Implement fake QUIT handling via a NOTICE when doing a replay.

Since user QUIT messages don't contain channel names, clients that didn't know which channels a nick was in when receiving a quit message for that nick can't show a per-channel QUIT notification.
Some clients just display the QUIT message in the server status window, others silently ignore it.
Cater for those clients by sending a NOTICE about the QUIT rather than replaying it - assuming the nick isn't still in any of our channels.

5 files changed, 119 insertions, 19 deletions

diff --git a/TODO b/TODO
index e10a4e9..8d254bd 100644
--- a/TODO
+++ b/TODO
@@ -2,16 +2,14 @@ All the TODOs sprinkled throughout the code!
 
 Configurable rotation of replay and debug logs.
 
+Automatic rotation of replay log along with debug log?
+
 Configurable timestamp format in logs.
 
 macOS compiler may need limits.h included in structures.h.
 
 "Starting log replay...." followed by "Unable to read replay log file!" even though replay seemed to work?
 
-Sometimes replaymode = "lastspoke" will replay the last message you sent if you spoke last and sometimes it doesn't - change to always include your last message?
-Time based issue due to "seconds ago" rather than specific timestamp?  Perhaps extract timestamp and replay from there.
-(Pending real world testing to be marked as fixed.)
-
 Can memory usage be reduced further?  (e.g. better channel struct management)
 
 Ability to load new certificate whilst running.
diff --git a/functions.c b/functions.c
index 6d85d8e..6f8d131 100644
--- a/functions.c
+++ b/functions.c
@@ -1446,6 +1446,38 @@ int updatenickinallchannels(char *nickuserhost, char *newnick, struct channel *c
   return 1;
 }
 
+// Check if "nick" is in any channel or not.
+// Return 1 if it is, or 0 if not.
+int isnickinanychannel(struct channel *channels, int maxchannelcount, char *nick) {
+  debugprint(DEBUG_FULL, "isnickinanychannel(): given '%s'.\n", nick);
+
+  // Make sure the nick has a length of at least one
+  if (strlen(nick) < 1) {
+    debugprint(DEBUG_CRIT, "isnickinanychannel(): nick has no length, returning 0!\n");
+    return 0;
+  }
+
+  // Go through all channels and see if nick is present
+  for (int i = 0; i < maxchannelcount; i++) {
+    // Don't bother checking this channel index if it isn't used
+    if (!channels[i].name[0]) {
+      continue;
+    }
+    // Go through all nicks in channel
+    for (int j = 0; j < MAXCHANNICKS; j++) {
+      // See if the nick is here
+      if (strlen(channels[i].nicks[j]) == strlen(nick) && !strcmp(channels[i].nicks[j], nick)) {
+        // Found it!
+        debugprint(DEBUG_FULL, "isnickinanychannel(): nick '%s' found in channel '%s', returning 1.\n", nick, channels[i].name);
+        return 1;
+      }
+    }
+  }
+
+  debugprint(DEBUG_FULL, "isnickinanychannel(): nick '%s' not found in any channel '%s', returning 0.\n", nick);
+  return 0;
+}
+
 // Populate our channels struct with all nicks in a RPL_NAMREPLY
 // Returns 1 on success or 0 on failure
 int addnamereplytochannel(char *namereply, struct channel *channels, int maxchannelcount) {
diff --git a/functions.h b/functions.h
index 28b6413..5799aa6 100644
--- a/functions.h
+++ b/functions.h
@@ -205,6 +205,10 @@ int removenickfromallchannels(char *nickuserhost, struct channel *channels, int
 // Returns 1 on success or 0 on failure
 int updatenickinallchannels(char *nickuserhost, char *newnick, struct channel *channels, int maxchannelcount);
 
+// Check if "nick" is in a channel or not.
+// Return 1 if it is, or 0 if not.
+int isnickinanychannel(struct channel *channels, int maxchannelcount, char *nick);
+
 // Populate our channels struct with all nicks in a RPL_NAMREPLY
 // Returns 1 on success or 0 on failure
 int addnamereplytochannel(char *namereply, struct channel *channels, int maxchannelcount);
diff --git a/replay.c b/replay.c
index c63e859..b90431c 100644
--- a/replay.c
+++ b/replay.c
@@ -45,9 +45,11 @@ int gettimestamp(char *str) {
 }
 
 // Set 'str' to a string with the leading unixtime timestamp removed.
+// Record the stripped timestamp in 'origtimestamp'.
 // Returns 1 on success, 0 on failure
-int striptimestamp(char *str) {
+int striptimestamp(char *str, int *origtimestamp) {
   char line[MAXCHAR];
+  char origtimestr[MAXCHAR];
   int count = 0;
 
   // Make sure we're starting with a digit
@@ -58,10 +60,15 @@ int striptimestamp(char *str) {
   // Skip over each digit until we encounter a non-digit, record the position
   for (int i = 0; i < TIMELEN; i++) {
     if (isdigit(str[i])) {
+      // Copy timestamp into 'origtimestr'
+      origtimestr[i] = str[i];
       count++;
     }
   }
 
