8 files changed, 347 insertions, 82 deletions

diff --git a/toxav/groupav.c b/toxav/groupav.c
index 55a5fe55..4c16d1de 100644
--- a/toxav/groupav.c
+++ b/toxav/groupav.c
@@ -473,7 +473,7 @@ int add_av_groupchat(const Logger *log, Tox *tox, Group_Chats *g_c, audio_data_c
     }
 
     if (groupchat_enable_av(log, tox, g_c, groupnumber, audio_callback, userdata) == -1) {
-        del_groupchat(g_c, groupnumber);
+        del_groupchat(g_c, groupnumber, true);
         return -1;
     }
 
@@ -495,7 +495,7 @@ int join_av_groupchat(const Logger *log, Tox *tox, Group_Chats *g_c, uint32_t fr
     }
 
     if (groupchat_enable_av(log, tox, g_c, groupnumber, audio_callback, userdata) == -1) {
-        del_groupchat(g_c, groupnumber);
+        del_groupchat(g_c, groupnumber, true);
         return -1;
     }
 
diff --git a/toxcore/group.c b/toxcore/group.c
index 99f72336..b345a01c 100644
--- a/toxcore/group.c
+++ b/toxcore/group.c
@@ -271,6 +271,7 @@ typedef enum Groupchat_Closest {
 
 static int add_to_closest(Group_Chats *g_c, uint32_t groupnumber, const uint8_t *real_pk, const uint8_t *temp_pk)
 {
+    // TODO(zugz): this can be const. Similarly throughout the file.
     Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
@@ -1033,12 +1034,15 @@ int add_groupchat(Group_Chats *g_c, uint8_t type)
     return groupnumber;
 }
 
-/* Delete a groupchat from the chats array.
+static int group_leave(const Group_Chats *g_c, uint32_t groupnumber);
+
+/* Delete a groupchat from the chats array, informing the group first as
+ * appropriate.
  *
  * return 0 on success.
  * return -1 if groupnumber is invalid.
  */
-int del_groupchat(Group_Chats *g_c, uint32_t groupnumber)
+int del_groupchat(Group_Chats *g_c, uint32_t groupnumber, bool leave_permanently)
 {
     Group_c *g = get_group_c(g_c, groupnumber);
 
@@ -1046,6 +1050,10 @@ int del_groupchat(Group_Chats *g_c, uint32_t groupnumber)
         return -1;
     }
 
+    if (leave_permanently) {
+        group_leave(g_c, groupnumber);
+    }
+
     for (uint32_t i = 0; i < MAX_GROUP_CONNECTIONS; ++i) {
         if (g->close[i].type == GROUPCHAT_CLOSE_NONE) {
             continue;
@@ -1071,14 +1079,14 @@ int del_groupchat(Group_Chats *g_c, uint32_t groupnumber)
     return wipe_group_chat(g_c, groupnumber);
 }
 
-/* Copy the public key of peernumber who is in groupnumber to pk.
- * pk must be CRYPTO_PUBLIC_KEY_SIZE long.
+/* Copy the public key of (frozen, if frozen is true) peernumber who is in
+ * groupnumber to pk. pk must be CRYPTO_PUBLIC_KEY_SIZE long.
  *
  * return 0 on success
  * return -1 if groupnumber is invalid.
  * return -2 if peernumber is invalid.
  */
-int group_peer_pubkey(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *pk)
+int group_peer_pubkey(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *pk, bool frozen)
 {
     Group_c *g = get_group_c(g_c, groupnumber);
 
@@ -1086,21 +1094,24 @@ int group_peer_pubkey(const Group_Chats *g_c, uint32_t groupnumber, int peernumb
         return -1;
     }
 
-    if ((uint32_t)peernumber >= g->numpeers) {
+    const Group_Peer *list = frozen ? g->frozen : g->group;
+    const uint32_t num = frozen ? g->numfrozen : g->numpeers;
+
+    if ((uint32_t)peernumber >= num) {
         return -2;
     }
 
