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

#include <zenutil/filebuildstorage.h>

#include <zencore/basicfile.h>
#include <zencore/compactbinarybuilder.h>
#include <zencore/compactbinaryvalidation.h>
#include <zencore/fmtutils.h>
#include <zencore/scopeguard.h>
#include <zencore/timer.h>
#include <zencore/trace.h>

namespace zen {

using namespace std::literals;

class FileBuildStorage : public BuildStorage
{
public:
	explicit FileBuildStorage(const std::filesystem::path& StoragePath,
							  BuildStorage::Statistics&	   Stats,
							  bool						   EnableJsonOutput,
							  double					   LatencySec,
							  double					   DelayPerKBSec)
	: m_StoragePath(StoragePath)
	, m_Stats(Stats)
	, m_EnableJsonOutput(EnableJsonOutput)
	, m_LatencySec(LatencySec)
	, m_DelayPerKBSec(DelayPerKBSec)
	{
		CreateDirectories(GetBuildsFolder());
		CreateDirectories(GetBlobsFolder());
		CreateDirectories(GetBlobsMetadataFolder());
	}

	virtual ~FileBuildStorage() {}

	virtual CbObject ListNamespaces(bool bRecursive) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::ListNamespaces");
		ZEN_UNUSED(bRecursive);

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		CbObjectWriter Writer;
		Writer.BeginArray("results");
		{
		}
		Writer.EndArray();	// results

		Writer.Finalize();
		ReceivedBytes = Writer.GetSaveSize();
		return Writer.Save();
	}

	virtual CbObject ListBuilds(CbObject Query) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::ListBuilds");
		ZEN_UNUSED(Query);

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = Query.GetSize();

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		const std::filesystem::path BuildFolder = GetBuildsFolder();
		DirectoryContent			Content;
		GetDirectoryContent(BuildFolder, DirectoryContentFlags::IncludeDirs, Content);
		CbObjectWriter Writer;
		Writer.BeginArray("results");
		{
			for (const std::filesystem::path& BuildPath : Content.Directories)
			{
				Oid BuildId = Oid::TryFromHexString(BuildPath.stem().string());
				if (BuildId != Oid::Zero)
				{
					Writer.BeginObject();
					{
						Writer.AddObjectId("buildId", BuildId);
						Writer.AddObject("metadata", ReadBuild(BuildId)["metadata"sv].AsObjectView());
					}
					Writer.EndObject();
				}
			}
		}
		Writer.EndArray();	// results

		Writer.Finalize();
		ReceivedBytes = Writer.GetSaveSize();
		return Writer.Save();
	}

	virtual CbObject PutBuild(const Oid& BuildId, const CbObject& MetaData) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::PutBuild");
		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = MetaData.GetSize();

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		CbObjectWriter BuildObject;
		BuildObject.AddObject("metadata", MetaData);
		BuildObject.AddInteger("chunkSize"sv, 32u * 1024u * 1024u);
		WriteBuild(BuildId, BuildObject.Save());

		CbObjectWriter BuildResponse;
		BuildResponse.AddInteger("chunkSize"sv, 32u * 1024u * 1024u);
		BuildResponse.Finalize();
		ReceivedBytes = BuildResponse.GetSaveSize();
		return BuildResponse.Save();
	}

	virtual CbObject GetBuild(const Oid& BuildId) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::GetBuild");
		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		CbObject Build = ReadBuild(BuildId);
		ReceivedBytes  = Build.GetSize();
		return Build;
	}

	virtual void FinalizeBuild(const Oid& BuildId) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::FinalizeBuild");
		ZEN_UNUSED(BuildId);

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });
	}

	virtual std::pair<IoHash, std::vector<IoHash>> PutBuildPart(const Oid&		 BuildId,
																const Oid&		 BuildPartId,
																std::string_view PartName,
																const CbObject&	 MetaData) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::PutBuildPart");
		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = MetaData.GetSize();

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		const std::filesystem::path BuildPartDataPath = GetBuildPartPath(BuildId, BuildPartId);
		CreateDirectories(BuildPartDataPath.parent_path());

		TemporaryFile::SafeWriteFile(BuildPartDataPath, MetaData.GetView());
		m_WrittenBytes += MetaData.GetSize();
		WriteAsJson(BuildPartDataPath, MetaData);

		IoHash RawHash = IoHash::HashBuffer(MetaData.GetView());

