// Copyright 1998-2019 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"
	#include "ISlateReflectorModule.h"
	#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);

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

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

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

	if (bImplicitSendFromCmd && 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> bNoDialog = TOptional<bool>())
{
	if (!IsEngineExitRequested() && ErrorReport.HasFilesToUpload() && FPrimaryCrashProperties::Get() != nullptr)
	{
		const bool bUnattended =
#if CRASH_REPORT_UNATTENDED_ONLY
			true;
#else
			bNoDialog.IsSet() ? bNoDialog.GetValue() : FApp::IsUnattended();
#endif // CRASH_REPORT_UNATTENDED_ONLY

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

		if (bUnattended)
		{
			return RunUnattended(ErrorReport);
		}
#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);
				}
			}
			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);
		// 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 IsMonitoredProcessAlive = [&MonitoredProcess](int32& OutReturnCode) -> bool
		{
			// The monitored process is considered "alive" if the process is running, and no return code has been set
			return MonitoredProcess.IsValid() && FPlatformProcess::IsProcRunning(MonitoredProcess) && !FPlatformProcess::GetProcReturnCode(MonitoredProcess, &OutReturnCode);
		};

		// Keep track of whether we've initialized the analytics system
		bool bInitializedAnalytics = false;

		// This IsApplicationAlive() call is quite expensive, perform it at low frequency.
		int32 ApplicationReturnCode = 0;
		bool bApplicationAlive = IsMonitoredProcessAlive(ApplicationReturnCode);
		while (bApplicationAlive && !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();
						bInitializedAnalytics = true;
					}

					// 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.bSendUnattendedBugReports;
					const SubmitCrashReportResult Result = SendErrorReport(ErrorReport, bNoDialog);

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

			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)
			{
				bApplicationAlive = IsMonitoredProcessAlive(ApplicationReturnCode);
			}

			LastTime = CurrentTime;
		}

#if CRASH_REPORT_WITH_MTBF
		{
			// 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)
					bApplicationAlive = IsMonitoredProcessAlive(ApplicationReturnCode);
					if (!bApplicationAlive)
					{
						if (!FCrashReportAnalytics::IsAvailable())
						{
							FCrashReportAnalytics::Initialize();
						}

						// initialize analytics
						TUniquePtr<FEditorSessionSummarySender> EditorSessionSummarySender = MakeUnique<FEditorSessionSummarySender>(FCrashReportAnalytics::GetProvider(), TEXT("CrashReportClient"), MonitorPid);
						EditorSessionSummarySender->SetCurrentSessionExitCode(MonitorPid, ApplicationReturnCode);

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

		FPlatformProcess::CloseProc(MonitoredProcess);

		if (bInitializedAnalytics)
		{
			FCrashReportAnalytics::Shutdown();
			bInitializedAnalytics = false;
		}
	}

	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();
}