Fix firmware download

src/activities/settings/OtaUpdateActivity.cpp

@@ -31,6 +31,7 @@ void OtaUpdateActivity::onWifiSelectionComplete(const bool success) {
     LOG_DBG("OTA", "Update check failed: %d", res);
     {
       RenderLock lock(*this);
+      failureReason = res;
       state = FAILED;
     }
     return;
@@ -126,6 +127,35 @@ void OtaUpdateActivity::render(RenderLock&&) {
     GUI.drawButtonHints(renderer, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
   } else if (state == FAILED) {
     renderer.drawCenteredText(UI_10_FONT_ID, top, tr(STR_UPDATE_FAILED), true, EpdFontFamily::BOLD);
+    const char* reason = "";
+    switch (failureReason) {
+      case OtaUpdater::HTTP_ERROR:
+        reason = "Network error (HTTP request failed)";
+        break;
+      case OtaUpdater::JSON_PARSE_ERROR:
+        reason = "Could not parse release info";
+        break;
+      case OtaUpdater::UPDATE_OLDER_ERROR:
+        reason = "Available version is not newer";
+        break;
+      case OtaUpdater::OOM_ERROR:
+        reason = "Out of memory";
+        break;
+      case OtaUpdater::INTERNAL_UPDATE_ERROR:
+        reason = "Internal update error";
+        break;
+      case OtaUpdater::NO_UPDATE:
+        reason = "No firmware asset found";
+        break;
+      case OtaUpdater::VALIDATE_FAILED:
+        reason = "Image validation failed - please flash via USB";
+        break;
+      default:
+        break;
+    }
+    if (reason[0] != '\0') {
+      renderer.drawCenteredText(SMALL_FONT_ID, top + height + metrics.verticalSpacing, reason);
+    }
     const auto labels = mappedInput.mapLabels(tr(STR_BACK), "", "", "");
     GUI.drawButtonHints(renderer, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
   } else if (state == FINISHED) {
@@ -151,6 +181,7 @@ void OtaUpdateActivity::loop() {
         LOG_DBG("OTA", "Update begin failed: %d", beginResult);
         {
           RenderLock lock(*this);
+          failureReason = beginResult;
           state = FAILED;
         }
         requestUpdate();
@@ -205,6 +236,7 @@ void OtaUpdateActivity::loop() {
     LOG_DBG("OTA", "Update failed: %d", res);
     {
       RenderLock lock(*this);
+      failureReason = res;
       state = FAILED;
     }
     requestUpdate();