		CbObjectWriter Writer;
		{
			CbObject	 BuildObject  = ReadBuild(BuildId);
			CbObjectView PartsObject  = BuildObject["parts"sv].AsObjectView();
			CbObjectView MetaDataView = BuildObject["metadata"sv].AsObjectView();

			Writer.AddObject("metadata"sv, MetaDataView);
			Writer.BeginObject("parts"sv);
			{
				for (CbFieldView PartView : PartsObject)
				{
					if (PartView.GetName() != PartName)
					{
						Writer.AddObjectId(PartView.GetName(), PartView.AsObjectId());
					}
				}
				Writer.AddObjectId(PartName, BuildPartId);
			}
			Writer.EndObject();	 // parts
		}
		WriteBuild(BuildId, Writer.Save());

		std::vector<IoHash> NeededAttachments = GetNeededAttachments(MetaData);

		ReceivedBytes = sizeof(IoHash) * NeededAttachments.size();

		return std::make_pair(RawHash, std::move(NeededAttachments));
	}

	virtual CbObject GetBuildPart(const Oid& BuildId, const Oid& BuildPartId) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::GetBuildPart");
		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		const std::filesystem::path BuildPartDataPath = GetBuildPartPath(BuildId, BuildPartId);

		IoBuffer Payload = ReadFile(BuildPartDataPath).Flatten();

		ZEN_ASSERT(ValidateCompactBinary(Payload.GetView(), CbValidateMode::Default) == CbValidateError::None);

		CbObject BuildPartObject = CbObject(SharedBuffer(Payload));

		ReceivedBytes = BuildPartObject.GetSize();

		return BuildPartObject;
	}

	virtual std::vector<IoHash> FinalizeBuildPart(const Oid& BuildId, const Oid& BuildPartId, const IoHash& PartHash) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::FinalizeBuildPart");
		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		const std::filesystem::path BuildPartDataPath = GetBuildPartPath(BuildId, BuildPartId);
		IoBuffer					Payload			  = ReadFile(BuildPartDataPath).Flatten();

		IoHash RawHash = IoHash::HashBuffer(Payload.GetView());
		if (RawHash != PartHash)
		{
			throw std::runtime_error(
				fmt::format("Failed finalizing build part {}: Expected hash {}, got {}", BuildPartId, PartHash, RawHash));
		}

		CbObject			BuildPartObject = CbObject(SharedBuffer(Payload));
		std::vector<IoHash> NeededAttachments(GetNeededAttachments(BuildPartObject));

		ReceivedBytes = NeededAttachments.size() * sizeof(IoHash);

		return NeededAttachments;
	}

	virtual void PutBuildBlob(const Oid&			 BuildId,
							  const IoHash&			 RawHash,
							  ZenContentType		 ContentType,
							  const CompositeBuffer& Payload) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::PutBuildBlob");
		ZEN_UNUSED(BuildId);
		ZEN_ASSERT(ContentType == ZenContentType::kCompressedBinary);

		ZEN_ASSERT_SLOW(ValidateCompressedBuffer(RawHash, Payload));

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = Payload.GetSize();

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		const std::filesystem::path BlockPath = GetBlobPayloadPath(RawHash);
		if (!IsFile(BlockPath))
		{
			CreateDirectories(BlockPath.parent_path());
			TemporaryFile::SafeWriteFile(BlockPath, Payload.Flatten().GetView());
		}

		ReceivedBytes = Payload.GetSize();
	}

	virtual std::vector<std::function<void()>> PutLargeBuildBlob(const Oid&												   BuildId,
																 const IoHash&											   RawHash,
																 ZenContentType											   ContentType,
																 uint64_t												   PayloadSize,
																 std::function<IoBuffer(uint64_t Offset, uint64_t Size)>&& Transmitter,
																 std::function<void(uint64_t, bool)>&& OnSentBytes) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::PutLargeBuildBlob");
		ZEN_UNUSED(BuildId);
		ZEN_UNUSED(ContentType);

