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

#include "UnrealVirtualizationToolApp.h"

#include "GenericPlatform/GenericPlatformOutputDevices.h"
#include "HAL/FeedbackContextAnsi.h"
#include "HAL/FileManager.h"
#include "Interfaces/IPluginManager.h"
#include "ISourceControlModule.h"
#include "ISourceControlProvider.h"
#include "Misc/CommandLine.h"
#include "Misc/ConfigCacheIni.h"
#include "Misc/FileHelper.h"
#include "Misc/Parse.h"
#include "Misc/Paths.h"
#include "Misc/PathViews.h"
#include "SourceControlInitSettings.h"
#include "SourceControlOperations.h"
#include "UnrealVirtualizationTool.h"
#include "Virtualization/VirtualizationSystem.h"

namespace UE::Virtualization
{

namespace
{

/** Utility for testing if a file path resolves to a valid package file or not */
bool IsPackageFile(const FString FilePath)
{
	// ::IsPackageExtension requires a TCHAR so we cannot use FPathViews here
	const FString Extension = FPaths::GetExtension(FilePath);

	// Currently we don't virtualize text based assets so no call to FPackageName::IsTextPackageExtension
	return FPackageName::IsPackageExtension(*Extension);
}

/** Utility to find the two string values we need for a mount point based on the project file path */
void ConvertToMountPoint(const FString& ProjectFilePath, FString& OutRootPath, FString& OutContentPath)
{
	FStringView BaseFilename = FPathViews::GetBaseFilename(ProjectFilePath);

	OutRootPath = *WriteToString<260>(TEXT("/"), BaseFilename, TEXT("/"));
	OutContentPath = FPaths::GetPath(ProjectFilePath) / TEXT("Content");
}

/** 
 * Utility to clean up the tags we got from the virtualization system. Convert the FText to FString and
 * discard any duplicate entries. 
 */
TArray<FString> BuildFinalTagDescriptions(TArray<FText>& DescriptionTags)
{
	TArray<FString> CleanedDescriptions;
	CleanedDescriptions.Reserve(DescriptionTags.Num());

	for (const FText& Tag : DescriptionTags)
	{
		CleanedDescriptions.AddUnique(Tag.ToString());
	}

	return CleanedDescriptions;
}

/** 
 * Utility taken from UGameFeatureData::ReloadConfigs that allows us to apply changes to the ini files (after
 * loading them from game feature plugins for example) and have the changes applied to UObjects.
 * For our use case we need this so that optin/optout settings for UVirtualizationFilterSettings are applied.
 * 
 * This is required because we perform filtering at payload submission time. If we change filtering to be 
 * applied when a package is saved (i.e. when the package trailer is created) then we can remove this.
 * If we opt to keep the current strategy then this code should be moved to a location where it can be shared
 * by both this tool and the game feature plugin system rather than maintaining two copies.
 */
void ReloadConfigs(FConfigFile& PluginConfig)
{
	// Reload configs so objects get the changes
	for (const auto& ConfigEntry : PluginConfig)
	{
		// Skip out if someone put a config section in the INI without any actual data
		if (ConfigEntry.Value.Num() == 0)
		{
			continue;
		}

		const FString& SectionName = ConfigEntry.Key;

		// @todo: This entire overarching process is very similar in its goals as that of UOnlineHotfixManager::HotfixIniFile.
		// Could consider a combined refactor of the hotfix manager, the base config cache system, etc. to expose an easier way to support this pattern

		// INI files might be handling per-object config items, so need to handle them specifically
		const int32 PerObjConfigDelimIdx = SectionName.Find(" ");
		if (PerObjConfigDelimIdx != INDEX_NONE)
		{
			const FString ObjectName = SectionName.Left(PerObjConfigDelimIdx);
			const FString ClassName = SectionName.Mid(PerObjConfigDelimIdx + 1);