-    memcpy(pk, g->group[peernumber].real_pk, CRYPTO_PUBLIC_KEY_SIZE);
+    memcpy(pk, list[peernumber].real_pk, CRYPTO_PUBLIC_KEY_SIZE);
     return 0;
 }
 
 /*
- * Return the size of peernumber's name.
+ * Return the size of (frozen, if frozen is true) peernumber's name.
  *
  * return -1 if groupnumber is invalid.
  * return -2 if peernumber is invalid.
  */
-int group_peername_size(const Group_Chats *g_c, uint32_t groupnumber, int peernumber)
+int group_peername_size(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, bool frozen)
 {
     Group_c *g = get_group_c(g_c, groupnumber);
 
@@ -1108,25 +1119,28 @@ int group_peername_size(const Group_Chats *g_c, uint32_t groupnumber, int peernu
         return -1;
     }
 
-    if ((uint32_t)peernumber >= g->numpeers) {
+    const Group_Peer *list = frozen ? g->frozen : g->group;
+    const uint32_t num = frozen ? g->numfrozen : g->numpeers;
+
+    if ((uint32_t)peernumber >= num) {
         return -2;
     }
 
-    if (g->group[peernumber].nick_len == 0) {
+    if (list[peernumber].nick_len == 0) {
         return 0;
     }
 
-    return g->group[peernumber].nick_len;
+    return list[peernumber].nick_len;
 }
 
-/* Copy the name of peernumber who is in groupnumber to name.
- * name must be at least MAX_NAME_LENGTH long.
+/* Copy the name of (frozen, if frozen is true) peernumber who is in
+ * groupnumber to name. name must be at least MAX_NAME_LENGTH long.
  *
  * return length of name if success
  * return -1 if groupnumber is invalid.
  * return -2 if peernumber is invalid.
  */
-int group_peername(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *name)
+int group_peername(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *name, bool frozen)
 {
     Group_c *g = get_group_c(g_c, groupnumber);
 
@@ -1134,19 +1148,46 @@ int group_peername(const Group_Chats *g_c, uint32_t groupnumber, int peernumber,
         return -1;
     }
 
-    if ((uint32_t)peernumber >= g->numpeers) {
+    const Group_Peer *list = frozen ? g->frozen : g->group;
+    const uint32_t num = frozen ? g->numfrozen : g->numpeers;
+
+    if ((uint32_t)peernumber >= num) {
         return -2;
     }
 
-    if (g->group[peernumber].nick_len == 0) {
+    if (list[peernumber].nick_len == 0) {
         return 0;
     }
 
-    memcpy(name, g->group[peernumber].nick, g->group[peernumber].nick_len);
-    return g->group[peernumber].nick_len;
+    memcpy(name, list[peernumber].nick, list[peernumber].nick_len);
+    return list[peernumber].nick_len;
 }
 
-/* List all the peers in the group chat.
+/* Copy last active timestamp of frozennumber who is in groupnumber to
+ * last_active.
+ *
+ * return 0 on success.
+ * return -1 if groupnumber is invalid.
+ * return -2 if frozennumber is invalid.
+ */
+int group_frozen_last_active(const Group_Chats *g_c, uint32_t groupnumber, int peernumber,
+                             uint64_t *last_active)
+{
+    Group_c *g = get_group_c(g_c, groupnumber);
+
+    if (!g) {
+        return -1;
+    }
+
+    if ((uint32_t)peernumber >= g->numfrozen) {
+        return -2;
+    }
+
+    *last_active = g->frozen[peernumber].last_active;
+    return 0;
+}
+
+/* List all the (frozen, if frozen is true) peers in the group chat.
  *
  * Copies the names of the peers to the name[length][MAX_NAME_LENGTH] array.
  *
@@ -1157,7 +1198,7 @@ int group_peername(const Group_Chats *g_c, uint32_t groupnumber, int peernumber,
  * return -1 on failure.
  */
 int group_names(const Group_Chats *g_c, uint32_t groupnumber, uint8_t names[][MAX_NAME_LENGTH], uint16_t lengths[],
-                uint16_t length)
+                uint16_t length, bool frozen)
 {
     Group_c *g = get_group_c(g_c, groupnumber);
 