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		const std::filesystem::path BlockPath = GetBlobPayloadPath(RawHash);
		if (!IsFile(BlockPath))
		{
			CreateDirectories(BlockPath.parent_path());

			struct WorkloadData
			{
				std::function<IoBuffer(uint64_t Offset, uint64_t Size)> Transmitter;
				std::function<void(uint64_t, bool)>						OnSentBytes;
				TemporaryFile											TempFile;
				std::atomic<size_t>										PartsLeft;
			};

			std::shared_ptr<WorkloadData> Workload(std::make_shared<WorkloadData>());
			Workload->Transmitter = std::move(Transmitter);
			Workload->OnSentBytes = std::move(OnSentBytes);
			std::error_code Ec;
			Workload->TempFile.CreateTemporary(BlockPath.parent_path(), Ec);

			if (Ec)
			{
				throw std::runtime_error(
					fmt::format("Failed opening temporary file '{}': {} ({})", Workload->TempFile.GetPath(), Ec.message(), Ec.value()));
			}

			std::vector<std::function<void()>> WorkItems;
			uint64_t						   Offset = 0;
			while (Offset < PayloadSize)
			{
				uint64_t Size = Min(32u * 1024u * 1024u, PayloadSize - Offset);

				WorkItems.push_back([this, RawHash, BlockPath, Workload, Offset, Size]() {
					ZEN_TRACE_CPU("FileBuildStorage::PutLargeBuildBlob_Work");
					IoBuffer PartPayload = Workload->Transmitter(Offset, Size);

					uint64_t ReceivedBytes = 0;
					uint64_t SentBytes	   = PartPayload.GetSize();

					SimulateLatency(SentBytes, 0);
					auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

					Stopwatch ExecutionTimer;
					auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

					std::error_code Ec;
					Workload->TempFile.Write(PartPayload, Offset, Ec);
					if (Ec)
					{
						throw std::runtime_error(fmt::format("Failed writing to temporary file '{}': {} ({})",
															 Workload->TempFile.GetPath(),
															 Ec.message(),
															 Ec.value()));
					}

					const bool IsLastPart = Workload->PartsLeft.fetch_sub(1) == 1;
					if (IsLastPart)
					{
						Workload->TempFile.Flush();
						ZEN_ASSERT_SLOW(ValidateCompressedBuffer(RawHash, CompositeBuffer(Workload->TempFile.ReadAll())));
						Workload->TempFile.MoveTemporaryIntoPlace(BlockPath, Ec);
						if (Ec)
						{
							throw std::runtime_error(fmt::format("Failed moving temporary file '{}' to '{}': {} ({})",
																 Workload->TempFile.GetPath(),
																 BlockPath,
																 Ec.message(),
																 Ec.value()));
						}
					}
					Workload->OnSentBytes(SentBytes, IsLastPart);
				});

				Offset += Size;
			}
			Workload->PartsLeft.store(WorkItems.size());
			return WorkItems;
		}
		return {};
	}

	virtual IoBuffer GetBuildBlob(const Oid& BuildId, const IoHash& RawHash, uint64_t RangeOffset, uint64_t RangeBytes) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::GetBuildBlob");
		ZEN_UNUSED(BuildId);

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		const std::filesystem::path BlockPath = GetBlobPayloadPath(RawHash);
		if (IsFile(BlockPath))
		{
			BasicFile File(BlockPath, BasicFile::Mode::kRead);
			IoBuffer  Payload;
			if (RangeOffset != 0 || RangeBytes != (uint64_t)-1)
			{
				Payload = IoBuffer(RangeBytes);
				File.Read(Payload.GetMutableView().GetData(), RangeBytes, RangeOffset);
			}
			else
			{
				Payload = File.ReadAll();
				ZEN_ASSERT_SLOW(ValidateCompressedBuffer(RawHash, CompositeBuffer(SharedBuffer(Payload))));
			}
			Payload.SetContentType(ZenContentType::kCompressedBinary);
			ReceivedBytes = Payload.GetSize();
			return Payload;
		}
		return IoBuffer{};
	}

	virtual std::vector<std::function<void()>> GetLargeBuildBlob(const Oid&													   BuildId,
																 const IoHash&												   RawHash,
																 uint64_t													   ChunkSize,
																 std::function<void(uint64_t Offset, const IoBuffer& Chunk)>&& OnReceive,
																 std::function<void()>&& OnComplete) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::GetLargeBuildBlob");
		ZEN_UNUSED(BuildId);