			// Try to find the class specified by the per-object config
			UClass* ObjClass = FindObject<UClass>(ANY_PACKAGE, *ClassName);
			if (ObjClass)
			{
				// Now try to actually find the object it's referencing specifically and update it
				// @note: Choosing not to warn on not finding it for now, as Fortnite has transient uses instantiated at run-time (might not be constructed yet)
				UObject* PerObjConfigObj = StaticFindObject(ObjClass, ANY_PACKAGE, *ObjectName, true);
				if (PerObjConfigObj)
				{
					// Intentionally using LoadConfig instead of ReloadConfig, since we do not want to call modify/preeditchange/posteditchange on the objects changed when GIsEditor
					PerObjConfigObj->LoadConfig(nullptr, nullptr, UE::LCPF_ReloadingConfigData | UE::LCPF_ReadParentSections, nullptr);
				}
			}
			else
			{
				PLATFORM_BREAK();
				//	UE_LOG(LogGameFeatures, Warning, TEXT("[GameFeatureData %s]: Couldn't find PerObjectConfig class %s for %s while processing %s, config changes won't be reloaded."), *GetPathNameSafe(this), *ClassName, *ObjectName, *PluginConfig.Name.ToString());
			}
		}
		// Standard INI section case
		else
		{
			// Find the affected class and push updates to all instances of it, including children
			// @note:	Intentionally not using the propagation flags inherent in ReloadConfig to handle this, as it utilizes a naive complete object iterator
			//			and tanks performance pretty badly
			UClass* ObjClass = FindObjectSafe<UClass>(ANY_PACKAGE, *SectionName, true);
			if (ObjClass)
			{
				TArray<UObject*> FoundObjects;
				GetObjectsOfClass(ObjClass, FoundObjects, true, RF_NoFlags);
				for (UObject* CurFoundObj : FoundObjects)
				{
					if (IsValid(CurFoundObj))
					{
						// Intentionally using LoadConfig instead of ReloadConfig, since we do not want to call modify/preeditchange/posteditchange on the objects changed when GIsEditor
						CurFoundObj->LoadConfig(nullptr, nullptr, UE::LCPF_ReloadingConfigData | UE::LCPF_ReadParentSections, nullptr);
					}
				}
			}
		}
	}
}

/** Utility to get EMode from a string */
void LexFromString(EMode& OutValue, const FStringView& InString)
{
	if (InString == TEXT("Changelist"))
	{
		OutValue = EMode::Changelist;
	}
	else if (InString == TEXT("PackageList"))
	{
		OutValue = EMode::PackageList;
	}
	else
	{
		OutValue = EMode::Unknown;
	}
}

/** 
 * This class can be used to prevent log messages from other systems being logged with the Display verbosity.
 * In practical terms this means as long as the class is alive, only LogVirtualizationTool messages will
 * be logged to the display meaning the user will have less information to deal with.
 */
class FOverrideOutputDevice final : public FFeedbackContextAnsi
{
public:
	FOverrideOutputDevice()
	{
		OriginalLog = GWarn;
		GWarn = this;
	}

	virtual ~FOverrideOutputDevice()
	{
		GWarn = OriginalLog;
	}

	virtual void Serialize(const TCHAR* V, ELogVerbosity::Type Verbosity, const class FName& Category) override
	{
		if (Verbosity == ELogVerbosity::Display && Category != LogVirtualizationTool.GetCategoryName())
		{
			Verbosity = ELogVerbosity::Log;
		}

		FFeedbackContextAnsi::Serialize(V, Verbosity, Category);
	}

private: 
	FFeedbackContext* OriginalLog;
};

} // namespace

FUnrealVirtualizationToolApp::FUnrealVirtualizationToolApp()
{

}

FUnrealVirtualizationToolApp::~FUnrealVirtualizationToolApp()
{

}

EInitResult FUnrealVirtualizationToolApp::Initialize()
{
	TRACE_CPUPROFILER_EVENT_SCOPE(Initialize);

	UE_LOG(LogVirtualizationTool, Display, TEXT("Initializing..."));

	// Display the log path to the user so that they can more easily find it
	// Note that ::GetAbsoluteLogFilename does not always return an absolute filename
	FString LogFilePath = FGenericPlatformOutputDevices::GetAbsoluteLogFilename();
	LogFilePath = IFileManager::Get().ConvertToAbsolutePathForExternalAppForRead(*LogFilePath);

	UE_LOG(LogVirtualizationTool, Display, TEXT("Logging process to '%s'"), *LogFilePath);

