// Copyright 1998-2017 Epic Games, Inc. All Rights Reserved.

#include "CookedIterativeNetworkFile.h"
#include "Templates/ScopedPointer.h"
#include "Misc/CommandLine.h"
#include "Misc/ScopeLock.h"
#include "Modules/ModuleManager.h"
#include "HAL/IPlatformFileModule.h"
#include "UniquePtr.h"
#include "Misc/EngineVersion.h"

DEFINE_LOG_CATEGORY(LogCookedIterativeNetworkFile);

bool FCookedIterativeNetworkFile::InitializeInternal(IPlatformFile* Inner, const TCHAR* HostIP)
{
	if ( Inner->GetLowerLevel() == nullptr )
	{
		UE_LOG(LogCookedIterativeNetworkFile, Fatal, TEXT("Platform file is missing it's inner.  Is pak file deployed?") );
	}
	

	PakPlatformFile = Inner;

	return FNetworkPlatformFile::InitializeInternal(Inner->GetLowerLevel(), HostIP );
}


void FCookedIterativeNetworkFile::ProcessServerCachedFilesResponse(FArrayReader& Response, const int32 ServerPackageVersion, const int32 ServerPackageLicenseeVersion)
{
	FNetworkPlatformFile::ProcessServerCachedFilesResponse(Response, ServerPackageVersion, ServerPackageLicenseeVersion);


	// some of our stuff is on here too!
	
	// receive a list of the cache files and their timestamps
	TMap<FString, FDateTime> ServerValidPakFileFiles;
	Response << ServerValidPakFileFiles;


	for ( const auto& ServerPakFileFile : ServerValidPakFileFiles )
	{
		// the server should contain all these files
		FString Path = FPaths::GetPath( ServerPakFileFile.Key);
		FString Filename = FPaths::GetCleanFilename(ServerPakFileFile.Key);

		FServerTOC::FDirectory* ServerDirectory = ServerFiles.FindDirectory(Path);
		if ( !ServerDirectory)
		{
			UE_LOG(LogCookedIterativeNetworkFile, Warning, TEXT("Unable to find directory %s while trying to resolve pak file %s"), *Path, *ServerPakFileFile.Key );
		}
		else
		{
			FDateTime* ServerDate = ServerDirectory->Find(Filename);
			if ( !ServerDate )
			{
				UE_LOG(LogCookedIterativeNetworkFile, Warning, TEXT("Unable to find filename %s while trying to resolve pak file %s"), *Filename, *ServerPakFileFile.Key);
			}
		}

		// check the file is accessable 
		if (!PakPlatformFile->FileExists(*ServerPakFileFile.Key))
		{
			UE_LOG(LogCookedIterativeNetworkFile, Warning, TEXT("Unable to find file %s in pak file.  Server says it should be!"), *ServerPakFileFile.Key)
		}

		ValidPakFileFiles.AddFileOrDirectory(ServerPakFileFile.Key, ServerPakFileFile.Value);

		UE_LOG(LogCookedIterativeNetworkFile, Display, TEXT("Using pak file %s"), *ServerPakFileFile.Key);
	}
}

FString FCookedIterativeNetworkFile::GetVersionInfo() const
{
	FString VersionInfo = FString::Printf(TEXT("%s %d"), *FEngineVersion::CompatibleWith().GetBranch(), FEngineVersion::CompatibleWith().GetChangelist() );

	return VersionInfo;
}

bool FCookedIterativeNetworkFile::ShouldPassToPak(const TCHAR* Filename) const
{
	if ( FCString::Stricmp( *FPaths::GetExtension(Filename), TEXT("ufont") ) == 0 )
	{
		FString Path = FPaths::GetPath( Filename );

		const FServerTOC::FDirectory* Directory = ValidPakFileFiles.FindDirectory(Path);
		if ( Directory )
		{
			FString StringFilename = Filename;
			for ( const auto& File : *Directory )
			{
				if ( File.Key.StartsWith( StringFilename ) )
				{
					return true;
				}
			}
			return false;
		}
		else
		{
			return false;
		}
	}