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		const std::filesystem::path BlockPath = GetBlobPayloadPath(RawHash);
		if (IsFile(BlockPath))
		{
			struct WorkloadData
			{
				std::atomic<uint64_t>										BytesRemaining;
				BasicFile													BlobFile;
				std::function<void(uint64_t Offset, const IoBuffer& Chunk)> OnReceive;
				std::function<void()>										OnComplete;
			};

			std::shared_ptr<WorkloadData> Workload(std::make_shared<WorkloadData>());
			Workload->BlobFile.Open(BlockPath, BasicFile::Mode::kRead);
			const uint64_t BlobSize = Workload->BlobFile.FileSize();

			Workload->OnReceive		 = std::move(OnReceive);
			Workload->OnComplete	 = std::move(OnComplete);
			Workload->BytesRemaining = BlobSize;

			std::vector<std::function<void()>> WorkItems;
			uint64_t						   Offset = 0;
			while (Offset < BlobSize)
			{
				uint64_t Size = Min(ChunkSize, BlobSize - Offset);
				WorkItems.push_back([this, BlockPath, Workload, Offset, Size]() {
					ZEN_TRACE_CPU("FileBuildStorage::GetLargeBuildBlob_Work");

					uint64_t ReceivedBytes = 0;
					uint64_t SentBytes	   = 0;

					SimulateLatency(SentBytes, 0);
					auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

					Stopwatch ExecutionTimer;
					auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

					IoBuffer PartPayload(Size);
					Workload->BlobFile.Read(PartPayload.GetMutableView().GetData(), Size, Offset);
					ReceivedBytes = PartPayload.GetSize();
					Workload->OnReceive(Offset, PartPayload);
					uint64_t ByteRemaning = Workload->BytesRemaining.fetch_sub(Size);
					if (ByteRemaning == Size)
					{
						Workload->OnComplete();
					}
				});

				Offset += Size;
			}
			return WorkItems;
		}
		return {};
	}

	virtual bool PutBlockMetadata(const Oid& BuildId, const IoHash& BlockRawHash, const CbObject& MetaData) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::PutBlockMetadata");
		ZEN_UNUSED(BuildId);

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = MetaData.GetSize();

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		const std::filesystem::path BlockMetaDataPath = GetBlobMetadataPath(BlockRawHash);
		CreateDirectories(BlockMetaDataPath.parent_path());
		TemporaryFile::SafeWriteFile(BlockMetaDataPath, MetaData.GetView());
		WriteAsJson(BlockMetaDataPath, MetaData);
		return true;
	}

	virtual CbObject FindBlocks(const Oid& BuildId, uint64_t MaxBlockCount) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::FindBlocks");
		ZEN_UNUSED(BuildId);

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		uint64_t FoundCount = 0;

		DirectoryContent Content;
		GetDirectoryContent(GetBlobsMetadataFolder(), DirectoryContentFlags::IncludeFiles, Content);
		CbObjectWriter Writer;
		Writer.BeginArray("blocks");
		for (const std::filesystem::path& MetaDataFile : Content.Files)
		{
			IoHash ChunkHash;
			if (IoHash::TryParse(MetaDataFile.stem().string(), ChunkHash))
			{
				std::filesystem::path BlockPath = GetBlobPayloadPath(ChunkHash);
				if (IsFile(BlockPath))
				{
					IoBuffer BlockMetaDataPayload = ReadFile(MetaDataFile).Flatten();

					CbObject BlockObject = CbObject(SharedBuffer(BlockMetaDataPayload));
					Writer.AddObject(BlockObject);
					FoundCount++;
					if (FoundCount == MaxBlockCount)
					{
						break;
					}
				}
			}
		}
		Writer.EndArray();	// blocks

		Writer.Finalize();
		ReceivedBytes = Writer.GetSaveSize();
		return Writer.Save();
	}

	virtual CbObject GetBlockMetadatas(const Oid& BuildId, std::span<const IoHash> BlockHashes) override
	{
		ZEN_TRACE_CPU("FileBuildStorage::GetBlockMetadata");
		ZEN_UNUSED(BuildId);

		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = sizeof(Oid) + sizeof(IoHash) * BlockHashes.size();

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		CbObjectWriter Writer;
		Writer.BeginArray("blocks");

		for (const IoHash& BlockHash : BlockHashes)
		{
			std::filesystem::path MetaDataFile = GetBlobMetadataPath(BlockHash);
			if (IsFile(MetaDataFile))
			{
				IoBuffer BlockMetaDataPayload = ReadFile(MetaDataFile).Flatten();