	EInitResult CmdLineResult = TryParseCmdLine();
	if (CmdLineResult != EInitResult::Success)
	{
		return CmdLineResult;
	}

	if (!TryLoadModules())
	{
		return EInitResult::Error;
	}

	if (!TryInitEnginePlugins())
	{
		return EInitResult::Error;
	}

	TArray<FString> Packages;
	switch (Mode)
	{
		case EMode::Changelist:
			if (!TryParseChangelist(Packages))
			{
				return EInitResult::Error;
			}
			break;

		case EMode::PackageList:
			if (!TryParsePackageList(Packages))
			{
				return EInitResult::Error;
			}
			break;

		default:
			UE_LOG(LogVirtualizationTool, Display, TEXT("Unknown mode, cannot find packages!"));
			return EInitResult::Error;
			break;
	}

	if (!TrySortFilesByProject(Packages))
	{
		return EInitResult::Error;
	}

	UE_LOG(LogVirtualizationTool, Display, TEXT("Initialization complete!"));

	return EInitResult::Success;
}

bool FUnrealVirtualizationToolApp::Run()
{
	TRACE_CPUPROFILER_EVENT_SCOPE(Run);

	TArray<FString> FinalDescriptionTags;

	if (EnumHasAllFlags(ProcessOptions, EProcessOptions::Virtualize))
	{
		UE_LOG(LogVirtualizationTool, Display, TEXT("Running the virtualization process..."));

		TArray<FText> DescriptionTags;

		for (const FProject& Project : Projects)
		{
			TStringBuilder<128> ProjectName;
			ProjectName  << Project.GetProjectName();

			UE_LOG(LogVirtualizationTool, Display, TEXT("\tChecking package(s) for the project '%s'..."), ProjectName.ToString());

			FConfigFile EngineConfigWithProject;
			if (!Project.TryLoadConfig(EngineConfigWithProject))
			{
				return false;
			}

			Project.RegisterMountPoints();

			UE::Virtualization::FInitParams InitParams(ProjectName, EngineConfigWithProject);
			UE::Virtualization::Initialize(InitParams);

			TArray<FString> Packages = Project.GetAllPackages();

			TArray<FText> Errors;
			UE::Virtualization::IVirtualizationSystem::Get().TryVirtualizePackages(Packages, DescriptionTags, Errors);

			if (!Errors.IsEmpty())
			{
				UE_LOG(LogVirtualizationTool, Error, TEXT("The virtualization process failed with the following errors:"));
				for (const FText& Error : Errors)
				{
					UE_LOG(LogVirtualizationTool, Error, TEXT("\t%s"), *Error.ToString());
				}
				return false;
			}

			UE_LOG(LogVirtualizationTool, Display, TEXT("\tCheck complete"));

			UE::Virtualization::Shutdown();
			Project.UnRegisterMountPoints();
		}

		FinalDescriptionTags = BuildFinalTagDescriptions(DescriptionTags);
	}
	else
	{
		UE_LOG(LogVirtualizationTool, Display, TEXT("Skipping the virtualization process"));
	}

	if (Mode == EMode::Changelist)
	{
		if (!TrySubmitChangelist(FinalDescriptionTags))
		{
			return false;
		}
	}

	return true;
}

void FUnrealVirtualizationToolApp::PrintCmdLineHelp() const
{
	UE_LOG(LogVirtualizationTool, Display, TEXT("Usage:"));
	UE_LOG(LogVirtualizationTool, Display, TEXT("UnrealVirtualizationTool -ClientSpecName=<name> -Mode=Changelist -Changelist=<number> [-nosubmit] [global options]"));
	UE_LOG(LogVirtualizationTool, Display, TEXT("\t[optional]-nosubmit (the changelist will be virtualized but not submitted)"));
	UE_LOG(LogVirtualizationTool, Display, TEXT("UnrealVirtualizationTool -ClientSpecName=<name> -Mode=PackageList -Path=<string> [global options]"));
	UE_LOG(LogVirtualizationTool, Display, TEXT("Global Options:"));
	UE_LOG(LogVirtualizationTool, Display, TEXT("\t-verbose (all log messages with display verbosity will be displayed, not just LogVirtualizationTool)"));
}

bool FUnrealVirtualizationToolApp::TrySubmitChangelist(const TArray<FString>& DescriptionTags)
{
	if (!EnumHasAllFlags(ProcessOptions, EProcessOptions::Submit))
	{
		UE_LOG(LogVirtualizationTool, Display, TEXT("Skipping submit of changelist '%s' due to cmdline options"), *ChangelistNumber);
		return true;
	}