@@ -1165,19 +1206,22 @@ int group_names(const Group_Chats *g_c, uint32_t groupnumber, uint8_t names[][MA
         return -1;
     }
 
+    const uint32_t num = frozen ? g->numfrozen : g->numpeers;
+
     unsigned int i;
 
-    for (i = 0; i < g->numpeers && i < length; ++i) {
-        lengths[i] = group_peername(g_c, groupnumber, i, names[i]);
+    for (i = 0; i < num && i < length; ++i) {
+        lengths[i] = group_peername(g_c, groupnumber, i, names[i], frozen);
     }
 
     return i;
 }
 
-/* Return the number of peers in the group chat on success.
+/* Return the number of (frozen, if frozen is true) peers in the group chat on
+ * success.
  * return -1 if groupnumber is invalid.
  */
-int group_number_peers(const Group_Chats *g_c, uint32_t groupnumber)
+int group_number_peers(const Group_Chats *g_c, uint32_t groupnumber, bool frozen)
 {
     Group_c *g = get_group_c(g_c, groupnumber);
 
@@ -1185,7 +1229,7 @@ int group_number_peers(const Group_Chats *g_c, uint32_t groupnumber)
         return -1;
     }
 
-    return g->numpeers;
+    return frozen ? g->numfrozen : g->numpeers;
 }
 
 /* return 1 if the peernumber corresponds to ours.
@@ -1597,18 +1641,18 @@ static int group_name_send(const Group_Chats *g_c, uint32_t groupnumber, const u
 }
 
 /* send message to announce leaving group
- * return true on success
- * return false on failure
+ * return 0 on success
+ * return -1 on failure
  */
-bool group_leave(const Group_Chats *g_c, uint32_t groupnumber)
+static int group_leave(const Group_Chats *g_c, uint32_t groupnumber)
 {
     Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
-        return false;
+        return -1;
     }
 
-    return group_kill_peer_send(g_c, groupnumber, g->peer_number) == 0;
+    return group_kill_peer_send(g_c, groupnumber, g->peer_number);
 }
 
 
@@ -2900,7 +2944,7 @@ void send_name_all_groups(Group_Chats *g_c)
     }
 }
 
-#define SAVED_PEER_SIZE_CONSTANT (2 * CRYPTO_PUBLIC_KEY_SIZE + 2 + 1)
+#define SAVED_PEER_SIZE_CONSTANT (2 * CRYPTO_PUBLIC_KEY_SIZE + sizeof(uint16_t) + sizeof(uint64_t) + 1)
 
 static uint32_t saved_peer_size(const Group_Peer *peer)
 {
@@ -2918,6 +2962,9 @@ static uint8_t *save_peer(const Group_Peer *peer, uint8_t *data)
     host_to_lendian_bytes16(data, peer->peer_number);
     data += sizeof(uint16_t);
 
+    host_to_lendian_bytes64(data, peer->last_active);
+    data += sizeof(uint64_t);
+
     *data = peer->nick_len;
     ++data;
 
@@ -3098,6 +3145,9 @@ static State_Load_Status load_conferences(Group_Chats *g_c, const uint8_t *data,
             lendian_bytes_to_host16(&peer->peer_number, data);
             data += sizeof(uint16_t);
 
+            lendian_bytes_to_host64(&peer->last_active, data);
+            data += sizeof(uint64_t);
+
             peer->nick_len = *data;
             ++data;
 
