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

#include "structuredcache.h"

#include <zencore/compactbinary.h>
#include <zencore/compactbinarybuilder.h>
#include <zencore/compactbinarypackage.h>
#include <zencore/compactbinaryvalidation.h>
#include <zencore/compress.h>
#include <zencore/enumflags.h>
#include <zencore/fmtutils.h>
#include <zencore/logging.h>
#include <zencore/scopeguard.h>
#include <zencore/stream.h>
#include <zencore/timer.h>
#include <zencore/trace.h>
#include <zenhttp/httpserver.h>
#include <zenhttp/httpshared.h>
#include <zenstore/cas.h>
#include <zenutil/cache/cache.h>

//#include "cachekey.h"
#include "monitoring/httpstats.h"
#include "structuredcachestore.h"
#include "upstream/jupiter.h"
#include "upstream/upstreamcache.h"
#include "upstream/zen.h"
#include "zenstore/cidstore.h"

#include <algorithm>
#include <atomic>
#include <filesystem>
#include <queue>
#include <thread>

#include <gsl/gsl-lite.hpp>

namespace zen {

using namespace std::literals;

//////////////////////////////////////////////////////////////////////////

CachePolicy
ParseCachePolicy(const HttpServerRequest::QueryParams& QueryParams)
{
	std::string_view PolicyText = QueryParams.GetValue("Policy"sv);
	return !PolicyText.empty() ? zen::ParseCachePolicy(PolicyText) : CachePolicy::Default;
}

CacheRecordPolicy
LoadCacheRecordPolicy(CbObjectView Object, CachePolicy DefaultPolicy = CachePolicy::Default)
{
	OptionalCacheRecordPolicy Policy = CacheRecordPolicy::Load(Object);
	return Policy ? std::move(Policy).Get() : CacheRecordPolicy(DefaultPolicy);
}

struct AttachmentCount
{
	uint32_t New	 = 0;
	uint32_t Valid	 = 0;
	uint32_t Invalid = 0;
	uint32_t Total	 = 0;
};

struct PutRequestData
{
	CacheKey		  Key;
	CbObjectView	  RecordObject;
	CacheRecordPolicy Policy;
};

//////////////////////////////////////////////////////////////////////////

HttpStructuredCacheService::HttpStructuredCacheService(ZenCacheStore&	  InCacheStore,
													   CidStore&		  InCidStore,
													   HttpStatsService&  StatsService,
													   HttpStatusService& StatusService,
													   UpstreamCache&	  UpstreamCache)
: m_Log(logging::Get("cache"))
, m_CacheStore(InCacheStore)
, m_StatsService(StatsService)
, m_StatusService(StatusService)
, m_CidStore(InCidStore)
, m_UpstreamCache(UpstreamCache)
{
	m_StatsService.RegisterHandler("z$", *this);
	m_StatusService.RegisterHandler("z$", *this);
}

HttpStructuredCacheService::~HttpStructuredCacheService()
{
	ZEN_INFO("closing structured cache");

	m_StatsService.UnregisterHandler("z$", *this);
	m_StatusService.UnregisterHandler("z$", *this);
}

const char*
HttpStructuredCacheService::BaseUri() const
{
	return "/z$/";
}

void
HttpStructuredCacheService::Flush()
{
}

void
HttpStructuredCacheService::Scrub(ScrubContext& Ctx)
{
	if (m_LastScrubTime == Ctx.ScrubTimestamp())
	{
		return;
	}

	m_LastScrubTime = Ctx.ScrubTimestamp();

	m_CidStore.Scrub(Ctx);
	m_CacheStore.Scrub(Ctx);
}

void
HttpStructuredCacheService::HandleRequest(HttpServerRequest& Request)
{
	CacheRef Ref;

	metrics::OperationTiming::Scope $(m_HttpRequests);

	if (!ValidateKeyUri(Request, /* out */ Ref))
	{
		std::string_view Key = Request.RelativeUri();

		if (Key == "$rpc")
		{
			return HandleRpcRequest(Request);
		}

		if (std::all_of(begin(Key), end(Key), [](const char c) { return std::isalnum(c); }))
		{
			// Bucket reference

			return HandleCacheBucketRequest(Request, Key);
		}

		return Request.WriteResponse(HttpResponseCode::BadRequest);	 // invalid URL
	}

	CachePolicy PolicyFromURL = ParseCachePolicy(Request.GetQueryParams());

	if (Ref.ValueContentId == IoHash::Zero)
	{
		return HandleCacheRecordRequest(Request, Ref, PolicyFromURL);
	}
	else
	{
		return HandleCacheValueRequest(Request, Ref, PolicyFromURL);
	}

