// Copyright Epic Games, Inc. All Rights Reserved.

#include "CrashReportClientApp.h"
#include "CrashReportClientDefines.h"
#include "Misc/Parse.h"
#include "Misc/CommandLine.h"
#include "Misc/QueuedThreadPool.h"
#include "Internationalization/Internationalization.h"
#include "Math/Vector2D.h"
#include "Misc/ConfigCacheIni.h"
#include "GenericPlatform/GenericApplication.h"
#include "Misc/App.h"
#include "CrashReportCoreConfig.h"
#include "GenericPlatform/GenericPlatformCrashContext.h"
#include "CrashDescription.h"
#include "CrashReportAnalytics.h"
#include "Modules/ModuleManager.h"
#include "HAL/PlatformApplicationMisc.h"
#include "HAL/PlatformCrashContext.h"
#include "IAnalyticsProviderET.h"
#include "XmlParser.h"

#if !CRASH_REPORT_UNATTENDED_ONLY
	#include "SCrashReportClient.h"
	#include "CrashReportClient.h"
	#include "CrashReportClientStyle.h"
#if !UE_BUILD_SHIPPING
	#include "ISlateReflectorModule.h"
#endif
	#include "Framework/Application/SlateApplication.h"
#endif // !CRASH_REPORT_UNATTENDED_ONLY

#include "CrashReportCoreUnattended.h"
#include "Async/TaskGraphInterfaces.h"
#include "RequiredProgramMainCPPInclude.h"

#include "MainLoopTiming.h"

#include "PlatformErrorReport.h"
#include "XmlFile.h"
#include "RecoveryService.h"

#if CRASH_REPORT_WITH_MTBF
#include "EditorAnalyticsSession.h"
#include "EditorSessionSummarySender.h"
#endif

class FRecoveryService;

/** Default main window size */
const FVector2D InitialWindowDimensions(740, 560);

/** Average tick rate the app aims for */
const float IdealTickRate = 30.f;

/** Set this to true in the code to open the widget reflector to debug the UI */
const bool RunWidgetReflector = false;

IMPLEMENT_APPLICATION(CrashReportClient, "CrashReportClient");
DEFINE_LOG_CATEGORY(CrashReportClientLog);

/** Directory containing the report */
static TArray<FString> FoundReportDirectoryAbsolutePaths;

/** Name of the game passed via the command line. */
static FString GameNameFromCmd;

/** GUID of the crash passed via the command line. */
static FString CrashGUIDFromCmd;

/** If we are implicitly sending its assumed we are also unattended for now */
static bool bImplicitSendFromCmd = false;
/** If we want to enable analytics */
static bool AnalyticsEnabledFromCmd = true;

/** If in monitor mode, watch this pid. */
static uint64 MonitorPid = 0;

/** If in monitor mode, pipe to read data from game. */
static void* MonitorReadPipe = nullptr;

/** If in monitor mode, pipe to write data to game. */
static void* MonitorWritePipe = nullptr;

/** Result of submission of report */
enum SubmitCrashReportResult {
	Failed,				// Failed to send report
	SuccessClosed,		// Succeeded sending report, user has not elected to relaunch
	SuccessRestarted,	// Succeeded sending report, user has elected to restart process
	SuccessContinue		// Succeeded sending report, continue running (if monitor mode).
};

/**
 * Look for the report to upload, either in the command line or in the platform's report queue
 */
void ParseCommandLine(const TCHAR* CommandLine)
{
	const TCHAR* CommandLineAfterExe = FCommandLine::RemoveExeName(CommandLine);

	FoundReportDirectoryAbsolutePaths.Empty();

	// Use the first argument if present and it's not a flag
	if (*CommandLineAfterExe)
	{
		TArray<FString> Switches;
		TArray<FString> Tokens;
		TMap<FString, FString> Params;
		{
			FString NextToken;
			while (FParse::Token(CommandLineAfterExe, NextToken, false))
			{
				if (**NextToken == TCHAR('-'))
				{
					new(Switches)FString(NextToken.Mid(1));
				}
				else
				{
					new(Tokens)FString(NextToken);
				}
			}

			for (int32 SwitchIdx = Switches.Num() - 1; SwitchIdx >= 0; --SwitchIdx)
			{
				FString& Switch = Switches[SwitchIdx];
				TArray<FString> SplitSwitch;
				if (2 == Switch.ParseIntoArray(SplitSwitch, TEXT("="), true))
				{
					Params.Add(SplitSwitch[0], SplitSwitch[1].TrimQuotes());
					Switches.RemoveAt(SwitchIdx);
				}
			}
		}

		if (Tokens.Num() > 0)
		{
			FoundReportDirectoryAbsolutePaths.Add(Tokens[0]);
		}

		GameNameFromCmd = Params.FindRef(TEXT("AppName"));

		CrashGUIDFromCmd = FString();
		if (Params.Contains(TEXT("CrashGUID")))
		{
			CrashGUIDFromCmd = Params.FindRef(TEXT("CrashGUID"));
		}
 
		if (Switches.Contains(TEXT("ImplicitSend")))
		{
			bImplicitSendFromCmd = true;
		}

		if (Switches.Contains(TEXT("NoAnalytics")))
		{
			AnalyticsEnabledFromCmd = false;
		}

		CrashGUIDFromCmd = Params.FindRef(TEXT("CrashGUID"));
		MonitorPid = FPlatformString::Atoi64(*Params.FindRef(TEXT("MONITOR")));
		MonitorReadPipe = (void*) FPlatformString::Atoi64(*Params.FindRef(TEXT("READ")));
		MonitorWritePipe = (void*) FPlatformString::Atoi64(*Params.FindRef(TEXT("WRITE")));
	}

	if (FoundReportDirectoryAbsolutePaths.Num() == 0)
	{
		FPlatformErrorReport::FindMostRecentErrorReports(FoundReportDirectoryAbsolutePaths, FTimespan::FromDays(30));  //FTimespan::FromMinutes(30));
	}
}

/**
 * Find the error report folder and check it matches the app name if provided
 */
FPlatformErrorReport LoadErrorReport()
{
	if (FoundReportDirectoryAbsolutePaths.Num() == 0)
	{
		UE_LOG(CrashReportClientLog, Warning, TEXT("No error report found"));
		return FPlatformErrorReport();
	}

	for (const FString& ReportDirectoryAbsolutePath : FoundReportDirectoryAbsolutePaths)
	{
		FPlatformErrorReport ErrorReport(ReportDirectoryAbsolutePath);

		FString Filename;
		// CrashContext.runtime-xml has the precedence over the WER
		if (ErrorReport.FindFirstReportFileWithExtension(Filename, FGenericCrashContext::CrashContextExtension))
		{
			FPrimaryCrashProperties::Set(new FCrashContext(ReportDirectoryAbsolutePath / Filename));
		}
		else if (ErrorReport.FindFirstReportFileWithExtension(Filename, TEXT(".xml")))
		{
			FPrimaryCrashProperties::Set(new FCrashWERContext(ReportDirectoryAbsolutePath / Filename));
		}
		else
		{
			continue;
		}

#if CRASH_REPORT_UNATTENDED_ONLY
		return ErrorReport;
#else
		bool NameMatch = false;
		if (GameNameFromCmd.IsEmpty() || GameNameFromCmd == FPrimaryCrashProperties::Get()->GameName)
		{
			NameMatch = true;
		}

		bool GUIDMatch = false;
		if (CrashGUIDFromCmd.IsEmpty() || CrashGUIDFromCmd == FPrimaryCrashProperties::Get()->CrashGUID)
		{
			GUIDMatch = true;
		}

		if (NameMatch && GUIDMatch)
		{
			FString ConfigFilename;
			if (ErrorReport.FindFirstReportFileWithExtension(ConfigFilename, FGenericCrashContext::CrashConfigExtension))
			{
				FConfigFile CrashConfigFile;
				CrashConfigFile.Read(ReportDirectoryAbsolutePath / ConfigFilename);
				FCrashReportCoreConfig::Get().SetProjectConfigOverrides(CrashConfigFile);
			}

			return ErrorReport;
		}
#endif
	}

	// Don't display or upload anything if we can't find the report we expected
	return FPlatformErrorReport();
}

static void OnRequestExit()
{
	RequestEngineExit(TEXT("OnRequestExit"));
}

#if !CRASH_REPORT_UNATTENDED_ONLY
SubmitCrashReportResult RunWithUI(FPlatformErrorReport ErrorReport)
{
	// create the platform slate application (what FSlateApplication::Get() returns)
	TSharedRef<FSlateApplication> Slate = FSlateApplication::Create(MakeShareable(FPlatformApplicationMisc::CreateApplication()));

	// initialize renderer
	TSharedRef<FSlateRenderer> SlateRenderer = GetStandardStandaloneRenderer();

	// Grab renderer initialization retry settings from ini
	int32 SlateRendererInitRetryCount = 10;
	GConfig->GetInt(TEXT("CrashReportClient"), TEXT("UIInitRetryCount"), SlateRendererInitRetryCount, GEngineIni);
	double SlateRendererInitRetryInterval = 2.0;
	GConfig->GetDouble(TEXT("CrashReportClient"), TEXT("UIInitRetryInterval"), SlateRendererInitRetryInterval, GEngineIni);

	// Try to initialize the renderer. It's possible that we launched when the driver crashed so try a few times before giving up.
	bool bRendererInitialized = false;
	bool bRendererFailedToInitializeAtLeastOnce = false;
	do 
	{
		SlateRendererInitRetryCount--;
		bRendererInitialized = FSlateApplication::Get().InitializeRenderer(SlateRenderer, true);
		if (!bRendererInitialized && SlateRendererInitRetryCount > 0)
		{
			bRendererFailedToInitializeAtLeastOnce = true;
			FPlatformProcess::Sleep(SlateRendererInitRetryInterval);
		}
	} while (!bRendererInitialized && SlateRendererInitRetryCount > 0);

	if (!bRendererInitialized)
	{
		// Close down the Slate application
		FSlateApplication::Shutdown();
		return Failed;
	}
	else if (bRendererFailedToInitializeAtLeastOnce)
	{
		// Wait until the driver is fully restored
		FPlatformProcess::Sleep(2.0f);

		// Update the display metrics
		FDisplayMetrics DisplayMetrics;
		FDisplayMetrics::RebuildDisplayMetrics(DisplayMetrics);
		FSlateApplication::Get().GetPlatformApplication()->OnDisplayMetricsChanged().Broadcast(DisplayMetrics);
	}

	// Set up the main ticker
	FMainLoopTiming MainLoop(IdealTickRate, EMainLoopOptions::UsingSlate);

	// set the normal UE4 IsEngineExitRequested() when outer frame is closed
	FSlateApplication::Get().SetExitRequestedHandler(FSimpleDelegate::CreateStatic(&OnRequestExit));

	// Prepare the custom Slate styles
	FCrashReportClientStyle::Initialize();

	// Create the main implementation object
	TSharedRef<FCrashReportClient> CrashReportClient = MakeShareable(new FCrashReportClient(ErrorReport));

	// open up the app window	
	TSharedRef<SCrashReportClient> ClientControl = SNew(SCrashReportClient, CrashReportClient);

	TSharedRef<SWindow> Window = FSlateApplication::Get().AddWindow(
		SNew(SWindow)
		.Title(NSLOCTEXT("CrashReportClient", "CrashReportClientAppName", "Unreal Engine 4 Crash Reporter"))
		.HasCloseButton(FCrashReportCoreConfig::Get().IsAllowedToCloseWithoutSending())
		.ClientSize(InitialWindowDimensions)
		[
			ClientControl
		]);

	Window->SetRequestDestroyWindowOverride(FRequestDestroyWindowOverride::CreateSP(CrashReportClient, &FCrashReportClient::RequestCloseWindow));

	// Setting focus seems to have to happen after the Window has been added
	FSlateApplication::Get().ClearKeyboardFocus(EFocusCause::Cleared);

#if !UE_BUILD_SHIPPING
	// Debugging code
	if (RunWidgetReflector)
	{
		FModuleManager::LoadModuleChecked<ISlateReflectorModule>("SlateReflector").DisplayWidgetReflector();
	}
#endif

	// Bring the window to the foreground as it may be behind the crashed process
	Window->HACK_ForceToFront();
	Window->BringToFront();

	// loop until the app is ready to quit
	while (!(IsEngineExitRequested() || CrashReportClient->IsUploadComplete()))
	{
		MainLoop.Tick();

		if (CrashReportClient->ShouldWindowBeHidden())
		{
			Window->HideWindow();
		}
	}

	// Make sure the window is hidden, because it might take a while for the background thread to finish.
	Window->HideWindow();

	// Stop the background thread
	CrashReportClient->StopBackgroundThread();

	// Clean up the custom styles
	FCrashReportClientStyle::Shutdown();

	// Close down the Slate application
	FSlateApplication::Shutdown();

	// Detect if ensure, if user has selected to restart or close.	
	return CrashReportClient->GetIsSuccesfullRestart() ? SuccessRestarted : (FPrimaryCrashProperties::Get()->bIsEnsure ? SuccessContinue : SuccessClosed);
}
#endif // !CRASH_REPORT_UNATTENDED_ONLY

// When we want to implicitly send and use unattended we still want to show a message box of a crash if possible
class FMessageBoxThread : public FRunnable
{
	virtual uint32 Run() override
	{
		// We will not have any GUI for the crash reporter if we are sending implicitly, so pop a message box up at least
		if (FApp::CanEverRender())
		{
			FPlatformMisc::MessageBoxExt(EAppMsgType::Ok,
				*NSLOCTEXT("MessageDialog", "ReportCrash_Body", "The application has crashed and will now close. We apologize for the inconvenience.").ToString(),
				*NSLOCTEXT("MessageDialog", "ReportCrash_Title", "Application Crash Detected").ToString());
		}

		return 0;
	}
};

SubmitCrashReportResult RunUnattended(FPlatformErrorReport ErrorReport, bool bImplicitSend)
{
	// Set up the main ticker
	FMainLoopTiming MainLoop(IdealTickRate, EMainLoopOptions::CoreTickerOnly);

	// In the unattended mode we don't send any PII.
	FCrashReportCoreUnattended CrashReportClient(ErrorReport);
	ErrorReport.SetUserComment(NSLOCTEXT("CrashReportClient", "UnattendedMode", "Sent in the unattended mode"));

	FMessageBoxThread MessageBox;
	FRunnableThread* MessageBoxThread = nullptr;

	if (bImplicitSend)
	{
		MessageBoxThread = FRunnableThread::Create(&MessageBox, TEXT("CrashReporter_MessageBox"));
	}

	// loop until the app is ready to quit
	while (!(IsEngineExitRequested() || CrashReportClient.IsUploadComplete()))
	{
		MainLoop.Tick();
	}

	if (bImplicitSend && MessageBoxThread)
	{
		MessageBoxThread->WaitForCompletion();
	}

	// Continue running in case of ensures, otherwise close
	return FPrimaryCrashProperties::Get()->bIsEnsure ? SuccessContinue : SuccessClosed;
}

FPlatformErrorReport CollectErrorReport(FRecoveryService* RecoveryService, uint32 Pid, const FSharedCrashContext& SharedCrashContext, void* WritePipe)
{
	// @note: This API is only partially implemented on Mac OS and Linux.
	FProcHandle ProcessHandle = FPlatformProcess::OpenProcess(Pid);