@@ -3189,7 +3239,7 @@ void do_groupchats(Group_Chats *g_c, void *userdata)
 void kill_groupchats(Group_Chats *g_c)
 {
     for (uint16_t i = 0; i < g_c->num_chats; ++i) {
-        del_groupchat(g_c, i);
+        del_groupchat(g_c, i, false);
     }
 
     m_callback_conference_invite(g_c->m, nullptr);
diff --git a/toxcore/group.h b/toxcore/group.h
index 148de0c1..83015273 100644
--- a/toxcore/group.h
+++ b/toxcore/group.h
@@ -238,38 +238,51 @@ void g_callback_peer_list_changed(Group_Chats *g_c, peer_list_changed_cb *functi
  */
 int add_groupchat(Group_Chats *g_c, uint8_t type);
 
-/* Delete a groupchat from the chats array.
+/* Delete a groupchat from the chats array, informing the group first as
+ * appropriate.
  *
  * return 0 on success.
  * return -1 if groupnumber is invalid.
  */
-int del_groupchat(Group_Chats *g_c, uint32_t groupnumber);
+int del_groupchat(Group_Chats *g_c, uint32_t groupnumber, bool leave_permanently);
 
-/* Copy the public key of peernumber who is in groupnumber to pk.
+/* Copy the public key of (frozen, if frozen is true) peernumber who is in
+ * groupnumber to pk.
  * pk must be CRYPTO_PUBLIC_KEY_SIZE long.
  *
  * return 0 on success
  * return -1 if groupnumber is invalid.
  * return -2 if peernumber is invalid.
  */
-int group_peer_pubkey(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *pk);
+int group_peer_pubkey(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *pk, bool frozen);
 
 /*
- * Return the size of peernumber's name.
+ * Return the size of (frozen, if frozen is true) peernumber's name.
  *
  * return -1 if groupnumber is invalid.
  * return -2 if peernumber is invalid.
  */
-int group_peername_size(const Group_Chats *g_c, uint32_t groupnumber, int32_t peernumber);
+int group_peername_size(const Group_Chats *g_c, uint32_t groupnumber, int32_t peernumber, bool frozen);
 
-/* Copy the name of peernumber who is in groupnumber to name.
+/* Copy the name of (frozen, if frozen is true) peernumber who is in
+ * groupnumber to name.
  * name must be at least MAX_NAME_LENGTH long.
  *
  * return length of name if success
  * return -1 if groupnumber is invalid.
  * return -2 if peernumber is invalid.
  */
-int group_peername(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *name);
+int group_peername(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *name, bool frozen);
+
+/* Copy last active timestamp of frozen peernumber who is in groupnumber to
+ * last_active.
+ *
+ * return 0 on success.
+ * return -1 if groupnumber is invalid.
+ * return -2 if peernumber is invalid.
+ */
+int group_frozen_last_active(const Group_Chats *g_c, uint32_t groupnumber, int peernumber,
+                             uint64_t *last_active);
 
 /* invite friendnumber to groupnumber
  *
@@ -306,12 +319,6 @@ int group_message_send(const Group_Chats *g_c, uint32_t groupnumber, const uint8
  */
 int group_action_send(const Group_Chats *g_c, uint32_t groupnumber, const uint8_t *action, uint16_t length);
 
-/* send message to announce leaving group
- * return true on success
- * return false on failure
- */
-bool group_leave(const Group_Chats *g_c, uint32_t groupnumber);
-
 /* set the group's title, limited to MAX_NAME_LENGTH
  * return 0 on success
  * return -1 if groupnumber is invalid.
@@ -336,10 +343,11 @@ int group_title_get_size(const Group_Chats *g_c, uint32_t groupnumber);
  */
 int group_title_get(const Group_Chats *g_c, uint32_t groupnumber, uint8_t *title);
 
-/* Return the number of peers in the group chat on success.
+/* Return the number of (frozen, if frozen is true) peers in the group chat on
+ * success.
  * return -1 if groupnumber is invalid.
  */
-int group_number_peers(const Group_Chats *g_c, uint32_t groupnumber);
+int group_number_peers(const Group_Chats *g_c, uint32_t groupnumber, bool frozen);
 