	if ( ValidPakFileFiles.FindFile(Filename) != nullptr )
	{
		return true;
	}
	// if we are searching for the .uexp or .ubulk or any of those content extra files.... 
	// then change it to the original,  if we are using the pak version of the original file then we want the bulk / uexp file to be the same
	// potential async issue here if the file is invalidated after we start loading the original but before we load the uexp 
	// not much we can do about that though... 
	FString OriginalName = FPaths::ChangeExtension(Filename, TEXT("uasset"));
	if ( ValidPakFileFiles.FindFile(OriginalName) )
	{
		return true;
	}
	OriginalName = FPaths::ChangeExtension(Filename, TEXT("umap"));
	if ( ValidPakFileFiles.FindFile(OriginalName))
	{
		return true;
	}

	return false;
}


bool		FCookedIterativeNetworkFile::FileExists(const TCHAR* Filename)
{
	if ( ShouldPassToPak(Filename) )
	{
		PakPlatformFile->FileExists(Filename);
		return true;
	}
	return FNetworkPlatformFile::FileExists(Filename);
}

int64 FCookedIterativeNetworkFile::FileSize(const TCHAR* Filename)
{
	if ( ShouldPassToPak(Filename) )
	{
		return PakPlatformFile->FileSize(Filename);
	}
	else
	{
		return FNetworkPlatformFile::FileSize(Filename);
	}
}
bool FCookedIterativeNetworkFile::DeleteFile(const TCHAR* Filename)
{
	// delete both of these entries
	ValidPakFileFiles.RemoveFileOrDirectory(Filename);
	return FNetworkPlatformFile::DeleteFile(Filename);
}

bool FCookedIterativeNetworkFile::IsReadOnly(const TCHAR* Filename)
{
	if ( ShouldPassToPak(Filename) )
	{
		return PakPlatformFile->IsReadOnly(Filename);
	}

	return FNetworkPlatformFile::IsReadOnly(Filename);
}

bool FCookedIterativeNetworkFile::SetReadOnly(const TCHAR* Filename, bool bNewReadOnlyValue)
{
	if (ShouldPassToPak(Filename))
	{
		return PakPlatformFile->SetReadOnly(Filename, bNewReadOnlyValue);
	}
	return FNetworkPlatformFile::SetReadOnly(Filename, bNewReadOnlyValue);
}
FDateTime FCookedIterativeNetworkFile::GetTimeStamp(const TCHAR* Filename)
{
	if ( ShouldPassToPak(Filename) )
	{
		return PakPlatformFile->GetTimeStamp(Filename);
	}
	return FNetworkPlatformFile::GetTimeStamp(Filename);
}


void FCookedIterativeNetworkFile::OnFileUpdated(const FString& LocalFilename)
{
	FNetworkPlatformFile::OnFileUpdated(LocalFilename);
	ValidPakFileFiles.RemoveFileOrDirectory(LocalFilename);
}


IFileHandle* FCookedIterativeNetworkFile::OpenRead(const TCHAR* Filename, bool bAllowWrite)
{
	if ( ShouldPassToPak(Filename) )
	{
		return PakPlatformFile->OpenRead(Filename, bAllowWrite);
	}
	return FNetworkPlatformFile::OpenRead(Filename, bAllowWrite);
}
IFileHandle* FCookedIterativeNetworkFile::OpenWrite(const TCHAR* Filename, bool bAppend, bool bAllowRead)
{
	if (ShouldPassToPak(Filename))
	{
		return PakPlatformFile->OpenWrite(Filename, bAppend, bAllowRead);
	}
	// FNetworkPlatformFile::CreateDirectoryTree(Directory);
	return FNetworkPlatformFile::OpenWrite(Filename, bAppend, bAllowRead);
}

bool FCookedIterativeNetworkFile::CopyFile(const TCHAR* To, const TCHAR* From, EPlatformFileRead ReadFlags, EPlatformFileWrite WriteFlags)
{
	return PakPlatformFile->CopyFile(To, From, ReadFlags, WriteFlags);
}