	UE_LOG(LogVirtualizationTool, Display, TEXT("Attempting to submit the changelist '%s'"), *ChangelistNumber);

	if (!SCCProvider.IsValid())
	{
		if (!TryConnectToSourceControl())
		{
			UE_LOG(LogVirtualizationTool, Error, TEXT("Submit failed, cannot find a valid source control provider"));
			return false;
		}
	}

	if (!ChangelistToSubmit.IsValid())
	{
		// This should not be possible, the check and error message is to guard against potential future problems only.
		UE_LOG(LogVirtualizationTool, Error, TEXT("Submit failed, could not find the changelist"));
		return false;
	}

	FSourceControlChangelistRef Changelist = ChangelistToSubmit.ToSharedRef();
	FSourceControlChangelistStatePtr ChangelistState = SCCProvider->GetState(Changelist, EStateCacheUsage::Use);

	if (!ChangelistState.IsValid())
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Submit failed, failed to find the state for the changelist"));
		return false;
	}

	TSharedRef<FCheckIn, ESPMode::ThreadSafe> CheckInOperation = ISourceControlOperation::Create<FCheckIn>();

	// Grab the original changelist description then append our tags afterwards
	TStringBuilder<512> Description;
	Description << ChangelistState->GetDescriptionText().ToString();

	for (const FString& Tag : DescriptionTags)
	{
		Description << TEXT("\n") << Tag;
	}

	CheckInOperation->SetDescription(FText::FromString(Description.ToString()));

	if (SCCProvider->Execute(CheckInOperation, Changelist) == ECommandResult::Succeeded)
	{
		UE_LOG(LogVirtualizationTool, Display, TEXT("%s"), *CheckInOperation->GetSuccessMessage().ToString());	
		return true;
	}
	else
	{
		// Even when log suppression is active we still show errors to the users and as the source control
		// operation should have logged the problem as an error the user will see it. This means we don't 
		// have to extract it from CheckInOperation .
		UE_LOG(LogVirtualizationTool, Error, TEXT("Submit failed, please check the log!"));

		return false;
	}
}

bool FUnrealVirtualizationToolApp::TryLoadModules()
{
	if (FModuleManager::Get().LoadModule(TEXT("Virtualization"), ELoadModuleFlags::LogFailures) == nullptr)
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to load the 'Virtualization' module"));
	}

	return true;
}

bool FUnrealVirtualizationToolApp::TryInitEnginePlugins()
{
	TRACE_CPUPROFILER_EVENT_SCOPE(TryInitEnginePlugins);

	UE_LOG(LogVirtualizationTool, Log, TEXT("Loading Engine Plugins"));

	IPluginManager& PluginMgr = IPluginManager::Get();

	const FString PerforcePluginPath = FPaths::EnginePluginsDir() / TEXT("Developer/PerforceSourceControl/PerforceSourceControl.uplugin");
	FText ErrorMsg;
	if (!PluginMgr.AddToPluginsList(PerforcePluginPath, &ErrorMsg))
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to find 'PerforceSourceControl' plugin due to: %s"), *ErrorMsg.ToString());
		return false;
	}

	PluginMgr.MountNewlyCreatedPlugin(TEXT("PerforceSourceControl"));

	TSharedPtr<IPlugin> Plugin = PluginMgr.FindPlugin(TEXT("PerforceSourceControl"));
	if (Plugin == nullptr || !Plugin->IsEnabled())
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("The 'PerforceSourceControl' plugin is disabled."));
		return false;
	}

	return true;
}

bool FUnrealVirtualizationToolApp::TryConnectToSourceControl()
{
	TRACE_CPUPROFILER_EVENT_SCOPE(TryConnectToSourceControl);

	UE_LOG(LogVirtualizationTool, Log, TEXT("Trying to connect to source control..."));

	FSourceControlInitSettings SCCSettings(FSourceControlInitSettings::EBehavior::OverrideAll);
	SCCSettings.AddSetting(TEXT("P4Client"), ClientSpecName);