 /* return 1 if the peernumber corresponds to ours.
  * return 0 if the peernumber is not ours.
@@ -349,7 +357,7 @@ int group_number_peers(const Group_Chats *g_c, uint32_t groupnumber);
  */
 int group_peernumber_is_ours(const Group_Chats *g_c, uint32_t groupnumber, int peernumber);
 
-/* List all the peers in the group chat.
+/* List all the (frozen, if frozen is true) peers in the group chat.
  *
  * Copies the names of the peers to the name[length][MAX_NAME_LENGTH] array.
  *
@@ -360,7 +368,7 @@ int group_peernumber_is_ours(const Group_Chats *g_c, uint32_t groupnumber, int p
  * return -1 on failure.
  */
 int group_names(const Group_Chats *g_c, uint32_t groupnumber, uint8_t names[][MAX_NAME_LENGTH], uint16_t lengths[],
-                uint16_t length);
+                uint16_t length, bool frozen);
 
 /* Set handlers for custom lossy packets. */
 void group_lossy_packet_registerhandler(Group_Chats *g_c, uint8_t byte, lossy_packet_cb *function);
diff --git a/toxcore/state.c b/toxcore/state.c
index 919c2e8c..bca7a151 100644
--- a/toxcore/state.c
+++ b/toxcore/state.c
@@ -84,6 +84,28 @@ uint16_t host_to_lendian16(uint16_t host)
     return lendian_to_host16(host);
 }
 
+void host_to_lendian_bytes64(uint8_t *dest, uint64_t num)
+{
+#ifdef WORDS_BIGENDIAN
+    num = ((num << 8) & 0xFF00FF00FF00FF00) | ((num >> 8) & 0xFF00FF00FF00FF);
+    num = ((num << 16) & 0xFFFF0000FFFF0000) | ((num >> 16) & 0xFFFF0000FFFF);
+    num = (num << 32) | (num >> 32);
+#endif
+    memcpy(dest, &num, sizeof(uint64_t));
+}
+
+void lendian_bytes_to_host64(uint64_t *dest, const uint8_t *lendian)
+{
+    uint64_t d;
+    memcpy(&d, lendian, sizeof(uint64_t));
+#ifdef WORDS_BIGENDIAN
+    d = ((d << 8) & 0xFF00FF00FF00FF00) | ((d >> 8) & 0xFF00FF00FF00FF);
+    d = ((d << 16) & 0xFFFF0000FFFF0000) | ((d >> 16) & 0xFFFF0000FFFF);
+    d = (d << 32) | (d >> 32);
+#endif
+    *dest = d;
+}
+
 void host_to_lendian_bytes32(uint8_t *dest, uint32_t num)
 {
 #ifdef WORDS_BIGENDIAN
diff --git a/toxcore/state.h b/toxcore/state.h
index 6e3c897e..829036d8 100644
--- a/toxcore/state.h
+++ b/toxcore/state.h
@@ -58,6 +58,9 @@ uint8_t *state_write_section_header(uint8_t *data, uint16_t cookie_type, uint32_
 uint16_t lendian_to_host16(uint16_t lendian);
 uint16_t host_to_lendian16(uint16_t host);
 
+void host_to_lendian_bytes64(uint8_t *dest, uint64_t num);
+void lendian_bytes_to_host64(uint64_t *dest, const uint8_t *lendian);
+
 void host_to_lendian_bytes32(uint8_t *dest, uint32_t num);
 void lendian_bytes_to_host32(uint32_t *dest, const uint8_t *lendian);
 
diff --git a/toxcore/tox.api.h b/toxcore/tox.api.h
index 53788473..ba1932f4 100644
--- a/toxcore/tox.api.h
+++ b/toxcore/tox.api.h
@@ -2257,32 +2257,32 @@ namespace conference {
     CONFERENCE_NOT_FOUND,
   }
 
