Add profile pref to store time of last Assistant interaction.

This pref will eventually be used to target onboarding features to
users who have not been using Assistant for a long time.

Bug: b:161908220
Change-Id: I336b8193182765054126abf504c786c766ff51fc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2314157
Commit-Queue: David Black <dmblack@google.com>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Jeroen Dhollander <jeroendh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791546}

ash/assistant/assistant_controller_impl.cc

@@ -53,6 +53,7 @@ AssistantControllerImpl::~AssistantControllerImpl() {
 void AssistantControllerImpl::RegisterProfilePrefs(
     PrefRegistrySimple* registry) {
   registry->RegisterIntegerPref(prefs::kAssistantNumWarmerWelcomeTriggered, 0);
+  AssistantInteractionControllerImpl::RegisterProfilePrefs(registry);
 }
 
 void AssistantControllerImpl::BindReceiver(

ash/assistant/assistant_interaction_controller_impl.cc

@@ -35,6 +35,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chromeos/services/assistant/public/cpp/features.h"
+#include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
 #include "mojo/public/cpp/bindings/remote.h"
 #include "net/base/url_util.h"
@@ -111,6 +112,13 @@ AssistantInteractionControllerImpl::~AssistantInteractionControllerImpl() {
     assistant_->RemoveAssistantInteractionSubscriber(this);
 }
 
+// static
+void AssistantInteractionControllerImpl::RegisterProfilePrefs(
+    PrefRegistrySimple* registry) {
+  registry->RegisterTimePref(prefs::kAssistantTimeOfLastInteraction,
+                             base::Time());
+}
+
 void AssistantInteractionControllerImpl::SetAssistant(
     chromeos::assistant::Assistant* assistant) {
   if (assistant_)
@@ -127,6 +135,12 @@ const AssistantInteractionModel* AssistantInteractionControllerImpl::GetModel()
   return &model_;
 }
 
+base::TimeDelta
+AssistantInteractionControllerImpl::GetTimeDeltaSinceLastInteraction() const {
+  return base::Time::Now() -
+         pref_service()->GetTime(prefs::kAssistantTimeOfLastInteraction);
+}
+
 void AssistantInteractionControllerImpl::StartTextInteraction(
     const std::string& text,
     bool allow_tts,
@@ -319,6 +333,13 @@ void AssistantInteractionControllerImpl::OnMicStateChanged(MicState mic_state) {
 
 void AssistantInteractionControllerImpl::OnCommittedQueryChanged(
     const AssistantQuery& assistant_query) {
+  // Update the time of the last Assistant interaction so that we can later
+  // determine how long it has been since a user interacted with the Assistant.
+  // NOTE: We do this in OnCommittedQueryChanged() to filter out accidental
+  // interactions that would still have triggered OnInteractionStarted().
+  pref_service()->SetTime(prefs::kAssistantTimeOfLastInteraction,
+                          base::Time::Now());
+
   std::string query;
   switch (assistant_query.type()) {
     case AssistantQueryType::kText: {

ash/assistant/assistant_interaction_controller_impl.h

@@ -26,6 +26,8 @@
 #include "chromeos/services/assistant/public/cpp/assistant_service.h"
 #include "mojo/public/cpp/bindings/receiver.h"
 
+class PrefRegistrySimple;
+
 namespace ash {
 
 class AssistantControllerImpl;
@@ -55,11 +57,14 @@ class AssistantInteractionControllerImpl
       AssistantControllerImpl* assistant_controller);
   ~AssistantInteractionControllerImpl() override;
 
+  static void RegisterProfilePrefs(PrefRegistrySimple* registry);
+
   // Provides a pointer to the |assistant| owned by AssistantService.
   void SetAssistant(chromeos::assistant::Assistant* assistant);
 
   // AssistantInteractionController:
   const AssistantInteractionModel* GetModel() const override;
+  base::TimeDelta GetTimeDeltaSinceLastInteraction() const override;
   void StartTextInteraction(const std::string& text,
                             bool allow_tts,
                             AssistantQuerySource query_source) override;

ash/assistant/assistant_interaction_controller_impl_unittest.cc

@@ -24,6 +24,7 @@
 #include "base/test/scoped_feature_list.h"
 #include "chromeos/services/assistant/public/cpp/assistant_service.h"
 #include "chromeos/services/assistant/public/cpp/features.h"
+#include "chromeos/services/assistant/test_support/mock_assistant_interaction_subscriber.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 namespace ash {
@@ -38,6 +39,8 @@ using chromeos::assistant::AssistantInteractionType;
 using chromeos::assistant::AssistantQuerySource;
 using chromeos::assistant::AssistantSuggestion;
 using chromeos::assistant::AssistantSuggestionType;
+using chromeos::assistant::MockAssistantInteractionSubscriber;
+using chromeos::assistant::ScopedAssistantInteractionSubscriber;
 
 using ::testing::Invoke;
 using ::testing::Mock;
@@ -250,6 +253,30 @@ TEST_P(AssistantInteractionControllerImplTest, ShouldDisplayGenericErrorOnce) {
   EXPECT_EQ(ui_elements.front()->type(), AssistantUiElementType::kError);
 }
 
