* BaseChatMesh::sendGroupMessage() added

* companion radio, RESP_CODE_CHANNEL_MSG_RECV, CMD_SEND_CHANNEL_TXT_MSG

examples/companion_radio/main.cpp

@@ -364,6 +364,7 @@ protected:
   void onChannelMessageRecv(const mesh::GroupChannel& channel, int in_path_len, uint32_t timestamp, const char *text) override {
     int i = 0;
     out_frame[i++] = RESP_CODE_CHANNEL_MSG_RECV;
+    out_frame[i++] = 0;  // FUTURE: channel_idx (will just be 'public' for now)
     out_frame[i++] = in_path_len < 0 ? 0xFF : in_path_len;
     out_frame[i++] = TXT_TYPE_PLAIN;
     memcpy(&out_frame[i], &timestamp, 4); i += 4;
@@ -525,26 +526,18 @@ public:
         writeErrFrame(); // unknown recipient, or unsuported TXT_TYPE_*
       }
     } else if (cmd_frame[0] == CMD_SEND_CHANNEL_TXT_MSG) {  // send GroupChannel msg
-  #if 0  //TODO
-      uint8_t temp[5+MAX_TEXT_LEN+32];
-      uint32_t timestamp = getRTCClock()->getCurrentTime();
-      memcpy(temp, &timestamp, 4);   // mostly an extra blob to help make packet_hash unique
-      temp[4] = 0;  // attempt and flags
-
-      sprintf((char *) &temp[5], "%s: %s", self_name, &command[7]);  // <sender>: <msg>
-      temp[5 + MAX_TEXT_LEN] = 0;  // truncate if too long
+      int i = 1;
+      uint8_t txt_type = cmd_frame[i++];  // should be TXT_TYPE_PLAIN
+      uint8_t channel_idx = cmd_frame[i++];   // reserved future
+      uint32_t msg_timestamp;
+      memcpy(&msg_timestamp, &cmd_frame[i], 4); i += 4;
+      const char *text = (char *) &cmd_frame[i];
 
-      int len = strlen((char *) &temp[5]);
-      auto pkt = createGroupDatagram(PAYLOAD_TYPE_GRP_TXT, *_public, temp, 5 + len);
-      if (pkt) {
-        sendFlood(pkt);
-        Serial.println("   Sent.");
+      if (txt_type == TXT_TYPE_PLAIN && sendGroupMessage(msg_timestamp, *_public, _prefs.node_name, text, len - i)) {   // hard-coded to 'public' channel for now
+        writeOKFrame();
       } else {
-        Serial.println("   ERROR: unable to send");
+        writeErrFrame();
       }
-  #else
-      writeErrFrame();
-  #endif
     } else if (cmd_frame[0] == CMD_GET_CONTACTS) {  // get Contact list
       if (_iter_started) {
         writeErrFrame();   // iterator is currently busy

src/helpers/BaseChatMesh.cpp

@@ -220,6 +220,27 @@ int  BaseChatMesh::sendMessage(const ContactInfo& recipient, uint32_t timestamp,
   return rc;
 }
 
+bool BaseChatMesh::sendGroupMessage(uint32_t timestamp, mesh::GroupChannel& channel, const char* sender_name, const char* text, int text_len) {
+  uint8_t temp[5+MAX_TEXT_LEN+32];
+  memcpy(temp, &timestamp, 4);   // mostly an extra blob to help make packet_hash unique
+  temp[4] = 0;  // TXT_TYPE_PLAIN
+
+  sprintf((char *) &temp[5], "%s: ", sender_name);  // <sender>: <msg>
+  char *ep = strchr((char *) &temp[5], 0);
+  int prefix_len = ep - (char *) &temp[5];
+
+  if (text_len + prefix_len > MAX_TEXT_LEN) text_len = MAX_TEXT_LEN - prefix_len;
+  memcpy(ep, text, text_len);
+  ep[text_len] = 0;  // null terminator
+
+  auto pkt = createGroupDatagram(PAYLOAD_TYPE_GRP_TXT, channel, temp, 5 + prefix_len + text_len);
+  if (pkt) {
+    sendFlood(pkt);
+    return true;
+  }
+  return false;
+}
+
 void BaseChatMesh::resetPathTo(ContactInfo& recipient) {
   recipient.out_path_len = -1;
 }

src/helpers/BaseChatMesh.h

@@ -98,6 +98,7 @@ protected:
 public:
   mesh::Packet* createSelfAdvert(const char* name, double lat=0.0, double lon=0.0);
   int  sendMessage(const ContactInfo& recipient, uint32_t timestamp, uint8_t attempt, const char* text, uint32_t& expected_ack, uint32_t& est_timeout);
+  bool sendGroupMessage(uint32_t timestamp, mesh::GroupChannel& channel, const char* sender_name, const char* text, int text_len);
   void resetPathTo(ContactInfo& recipient);
   void scanRecentContacts(int last_n, ContactVisitor* visitor);
   ContactInfo* searchContactsByPrefix(const char* name_prefix);