	SCCProvider = ISourceControlModule::Get().CreateProvider(FName("Perforce"), TEXT("UnrealVirtualizationTool"), SCCSettings);
	if (SCCProvider.IsValid())
	{
		return true;
	}
	else
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to create a perforce connection"));
		return false;
	}
}

EInitResult FUnrealVirtualizationToolApp::TryParseCmdLine()
{
	TRACE_CPUPROFILER_EVENT_SCOPE(TryParseCmdLine);

	UE_LOG(LogVirtualizationTool, Log, TEXT("Parsing the commandline"));

	const TCHAR* CmdLine = FCommandLine::Get();

	if (CmdLine == nullptr || CmdLine[0] == TEXT('\0'))
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("No commandline parameters found!"));
		PrintCmdLineHelp();
		return EInitResult::Error;
	}

	if (FParse::Param(CmdLine, TEXT("Help")) || FParse::Param(CmdLine, TEXT("?")))
	{
		UE_LOG(LogVirtualizationTool, Display, TEXT("Commandline help requested"));
		PrintCmdLineHelp();
		return EInitResult::EarlyOut;
	}

	// First parse the command line options that can apply to all modes

	if (!FParse::Value(CmdLine, TEXT("-ClientSpecName="), ClientSpecName))
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to find cmdline switch 'ClientSpecName', this is a required parameter!"));
		PrintCmdLineHelp();
		return EInitResult::Error;
	}

	if (FParse::Param(CmdLine, TEXT("Verbose")))
	{
		UE_LOG(LogVirtualizationTool, Display, TEXT("Cmdline parameter '-Verbose' found, no longer supressing Display log messages!"));
	}
	else
	{
		OutputDeviceOverride = MakeUnique<FOverrideOutputDevice>();
	}

	// Now parse the mode specific command line options

	FString ModeAsString;
	if (!FParse::Value(CmdLine, TEXT("-Mode="), ModeAsString))
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to find cmdline switch 'Mode', this is a required parameter!"));
		PrintCmdLineHelp();
		return EInitResult::Error;
	}

	LexFromString(Mode, ModeAsString);

	switch (Mode)
	{
		case EMode::Changelist:
			return TryParseChangelistCmdLine(CmdLine);
			break;
		case EMode::PackageList:
			return TryParsePackageListCmdLine(CmdLine);
			break;
		case EMode::Unknown:
		default:
			UE_LOG(LogVirtualizationTool, Error, TEXT("Unexpected value for the cmdline switch 'Mode', this is a required parameter!"));
			PrintCmdLineHelp();
			return EInitResult::Error;

			break;
	}
}

EInitResult	FUnrealVirtualizationToolApp::TryParseChangelistCmdLine(const TCHAR* CmdLine)
{
	if (FParse::Value(CmdLine, TEXT("-Changelist="), ChangelistNumber))
	{
		// Optional switches
		if (FParse::Param(CmdLine, TEXT("NoSubmit")))
		{
			UE_LOG(LogVirtualizationTool, Display, TEXT("Cmdline parameter '-NoSubmit' found, the changelist will be virtualized but not submitted!"));
		}
		else
		{
			ProcessOptions |= EProcessOptions::Submit;
		}

		UE_LOG(LogVirtualizationTool, Display, TEXT("Attempting to virtualize changelist '%s'"), *ChangelistNumber);
		
		return EInitResult::Success;
	}
	else
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to find cmdline switch 'Changelist', this is a required parameter for the 'Changelist' mode!"));
		PrintCmdLineHelp();
		return EInitResult::Error;
	}
}

EInitResult FUnrealVirtualizationToolApp::TryParsePackageListCmdLine(const TCHAR* CmdLine)
{
	if (FParse::Value(CmdLine, TEXT("-Path="), PackageListPath))
	{
		UE_LOG(LogVirtualizationTool, Display, TEXT("Virtualizing packages found in package list: '%s'"), *PackageListPath);
		return EInitResult::Success;
	}
	else
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to find cmdline switch 'Path', this is a required parameter for the 'PackageList mode!"));
		PrintCmdLineHelp();
		return EInitResult::Error;
	}	
}

bool FUnrealVirtualizationToolApp::TryParseChangelist(TArray<FString>& OutPackages)
{
	TRACE_CPUPROFILER_EVENT_SCOPE(TryParseChangelist);

	if (!TryConnectToSourceControl())
	{
		return false;
	}

	UE_LOG(LogVirtualizationTool, Display, TEXT("Attempting to parse changelist '%s' in workspace '%s'"), *ChangelistNumber, *ClientSpecName);

	if (!SCCProvider.IsValid())
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("No valid source control connection found!"));
		return false;
	}