+TEST_P(AssistantInteractionControllerImplTest,
+       ShouldUpdateTimeOfLastInteraction) {
+  MockAssistantInteractionSubscriber mock_subscriber;
+  ScopedAssistantInteractionSubscriber scoped_subscriber{&mock_subscriber};
+  scoped_subscriber.Add(assistant_service());
+
+  base::RunLoop run_loop;
+  base::Time actual_time_of_last_interaction;
+  EXPECT_CALL(mock_subscriber, OnInteractionStarted)
+      .WillOnce(Invoke([&](const AssistantInteractionMetadata& metadata) {
+        actual_time_of_last_interaction = base::Time::Now();
+        run_loop.QuitClosure().Run();
+      }));
+
+  ShowAssistantUi();
+  MockTextInteraction().WithTextResponse("<Any-Text-Response>");
+  run_loop.Run();
+
+  auto actual = interaction_controller()->GetTimeDeltaSinceLastInteraction();
+  auto expected = base::Time::Now() - actual_time_of_last_interaction;
+
+  EXPECT_NEAR(actual.InSeconds(), expected.InSeconds(), 1);
+}
+
 // We parameterize all AssistantInteractionControllerImplTests to verify that
 // they work for both response processing v1 as well as response processing v2.
 INSTANTIATE_TEST_SUITE_P(All,

ash/public/cpp/ash_pref_names.cc

@@ -452,6 +452,10 @@ const char kDetachableBaseDevices[] = "ash.detachable_base.devices";
 const char kAssistantNumWarmerWelcomeTriggered[] =
     "ash.assistant.num_warmer_welcome_triggered";
 
+// Pref storing the time of the last Assistant interaction.
+const char kAssistantTimeOfLastInteraction[] =
+    "ash.assistant.time_of_last_interaction";
+
 // Whether the user is allowed to disconnect and configure VPN connections.
 const char kVpnConfigAllowed[] = "vpn_config_allowed";
 

ash/public/cpp/ash_pref_names.h

@@ -171,6 +171,7 @@ ASH_PUBLIC_EXPORT extern const char kDetachableBaseDevices[];
 ASH_PUBLIC_EXPORT extern const char kCursorMotionBlurEnabled[];
 
 ASH_PUBLIC_EXPORT extern const char kAssistantNumWarmerWelcomeTriggered[];
+ASH_PUBLIC_EXPORT extern const char kAssistantTimeOfLastInteraction[];
 
 ASH_PUBLIC_EXPORT extern const char kVpnConfigAllowed[];
 

ash/public/cpp/assistant/controller/assistant_interaction_controller.h

@@ -10,6 +10,10 @@
 #include "ash/public/cpp/ash_public_export.h"
 #include "chromeos/services/assistant/public/cpp/assistant_service.h"
 
+namespace base {
+class TimeDelta;
+}  // namespace base
+
 namespace ash {
 
 class AssistantInteractionModel;
@@ -23,6 +27,10 @@ class ASH_PUBLIC_EXPORT AssistantInteractionController {
   // Returns a pointer to the underlying model.
   virtual const AssistantInteractionModel* GetModel() const = 0;
 
+  // Returns the TimeDelta since the last Assistant interaction. Note that the
+  // last interaction may have been performed in a different user session.
+  virtual base::TimeDelta GetTimeDeltaSinceLastInteraction() const = 0;
+
   // Start Assistant text interaction.
   virtual void StartTextInteraction(
       const std::string& query,

chromeos/services/assistant/BUILD.gn

@@ -140,6 +140,7 @@ source_set("tests") {
   testonly = true
   deps = [
     ":lib",
+    ":test_support",
     "//ash/public/cpp/assistant/test_support",
     "//ash/public/mojom",
     "//base",
@@ -187,8 +188,6 @@ source_set("tests") {
       "test_support/fake_platform_api.h",
       "test_support/fake_service_context.cc",
       "test_support/fake_service_context.h",
-      "test_support/mock_assistant_interaction_subscriber.cc",
-      "test_support/mock_assistant_interaction_subscriber.h",
       "test_support/mock_media_manager.cc",
       "test_support/mock_media_manager.h",
     ]
@@ -212,6 +211,8 @@ static_library("test_support") {
   sources = [
     "test_support/mock_assistant.cc",
     "test_support/mock_assistant.h",
+    "test_support/mock_assistant_interaction_subscriber.cc",
+    "test_support/mock_assistant_interaction_subscriber.h",
   ]
   deps = [
     "//base",