+  origtimestr[count] = '\0';
+  *origtimestamp = strtol(origtimestr, NULL, 10);
+
   // Skip over the space
   count++;
 
@@ -85,7 +92,8 @@ int striptimestamp(char *str) {
 // :foo!bar@baz PRIVMSG foo :[17:41:41] hello world
 // Or the same but e.g. [DD/MM/YY HH:MM:SS] if replaydates == 1.
 // Only inserts the formatted time for PRIVMSGs at the moment (and maybe only needs to!).
-void formattime(char *str, int replaydates) {
+// Saves the original timestamp in 'origtimestamp' either way.
+void formattime(char *str, int replaydates, int *origtimestamp) {
   // Extract the timestamp for conversion into [HH:MM:SS]
   char timestr[TIMELEN];
   sprintf(timestr, "%d", gettimestamp(str)); // Convert int time to string time
@@ -99,8 +107,8 @@ void formattime(char *str, int replaydates) {
     strftime(timestampf, DATETIMELEN, "[%H:%M:%S]", &tm);
   }
 
-  // Strip the original unixtimestamp
-  striptimestamp(str);
+  // Strip the original unixtimestamp, recording the original timestamp in case it's needed
+  striptimestamp(str, origtimestamp);
 
   // Take note of the length
   int len = strlen(str);
@@ -179,10 +187,12 @@ void formattime(char *str, int replaydates) {
 // 1. TOPIC/JOIN/PART but we're not in the channel any more
 // 2. TOPIC/JOIN/PART and it was from us
 // 3. NICK from us but not our current nick
+// 4. QUIT from a nick that is not currently in any channel (in which case
+//    'sourcefd' is used to fake the QUIT using a NOTICE)
 // Returns 1 if the replay line should go through as is
 // Returns 0 if the replay line should be skipped
 // Returns -1 on error
-int sanitisereplay (char *str, struct ircdstate *ircdstate, struct channel *channels) {
+int sanitisereplay (char *str, int sourcefd, int *origtimestamp, struct client *clients, struct settings *settings,struct ircdstate *ircdstate, struct channel *channels) {
   // Check if the replay line is a TOPIC, a JOIN, or a PART so we don't
   // replay those if we are not currently in the channel they are from
   // otherwise clients and state go a bit mad.
@@ -208,6 +218,9 @@ int sanitisereplay (char *str, struct ircdstate *ircdstate, struct channel *chan
     strncpy(tokens[i], token, strlen(token) + 1);
   }
 
+  // Done with strcopy
+  free(strcopyPtr);
+
   if (strncmp(tokens[1], "TOPIC", strlen("TOPIC")) == 0 ||
       strncmp(tokens[1], "JOIN", strlen("JOIN")) == 0 ||
       strncmp(tokens[1], "PART", strlen("PART")) == 0) {
@@ -224,7 +237,6 @@ int sanitisereplay (char *str, struct ircdstate *ircdstate, struct channel *chan
     if (!inchannel(channels, ircdstate->maxchannelcount, tokens[2] + offset) ||
         ((strlen(tokens[0]) == strlen(ircdstate->ircnick)) && (strncmp(tokens[0], ircdstate->ircnick, strlen(tokens[0])) == 0))) {
       debugprint(DEBUG_FULL, "sanitisereplay(): Not sending '%s' replay line '%s'.\n", tokens[1], str);
-      free(strcopyPtr);
       return 0;
     }
   }
@@ -235,12 +247,63 @@ int sanitisereplay (char *str, struct ircdstate *ircdstate, struct channel *chan
 
     if ((strlen(tokens[0]) == strlen(ircdstate->ircnick)) && (strncmp(tokens[0], ircdstate->ircnick, strlen(tokens[0])) == 0)) {
       debugprint(DEBUG_FULL, "sanitisereplay(): Not sending '%s' replay line '%s'.\n", tokens[1], str);
-      free(strcopyPtr);
       return 0;
     }
   }
 