	// First init the static crash context state
	FPlatformCrashContext::InitializeFromContext(
		SharedCrashContext.SessionContext,
		SharedCrashContext.EnabledPluginsNum > 0 ? &SharedCrashContext.DynamicData[SharedCrashContext.EnabledPluginsOffset] : nullptr,
		SharedCrashContext.EngineDataNum > 0 ? &SharedCrashContext.DynamicData[SharedCrashContext.EngineDataOffset] : nullptr,
		SharedCrashContext.GameDataNum > 0 ? &SharedCrashContext.DynamicData[SharedCrashContext.GameDataOffset] : nullptr
	);
	// Next create a crash context for the crashed process.
	FPlatformCrashContext CrashContext(SharedCrashContext.CrashType, SharedCrashContext.ErrorMessage);
	CrashContext.SetCrashedProcess(ProcessHandle);
	CrashContext.SetCrashedThreadId(SharedCrashContext.CrashingThreadId);
	CrashContext.SetNumMinidumpFramesToIgnore(SharedCrashContext.NumStackFramesToIgnore);

	// Initialize the stack walking for the monitored process
	FPlatformStackWalk::InitStackWalkingForProcess(ProcessHandle);

	for (uint32 ThreadIdx = 0; ThreadIdx < SharedCrashContext.NumThreads; ThreadIdx++)
	{
		const uint32 ThreadId = SharedCrashContext.ThreadIds[ThreadIdx];
		uint64 StackFrames[CR_MAX_STACK_FRAMES] = {0};
		const uint32 StackFrameCount = FPlatformStackWalk::CaptureThreadStackBackTrace(
			ThreadId, 
			StackFrames,
			CR_MAX_STACK_FRAMES
		);

		CrashContext.AddPortableThreadCallStack(
			SharedCrashContext.ThreadIds[ThreadIdx],
			&SharedCrashContext.ThreadNames[ThreadIdx*CR_MAX_THREAD_NAME_CHARS],
			StackFrames,
			StackFrameCount
		);

		// Add the crashing stack specifically. Is this really needed?
		if (ThreadId == SharedCrashContext.CrashingThreadId)
		{
			CrashContext.SetPortableCallStack(
				StackFrames + SharedCrashContext.NumStackFramesToIgnore,
				StackFrameCount - SharedCrashContext.NumStackFramesToIgnore
			);
		}
	}

	// Setup the FPrimaryCrashProperties singleton. If the path is not set it is most likely
	// that we have crashed during static init, in which case we need to construct a directory
	// ourself.
	CrashContext.SerializeContentToBuffer();

	FString ReportDirectoryAbsolutePath(SharedCrashContext.CrashFilesDirectory);
	bool DirectoryExists = true;
	if (ReportDirectoryAbsolutePath.IsEmpty())
	{
		DirectoryExists = FGenericCrashContext::CreateCrashReportDirectory(
			SharedCrashContext.SessionContext.CrashGUIDRoot,
			0,
			ReportDirectoryAbsolutePath);
	}

	// Copy platform specific files (e.g. minidump) to output directory if it exists
	if (DirectoryExists)
	{
		CrashContext.CopyPlatformSpecificFiles(*ReportDirectoryAbsolutePath, SharedCrashContext.PlatformCrashContext);
	}

	// At this point the game can continue execution. It is important this happens
	// as soon as thread state and minidump has been created, so that ensures cause
	// as little hitch as possible.
	uint8 ResponseCode[] = { 0xd, 0xe, 0xa, 0xd };
	FPlatformProcess::WritePipe(WritePipe, ResponseCode, sizeof(ResponseCode));

	// Write out the XML file.
	const FString CrashContextXMLPath = FPaths::Combine(*ReportDirectoryAbsolutePath, FPlatformCrashContext::CrashContextRuntimeXMLNameW);
	CrashContext.SerializeAsXML(*CrashContextXMLPath);

#if CRASH_REPORT_WITH_RECOVERY
	if (RecoveryService && 
		DirectoryExists && 
		SharedCrashContext.UserSettings.bSendUsageData && 
		SharedCrashContext.CrashType != ECrashContextType::Ensure)
	{
		RecoveryService->CollectFiles(ReportDirectoryAbsolutePath);
	}
#endif

	const TCHAR* CrachContextBuffer = *CrashContext.GetBuffer();
	FPrimaryCrashProperties::Set(new FCrashContext(ReportDirectoryAbsolutePath / TEXT("CrashContext.runtime-xml"), CrachContextBuffer));

	FPlatformErrorReport ErrorReport(ReportDirectoryAbsolutePath);

#if CRASH_REPORT_UNATTENDED_ONLY
	return ErrorReport;
#else

	FString ConfigFilename;
	if (ErrorReport.FindFirstReportFileWithExtension(ConfigFilename, FGenericCrashContext::CrashConfigExtension))
	{
		FConfigFile CrashConfigFile;
		CrashConfigFile.Read(ReportDirectoryAbsolutePath / ConfigFilename);
		FCrashReportCoreConfig::Get().SetProjectConfigOverrides(CrashConfigFile);
	}

	return ErrorReport;
#endif
}

SubmitCrashReportResult SendErrorReport(FPlatformErrorReport& ErrorReport, 
	TOptional<bool> bNoDialogOpt = TOptional<bool>(), 
	TOptional<bool> bImplicitSendOpt = TOptional<bool>())
{
	if (!IsEngineExitRequested() && ErrorReport.HasFilesToUpload() && FPrimaryCrashProperties::Get() != nullptr)
	{
		const bool bImplicitSend = bImplicitSendOpt.Get(false);
		const bool bUnattended =
#if CRASH_REPORT_UNATTENDED_ONLY
			true;
#else
			bNoDialogOpt.Get(FApp::IsUnattended()) || bImplicitSend;
#endif // CRASH_REPORT_UNATTENDED_ONLY