				CbObject BlockObject = CbObject(SharedBuffer(BlockMetaDataPayload));
				Writer.AddObject(BlockObject);
			}
		}
		Writer.EndArray();	// blocks
		Writer.Finalize();
		ReceivedBytes = Writer.GetSaveSize();
		return Writer.Save();
	}

	virtual void PutBuildPartStats(const Oid&								  BuildId,
								   const Oid&								  BuildPartId,
								   const tsl::robin_map<std::string, double>& FloatStats) override
	{
		uint64_t ReceivedBytes = 0;
		uint64_t SentBytes	   = 0;

		SimulateLatency(SentBytes, 0);
		auto _ = MakeGuard([&]() { SimulateLatency(0, ReceivedBytes); });

		Stopwatch ExecutionTimer;
		auto	  __ = MakeGuard([&]() { AddStatistic(ExecutionTimer, SentBytes, ReceivedBytes); });

		CbObjectWriter Request;
		Request.BeginObject("floatStats"sv);
		for (auto It : FloatStats)
		{
			Request.AddFloat(It.first, It.second);
		}
		Request.EndObject();
		Request.Finalize();
		SentBytes = Request.GetSaveSize();

		const std::filesystem::path BuildPartStatsDataPath = GetBuildPartStatsPath(BuildId, BuildPartId);
		CreateDirectories(BuildPartStatsDataPath.parent_path());

		CbObject Payload = Request.Save();

		TemporaryFile::SafeWriteFile(BuildPartStatsDataPath, Payload.GetView());
		WriteAsJson(BuildPartStatsDataPath, Payload);
	}

protected:
	std::filesystem::path GetBuildsFolder() const { return m_StoragePath / "builds"; }
	std::filesystem::path GetBlobsFolder() const { return m_StoragePath / "blobs"; }
	std::filesystem::path GetBlobsMetadataFolder() const { return m_StoragePath / "blocks"; }
	std::filesystem::path GetBuildFolder(const Oid& BuildId) const { return GetBuildsFolder() / BuildId.ToString(); }

	std::filesystem::path GetBuildPath(const Oid& BuildId) const { return GetBuildFolder(BuildId) / "metadata.cb"; }

	std::filesystem::path GetBuildPartFolder(const Oid& BuildId, const Oid& BuildPartId) const
	{
		return GetBuildFolder(BuildId) / "parts" / BuildPartId.ToString();
	}

	std::filesystem::path GetBuildPartPath(const Oid& BuildId, const Oid& BuildPartId) const
	{
		return GetBuildPartFolder(BuildId, BuildPartId) / "metadata.cb";
	}

	std::filesystem::path GetBuildPartStatsPath(const Oid& BuildId, const Oid& BuildPartId) const
	{
		return GetBuildPartFolder(BuildId, BuildPartId) / fmt::format("stats_{}.cb", Oid::NewOid());
	}

	std::filesystem::path GetBlobPayloadPath(const IoHash& RawHash) const { return GetBlobsFolder() / fmt::format("{}.cbz", RawHash); }

	std::filesystem::path GetBlobMetadataPath(const IoHash& RawHash) const
	{
		return GetBlobsMetadataFolder() / fmt::format("{}.cb", RawHash);
	}

	void SimulateLatency(uint64_t ReceiveSize, uint64_t SendSize)
	{
		double SleepSec = m_LatencySec;
		if (m_DelayPerKBSec > 0.0)
		{
			SleepSec += m_DelayPerKBSec * (double(SendSize + ReceiveSize) / 1024u);
		}
		if (SleepSec > 0)
		{
			Sleep(int(SleepSec * 1000));
		}
	}

	void WriteAsJson(const std::filesystem::path& OriginalPath, CbObjectView Data) const
	{
		if (m_EnableJsonOutput)
		{
			ExtendableStringBuilder<128> SB;
			CompactBinaryToJson(Data, SB);
			std::filesystem::path JsonPath = OriginalPath;
			JsonPath.replace_extension(".json");
			std::string_view JsonMetaData = SB.ToView();
			TemporaryFile::SafeWriteFile(JsonPath, MemoryView(JsonMetaData.data(), JsonMetaData.length()));
		}
	}

	void WriteBuild(const Oid& BuildId, CbObjectView Data)
	{
		const std::filesystem::path BuildDataPath = GetBuildPath(BuildId);
		CreateDirectories(BuildDataPath.parent_path());
		TemporaryFile::SafeWriteFile(BuildDataPath, Data.GetView());
		WriteAsJson(BuildDataPath, Data);
	}