bool FCookedIterativeNetworkFile::MoveFile(const TCHAR* To, const TCHAR* From)
{
	if (ShouldPassToPak(From))
	{
		return PakPlatformFile->MoveFile(To, From);
	}
	return FNetworkPlatformFile::MoveFile(To, From);
}

bool FCookedIterativeNetworkFile::DirectoryExists(const TCHAR* Directory)
{
	if ( ValidPakFileFiles.FindDirectory(Directory) )
	{
		return true;
	}
	return FNetworkPlatformFile::DirectoryExists(Directory);
}

bool FCookedIterativeNetworkFile::CreateDirectoryTree(const TCHAR* Directory)
{
	return FNetworkPlatformFile::CreateDirectoryTree(Directory);
}

bool FCookedIterativeNetworkFile::CreateDirectory(const TCHAR* Directory)
{
	return FNetworkPlatformFile::CreateDirectory(Directory);
}

bool FCookedIterativeNetworkFile::DeleteDirectory(const TCHAR* Directory)
{
	bool bSucceeded = false;
	if( ValidPakFileFiles.FindDirectory(Directory) )
	{
		bSucceeded |= ValidPakFileFiles.RemoveFileOrDirectory(Directory) > 0 ? true : false;
	}
	bSucceeded |= FNetworkPlatformFile::DeleteDirectory(Directory);
	return bSucceeded;
}

bool FCookedIterativeNetworkFile::DeleteDirectoryRecursively(const TCHAR* Directory)
{
	bool bSucceeded = false;
	if (ValidPakFileFiles.FindDirectory(Directory))
	{
		bSucceeded |= ValidPakFileFiles.RemoveFileOrDirectory(Directory) > 0 ? true : false;
	}
	bSucceeded |= FNetworkPlatformFile::DeleteDirectoryRecursively(Directory);
	return bSucceeded;
}


bool		FCookedIterativeNetworkFile::IterateDirectory(const TCHAR* Directory, IPlatformFile::FDirectoryVisitor& Visitor)
{
	//return PakPlatformFile->IterateDirectory(Directory, Visitor);
	return FNetworkPlatformFile::IterateDirectory(Directory, Visitor);
}

bool FCookedIterativeNetworkFile::IterateDirectoryRecursively(const TCHAR* Directory, IPlatformFile::FDirectoryVisitor& Visitor)
{
	return FNetworkPlatformFile::IterateDirectoryRecursively(Directory, Visitor);
}


FFileStatData FCookedIterativeNetworkFile::GetStatData(const TCHAR* FilenameOrDirectory)
{
	if (ShouldPassToPak(FilenameOrDirectory))
	{
		return PakPlatformFile->GetStatData(FilenameOrDirectory);
	}
	return FNetworkPlatformFile::GetStatData(FilenameOrDirectory);
}


bool FCookedIterativeNetworkFile::IterateDirectoryStat(const TCHAR* Directory, IPlatformFile::FDirectoryStatVisitor& Visitor)
{
	return FNetworkPlatformFile::IterateDirectoryStat(Directory, Visitor);
}

bool FCookedIterativeNetworkFile::IterateDirectoryStatRecursively(const TCHAR* Directory, IPlatformFile::FDirectoryStatVisitor& Visitor)
{
	return FNetworkPlatformFile::IterateDirectoryStatRecursively(Directory, Visitor);
}







/**
 * A helper class for wrapping some of the network file payload specifics
 */
/*
class FStreamingNetworkFileArchive
	: public FBufferArchive
{
public:

	FStreamingNetworkFileArchive(uint32 Command)
	{
		// make sure the command is at the start
		*this << Command;
	}

	// helper to serialize TCHAR* (there are a lot)
	FORCEINLINE friend FStreamingNetworkFileArchive& operator<<(FStreamingNetworkFileArchive& Ar, const TCHAR*& Str)
	{
		FString Temp(Str);
		Ar << Temp;
		return Ar;
	}
};
*/