		ErrorReport.SetCrashReportClientVersion(FCrashReportCoreConfig::Get().GetVersion());

		if (bUnattended)
		{
			return RunUnattended(ErrorReport, bImplicitSend);
		}
#if !CRASH_REPORT_UNATTENDED_ONLY
		else
		{
			const SubmitCrashReportResult Result = RunWithUI(ErrorReport);
			if (Result == Failed)
			{
				// UI failed to initialize, probably due to driver crash. Send in unattended mode if allowed.
				bool bCanSendWhenUIFailedToInitialize = true;
				GConfig->GetBool(TEXT("CrashReportClient"), TEXT("CanSendWhenUIFailedToInitialize"), bCanSendWhenUIFailedToInitialize, GEngineIni);
				if (bCanSendWhenUIFailedToInitialize && !FCrashReportCoreConfig::Get().IsAllowedToCloseWithoutSending())
				{
					return RunUnattended(ErrorReport, bImplicitSend);
				}
			}
			return Result;
		}
#endif // !CRASH_REPORT_UNATTENDED_ONLY

	}
	return Failed;
}

bool IsCrashReportAvailable(uint32 WatchedProcess, FSharedCrashContext& CrashContext, void* ReadPipe)
{
	static TArray<uint8> Buffer;
	Buffer.Reserve(8 * 1024); // This allocates only once because Buffer is static.

	if (FPlatformProcess::ReadPipeToArray(ReadPipe, Buffer))
	{
		FPlatformMemory::Memcpy(&CrashContext, Buffer.GetData(), Buffer.Num());
		return true;
	}
	return false;
}

static void DeleteTempCrashContextFile(uint64 ProcessID)
{
	const FString SessionContextFile = FGenericCrashContext::GetTempSessionContextFilePath(ProcessID);
	FPlatformFileManager::Get().GetPlatformFile().DeleteFile(*SessionContextFile);
}

#if CRASH_REPORT_WITH_MTBF

template <typename Type>
bool FindAndParseValue(const TMap<FString, FString>& Map, const FString& Key, Type& OutValue)
{
	const FString* ValueString = Map.Find(Key);
	if (ValueString != nullptr)
	{
		TTypeFromString<Type>::FromString(OutValue, **ValueString);
		return true;
	}

	return false;
}

template <size_t Size>
bool FindAndCopyValue(const TMap<FString, FString>& Map, const FString& Key, TCHAR (&OutValue)[Size])
{
	const FString* ValueString = Map.Find(Key);
	if (ValueString != nullptr)
	{
		FCString::Strncpy(OutValue, **ValueString, Size);
		return true;
	}

	return false;
}

static bool LoadTempCrashContextFromFile(FSharedCrashContext& CrashContext, uint64 ProcessID)
{
	const FString TempContextFilePath = FGenericCrashContext::GetTempSessionContextFilePath(ProcessID);

	FXmlFile File;
	if (!File.LoadFile(TempContextFilePath))
	{
		return false;
	}

	TMap<FString, FString> ContextProperties;
	for (FXmlNode* Node : File.GetRootNode()->GetChildrenNodes())
	{
		ContextProperties.Add(Node->GetTag(), Node->GetContent());
	}

	FSessionContext& SessionContext = CrashContext.SessionContext;

