Add advertising logic for DCT

PiperOrigin-RevId: 733752366

connections/implementation/client_proxy.cc

@@ -28,9 +28,9 @@
 #include "absl/container/flat_hash_map.h"
 #include "absl/container/flat_hash_set.h"
 #include "absl/functional/any_invocable.h"
+#include "absl/random/random.h"
 #include "absl/strings/escaping.h"
 #include "absl/strings/string_view.h"
-#include "absl/time/time.h"
 #include "absl/types/span.h"
 #include "connections/advertising_options.h"
 #include "connections/connection_options.h"
@@ -39,6 +39,7 @@
 #include "connections/implementation/analytics/analytics_recorder.h"
 #include "connections/implementation/analytics/discovery_metadata_params.h"
 #include "connections/implementation/flags/nearby_connections_feature_flags.h"
+#include "connections/implementation/mediums/advertisements/dct_advertisement.h"
 #include "connections/listeners.h"
 #include "connections/medium_selector.h"
 #include "connections/payload.h"
@@ -107,6 +108,9 @@ ClientProxy::ClientProxy(::nearby::analytics::EventLogger* event_logger)
   NEARBY_LOGS(INFO) << "[safe-to-disconnect]: Local enabled: "
                     << supports_safe_to_disconnect_
                     << "; Version: " << local_safe_to_disconnect_version_;
+  // Generate a 7 bits dedup value.
+  absl::BitGen bitgen;
+  dct_dedup_ = absl::Uniform(bitgen, 0, 1 << 7);
 }
 
 ClientProxy::~ClientProxy() { Reset(); }
@@ -115,24 +119,29 @@ std::int64_t ClientProxy::GetClientId() const { return client_id_; }
 
 std::string ClientProxy::GetLocalEndpointId() {
   MutexLock lock(&mutex_);
-  if (!local_endpoint_id_.empty()) {
-    NEARBY_LOGS(INFO) << __func__
-                      << ": Reusing cached endpoint id: " << local_endpoint_id_;
+  if (IsDctEnabled() && GetEndpointIdForDct().has_value()) {
+    NEARBY_LOGS(INFO) << "DCT is using genereted endpoint id.";
+    return GetEndpointIdForDct().value();
+  } else {
+    if (!local_endpoint_id_.empty()) {
+      NEARBY_LOGS(INFO) << __func__ << ": Reusing cached endpoint id: "
+                        << local_endpoint_id_;
+      return local_endpoint_id_;
+    }
+    if (external_device_provider_ == nullptr) {
+      local_endpoint_id_ = GenerateLocalEndpointId();
+      NEARBY_LOGS(INFO) << __func__ << ": Locally generating endpoint id: "
+                        << local_endpoint_id_;
+    } else {
+      local_endpoint_id_ =
+          external_device_provider_->GetLocalDevice()->GetEndpointId();
+      NEARBY_LOGS(INFO)
+          << __func__
+          << ": From external device provider, populating endpoint id: "
+          << local_endpoint_id_;
+    }
     return local_endpoint_id_;
   }
-  if (external_device_provider_ == nullptr) {
-    local_endpoint_id_ = GenerateLocalEndpointId();
-    NEARBY_LOGS(INFO) << __func__ << ": Locally generating endpoint id: "
-                      << local_endpoint_id_;
-  } else {
-    local_endpoint_id_ =
-        external_device_provider_->GetLocalDevice()->GetEndpointId();
-    NEARBY_LOGS(INFO)
-        << __func__
-        << ": From external device provider, populating endpoint id: "
-        << local_endpoint_id_;
-  }
-  return local_endpoint_id_;
 }
 
 const NearbyDevice* ClientProxy::GetLocalDevice() {
@@ -1301,6 +1310,48 @@ void ClientProxy::SetWebRtcNonCellular(bool webrtc_non_cellular) {
       webrtc_non_cellular_ = webrtc_non_cellular;
 }
 
+bool ClientProxy::IsDctEnabled() const {
+  if (api::ImplementationPlatform::GetCurrentOS() != api::OSName::kApple) {
+    return false;
+  }
+
+#if defined(NC_IOS_SDK)
+  return true;
+#else
+  return false;
+#endif
+}
+
+uint8_t ClientProxy::GetDctDedup() const { return dct_dedup_; }
+
+void ClientProxy::UpdateDctDeviceName(absl::string_view device_name) {
+  if (!dct_device_name_.empty() && dct_device_name_ != device_name) {
+    // Need to update dedup value if device name is changed.
+    absl::BitGen bitgen;
+    dct_dedup_ = absl::Uniform(bitgen, 0, 1 << 7);
+  }
+
+  dct_device_name_ = device_name;
+
+  // The DCT endpoint ID should be derived from device name and dedup value.
+  std::optional<std::string> dct_endpoint_id =
+      advertisements::ble::DctAdvertisement::GenerateEndpointId(
+          dct_dedup_, dct_device_name_);
+  if (dct_endpoint_id.has_value()) {
+    dct_endpoint_id_ = *dct_endpoint_id;
+  } else {
+    dct_endpoint_id_.clear();
+  }
+}
+
+std::optional<std::string> ClientProxy::GetEndpointIdForDct() const {
+  if (dct_endpoint_id_.empty()) {
+    return std::nullopt;
+  }
+
+  return dct_endpoint_id_;
+}
+
 std::string ClientProxy::ToString(PayloadProgressInfo::Status status) const {
   switch (status) {
     case PayloadProgressInfo::Status::kSuccess: