player->cnum);
-    /*
-     * randomly round up to the nearest minute,
-     * charging at least 15 seconds.
-     */
     time(&natp->nat_last_logout);
-    secs = MAX(natp->nat_last_logout - player->lasttime, 15);
-    natp->nat_timeused += secs;
     putnat(natp);
+    update_timeused(natp->nat_last_logout);
+    enforce_minimum_session_time();
     pr("Bye-bye\n");
     journal_logout();
 }
@@ -182,27 +177,7 @@ status(void)
 	pr("You are no longer broke!\n");
 
     time(&player->curup);
-    second = player->curup - player->lasttime;
-    if (second > 0) {
-	player->timeleft -= second;
-	if (player->timeleft <= 0) {
-	    /*
-	     * countdown timer "player->timeleft" has expired.
-	     * either day change, or hours restriction
-	     */
-	    daychange(player->curup);
-	    if (!gamehours(player->curup)) {
-		pr("Empire hours restriction in force\n");
-		if (natp->nat_stat != STAT_GOD) {
-		    putnat(natp);
-		    return 0;
-		}
-	    }
-	    player->timeleft = gettimeleft(player->curup, m_m_p_d);
-	}
-	player->lasttime += second;
-	natp->nat_timeused += second;
-    }
+    update_timeused(player->curup);
     if (natp->nat_stat == STAT_ACTIVE &&
 	natp->nat_timeused > m_m_p_d * 60) {
 	pr("Max minutes per day limit exceeded.\n");

src/lib/subs/natsub.c

@@ -84,7 +84,6 @@ nat_reset(struct natstr *natp, enum nat_status stat, coord x, coord y)
 	natp->nat_yorg = 0;
     }
 
-    natp->nat_dayno = 0;
     natp->nat_timeused = 0;
     natp->nat_update = 0;