	FindAndParseValue(ContextProperties, TEXT("SecondsSinceStart"), SessionContext.SecondsSinceStart);
	FindAndParseValue(ContextProperties, TEXT("IsInternalBuild"), SessionContext.bIsInternalBuild);
	FindAndParseValue(ContextProperties, TEXT("IsPerforceBuild"), SessionContext.bIsPerforceBuild);
	FindAndParseValue(ContextProperties, TEXT("IsSourceDistribution"), SessionContext.bIsSourceDistribution);
	FindAndCopyValue(ContextProperties, TEXT("GameName"), SessionContext.GameName);
	FindAndCopyValue(ContextProperties, TEXT("ExecutableName"), SessionContext.ExecutableName);
	FindAndCopyValue(ContextProperties, TEXT("GameSessionID"), SessionContext.GameSessionID);
	FindAndCopyValue(ContextProperties, TEXT("EngineMode"), SessionContext.EngineMode);
	FindAndCopyValue(ContextProperties, TEXT("EngineModeEx"), SessionContext.EngineModeEx);
	FindAndCopyValue(ContextProperties, TEXT("DeploymentName"), SessionContext.DeploymentName);
	FindAndCopyValue(ContextProperties, TEXT("CommandLine"), SessionContext.CommandLine);
	FindAndParseValue(ContextProperties, TEXT("LanguageLCID"), SessionContext.LanguageLCID);
	FindAndCopyValue(ContextProperties, TEXT("AppDefaultLocale"), SessionContext.DefaultLocale);
	FindAndParseValue(ContextProperties, TEXT("IsUE4Release"), SessionContext.bIsUE4Release);
	FindAndCopyValue(ContextProperties, TEXT("UserName"), SessionContext.UserName);
	FindAndCopyValue(ContextProperties, TEXT("BaseDir"), SessionContext.BaseDir);
	FindAndCopyValue(ContextProperties, TEXT("RootDir"), SessionContext.RootDir);
	FindAndCopyValue(ContextProperties, TEXT("LoginId"), SessionContext.LoginIdStr);
	FindAndCopyValue(ContextProperties, TEXT("EpicAccountId"), SessionContext.EpicAccountId);
	FindAndCopyValue(ContextProperties, TEXT("UserActivityHint"), SessionContext.UserActivityHint);
	FindAndParseValue(ContextProperties, TEXT("CrashDumpMode"), SessionContext.CrashDumpMode);
	FindAndCopyValue(ContextProperties, TEXT("GameStateName"), SessionContext.GameStateName);
	FindAndParseValue(ContextProperties, TEXT("Misc.NumberOfCores"), SessionContext.NumberOfCores);
	FindAndParseValue(ContextProperties, TEXT("Misc.NumberOfCoresIncludingHyperthreads"), SessionContext.NumberOfCoresIncludingHyperthreads);
	FindAndCopyValue(ContextProperties, TEXT("Misc.CPUVendor"), SessionContext.CPUVendor);
	FindAndCopyValue(ContextProperties, TEXT("Misc.CPUBrand"), SessionContext.CPUBrand);
	FindAndCopyValue(ContextProperties, TEXT("Misc.PrimaryGPUBrand"), SessionContext.PrimaryGPUBrand);
	FindAndCopyValue(ContextProperties, TEXT("Misc.OSVersionMajor"), SessionContext.OsVersion);
	FindAndCopyValue(ContextProperties, TEXT("Misc.OSVersionMinor"), SessionContext.OsSubVersion);
	FindAndParseValue(ContextProperties, TEXT("MemoryStats.AvailablePhysical"), SessionContext.MemoryStats.AvailablePhysical);
	FindAndParseValue(ContextProperties, TEXT("MemoryStats.AvailableVirtual"), SessionContext.MemoryStats.AvailableVirtual);
	FindAndParseValue(ContextProperties, TEXT("MemoryStats.UsedPhysical"), SessionContext.MemoryStats.UsedPhysical);
	FindAndParseValue(ContextProperties, TEXT("MemoryStats.PeakUsedPhysical"), SessionContext.MemoryStats.PeakUsedPhysical);
	FindAndParseValue(ContextProperties, TEXT("MemoryStats.UsedVirtual"), SessionContext.MemoryStats.UsedVirtual);
	FindAndParseValue(ContextProperties, TEXT("MemoryStats.PeakUsedVirtual"), SessionContext.MemoryStats.PeakUsedVirtual);
	FindAndParseValue(ContextProperties, TEXT("MemoryStats.bIsOOM"), SessionContext.bIsOOM);
	FindAndParseValue(ContextProperties, TEXT("MemoryStats.OOMAllocationSize"), SessionContext.OOMAllocationSize);
	FindAndParseValue(ContextProperties, TEXT("MemoryStats.OOMAllocationAlignment"), SessionContext.OOMAllocationAlignment);

	// user settings
	FUserSettingsContext& UserSettings = CrashContext.UserSettings;

	FindAndParseValue(ContextProperties, TEXT("NoDialog"), UserSettings.bNoDialog);
	FindAndParseValue(ContextProperties, TEXT("SendUnattendedBugReports"), UserSettings.bSendUnattendedBugReports);
	FindAndParseValue(ContextProperties, TEXT("SendUsageData"), UserSettings.bSendUsageData);
	FindAndCopyValue(ContextProperties, TEXT("LogFilePath"), UserSettings.LogFilePath);

	return true;
}

static void HandleAbnormalShutdown(FSharedCrashContext& CrashContext, uint64 ProcessID, void* WritePipe, const TSharedPtr<FRecoveryService>& RecoveryService)
{
	CrashContext.CrashType = ECrashContextType::AbnormalShutdown;

	IPlatformFile& PlatformFile = FPlatformFileManager::Get().GetPlatformFile();

	// create a temporary crash directory
	const FString TempCrashDirectory = FPlatformProcess::UserTempDir() / FString::Printf(TEXT("UECrashContext-%d"), ProcessID);
	FCString::Strcpy(CrashContext.CrashFilesDirectory, *TempCrashDirectory);

	if (PlatformFile.CreateDirectory(CrashContext.CrashFilesDirectory))
	{
		// copy the log file to the temporary directory
		const FString LogDestination = TempCrashDirectory / FPaths::GetCleanFilename(CrashContext.UserSettings.LogFilePath);
		PlatformFile.CopyFile(*LogDestination, CrashContext.UserSettings.LogFilePath);

		FPlatformErrorReport ErrorReport = CollectErrorReport(RecoveryService.Get(), ProcessID, CrashContext, WritePipe);
		SubmitCrashReportResult Result = SendErrorReport(ErrorReport, /*bNoDialog*/ true);

		// delete the temporary directory
		PlatformFile.DeleteDirectoryRecursively(*TempCrashDirectory);

		if (CrashContext.UserSettings.bSendUsageData)
		{
			// If analytics is enabled make sure they are submitted now.
			FCrashReportAnalytics::GetProvider().BlockUntilFlushed(5.0f);
		}
	}
}

static bool WasAbnormalShutdown(const FEditorSessionSummarySender& SessionSummarySender)
{
	FEditorAnalyticsSession AnalyticsSession;
	if (SessionSummarySender.FindCurrentSession(AnalyticsSession))
	{
		// check if this was an abnormal shutdown (aka. none of the known shutdown types, and not debugged)
		if (AnalyticsSession.bCrashed == false &&
			AnalyticsSession.bGPUCrashed == false &&
			AnalyticsSession.bWasShutdown == false &&
			AnalyticsSession.bIsTerminating == false &&
			AnalyticsSession.bWasEverDebugger == false)
		{
			return true;
		}
	}

	return false;
}

#endif 

void RunCrashReportClient(const TCHAR* CommandLine)
{
	// Override the stack size for the thread pool.
	FQueuedThreadPool::OverrideStackSize = 256 * 1024;