	return;
}

void
HttpStructuredCacheService::HandleCacheBucketRequest(HttpServerRequest& Request, std::string_view Bucket)
{
	switch (Request.RequestVerb())
	{
		case HttpVerb::kHead:
		case HttpVerb::kGet:
			{
				// Query stats
			}
			break;

		case HttpVerb::kDelete:
			// Drop bucket

			if (m_CacheStore.DropBucket(Bucket))
			{
				return Request.WriteResponse(HttpResponseCode::OK);
			}
			else
			{
				return Request.WriteResponse(HttpResponseCode::NotFound);
			}
			break;

		default:
			break;
	}
}

void
HttpStructuredCacheService::HandleCacheRecordRequest(HttpServerRequest& Request, const CacheRef& Ref, CachePolicy PolicyFromURL)
{
	switch (Request.RequestVerb())
	{
		case HttpVerb::kHead:
		case HttpVerb::kGet:
			{
				HandleGetCacheRecord(Request, Ref, PolicyFromURL);
			}
			break;

		case HttpVerb::kPut:
			HandlePutCacheRecord(Request, Ref, PolicyFromURL);
			break;
		default:
			break;
	}
}

void
HttpStructuredCacheService::HandleGetCacheRecord(zen::HttpServerRequest& Request, const CacheRef& Ref, CachePolicy PolicyFromURL)
{
	const ZenContentType AcceptType	   = Request.AcceptContentType();
	const bool			 SkipData	   = EnumHasAllFlags(PolicyFromURL, CachePolicy::SkipData);
	const bool			 PartialRecord = EnumHasAllFlags(PolicyFromURL, CachePolicy::PartialRecord);

	bool		  Success = false;
	ZenCacheValue ClientResultValue;
	if (!EnumHasAnyFlags(PolicyFromURL, CachePolicy::Query))
	{
		return Request.WriteResponse(HttpResponseCode::OK);
	}

	if (EnumHasAllFlags(PolicyFromURL, CachePolicy::QueryLocal) && m_CacheStore.Get(Ref.BucketSegment, Ref.HashKey, ClientResultValue))
	{
		Success = true;

		if (AcceptType == ZenContentType::kCbPackage)
		{
			CbPackage Package;
			uint32_t  MissingCount = 0;

			CbObjectView CacheRecord(ClientResultValue.Value.Data());
			CacheRecord.IterateAttachments([this, &MissingCount, &Package, SkipData](CbFieldView AttachmentHash) {
				if (SkipData)
				{
					MissingCount += m_CidStore.ContainsChunk(AttachmentHash.AsHash()) ? 0 : 1;
				}
				else
				{
					if (IoBuffer Chunk = m_CidStore.FindChunkByCid(AttachmentHash.AsHash()))
					{
						Package.AddAttachment(CbAttachment(CompressedBuffer::FromCompressed(SharedBuffer(Chunk))));
					}
					else
					{
						MissingCount++;
					}
				}
			});

			Success = MissingCount == 0 || PartialRecord;

			if (Success)
			{
				Package.SetObject(LoadCompactBinaryObject(ClientResultValue.Value));

				BinaryWriter MemStream;
				Package.Save(MemStream);

				ClientResultValue.Value = IoBuffer(IoBuffer::Clone, MemStream.Data(), MemStream.Size());
				ClientResultValue.Value.SetContentType(HttpContentType::kCbPackage);
			}
		}
	}

	if (Success)
	{
		ZEN_DEBUG("HIT - '{}/{}' {} '{}' (LOCAL)",
				  Ref.BucketSegment,
				  Ref.HashKey,
				  NiceBytes(ClientResultValue.Value.Size()),
				  ToString(ClientResultValue.Value.GetContentType()));

		m_CacheStats.HitCount++;
		if (SkipData && AcceptType == ZenContentType::kBinary)
		{
			return Request.WriteResponse(HttpResponseCode::OK);
		}
		else
		{
			// Other types handled SkipData when constructing the ClientResultValue
			return Request.WriteResponse(HttpResponseCode::OK, ClientResultValue.Value.GetContentType(), ClientResultValue.Value);
		}
	}
	else if (!EnumHasAllFlags(PolicyFromURL, CachePolicy::QueryRemote))
	{
		ZEN_DEBUG("MISS - '{}/{}' '{}'", Ref.BucketSegment, Ref.HashKey, ToString(AcceptType));
		m_CacheStats.MissCount++;
		return Request.WriteResponse(HttpResponseCode::NotFound);
	}

	// Issue upstream query asynchronously in order to keep requests flowing without
	// hogging I/O servicing threads with blocking work