/*
class FStreamingNetworkFileHandle
	: public IFileHandle
{
	FStreamingNetworkPlatformFile& Network;
	FString Filename;
	uint64 HandleId;
	int64 FilePos;
	int64 FileSize;
	bool bWritable;
	bool bReadable;
	uint8 BufferCache[2][GBufferCacheSize];
	int64 CacheStart[2];
	int64 CacheEnd[2];
	bool LazySeek;
	int32 CurrentCache;

public:

	FStreamingNetworkFileHandle(FStreamingNetworkPlatformFile& InNetwork, const TCHAR* InFilename, uint64 InHandleId, int64 InFileSize, bool bWriting)
		: Network(InNetwork)
		, Filename(InFilename)
		, HandleId(InHandleId)
		, FilePos(0)
		, FileSize(InFileSize)
		, bWritable(bWriting)
		, bReadable(!bWriting)
		, LazySeek(false)
		,CurrentCache(0)
	{
		CacheStart[0] = CacheStart[1] = -1;
		CacheEnd[0] = CacheEnd[1] = -1;
	}

	~FStreamingNetworkFileHandle()
	{
		Network.SendCloseMessage(HandleId);
	}

	virtual int64 Size() override
	{
		return FileSize;
	}

	virtual int64 Tell() override
	{
		return FilePos;
	}

	virtual bool Seek(int64 NewPosition) override
	{
		if( bWritable )
		{
			if( NewPosition == FilePos )
			{
				return true;
			}

			if (NewPosition >= 0 && NewPosition <= FileSize)
			{
				if (Network.SendSeekMessage(HandleId, NewPosition))
				{
					FilePos = NewPosition;

					return true;
				}
			}
		}
		else if( bReadable )
		{
			if (NewPosition >= 0 && NewPosition <= FileSize)
			{
				if (NewPosition < CacheStart[0] || NewPosition >= CacheEnd[0] || CacheStart[0] == -1)
				{
					if (NewPosition < CacheStart[1] || NewPosition >= CacheEnd[1] || CacheStart[1] == -1)
					{
						LazySeek = true;
						FilePos = NewPosition;
						if (CacheStart[CurrentCache] != -1)
						{
							CurrentCache++;
							CurrentCache %= 2;
							CacheStart[CurrentCache] = -1; // Invalidate the cache
						}

						return true;
					}
					else
					{
						LazySeek = false;
						FilePos = NewPosition;
						CurrentCache = 1;

						return true;
					}
				}
				else
				{
					LazySeek = false;
					FilePos = NewPosition;
					CurrentCache = 0;

					return true;
				}
			}
		}

		return false;
	}

	virtual bool SeekFromEnd(int64 NewPositionRelativeToEnd = 0) override
	{
		return Seek(FileSize + NewPositionRelativeToEnd);
	}

	virtual bool Read(uint8* Destination, int64 BytesToRead) override
	{
		bool Result = false;
		if (bReadable && BytesToRead >= 0 && BytesToRead + FilePos <= FileSize)
		{
			if (BytesToRead == 0)
			{
				Result = true;
			}
			else
			{
				if (BytesToRead > GBufferCacheSize) // reading more than we cache
				{
					// if the file position is within the cache, copy out the remainder of the cache
					if (CacheStart[CurrentCache] != -1 && FilePos >= CacheStart[CurrentCache] && FilePos < CacheEnd[CurrentCache])
					{
						int64 CopyBytes = CacheEnd[CurrentCache]-FilePos;
						FMemory::Memcpy(Destination, BufferCache[CurrentCache]+(FilePos-CacheStart[CurrentCache]), CopyBytes);
						FilePos += CopyBytes;
						BytesToRead -= CopyBytes;
						Destination += CopyBytes;
					}

					if (Network.SendSeekMessage(HandleId, FilePos))
					{
						Result = Network.SendReadMessage(HandleId, Destination, BytesToRead);
					}
					if (Result)
					{
						FilePos += BytesToRead;
						CurrentCache++;
						CurrentCache %= 2;
						CacheStart[CurrentCache] = -1; // Invalidate the cache
					}
				}
				else
				{
					Result = true;