	// Increase the HttpSendTimeout to 5 minutes
	GConfig->SetFloat(TEXT("HTTP"), TEXT("HttpSendTimeout"), 5 * 60.0f, GEngineIni);

	// Initialize the engine. -Messaging enables MessageBus transports required by Concert (Recovery Service).
	FString FinalCommandLine(CommandLine);
#if CRASH_REPORT_WITH_RECOVERY
	FinalCommandLine += TEXT(" -Messaging -EnablePlugins=\"UdpMessaging,ConcertSyncServer\"");
#endif
	GEngineLoop.PreInit(*FinalCommandLine);
	check(GConfig && GConfig->IsReadyForUse());

	// Make sure all UObject classes are registered and default properties have been initialized
	ProcessNewlyLoadedUObjects();

	// Tell the module manager is may now process newly-loaded UObjects when new C++ modules are loaded
	FModuleManager::Get().StartProcessingNewlyLoadedObjects();

	// Load internal Concert plugins in the pre-default phase
	IPluginManager::Get().LoadModulesForEnabledPlugins(ELoadingPhase::PreDefault);

	// Load Concert Sync plugins in default phase
	IPluginManager::Get().LoadModulesForEnabledPlugins(ELoadingPhase::Default);

	// Initialize config.
	FCrashReportCoreConfig::Get();

	// Find the report to upload in the command line arguments
	ParseCommandLine(CommandLine);

	FPlatformErrorReport::Init();

	if (MonitorPid == 0) // Does not monitor any process.
	{
		if (AnalyticsEnabledFromCmd)
		{
			FCrashReportAnalytics::Initialize();
		}

		// Load error report generated by the process from disk
		FPlatformErrorReport ErrorReport = LoadErrorReport();
		const SubmitCrashReportResult Result = SendErrorReport(ErrorReport, FApp::IsUnattended(), bImplicitSendFromCmd);
		// We are not interested in the result of this

		if (AnalyticsEnabledFromCmd)
		{
			FCrashReportAnalytics::Shutdown();
		}
	}
	else // Launched in 'service mode - watches/serves a process'
	{
		const int32 IdealFramerate = 30;
		double LastTime = FPlatformTime::Seconds();
		const float IdealFrameTime = 1.0f / IdealFramerate;

		TSharedPtr<FRecoveryService> RecoveryServicePtr; // Note: Shared rather than Unique due to FRecoveryService only being a forward declaration in some builds
#if CRASH_REPORT_WITH_RECOVERY
		// Starts the disaster recovery service. This records transactions and allows users to recover from previous crashes.
		RecoveryServicePtr = MakeShared<FRecoveryService>(MonitorPid);
#endif

		FProcHandle MonitoredProcess = FPlatformProcess::OpenProcess(MonitorPid);
		if (!MonitoredProcess.IsValid())
		{
			UE_LOG(CrashReportClientLog, Error, TEXT("Failed to open monitor process handle!"));
		}

		auto GetProcessStatus = [](FProcHandle& ProcessHandle) -> TTuple<bool/*Running*/, TOptional<int32>/*ReturnCode*/>
		{
			bool bRunning = true;
			TOptional<int32> ProcessReturnCodeOpt; // Unknown by default.
			if (!ProcessHandle.IsValid())
			{
				bRunning = false;
			}
			else if (!FPlatformProcess::IsProcRunning(ProcessHandle))
			{
				bRunning = false;
				int32 ProcessReturnCode = 0;
				if (FPlatformProcess::GetProcReturnCode(ProcessHandle, &ProcessReturnCode)) // Is the return code available? (Not supported on all platforms)
				{
					ProcessReturnCodeOpt.Emplace(ProcessReturnCode);
				}
			}

			return MakeTuple(bRunning, ProcessReturnCodeOpt);
		};

		// This GetProcessStatus() call is expensive, perform it at low frequency.
		TTuple<bool/*bRunning*/, TOptional<int32>/*ExitCode*/> ProcessStatus = GetProcessStatus(MonitoredProcess);
		while (ProcessStatus.Get<0>() && !IsEngineExitRequested())
		{
			const double CurrentTime = FPlatformTime::Seconds();

			// If 'out-of-process' crash reporting was enabled.
			if (MonitorWritePipe && MonitorReadPipe)
			{
				// Check if the monitored process signaled a crash or an ensure.
				FSharedCrashContext CrashContext;
				if (IsCrashReportAvailable(MonitorPid, CrashContext, MonitorReadPipe))
				{
					const bool bReportCrashAnalyticInfo = CrashContext.UserSettings.bSendUsageData;
					if (bReportCrashAnalyticInfo)
					{
						FCrashReportAnalytics::Initialize();
					}

					// Build error report in memory.
					FPlatformErrorReport ErrorReport = CollectErrorReport(RecoveryServicePtr.Get(), MonitorPid, CrashContext, MonitorWritePipe);

