Decouple use of IMEngine Singleton in EventManagement

Author: yyzhong-g

src/app/BUILD.gn

@@ -432,7 +432,6 @@ static_library("app") {
     "CommandResponseSender.cpp",
     "EventLogging.h",
     "EventManagement.cpp",
-    "EventManagement.h",
     "FailSafeContext.cpp",
     "FailSafeContext.h",
     "GenericEventManagementTestEventTriggerHandler.cpp",
@@ -448,7 +447,8 @@ static_library("app") {
     #       Name with _ so that linter does not recognize it
     # "CommandResponseSender._h"
     # "ReadHandler._h",
-    # "WriteHandler._h"
+    # "WriteHandler._h",
+    # "EventManagement._h"
   ]
 
   public_deps = [

src/app/EventManagement.h

@@ -191,6 +191,18 @@ struct LogStorageResources
         PriorityLevel::Invalid; // Log priority level associated with the resources provided in this structure.
 };
 
+/**
+ * @brief
+ *  A EventScheduler to schedule deliveries of events.
+ */
+
+class EventScheduler
+{
+public:
+    virtual ~EventScheduler() = default;
+    CHIP_ERROR virtual ScheduleEventDelivery(ConcreteEventPath & aPath, uint32_t aBytesWritten) = 0;
+};
+
 /**
  * @brief
  *   A class for managing the in memory event logs.  See documentation at the
@@ -225,6 +237,9 @@ class EventManagement : public DataModel::EventsGenerator
      * @param[in] aMonotonicStartupTime  Time we should consider as "monotonic
      *                                   time 0" for cases when we use
      *                                   system-time event timestamps.
+     * 
+     * @param[in] apEventScheduler       Scheduler to deliver the event, default is the reporting
+     *                                   engine in InteractionModelEngine.
      *
      * @param[in] apEventScheduler       Scheduler to deliver the event, default is the reporting
      *                                   engine in InteractionModelEngine.
@@ -233,7 +248,8 @@ class EventManagement : public DataModel::EventsGenerator
     void Init(Messaging::ExchangeManager * apExchangeManager, uint32_t aNumBuffers, CircularEventBuffer * apCircularEventBuffer,
               const LogStorageResources * const apLogStorageResources,
               MonotonicallyIncreasingCounter<EventNumber> * apEventNumberCounter,
-              System::Clock::Milliseconds64 aMonotonicStartupTime, EventScheduler * apEventScheduler = nullptr);
+              System::Clock::Milliseconds64 aMonotonicStartupTime,
+              EventScheduler* apEventScheduler = nullptr);
 
     static EventManagement & GetInstance();
 
@@ -568,7 +584,7 @@ class EventManagement : public DataModel::EventsGenerator
 
     System::Clock::Milliseconds64 mMonotonicStartupTime;
 
-    EventScheduler * mpEventScheduler = nullptr;
+    EventScheduler* mpEventScheduler = nullptr;
 };
 
 } // namespace app

src/app/reporting/Engine.h

@@ -26,6 +26,7 @@
 
 #include <access/AccessControl.h>
 #include <app/EventScheduler.h>
+#include <app/EventManagement.h>
 #include <app/MessageDef/ReportDataMessage.h>
 #include <app/ReadHandler.h>
 #include <app/data-model-provider/ProviderChangeListener.h>
@@ -67,6 +68,8 @@ class Engine : public DataModel::ProviderChangeListener, public EventScheduler
 
     /**
      * Initializes the reporting engine. Should only be called once.
+     * 
+     * @param[in] A pointer to EventManagement. Use the global one by default.
      *
      * @param[in] A pointer to EventManagement. Use the global one by default.
      *