					// need to update the cache
					if (CacheStart[CurrentCache] == -1 && FileSize < GBufferCacheSize)
					{
						Result = Network.SendReadMessage(HandleId, BufferCache[CurrentCache], FileSize);
						if (Result)
						{
							CacheStart[CurrentCache] = 0;
							CacheEnd[CurrentCache] = FileSize;
						}
					}
					else if (FilePos + BytesToRead > CacheEnd[CurrentCache] || CacheStart[CurrentCache] == -1 || FilePos < CacheStart[CurrentCache])
					{
						// copy the data from FilePos to the end of the Cache to the destination as long as it is in the cache
						if (CacheStart[CurrentCache] != -1 && FilePos >= CacheStart[CurrentCache] && FilePos < CacheEnd[CurrentCache])
						{
							int64 CopyBytes = CacheEnd[CurrentCache]-FilePos;
							FMemory::Memcpy(Destination, BufferCache[CurrentCache]+(FilePos-CacheStart[CurrentCache]), CopyBytes);
							FilePos += CopyBytes;
							BytesToRead -= CopyBytes;
							Destination += CopyBytes;
						}

						// switch to the other cache
						if (CacheStart[CurrentCache] != -1)
						{
							CurrentCache++;
							CurrentCache %= 2;
						}

						int64 SizeToRead = GBufferCacheSize;

						if (FilePos + SizeToRead > FileSize)
						{
							SizeToRead = FileSize-FilePos;
						}

						if (Network.SendSeekMessage(HandleId, FilePos))
						{
							Result = Network.SendReadMessage(HandleId, BufferCache[CurrentCache], SizeToRead);
						}

						if (Result)
						{
							CacheStart[CurrentCache] = FilePos;
							CacheEnd[CurrentCache] = FilePos + SizeToRead;
						}
					}

					// copy from the cache to the destination
					if (Result)
					{
						FMemory::Memcpy(Destination, BufferCache[CurrentCache]+(FilePos-CacheStart[CurrentCache]), BytesToRead);
						FilePos += BytesToRead;
					}
				}
			}
		}

		return Result;
	}

	virtual bool Write(const uint8* Source, int64 BytesToWrite) override
	{
		bool Result = false;

		if (bWritable && BytesToWrite >= 0)
		{
			if (BytesToWrite == 0)
			{
				Result = true;
			}
			else
			{
				Result = Network.SendWriteMessage(HandleId, Source, BytesToWrite);

				if (Result)
				{
					FilePos += BytesToWrite;
					FileSize = FMath::Max<int64>(FilePos, FileSize);
				}
			}
		}

		return Result;
	}
};
*/


bool FCookedIterativeNetworkFile::ShouldBeUsed(IPlatformFile* Inner, const TCHAR* CmdLine) const
{
	bool bResult = FNetworkPlatformFile::ShouldBeUsed(Inner, CmdLine);

	if (bResult)
	{
		bResult = FParse::Param(CmdLine, TEXT("precookednetwork"));
	}

	return bResult;
}

/*
bool FCookedIterativeNetworkFile::InitializeInternal(IPlatformFile* Inner, const TCHAR* HostIP)
{
	// look for the commandline that will read files from over the network
	if (HostIP == nullptr)
	{
		UE_LOG(LogStreamingPlatformFile, Error, TEXT("No Host IP specified in the commandline."));
		bIsUsable = false;

		return false;
	}

	// optionally get the port from the command line
	int32 OverridePort;
	if (FParse::Value(FCommandLine::Get(), TEXT("fileserverport="), OverridePort))
	{
		UE_LOG(LogStreamingPlatformFile, Display, TEXT("Overriding file server port: %d"), OverridePort);
		FileServerPort = OverridePort;
	}

	// Send the filenames and timestamps to the server.
	FNetworkFileArchive Payload(NFS_Messages::GetFileList);
	FillGetFileList(Payload, true);

	// Send the directories over, and wait for a response.
	FArrayReader Response;

	if(SendPayloadAndReceiveResponse(Payload,Response))
	{
		// Receive the cooked version information.
		int32 ServerPackageVersion = 0;
		int32 ServerPackageLicenseeVersion = 0;
		ProcessServerInitialResponse(Response, ServerPackageVersion, ServerPackageLicenseeVersion);