	SCCProvider->Init(true);

	if (!SCCProvider->UsesChangelists())
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("The source control provider does not support the use of changelists"));
		return false;
	}

	TArray<FSourceControlChangelistRef> Changelists = SCCProvider->GetChangelists(EStateCacheUsage::ForceUpdate);
	if (Changelists.IsEmpty())
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to find any changelists"));
		return false;
	}

	TArray<FSourceControlChangelistStateRef> ChangelistsStates;
	if (SCCProvider->GetState(Changelists, ChangelistsStates, EStateCacheUsage::Use) != ECommandResult::Succeeded)
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to find changelist data"));
		return false;
	}

	for (FSourceControlChangelistStateRef& ChangelistState : ChangelistsStates)
	{
		const FText DisplayText = ChangelistState->GetDisplayText();

		if (ChangelistNumber == DisplayText.ToString())
		{
			TSharedRef<FUpdatePendingChangelistsStatus, ESPMode::ThreadSafe> Operation = ISourceControlOperation::Create<FUpdatePendingChangelistsStatus>();

			// TODO: Updating only the CL we want does not currently work and even if it did we still end up with a pointless
			// p4 changes command before updating the files. Given we know the changelist number via FSourceControlChangelistRef
			// we should be able to just request the file states be updated.
			// This is also a lot of code to write for a simple "give me all files in a changelist" operation, if we don't add
			// support directly in the API we should move this to a utility namespace in the source control module.

			FSourceControlChangelistRef Changelist = ChangelistState->GetChangelist();
			Operation->SetChangelistsToUpdate(MakeArrayView(&Changelist, 1));
			Operation->SetUpdateFilesStates(true);
			
			if (SCCProvider->Execute(Operation, EConcurrency::Synchronous) != ECommandResult::Succeeded)
			{
				UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to find the files in changelist '%s'"), *ChangelistNumber);
				return false;
			}

			const TArray<FSourceControlStateRef>& FilesinChangelist = ChangelistState->GetFilesStates();
			for (const FSourceControlStateRef& FileState : FilesinChangelist)
			{
				if (IsPackageFile(FileState->GetFilename()))
				{
					OutPackages.Add(FileState->GetFilename());
				}
				else
				{
					UE_LOG(LogVirtualizationTool, Log, TEXT("Ignoring non-package file '%s'"), *FileState->GetFilename());
				}
			}

			ChangelistToSubmit = Changelist;

			UE_LOG(LogVirtualizationTool, Display, TEXT("Found '%d' package file(s)"), OutPackages.Num());

			return true;
		}
	}

	UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to find the changelist '%s'"), *ChangelistNumber);
	return false;
}

bool FUnrealVirtualizationToolApp::TryParsePackageList(TArray<FString>& OutPackages)
{
	TRACE_CPUPROFILER_EVENT_SCOPE(TrySortFilesByProject);

	UE_LOG(LogVirtualizationTool, Display, TEXT("Parsing the package list..."));

	if (!IFileManager::Get().FileExists(*PackageListPath))
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("\tThe package list '%s' does not exist"), *PackageListPath);
		return false;
	}

	if (FFileHelper::LoadFileToStringArray(OutPackages, *PackageListPath))
	{
		// We don't have control over how the package list was generated so make sure that the paths
		// are in the format that we want.
		for (FString& PackagePath : OutPackages)
		{
			FPaths::NormalizeFilename(PackagePath);
		}

		UE_LOG(LogVirtualizationTool, Display, TEXT("\tFound '%d' package file(s)"), OutPackages.Num());
		return true;
	}
	else
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("\tFailed to parse the package list '%s'"), *PackageListPath);
		return false;
	}
}

bool FUnrealVirtualizationToolApp::TrySortFilesByProject(const TArray<FString>& Packages)
{
	TRACE_CPUPROFILER_EVENT_SCOPE(TrySortFilesByProject);