	Request.WriteResponseAsync([this, AcceptType, PolicyFromURL, Ref](HttpServerRequest& AsyncRequest) {
		bool		  Success		= false;
		const bool	  PartialRecord = EnumHasAllFlags(PolicyFromURL, CachePolicy::PartialRecord);
		const bool	  QueryLocal	= EnumHasAllFlags(PolicyFromURL, CachePolicy::QueryLocal);
		const bool	  StoreLocal	= EnumHasAllFlags(PolicyFromURL, CachePolicy::StoreLocal);
		const bool	  SkipData		= EnumHasAllFlags(PolicyFromURL, CachePolicy::SkipData);
		ZenCacheValue ClientResultValue;

		metrics::OperationTiming::Scope $(m_UpstreamGetRequestTiming);

		if (GetUpstreamCacheResult UpstreamResult = m_UpstreamCache.GetCacheRecord({Ref.BucketSegment, Ref.HashKey}, AcceptType);
			UpstreamResult.Success)
		{
			Success = true;

			ClientResultValue.Value = UpstreamResult.Value;
			ClientResultValue.Value.SetContentType(AcceptType);

			if (AcceptType == ZenContentType::kBinary || AcceptType == ZenContentType::kCbObject)
			{
				if (AcceptType == ZenContentType::kCbObject)
				{
					const CbValidateError ValidationResult = ValidateCompactBinary(UpstreamResult.Value, CbValidateMode::All);
					if (ValidationResult != CbValidateError::None)
					{
						Success = false;
						ZEN_WARN("Get - '{}/{}' '{}' FAILED, invalid compact binary object from upstream",
								 Ref.BucketSegment,
								 Ref.HashKey,
								 ToString(AcceptType));
					}

					// We do not do anything to the returned object for SkipData, only package attachments are cut when skipping data
				}

				if (Success && StoreLocal)
				{
					m_CacheStore.Put(Ref.BucketSegment, Ref.HashKey, ClientResultValue);
				}
			}
			else if (AcceptType == ZenContentType::kCbPackage)
			{
				CbPackage Package;
				if (Package.TryLoad(ClientResultValue.Value))
				{
					CbObject		CacheRecord = Package.GetObject();
					AttachmentCount Count;

					CacheRecord.IterateAttachments([this, &Package, &Ref, &Count, QueryLocal, StoreLocal](CbFieldView HashView) {
						if (const CbAttachment* Attachment = Package.FindAttachment(HashView.AsHash()))
						{
							if (CompressedBuffer Compressed = Attachment->AsCompressedBinary())
							{
								if (StoreLocal)
								{
									auto InsertResult = m_CidStore.AddChunk(Compressed);
									if (InsertResult.New)
									{
										Count.New++;
									}
								}
								Count.Valid++;
							}
							else
							{
								ZEN_WARN("Uncompressed value '{}' from upstream cache record '{}/{}'",
										 HashView.AsHash(),
										 Ref.BucketSegment,
										 Ref.HashKey);
								Count.Invalid++;
							}
						}
						else if (QueryLocal)
						{
							if (IoBuffer Chunk = m_CidStore.FindChunkByCid(HashView.AsHash()))
							{
								Package.AddAttachment(CbAttachment(CompressedBuffer::FromCompressed(SharedBuffer(Chunk))));
								Count.Valid++;
							}
						}
						Count.Total++;
					});

					if ((Count.Valid == Count.Total) || PartialRecord)
					{
						ZenCacheValue CacheValue;
						CacheValue.Value = CacheRecord.GetBuffer().AsIoBuffer();
						CacheValue.Value.SetContentType(ZenContentType::kCbObject);

						if (StoreLocal)
						{
							m_CacheStore.Put(Ref.BucketSegment, Ref.HashKey, CacheValue);
						}

						BinaryWriter MemStream;
						if (SkipData)
						{
							// Save a package containing only the object.
							CbPackage(Package.GetObject()).Save(MemStream);
						}
						else
						{
							Package.Save(MemStream);
						}

						ClientResultValue.Value = IoBuffer(IoBuffer::Clone, MemStream.Data(), MemStream.Size());
						ClientResultValue.Value.SetContentType(ZenContentType::kCbPackage);
					}
					else
					{
						Success = false;
						ZEN_WARN("Get - '{}/{}' '{}' FAILED, attachments missing in upstream package",
								 Ref.BucketSegment,
								 Ref.HashKey,
								 ToString(AcceptType));
					}
				}
				else
				{
					Success = false;
					ZEN_WARN("Get - '{}/{}' '{}' FAILED, invalid upstream package", Ref.BucketSegment, Ref.HashKey, ToString(AcceptType));
				}
			}
		}

		if (Success)
		{
			ZEN_DEBUG("HIT - '{}/{}' {} '{}' (UPSTREAM)",
					  Ref.BucketSegment,
					  Ref.HashKey,
					  NiceBytes(ClientResultValue.Value.Size()),
					  ToString(ClientResultValue.Value.GetContentType()));

