From beb293b783236b2befbab74b67445907f65a5be0 Mon Sep 17 00:00:00 2001
From: Sharad Binjola <sharadb@amazon.com>
Date: Thu, 16 Feb 2023 15:33:56 -0800
Subject: [PATCH] tv-casting-app: Implementing FabricDelegate to update cache
 on FabricIndex removal

---
 .../include/PersistenceManager.h              |  4 +-
 .../tv-casting-common/src/CastingServer.cpp   |  3 ++
 .../src/PersistenceManager.cpp                | 38 +++++++++++++++++++
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/examples/tv-casting-app/tv-casting-common/include/PersistenceManager.h b/examples/tv-casting-app/tv-casting-common/include/PersistenceManager.h
index 6d3f36b7801416..abdf62a7e1b3f7 100644
--- a/examples/tv-casting-app/tv-casting-common/include/PersistenceManager.h
+++ b/examples/tv-casting-app/tv-casting-common/include/PersistenceManager.h
@@ -23,13 +23,15 @@
 
 constexpr size_t kMaxCachedVideoPlayers = 32;
 
-class PersistenceManager
+class PersistenceManager : public chip::FabricTable::Delegate
 {
 public:
     CHIP_ERROR AddVideoPlayer(TargetVideoPlayerInfo * targetVideoPlayerInfo);
 
     CHIP_ERROR ReadAllVideoPlayers(TargetVideoPlayerInfo outVideoPlayers[]);
 
+    void OnFabricRemoved(const chip::FabricTable & fabricTable, chip::FabricIndex fabricIndex);
+    
     CHIP_ERROR PurgeVideoPlayerCache();
 
 private:
diff --git a/examples/tv-casting-app/tv-casting-common/src/CastingServer.cpp b/examples/tv-casting-app/tv-casting-common/src/CastingServer.cpp
index 654577e8e6b099..e6b51c76323be9 100644
--- a/examples/tv-casting-app/tv-casting-common/src/CastingServer.cpp
+++ b/examples/tv-casting-app/tv-casting-common/src/CastingServer.cpp
@@ -55,6 +55,9 @@ CHIP_ERROR CastingServer::Init(AppParams * AppParams)
     // Initialize binding handlers
     ReturnErrorOnFailure(InitBindingHandlers());
 
+    // Set FabricDelegate
+    chip::Server::GetInstance().GetFabricTable().AddFabricDelegate(&mPersistenceManager);
+
     // Add callback to send Content casting commands after commissioning completes
     ReturnErrorOnFailure(DeviceLayer::PlatformMgrImpl().AddEventHandler(DeviceEventCallback, 0));
 
diff --git a/examples/tv-casting-app/tv-casting-common/src/PersistenceManager.cpp b/examples/tv-casting-app/tv-casting-common/src/PersistenceManager.cpp
index c4cbafaa607467..a00d678f9d9a44 100644
--- a/examples/tv-casting-app/tv-casting-common/src/PersistenceManager.cpp
+++ b/examples/tv-casting-app/tv-casting-common/src/PersistenceManager.cpp
@@ -402,6 +402,44 @@ CHIP_ERROR PersistenceManager::ReadAllVideoPlayers(TargetVideoPlayerInfo outVide
     return CHIP_NO_ERROR;
 }
 
+void PersistenceManager::OnFabricRemoved(const FabricTable & fabricTable, FabricIndex fabricIndex)
+{
+    ChipLogProgress(AppServer, "PersistenceManager::OnFabricRemoved called for fabricIndex: %d", fabricIndex);
+    
+    // Read cached video players
+    TargetVideoPlayerInfo cachedVideoPlayers[kMaxCachedVideoPlayers];
+    CHIP_ERROR err = ReadAllVideoPlayers(cachedVideoPlayers);
+    if (err != CHIP_NO_ERROR)
+    {
+        ChipLogError(AppServer, "PersistenceManager::OnFabricRemoved could not read cached video players %" CHIP_ERROR_FORMAT, err.Format());
+    }
+
+    // Delete video players that match the passed in fabricIndex
+    for (size_t i = 0; i < kMaxCachedVideoPlayers && cachedVideoPlayers[i].IsInitialized(); i++)
+    {
+        if(cachedVideoPlayers[i].GetFabricIndex() == fabricIndex)
+        {   
+            ChipLogProgress(AppServer, "PersistenceManager::OnFabricRemoved removing video player with nodeId: 0x" ChipLogFormatX64 " from cache", ChipLogValueX64(cachedVideoPlayers[i].GetNodeId()));
+
+            // shift elements back by 1 and mark the last array element for deletion
+            size_t indexToDelete = i;
+            if(indexToDelete + 1 < kMaxCachedVideoPlayers && cachedVideoPlayers[indexToDelete + 1].IsInitialized())
+            {
+                while(indexToDelete + 1 < kMaxCachedVideoPlayers && cachedVideoPlayers[indexToDelete + 1].IsInitialized())
+                {
+                    cachedVideoPlayers[indexToDelete] = cachedVideoPlayers[indexToDelete + 1];
+                    indexToDelete++;
+                }
+            }
+
+            // memset cachedVideoPlayers[indexToDelete] to zeroes
+            memset(&cachedVideoPlayers[indexToDelete], 0, sizeof(cachedVideoPlayers[indexToDelete]));
+        }
+    }
+
+    WriteAllVideoPlayers(cachedVideoPlayers);
+}
+
 CHIP_ERROR PersistenceManager::PurgeVideoPlayerCache()
 {
     ChipLogProgress(AppServer, "PersistenceManager::PurgeVideoPlayerCache called");