-
-  namespace peer {
-
+  /**
+   * Error codes for peer info queries.
+   */
+  error for peer_query {
     /**
-     * Error codes for peer info queries.
+     * The conference number passed did not designate a valid conference.
      */
-    error for query {
-      /**
-       * The conference number passed did not designate a valid conference.
-       */
-      CONFERENCE_NOT_FOUND,
-      /**
-       * The peer number passed did not designate a valid peer.
-       */
-      PEER_NOT_FOUND,
-      /**
-       * The client is not connected to the conference.
-       */
-      NO_CONNECTION,
-    }
+    CONFERENCE_NOT_FOUND,
+    /**
+     * The peer number passed did not designate a valid peer.
+     */
+    PEER_NOT_FOUND,
+    /**
+     * The client is not connected to the conference.
+     */
+    NO_CONNECTION,
+  }
+
+
+  namespace peer {
 
     /**
      * Return the number of peers in the conference. Return value is unspecified on failure.
      */
     const uint32_t count(uint32_t conference_number)
-        with error for query;
+        with error for peer_query;
 
     uint8_t[size] name {
 
@@ -2290,7 +2290,7 @@ namespace conference {
        * Return the length of the peer's name. Return value is unspecified on failure.
        */
       size(uint32_t conference_number, uint32_t peer_number)
-          with error for query;
+          with error for peer_query;
 
       /**
        * Copy the name of peer_number who is in conference_number to name.
@@ -2299,7 +2299,7 @@ namespace conference {
        * @return true on success.
        */
       get(uint32_t conference_number, uint32_t peer_number)
-          with error for query;
+          with error for peer_query;
     }
 
     /**
@@ -2310,17 +2310,63 @@ namespace conference {
      */
     uint8_t[PUBLIC_KEY_SIZE] public_key {
       get(uint32_t conference_number, uint32_t peer_number)
-          with error for query;
+          with error for peer_query;
     }
 
     /**
      * Return true if passed peer_number corresponds to our own.
      */
     const bool number_is_ours(uint32_t conference_number, uint32_t peer_number)
-        with error for query;
+        with error for peer_query;
 
   }
 
+  namespace offline_peer {
+
+    /**
+     * Return the number of offline peers in the conference. Return value is unspecified on failure.
+     */
+    const uint32_t count(uint32_t conference_number)
+        with error for peer_query;
+
+    uint8_t[size] name {
+
+      /**
+       * Return the length of the offline peer's name. Return value is unspecified on failure.
+       */
+      size(uint32_t conference_number, uint32_t offline_peer_number)
+          with error for peer_query;
+
+      /**
+       * Copy the name of offline_peer_number who is in conference_number to name.
+       * name must be at least $MAX_NAME_LENGTH long.
+       *
+       * @return true on success.
+       */
+      get(uint32_t conference_number, uint32_t offline_peer_number)
+          with error for peer_query;
+    }
+
+    /**
+     * Copy the public key of offline_peer_number who is in conference_number to public_key.
+     * public_key must be $PUBLIC_KEY_SIZE long.
+     *
+     * @return true on success.
+     */
+    uint8_t[PUBLIC_KEY_SIZE] public_key {
+      get(uint32_t conference_number, uint32_t offline_peer_number)
+          with error for peer_query;
+    }
+
+    /**
+     * Return a unix-time timestamp of the last time offline_peer_number was seen to be active.
+     */
+    uint64_t last_active {
+      get(uint32_t conference_number, uint32_t offline_peer_number)
+        with error for peer_query;
+    }
+
+  }
 
   /**
    * Invites a friend to a conference.
diff --git a/toxcore/tox.c b/toxcore/tox.c
index 88a9bd50..d848102e 100644
--- a/toxcore/tox.c
+++ b/toxcore/tox.c
@@ -713,6 +713,7 @@ Tox_Connection tox_self_get_connection_status(const Tox *tox)
 {
     const Messenger *m = tox->m;
 