#if CRASH_REPORT_WITH_RECOVERY
					if (RecoveryServicePtr && !FPrimaryCrashProperties::Get()->bIsEnsure)
					{
						// Shutdown the recovery service, releasing the recovery database file lock (not sharable) as soon as possible to let a new instance take it and offer the user to recover.
						RecoveryServicePtr.Reset();
					}
#endif

					const bool bNoDialog = (CrashContext.UserSettings.bNoDialog || CrashContext.UserSettings.bImplicitSend) && CrashContext.UserSettings.bSendUnattendedBugReports;
					const SubmitCrashReportResult Result = SendErrorReport(ErrorReport, bNoDialog, CrashContext.UserSettings.bImplicitSend);

					if (bReportCrashAnalyticInfo)
					{
						// If analytics is enabled make sure they are submitted now.
						FCrashReportAnalytics::GetProvider().BlockUntilFlushed(5.0f);
						FCrashReportAnalytics::Shutdown();
					}
				}
			}

			FTaskGraphInterface::Get().ProcessThreadUntilIdle(ENamedThreads::GameThread);

			// Pump & Tick objects
			const double DeltaTime = CurrentTime - LastTime;
			FTicker::GetCoreTicker().Tick(DeltaTime);

			GFrameCounter++;
			FStats::AdvanceFrame(false);
			GLog->FlushThreadedLogs();

			// Run garbage collection for the UObjects for the rest of the frame or at least to 2 ms
			IncrementalPurgeGarbage(true, FMath::Max<float>(0.002f, IdealFrameTime - (FPlatformTime::Seconds() - LastTime)));

			// Throttle main thread main fps by sleeping if we still have time
			FPlatformProcess::Sleep(FMath::Max<float>(0.0f, IdealFrameTime - (FPlatformTime::Seconds() - LastTime)));

			// Check if the application is alive about every second. (This is an expensive call)
			if (GFrameCounter % IdealFramerate == 0)
			{
				ProcessStatus = GetProcessStatus(MonitoredProcess);
			}

			LastTime = CurrentTime;
		}

#if CRASH_REPORT_WITH_MTBF
		{
			// The loop above can exit before the Editor (monitored process) exits (because of IsEngineExitRequested()) if the user clicks 'Close Without Sending' very quickly, but for MTBF,
			// it is desirable to have the Editor process return code. Give some extra time to the Editor to exit. If it doesn't exit within 60 seconds the next CRC instance will sent the
			// current analytic report delayed, not ideal, but supported.
			float WaitTimeSeconds = 0;
			while (ProcessStatus.Get<0>() && WaitTimeSeconds < 60.f)
			{
				FPlatformProcess::Sleep(0.1f);
				WaitTimeSeconds += 0.1f;
				ProcessStatus = GetProcessStatus(MonitoredProcess);
			}

			// load our temporary crash context file
			FSharedCrashContext TempCrashContext;
			FMemory::Memzero(TempCrashContext);
			if (LoadTempCrashContextFromFile(TempCrashContext, MonitorPid))
			{
				TempCrashContext.SessionContext.ProcessId = MonitorPid;

				if (TempCrashContext.UserSettings.bSendUsageData)
				{
					// Query this again, as the crash reporting loop above may have exited before setting this information (via IsEngineExitRequested)
					ProcessStatus = GetProcessStatus(MonitoredProcess);
					if (!ProcessStatus.Get<0>()) // Process is 'not running' anymore?
					{
						FCrashReportAnalytics::Initialize();

						if (FCrashReportAnalytics::IsAvailable())
						{
							// initialize analytics
							TUniquePtr<FEditorSessionSummarySender> EditorSessionSummarySender = MakeUnique<FEditorSessionSummarySender>(FCrashReportAnalytics::GetProvider(), TEXT("CrashReportClient"), MonitorPid);
							TOptional<int32> ExitCodeOpt = ProcessStatus.Get<1>();
							if (ExitCodeOpt.IsSet()) // Is it known?
							{
								EditorSessionSummarySender->SetCurrentSessionExitCode(MonitorPid, ExitCodeOpt.GetValue());
							}

							if (TempCrashContext.UserSettings.bSendUnattendedBugReports)
							{
								// Send a spoofed crash report in the case that we detect an abnormal shutdown has occurred
								if (WasAbnormalShutdown(*EditorSessionSummarySender.Get()))
								{
									HandleAbnormalShutdown(TempCrashContext, MonitorPid, MonitorWritePipe, RecoveryServicePtr);
								}
							}

							// send analytics and shutdown
							EditorSessionSummarySender->Shutdown();
						}

						FCrashReportAnalytics::Shutdown();
					}
				}
			}
		}
#endif
		// clean up the context file
		DeleteTempCrashContextFile(MonitorPid);

		FPlatformProcess::CloseProc(MonitoredProcess);
	}

	FPrimaryCrashProperties::Shutdown();
	FPlatformErrorReport::ShutDown();

	RequestEngineExit(TEXT("CrashReportClientApp RequestExit"));

	// Allow the game thread to finish processing any latent tasks.
	FTaskGraphInterface::Get().ProcessThreadUntilIdle(ENamedThreads::GameThread);

	FEngineLoop::AppPreExit();
	FModuleManager::Get().UnloadModulesAtShutdown();
	FTaskGraphInterface::Shutdown();

	FEngineLoop::AppExit();
}