-  free(strcopyPtr);
+  // Fake QUIT handling.  Since user QUIT messages don't contain channel names, clients that
+  // didn't know which channels a nick was in when receiving a quit message for that nick
+  // can't show a per-channel QUIT notification.  Some clients just display the QUIT message
+  // in the server status window, others silently ignore it.  Cater for those clients by
+  // sending a NOTICE about the QUIT rather than replaying it - assuming the nick isn't
+  // still in any of our channels.
+  if (strncmp(tokens[1], "QUIT", strlen("QUIT")) == 0) {
+    extractnickfromprefix(tokens[0], 1);
+
+    // Only do any of this if the nick isn't in any channels
+    if (isnickinanychannel(channels, ircdstate->maxchannelcount, tokens[0])) {
+      return 1;
+    }
+
+    debugprint(DEBUG_FULL, "sanitisereplay(): Faking QUIT message as NOTICE for '%s'.\n", tokens[0]);
+
+    time_t rawtime = *origtimestamp;
+    struct tm tm;
+    char timestampf[DATETIMELEN]; // Formatted timestamp
+
+    // Format time, "ddd yyyy-mm-dd hh:mm:ss zzz"
+    tm = *localtime(&rawtime);
+    if (settings->replaydates) {
+      strftime(timestampf, DATETIMELEN, "[%x %H:%M:%S]", &tm);
+    } else {
+      strftime(timestampf, DATETIMELEN, "[%H:%M:%S]", &tm);
+    }
+
+    // Prepare a new temporary string for the original QUIT message
+    char *strcopyquit = strdup(str);
+    // Keep track of initial pointer for free()ing later
+    char *strcopyquitPtr = strcopyquit;
+    extractfinalparameter(strcopyquit);
+    // Remove trailing CRLF (if any)
+    if (strlen(strcopyquit) > 2) {
+      for (int i = 0; i < 2; i++) {
+        if (strcopyquit[strlen(strcopyquit) - 1] == '\n' || strcopyquit[strlen(strcopyquit) - 1] == '\r') {
+          strcopyquit[strlen(strcopyquit) - 1] = '\0';
+        }
+      }
+    }
+
+    char outgoingmsg[MAXDATASIZE];
+    if (!snprintf(outgoingmsg, MAXDATASIZE, "NOTICE %s :%s %s has quit (%s).", ircdstate->ircnick, timestampf, tokens[0], strcopyquit)) {
+      debugprint(DEBUG_CRIT, "sanitisereplay(): error: couldn't prepare fake QUIT message as NOTICE!\n");
+    } else {
+      sendtoclient(sourcefd, outgoingmsg, clients, settings, 0);
+    }
+
+    free(strcopyquitPtr);
+    return 1;
+  }
+
   return 1;
 }
 
@@ -292,7 +355,7 @@ int replaylinestime(int seconds, char *basedir) {
 // if settings.replaydates == 1.
 // Returns 1 on success, 0 on failure, or -1 if the line should be ignored.
 // TODO - This is horribly inefficient since it re-reads the entire file each call, rewrite this!
-int readreplayline(int seconds, int linenum, char *str, struct settings *settings, struct ircdstate *ircdstate) {
+int readreplayline(int seconds, int linenum, char *str, int *origtimestamp, struct settings *settings, struct ircdstate *ircdstate) {
   FILE *fp;
   char line[MAXCHAR];
   char filename[PATH_MAX];
@@ -339,7 +402,7 @@ int readreplayline(int seconds, int linenum, char *str, struct settings *setting
         }
         // ...then return it
         // Insert our formatted [HH:MM:SS] timestamp into the message
-        formattime(line, settings->replaydates);
+        formattime(line, settings->replaydates, origtimestamp);
 
         strncpy(str, line, strlen(line));
         str[strlen(line)] = '\0';
@@ -465,7 +528,9 @@ int doreplaytime(int sourcefd, int replayseconds, struct client *clients, struct
 
   // Replay those lines!
   for (int i = 0; i < numlines; i++) {
-    int ret = readreplayline(replayseconds, i, outgoingmsg, settings, ircdstate);
+    int origtimestamp;
+//    origtimestamp[0] = '\0';
+    int ret = readreplayline(replayseconds, i, outgoingmsg, &origtimestamp, settings, ircdstate);
     if (ret == 0) {
       debugprint(DEBUG_CRIT, "doreplaytime(): Error requesting replay line.\n");
       return 0;
@@ -474,7 +539,7 @@ int doreplaytime(int sourcefd, int replayseconds, struct client *clients, struct
       continue;
     }
 
-    if (sanitisereplay(outgoingmsg, ircdstate, channels) < 1) {
+    if (sanitisereplay(outgoingmsg, sourcefd, &origtimestamp, clients, settings, ircdstate, channels) < 1) {
       continue;
     }
 
@@ -539,12 +604,13 @@ int doreplaylastspoke(int sourcefd, long linenumber, struct client *clients, str
     }
 
     // Insert our formatted [HH:MM:SS] timestamp into the message
-    formattime(line, settings->replaydates);
+    int origtimestamp;
+    formattime(line, settings->replaydates, &origtimestamp);
 
     strncpy(outgoingmsg, line, strlen(line));
     outgoingmsg[strlen(line)] = '\0';
 
-    if (sanitisereplay(outgoingmsg, ircdstate, channels) < 1) {
+    if (sanitisereplay(outgoingmsg, sourcefd, &origtimestamp, clients, settings, ircdstate, channels) < 1) {
       continue;
     }
 
diff --git a/replay.h b/replay.h
index dcf6771..d2d2c6d 100644
--- a/replay.h
+++ b/replay.h
@@ -42,7 +42,7 @@
 // 'basedir' is the directory in which to find 'replay.log'.
 int replaylinestime(int seconds, char *basedir);
 
-int readreplayline(int seconds, int linenum, char *str, struct settings *settings, struct ircdstate *ircdstate);
+int readreplayline(int seconds, int linenum, char *str, int *origtimestamp, struct settings *settings, struct ircdstate *ircdstate);
 
 // Returns the line number in the replay log file on which 'nick' last spoke, or -1 if there is a problem.
 // 'basedir' is the directory in which to find 'replay.log'.