	UE_LOG(LogVirtualizationTool, Display, TEXT("Sorting files by project..."));

	for (const FString& PackagePath : Packages)
	{
		FString ProjectFilePath;
		FString PluginFilePath;

		if (TryFindProject(PackagePath, ProjectFilePath, PluginFilePath))
		{
			FProject& Project = FindOrAddProject(ProjectFilePath);
			if (PluginFilePath.IsEmpty())
			{
				Project.AddFile(PackagePath);
			}
			else
			{
				Project.AddPluginFile(PackagePath, PluginFilePath);
			}
		}
	}

	UE_LOG(LogVirtualizationTool, Display, TEXT("\tThe package files are associated with '%d' projects(s)"), Projects.Num());

	return true;
}

bool FUnrealVirtualizationToolApp::TryFindProject(const FString& PackagePath, FString& ProjectFilePath, FString& PluginFilePath) const
{
	TRACE_CPUPROFILER_EVENT_SCOPE(TryFindProject);

	// TODO: This could be heavily optimized by caching known project files

	const int32 ContentIndex = PackagePath.Find(TEXT("/content/"), ESearchCase::IgnoreCase, ESearchDir::FromEnd);
	if (ContentIndex != INDEX_NONE)
	{
		FString ProjectDirectory = PackagePath.Left(ContentIndex);
		FString PluginDirectory;
		
		TArray<FString> ProjectFile;
		TArray<FString> PluginFile;

		IFileManager::Get().FindFiles(ProjectFile, *ProjectDirectory, TEXT(".uproject"));

		if (ProjectFile.IsEmpty())
		{
			// Could be a plugin so lets check
			PluginDirectory = ProjectDirectory;
			IFileManager::Get().FindFiles(PluginFile, *PluginDirectory, TEXT(".uplugin"));

			if (PluginFile.Num() == 1)
			{
				PluginFilePath = PluginDirectory / PluginFile[0];

				const int32 PluginIndex = PluginDirectory.Find(TEXT("/plugins/"), ESearchCase::IgnoreCase, ESearchDir::FromEnd);
				if (PluginIndex != INDEX_NONE)
				{
					ProjectDirectory = PluginDirectory.Left(PluginIndex);
					IFileManager::Get().FindFiles(ProjectFile, *ProjectDirectory, TEXT(".uproject"));
				}
			}
			else if (PluginFile.Num() > 1)
			{
				UE_LOG(LogVirtualizationTool, Verbose, TEXT("Found multiple project files for '%s' at '%s'"), *PackagePath, *PluginDirectory);
				return false;
			}
		}

		if (ProjectFile.Num() == 1)
		{
			ProjectFilePath = ProjectDirectory / ProjectFile[0];
			return true;
		}
		else if (ProjectFile.IsEmpty())
		{
			UE_LOG(LogVirtualizationTool, Log, TEXT("Failed to find project file for '%s'"), *PackagePath);
			return false;
		}
		else
		{
			UE_LOG(LogVirtualizationTool, Verbose, TEXT("Found multiple project files for '%s' at '%s'"), *PackagePath, *ProjectDirectory);
			return false;
		}
	}
	else
	{
		UE_LOG(LogVirtualizationTool, Log, TEXT("File '%s' is not under a content directory"), *PackagePath);
		return false;
	}
}

FProject& FUnrealVirtualizationToolApp::FindOrAddProject(const FString& ProjectFilePath)
{
	FProject* Project = Projects.FindByPredicate([&ProjectFilePath](const FProject& Project)->bool
	{
		return Project.ProjectFilePath == ProjectFilePath;
	});

	if (Project != nullptr)
	{
		return *Project;
	}
	else
	{
		FProject& NewProject = Projects.AddDefaulted_GetRef();
		NewProject.ProjectFilePath = ProjectFilePath;

		return NewProject;
	}
}

void FProject::AddFile(const FString& PackagePath)
{
	PackagePaths.Add(PackagePath);
}

void FProject::AddPluginFile(const FString& PackagePath, const FString& PluginFilePath)
{
	FPlugin* Plugin = Plugins.FindByPredicate([&PluginFilePath](const FPlugin& Plugin)->bool
	{
		return Plugin.PluginFilePath == PluginFilePath;
	});

	if (Plugin == nullptr)
	{
		Plugin = &Plugins.AddDefaulted_GetRef();
		Plugin->PluginFilePath = PluginFilePath;
	}

	check(Plugin != nullptr);
	Plugin->PackagePaths.Add(PackagePath);
};