	CbObject ReadBuild(const Oid& BuildId)
	{
		const std::filesystem::path BuildDataPath = GetBuildPath(BuildId);
		FileContents				Content		  = ReadFile(BuildDataPath);
		if (Content.ErrorCode)
		{
			throw std::runtime_error(fmt::format("Failed reading build '{}' from '{}': {} ({})",
												 BuildId,
												 BuildDataPath,
												 Content.ErrorCode.message(),
												 Content.ErrorCode.value()));
		}
		IoBuffer Payload = Content.Flatten();
		ZEN_ASSERT(ValidateCompactBinary(Payload.GetView(), CbValidateMode::Default) == CbValidateError::None);
		CbObject BuildObject = CbObject(SharedBuffer(Payload));
		return BuildObject;
	}

	std::vector<IoHash> GetNeededAttachments(CbObjectView BuildPartObject)
	{
		std::vector<IoHash> NeededAttachments;
		BuildPartObject.IterateAttachments([&](CbFieldView FieldView) {
			const IoHash				AttachmentHash = FieldView.AsBinaryAttachment();
			const std::filesystem::path BlockPath	   = GetBlobPayloadPath(AttachmentHash);
			if (!IsFile(BlockPath))
			{
				NeededAttachments.push_back(AttachmentHash);
			}
		});
		return NeededAttachments;
	}

	bool ValidateCompressedBuffer(const IoHash& RawHash, const CompositeBuffer& Payload)
	{
		IoHash			 VerifyHash;
		uint64_t		 VerifySize;
		CompressedBuffer ValidateBuffer = CompressedBuffer::FromCompressed(Payload, VerifyHash, VerifySize);
		if (!ValidateBuffer)
		{
			return false;
		}
		if (VerifyHash != RawHash)
		{
			return false;
		}

		IoHashStream Hash;
		bool		 CouldDecompress = ValidateBuffer.DecompressToStream(
			0,
			(uint64_t)-1,
			[&](uint64_t SourceOffset, uint64_t SourceSize, uint64_t Offset, const CompositeBuffer& RangeBuffer) {
				ZEN_UNUSED(SourceOffset, SourceSize, Offset);
				for (const SharedBuffer& Segment : RangeBuffer.GetSegments())
				{
					Hash.Append(Segment.GetView());
				}
				return true;
			});
		if (!CouldDecompress)
		{
			return false;
		}
		if (Hash.GetHash() != VerifyHash)
		{
			return false;
		}
		return true;
	}

private:
	void AddStatistic(Stopwatch& ExecutionTimer, uint64_t UploadedBytes, uint64_t DownloadedBytes)
	{
		const uint64_t ElapsedUs = ExecutionTimer.GetElapsedTimeUs();
		m_Stats.TotalBytesWritten += UploadedBytes;
		m_Stats.TotalBytesRead += DownloadedBytes;
		m_Stats.TotalRequestTimeUs += ElapsedUs;
		m_Stats.TotalRequestCount++;
		SetAtomicMax(m_Stats.PeakSentBytes, UploadedBytes);
		SetAtomicMax(m_Stats.PeakReceivedBytes, DownloadedBytes);
		if (ElapsedUs > 0)
		{
			uint64_t BytesPerSec = ((UploadedBytes + DownloadedBytes) * 1000000u) / ElapsedUs;
			SetAtomicMax(m_Stats.PeakBytesPerSec, BytesPerSec);
		}
	}

	const std::filesystem::path m_StoragePath;
	BuildStorage::Statistics&	m_Stats;
	const bool					m_EnableJsonOutput = false;
	std::atomic<uint64_t>		m_WrittenBytes;

	const double m_LatencySec	 = 0.0;
	const double m_DelayPerKBSec = 0.0;
};

std::unique_ptr<BuildStorage>
CreateFileBuildStorage(const std::filesystem::path& StoragePath,
					   BuildStorage::Statistics&	Stats,
					   bool							EnableJsonOutput,
					   double						LatencySec,
					   double						DelayPerKBSec)
{
	return std::make_unique<FileBuildStorage>(StoragePath, Stats, EnableJsonOutput, LatencySec, DelayPerKBSec);
}

}  // namespace zen