feat: Add stbbr_for_presence_to for MUC join presence matching

- Add prime_for_presence_to() and prime_get_for_presence_to() in prime.c
- Add presence_to_callback() in server.c to handle MUC join presence
- Export stbbr_for_presence_to() in stabber.h
- Add stanzas_debug_last() for debugging failed verifications

src/server/prime.c

@@ -33,6 +33,7 @@
 static char *required_passwd = NULL;
 static GHashTable *idstubs = NULL;
 static GHashTable *querystubs = NULL;
+static GHashTable *presence_to_stubs = NULL;
 
 void
 prime_init(void)
@@ -40,6 +41,7 @@ prime_init(void)
     required_passwd = strdup("password");
     idstubs = g_hash_table_new_full(g_str_hash, g_str_equal, free, free);
     querystubs = g_hash_table_new_full(g_str_hash, g_str_equal, free, (GDestroyNotify)stanza_free);
+    presence_to_stubs = g_hash_table_new_full(g_str_hash, g_str_equal, free, (GDestroyNotify)stanza_free);
 }
 
 void
@@ -57,6 +59,11 @@ prime_free_all(void)
         g_hash_table_destroy(querystubs);
     }
     querystubs = NULL;
+
+    if (presence_to_stubs) {
+        g_hash_table_destroy(presence_to_stubs);
+    }
+    presence_to_stubs = NULL;
 }
 
 void
@@ -112,3 +119,25 @@ prime_get_for_query(const char *query)
     
     return g_hash_table_lookup(querystubs, query);
 }
+
+void
+prime_for_presence_to(const char *to_jid, char *stream)
+{
+    if (!presence_to_stubs) {
+        return;
+    }
+
+    log_println(STBBR_LOGDEBUG, "Received stub for presence to: %s, stanza: %s", to_jid, stream);
+    XMPPStanza *stanza = stanza_parse(stream);
+    g_hash_table_insert(presence_to_stubs, strdup(to_jid), stanza);
+}
+
+XMPPStanza*
+prime_get_for_presence_to(const char *to_jid)
+{
+    if (!presence_to_stubs) {
+        return NULL;
+    }
+    
+    return g_hash_table_lookup(presence_to_stubs, to_jid);
+}