header size is 3 only for customHuami category

header size should be 2 according to specification

fixes: #1895

doc/ble.md

@@ -149,21 +149,21 @@ InfiniTime uses the Alert Notification Service (ANS) for notifications. The rele
 The new alert characteristic allows sending new notifications to InfiniTime. It requires the following format:
 
 ```
-<category><amount>\x00<\x00-separated data>
+<category><amount><\x00-separated data>
 ```
 
 For example, here is what a normal notification looks like in Golang (language of `itd`):
 
 ```go
 // \x00 is the category for simple alert, and there is one new notification, hence \x01.
-"\x00\x01\x00Test Title\x00Test Body"
+"\x00\x01Test Title\x00Test Body"
 ```
 
 A call notification looks like so:
 
 ```go
 // \x03 is the category for calls, and there is one new call notification, hence \x01.
-"\x03\x01\x00Mary"
+"\x03\x01Mary"
 ```
 
 The `\x00` stands for hexadecimal `00` which means null.
@@ -180,6 +180,7 @@ Here is the list of categories and commands:
 - Schedule: `7`
 - High Prioritized Alert: `8`
 - Instant Message: `9`
+- Custom Huami: `xFA` - one extra byte for icon is added into header
 - All Alerts: `0xFF`
 
 These lists and information were retrieved from the following pages in the Nordic docs:

src/components/ble/AlertNotificationClient.cpp

@@ -144,7 +144,7 @@ int AlertNotificationClient::OnDescriptorDiscoveryEventCallback(uint16_t connect
 void AlertNotificationClient::OnNotification(ble_gap_event* event) {
   if (event->notify_rx.attr_handle == newAlertHandle) {
     constexpr size_t stringTerminatorSize = 1; // end of string '\0'
-    constexpr size_t headerSize = 3;
+    constexpr size_t headerSize = 2;
     const auto maxMessageSize {NotificationManager::MaximumMessageSize()};
     const auto maxBufferSize {maxMessageSize + headerSize};
 

src/components/ble/AlertNotificationService.cpp

@@ -47,23 +47,29 @@ AlertNotificationService::AlertNotificationService(System::SystemTask& systemTas
 int AlertNotificationService::OnAlert(struct ble_gatt_access_ctxt* ctxt) {
   if (ctxt->op == BLE_GATT_ACCESS_OP_WRITE_CHR) {
     constexpr size_t stringTerminatorSize = 1; // end of string '\0'
-    constexpr size_t headerSize = 3;
-    const auto maxMessageSize {NotificationManager::MaximumMessageSize()};
-    const auto maxBufferSize {maxMessageSize + headerSize};
+    size_t headerSize = 3;
 
     // Ignore notifications with empty message
     const auto packetLen = OS_MBUF_PKTLEN(ctxt->om);
     if (packetLen <= headerSize) {
       return 0;
     }
 
+    Categories category;
+    os_mbuf_copydata(ctxt->om, 0, 1, &category);
+
+    if (category != Categories::CustomHuami) {
+      headerSize = 2;
+    }
+
+    const auto maxMessageSize {NotificationManager::MaximumMessageSize()};
+    const auto maxBufferSize {maxMessageSize + headerSize};
+
     size_t bufferSize = std::min(packetLen + stringTerminatorSize, maxBufferSize);
     auto messageSize = std::min(maxMessageSize, (bufferSize - headerSize));
-    Categories category;
 
     NotificationManager::Notification notif;
     os_mbuf_copydata(ctxt->om, headerSize, messageSize - 1, notif.message.data());
-    os_mbuf_copydata(ctxt->om, 0, 1, &category);
     notif.message[messageSize - 1] = '\0';
     notif.size = messageSize;
 

src/components/ble/AlertNotificationService.h

@@ -45,6 +45,7 @@ namespace Pinetime {
         Schedule = 0x07,
         HighPrioritizedAlert = 0x08,
         InstantMessage = 0x09,
+        CustomHuami = 0xFA,
         All = 0xff
       };