core/telemetry_session: Remove usages of the global system accessor

Makes the dependency explicit in the TelemetrySession's interface
instead of making it a hidden dependency.

This also revealed a hidden issue with the way the telemetry session was
being initialized. It was attempting to retrieve the app loader and log
out title-specific information. However, this isn't always guaranteed to
be possible.

During the initialization phase, everything is being constructed. It
doesn't mean an actual title has been selected. This is what the Load()
function is for. This potentially results in dead code paths involving
the app loader. Instead, we explicitly add this information when we know
the app loader instance is available.

src/core/core.cpp

@@ -94,7 +94,6 @@ System::ResultStatus System::SingleStep() {
 
 System::ResultStatus System::Load(Frontend::EmuWindow& emu_window, const std::string& filepath) {
     app_loader = Loader::GetLoader(filepath);
-
     if (!app_loader) {
         LOG_CRITICAL(Core, "Failed to obtain loader for {}!", filepath);
         return ResultStatus::ErrorGetLoader;
@@ -125,6 +124,7 @@ System::ResultStatus System::Load(Frontend::EmuWindow& emu_window, const std::st
         return init_result;
     }
 
+    telemetry_session->AddInitialInfo(*app_loader);
     std::shared_ptr<Kernel::Process> process;
     const Loader::ResultStatus load_result{app_loader->Load(process)};
     kernel->SetCurrentProcess(process);

src/core/telemetry_session.cpp

@@ -91,7 +91,32 @@ bool VerifyLogin(const std::string& username, const std::string& token) {
 #endif
 }
 
-TelemetrySession::TelemetrySession() {
+TelemetrySession::TelemetrySession() = default;
+
+TelemetrySession::~TelemetrySession() {
+    // Log one-time session end information
+    const s64 shutdown_time{std::chrono::duration_cast<std::chrono::milliseconds>(
+                                std::chrono::system_clock::now().time_since_epoch())
+                                .count()};
+    AddField(Telemetry::FieldType::Session, "Shutdown_Time", shutdown_time);
+
+#ifdef ENABLE_WEB_SERVICE
+    auto backend = std::make_unique<WebService::TelemetryJson>(Settings::values.web_api_url,
+                                                               Settings::values.citra_username,
+                                                               Settings::values.citra_token);
+#else
+    auto backend = std::make_unique<Telemetry::NullVisitor>();
+#endif
+
+    // Complete the session, submitting to web service if necessary
+    field_collection.Accept(*backend);
+    if (Settings::values.enable_telemetry) {
+        backend->Complete();
+    }
+    backend = nullptr;
+}
+
+void TelemetrySession::AddInitialInfo(Loader::AppLoader& app_loader) {
     // Log one-time top-level information
     AddField(Telemetry::FieldType::None, "TelemetryId", GetTelemetryId());
 
@@ -101,7 +126,7 @@ TelemetrySession::TelemetrySession() {
                             .count()};
     AddField(Telemetry::FieldType::Session, "Init_Time", init_time);
     std::string program_name;
-    const Loader::ResultStatus res{System::GetInstance().GetAppLoader().ReadTitle(program_name)};
+    const Loader::ResultStatus res{app_loader.ReadTitle(program_name)};
     if (res == Loader::ResultStatus::Success) {
         AddField(Telemetry::FieldType::Session, "ProgramName", program_name);
     }
@@ -178,28 +203,6 @@ TelemetrySession::TelemetrySession() {
     AddField(Telemetry::FieldType::UserConfig, "System_RegionValue", Settings::values.region_value);
 }
 
-TelemetrySession::~TelemetrySession() {
-    // Log one-time session end information
-    const s64 shutdown_time{std::chrono::duration_cast<std::chrono::milliseconds>(
-                                std::chrono::system_clock::now().time_since_epoch())
-                                .count()};
-    AddField(Telemetry::FieldType::Session, "Shutdown_Time", shutdown_time);
-
-#ifdef ENABLE_WEB_SERVICE
-    auto backend = std::make_unique<WebService::TelemetryJson>(Settings::values.web_api_url,
-                                                               Settings::values.citra_username,
-                                                               Settings::values.citra_token);
-#else
-    auto backend = std::make_unique<Telemetry::NullVisitor>();
-#endif
-
-    // Complete the session, submitting to web service if necessary
-    field_collection.Accept(*backend);
-    if (Settings::values.enable_telemetry)
-        backend->Complete();
-    backend = nullptr;
-}
-
 bool TelemetrySession::SubmitTestcase() {
 #ifdef ENABLE_WEB_SERVICE
     auto backend = std::make_unique<WebService::TelemetryJson>(Settings::values.web_api_url,

src/core/telemetry_session.h

@@ -8,6 +8,10 @@
 #include <string>
 #include "common/telemetry.h"
 
+namespace Loader {
+class AppLoader;
+}
+
 namespace Core {
 
 /**
@@ -17,7 +21,7 @@ namespace Core {
  */
 class TelemetrySession {
 public:
-    TelemetrySession();
+    explicit TelemetrySession();
     ~TelemetrySession();
 
     TelemetrySession(const TelemetrySession&) = delete;
@@ -26,6 +30,22 @@ public:
     TelemetrySession(TelemetrySession&&) = delete;
     TelemetrySession& operator=(TelemetrySession&&) = delete;
 
+    /**
+     * Adds the initial telemetry info necessary when starting up a title.
+     *
+     * This includes information such as:
+     *   - Telemetry ID
+     *   - Initialization time
+     *   - Title ID
+     *   - Title name
+     *   - Title file format
+     *   - Miscellaneous settings values.
+     *
+     * @param app_loader The application loader to use to retrieve
+     *                   title-specific information.
+     */
+    void AddInitialInfo(Loader::AppLoader& app_loader);
+
     /**
      * Wrapper around the Telemetry::FieldCollection::AddField method.
      * @param type Type of the field to add.