FStringView FProject::GetProjectName() const
{
	return FPathViews::GetBaseFilename(ProjectFilePath);
}

TArray<FString> FProject::GetAllPackages() const
{
	TArray<FString> Packages = PackagePaths;
	for (const FPlugin& Plugin : Plugins)
	{
		Packages.Append(Plugin.PackagePaths);
	}

	return Packages;
}

void FProject::RegisterMountPoints() const
{
	TRACE_CPUPROFILER_EVENT_SCOPE(FProject::RegisterMountPoints);

	FString ProjectRootPath;
	FString ProjectContentPath;

	ConvertToMountPoint(ProjectFilePath, ProjectRootPath, ProjectContentPath);
	FPackageName::RegisterMountPoint(ProjectRootPath, ProjectContentPath);

	for (const FPlugin& Plugin : Plugins)
	{
		FString PluginRootPath;
		FString PluginContentPath;

		ConvertToMountPoint(Plugin.PluginFilePath, PluginRootPath, PluginContentPath);
		FPackageName::RegisterMountPoint(PluginRootPath, PluginContentPath);
	}
}

void FProject::UnRegisterMountPoints() const
{
	TRACE_CPUPROFILER_EVENT_SCOPE(FProject::UnRegisterMountPoints);

	for (const FPlugin& Plugin : Plugins)
	{
		FString PluginRootPath;
		FString PluginContentPath;

		ConvertToMountPoint(Plugin.PluginFilePath, PluginRootPath, PluginContentPath);
		FPackageName::UnRegisterMountPoint(PluginRootPath, PluginContentPath);
	}

	FString ProjectRootPath;
	FString ProjectContentPath;

	ConvertToMountPoint(ProjectFilePath, ProjectRootPath, ProjectContentPath);
	FPackageName::UnRegisterMountPoint(ProjectRootPath, ProjectContentPath);
}

bool FProject::TryLoadConfig(FConfigFile& OutConfig) const
{
	TRACE_CPUPROFILER_EVENT_SCOPE(FProject::TryLoadConfig);

	const FString ProjectPath = FPaths::GetPath(ProjectFilePath);
	const FString EngineConfigPath = FPaths::Combine(FPaths::EngineDir(), TEXT("Config/"));
	const FString ProjectConfigPath = FPaths::Combine(ProjectPath, TEXT("Config/"));

	OutConfig.Reset();

	if (!FConfigCacheIni::LoadExternalIniFile(OutConfig, TEXT("Engine"), *EngineConfigPath, *ProjectConfigPath, true))
	{
		UE_LOG(LogVirtualizationTool, Error, TEXT("Failed to load config files for the project '%s"), *ProjectFilePath);
		return false;
	}

	//  Note that the following is taken from UGameFeatureData::InitializeHierarchicalPluginIniFiles as with
	// ReloadConfigs if we decide to keep filtering at submission time, rather than save time then we should
	// probably move this code to a shared location rather than the copy/paste.
	for (const FPlugin& Plugin : Plugins)
	{
		const FString PluginName = FPaths::GetBaseFilename(Plugin.PluginFilePath);
		const FString PluginIniName = PluginName + TEXT("Engine");

		const FString PluginPath = FPaths::GetPath(Plugin.PluginFilePath);
		const FString PluginConfigPath = FPaths::Combine(PluginPath, TEXT("Config/"));

		FConfigFile PluginConfig;
		if (FConfigCacheIni::LoadExternalIniFile(PluginConfig, *PluginIniName, *EngineConfigPath, *PluginConfigPath, false) && (PluginConfig.Num() > 0))
		{
			const FString IniFile = GConfig->GetConfigFilename(TEXT("Engine"));

			if (FConfigFile* ExistingConfig = GConfig->FindConfigFile(IniFile))
			{
				const FString PluginIniPath = FString::Printf(TEXT("%s%s.ini"), *PluginConfigPath, *PluginIniName);
				if (ExistingConfig->Combine(PluginIniPath))
				{
					ReloadConfigs(PluginConfig);
				}
			}
		}
	}

	return true;
}

} // namespace UE::Virtualization