+    // TODO(zugz): this can be const. Similarly throughout the file.
     unsigned int ret = onion_connection_status(m->onion_c);
 
     if (ret == 2) {
@@ -1533,8 +1534,7 @@ uint32_t tox_conference_new(Tox *tox, Tox_Err_Conference_New *error)
 bool tox_conference_delete(Tox *tox, uint32_t conference_number, Tox_Err_Conference_Delete *error)
 {
     Messenger *m = tox->m;
-    group_leave(m->conferences_object, conference_number);
-    int ret = del_groupchat(m->conferences_object, conference_number);
+    int ret = del_groupchat(m->conferences_object, conference_number, true);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_DELETE_CONFERENCE_NOT_FOUND);
@@ -1548,7 +1548,7 @@ bool tox_conference_delete(Tox *tox, uint32_t conference_number, Tox_Err_Confere
 uint32_t tox_conference_peer_count(const Tox *tox, uint32_t conference_number, Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_number_peers(m->conferences_object, conference_number);
+    int ret = group_number_peers(m->conferences_object, conference_number, false);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_CONFERENCE_NOT_FOUND);
@@ -1563,7 +1563,7 @@ size_t tox_conference_peer_get_name_size(const Tox *tox, uint32_t conference_num
         Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peername_size(m->conferences_object, conference_number, peer_number);
+    int ret = group_peername_size(m->conferences_object, conference_number, peer_number, false);
 
     switch (ret) {
         case -1:
@@ -1583,7 +1583,7 @@ bool tox_conference_peer_get_name(const Tox *tox, uint32_t conference_number, ui
                                   Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peername(m->conferences_object, conference_number, peer_number, name);
+    int ret = group_peername(m->conferences_object, conference_number, peer_number, name, false);
 
     switch (ret) {
         case -1:
@@ -1603,7 +1603,7 @@ bool tox_conference_peer_get_public_key(const Tox *tox, uint32_t conference_numb
                                         uint8_t *public_key, Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peer_pubkey(m->conferences_object, conference_number, peer_number, public_key);
+    int ret = group_peer_pubkey(m->conferences_object, conference_number, peer_number, public_key, false);
 
     switch (ret) {
         case -1:
@@ -1643,6 +1643,106 @@ bool tox_conference_peer_number_is_ours(const Tox *tox, uint32_t conference_numb
     return ret;
 }
 