		// Make sure we can sync a file.
		FString TestSyncFile = FPaths::Combine(*(FPaths::EngineDir()), TEXT("Config/BaseEngine.ini"));
		IFileHandle* TestFileHandle = OpenRead(*TestSyncFile);
		if (TestFileHandle != nullptr)
		{
			uint8* FileContents = (uint8*)FMemory::Malloc(TestFileHandle->Size());
			if (!TestFileHandle->Read(FileContents, TestFileHandle->Size()))
			{
				UE_LOG(LogStreamingPlatformFile, Fatal, TEXT("Could not read test file %s."), *TestSyncFile);
			}
			FMemory::Free(FileContents);
			delete TestFileHandle;
		}
		else
		{
			UE_LOG(LogStreamingPlatformFile, Fatal, TEXT("Could not open test file %s."), *TestSyncFile);
		}

		FCommandLine::AddToSubprocessCommandline( *FString::Printf( TEXT("-StreamingHostIP=%s"), HostIP ) );

		return true; 
	}

	return false; 
}*/


FCookedIterativeNetworkFile::~FCookedIterativeNetworkFile()
{
}

/*
bool FStreamingNetworkPlatformFile::IterateDirectory(const TCHAR* InDirectory, IPlatformFile::FDirectoryVisitor& Visitor)
{
	FString RelativeDirectory = InDirectory;
	MakeStandardNetworkFilename(RelativeDirectory);
	// for .dll, etc searches that don't specify a path, we need to strip off the path
	// before we send it to the visitor
	bool bHadNoPath = InDirectory[0] == 0;

	// we loop until this is false
	bool RetVal = true;

	// Find the directory in TOC
	FServerTOC::FDirectory* ServerDirectory = ServerFiles.FindDirectory(RelativeDirectory);
	if (ServerDirectory != nullptr)
	{
		// loop over the server files and look if they are in this exact directory
		for (FServerTOC::FDirectory::TIterator It(*ServerDirectory); It && RetVal == true; ++It)
		{
			if (FPaths::GetPath(It.Key()) == RelativeDirectory)
			{
				// timestamps of 0 mean directories
				bool bIsDirectory = It.Value() == 0;
			
				// visit (stripping off the path if needed)
				RetVal = Visitor.Visit(bHadNoPath ? *FPaths::GetCleanFilename(It.Key()) : *It.Key(), bIsDirectory);
			}
		}
	}

	return RetVal;
}


bool FStreamingNetworkPlatformFile::IterateDirectoryRecursively(const TCHAR* InDirectory, IPlatformFile::FDirectoryVisitor& Visitor)
{
	FString RelativeDirectory = InDirectory;
	MakeStandardNetworkFilename(RelativeDirectory);
	// we loop until this is false
	bool RetVal = true;

	// loop over the server TOC
	for (TMap<FString, FServerTOC::FDirectory*>::TIterator DirIt(ServerFiles.Directories); DirIt && RetVal == true; ++DirIt)
	{
		if (DirIt.Key().StartsWith(RelativeDirectory))
		{
			FServerTOC::FDirectory& ServerDirectory = *DirIt.Value();
		
			// loop over the server files and look if they are in this exact directory
			for (FServerTOC::FDirectory::TIterator It(ServerDirectory); It && RetVal == true; ++It)
			{
				// timestamps of 0 mean directories
				bool bIsDirectory = It.Value() == 0;

				// visit!
				RetVal = Visitor.Visit(*It.Key(), bIsDirectory);
			}
		}
	}

	return RetVal;
}

*/


/**
 * Module for the streaming file
 */
class FCookedIterativeFileModule
	: public IPlatformFileModule
{
public:

	virtual IPlatformFile* GetPlatformFile() override
	{
		static TUniquePtr<IPlatformFile> AutoDestroySingleton = MakeUnique<FCookedIterativeNetworkFile>();
		return AutoDestroySingleton.Get();
	}
};


IMPLEMENT_MODULE(FCookedIterativeFileModule, CookedIterativeFile);