+uint32_t tox_conference_offline_peer_count(const Tox *tox, uint32_t conference_number,
+        Tox_Err_Conference_Peer_Query *error)
+{
+    const Messenger *m = tox->m;
+    int ret = group_number_peers(m->conferences_object, conference_number, true);
+
+    if (ret == -1) {
+        SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_CONFERENCE_NOT_FOUND);
+        return UINT32_MAX;
+    }
+
+    SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_OK);
+    return ret;
+}
+
+size_t tox_conference_offline_peer_get_name_size(const Tox *tox, uint32_t conference_number,
+        uint32_t offline_peer_number,
+        Tox_Err_Conference_Peer_Query *error)
+{
+    const Messenger *m = tox->m;
+    int ret = group_peername_size(m->conferences_object, conference_number, offline_peer_number, true);
+
+    switch (ret) {
+        case -1:
+            SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_CONFERENCE_NOT_FOUND);
+            return -1;
+
+        case -2:
+            SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_PEER_NOT_FOUND);
+            return -1;
+    }
+
+    SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_OK);
+    return ret;
+}
+
+bool tox_conference_offline_peer_get_name(const Tox *tox, uint32_t conference_number, uint32_t offline_peer_number,
+        uint8_t *name,
+        Tox_Err_Conference_Peer_Query *error)
+{
+    const Messenger *m = tox->m;
+    int ret = group_peername(m->conferences_object, conference_number, offline_peer_number, name, true);
+
+    switch (ret) {
+        case -1:
+            SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_CONFERENCE_NOT_FOUND);
+            return false;
+
+        case -2:
+            SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_PEER_NOT_FOUND);
+            return false;
+    }
+
+    SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_OK);
+    return true;
+}
+
+bool tox_conference_offline_peer_get_public_key(const Tox *tox, uint32_t conference_number,
+        uint32_t offline_peer_number,
+        uint8_t *public_key, Tox_Err_Conference_Peer_Query *error)
+{
+    const Messenger *m = tox->m;
+    int ret = group_peer_pubkey(m->conferences_object, conference_number, offline_peer_number, public_key, true);
+
+    switch (ret) {
+        case -1:
+            SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_CONFERENCE_NOT_FOUND);
+            return false;
+
+        case -2:
+            SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_PEER_NOT_FOUND);
+            return false;
+    }
+
+    SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_OK);
+    return true;
+}
+
+uint64_t tox_conference_offline_peer_get_last_active(const Tox *tox, uint32_t conference_number,
+        uint32_t offline_peer_number,
+        Tox_Err_Conference_Peer_Query *error)
+{
+    const Messenger *m = tox->m;
+    uint64_t last_active = UINT64_MAX;
+    int ret = group_frozen_last_active(m->conferences_object, conference_number, offline_peer_number, &last_active);
+
+    switch (ret) {
+        case -1:
+            SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_CONFERENCE_NOT_FOUND);
+            return UINT64_MAX;
+
+        case -2:
+            SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_PEER_NOT_FOUND);
+            return UINT64_MAX;
+    }
+
+    SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_OK);
+    return last_active;
+}
+
 bool tox_conference_invite(Tox *tox, uint32_t friend_number, uint32_t conference_number,
                            Tox_Err_Conference_Invite *error)
 {
diff --git a/toxcore/tox.h b/toxcore/tox.h
index ee8a01cc..94ffd32a 100644
--- a/toxcore/tox.h
+++ b/toxcore/tox.h
@@ -2631,6 +2631,42 @@ bool tox_conference_peer_get_public_key(const Tox *tox, uint32_t conference_numb
 bool tox_conference_peer_number_is_ours(const Tox *tox, uint32_t conference_number, uint32_t peer_number,
                                         TOX_ERR_CONFERENCE_PEER_QUERY *error);
 
+/**
+ * Return the number of offline peers in the conference. Return value is unspecified on failure.
+ */
+uint32_t tox_conference_offline_peer_count(const Tox *tox, uint32_t conference_number,
+        TOX_ERR_CONFERENCE_PEER_QUERY *error);
+
+/**
+ * Return the length of the offline peer's name. Return value is unspecified on failure.
+ */
+size_t tox_conference_offline_peer_get_name_size(const Tox *tox, uint32_t conference_number,
+        uint32_t offline_peer_number, TOX_ERR_CONFERENCE_PEER_QUERY *error);
+
+/**
+ * Copy the name of offline_peer_number who is in conference_number to name.
+ * name must be at least TOX_MAX_NAME_LENGTH long.
+ *
+ * @return true on success.
+ */
+bool tox_conference_offline_peer_get_name(const Tox *tox, uint32_t conference_number, uint32_t offline_peer_number,
+        uint8_t *name, TOX_ERR_CONFERENCE_PEER_QUERY *error);
+
+/**
+ * Copy the public key of offline_peer_number who is in conference_number to public_key.
+ * public_key must be TOX_PUBLIC_KEY_SIZE long.
+ *
+ * @return true on success.
+ */
+bool tox_conference_offline_peer_get_public_key(const Tox *tox, uint32_t conference_number,
+        uint32_t offline_peer_number, uint8_t *public_key, TOX_ERR_CONFERENCE_PEER_QUERY *error);
+
+/**
+ * Return a unix-time timestamp of the last time offline_peer_number was seen to be active.
+ */
+uint64_t tox_conference_offline_peer_get_last_active(const Tox *tox, uint32_t conference_number,
+        uint32_t offline_peer_number, TOX_ERR_CONFERENCE_PEER_QUERY *error);
+
 typedef enum TOX_ERR_CONFERENCE_INVITE {
 
     /**