			m_CacheStats.HitCount++;
			m_CacheStats.UpstreamHitCount++;

			if (SkipData && AcceptType == ZenContentType::kBinary)
			{
				AsyncRequest.WriteResponse(HttpResponseCode::OK);
			}
			else
			{
				// Other methods modify ClientResultValue to a version that has skipped the data but keeps the Object and optionally
				// metadata.
				AsyncRequest.WriteResponse(HttpResponseCode::OK, ClientResultValue.Value.GetContentType(), ClientResultValue.Value);
			}
		}
		else
		{
			ZEN_DEBUG("MISS - '{}/{}' '{}'", Ref.BucketSegment, Ref.HashKey, ToString(AcceptType));
			m_CacheStats.MissCount++;
			AsyncRequest.WriteResponse(HttpResponseCode::NotFound);
		}
	});
}

void
HttpStructuredCacheService::HandlePutCacheRecord(zen::HttpServerRequest& Request, const CacheRef& Ref, CachePolicy PolicyFromURL)
{
	IoBuffer Body = Request.ReadPayload();

	if (!Body || Body.Size() == 0)
	{
		return Request.WriteResponse(HttpResponseCode::BadRequest);
	}

	const HttpContentType ContentType = Request.RequestContentType();

	Body.SetContentType(ContentType);

	if (ContentType == HttpContentType::kBinary || ContentType == HttpContentType::kCompressedBinary)
	{
		ZEN_DEBUG("PUT - '{}/{}' {} '{}'", Ref.BucketSegment, Ref.HashKey, NiceBytes(Body.Size()), ToString(ContentType));
		m_CacheStore.Put(Ref.BucketSegment, Ref.HashKey, {.Value = Body});

		if (EnumHasAllFlags(PolicyFromURL, CachePolicy::StoreRemote))
		{
			m_UpstreamCache.EnqueueUpstream({.Type = ContentType, .Key = {Ref.BucketSegment, Ref.HashKey}});
		}

		Request.WriteResponse(HttpResponseCode::Created);
	}
	else if (ContentType == HttpContentType::kCbObject)
	{
		const CbValidateError ValidationResult = ValidateCompactBinary(MemoryView(Body.GetData(), Body.GetSize()), CbValidateMode::All);

		if (ValidationResult != CbValidateError::None)
		{
			ZEN_WARN("PUT - '{}/{}' '{}' FAILED, invalid compact binary", Ref.BucketSegment, Ref.HashKey, ToString(ContentType));
			return Request.WriteResponse(HttpResponseCode::BadRequest, HttpContentType::kText, "Compact binary validation failed"sv);
		}

		CachePolicy			Policy = PolicyFromURL;
		CbObjectView		CacheRecord(Body.Data());
		std::vector<IoHash> ValidAttachments;
		int32_t				TotalCount = 0;

		CacheRecord.IterateAttachments([this, &TotalCount, &ValidAttachments](CbFieldView AttachmentHash) {
			const IoHash Hash = AttachmentHash.AsHash();
			if (m_CidStore.ContainsChunk(Hash))
			{
				ValidAttachments.emplace_back(Hash);
			}
			TotalCount++;
		});

		ZEN_DEBUG("PUT - '{}/{}' {} '{}' attachments '{}/{}' (valid/total)",
				  Ref.BucketSegment,
				  Ref.HashKey,
				  NiceBytes(Body.Size()),
				  ToString(ContentType),
				  TotalCount,
				  ValidAttachments.size());

		Body.SetContentType(ZenContentType::kCbObject);
		m_CacheStore.Put(Ref.BucketSegment, Ref.HashKey, {.Value = Body});

		const bool IsPartialRecord = TotalCount != static_cast<int32_t>(ValidAttachments.size());

		if (EnumHasAllFlags(Policy, CachePolicy::StoreRemote) && !IsPartialRecord)
		{
			m_UpstreamCache.EnqueueUpstream({.Type			  = ZenContentType::kCbObject,
											 .Key			  = {Ref.BucketSegment, Ref.HashKey},
											 .ValueContentIds = std::move(ValidAttachments)});
		}

		Request.WriteResponse(HttpResponseCode::Created);
	}
	else if (ContentType == HttpContentType::kCbPackage)
	{
		CbPackage Package;

		if (!Package.TryLoad(Body))
		{
			ZEN_WARN("PUT - '{}/{}' '{}' FAILED, invalid package", Ref.BucketSegment, Ref.HashKey, ToString(ContentType));
			return Request.WriteResponse(HttpResponseCode::BadRequest, HttpContentType::kText, "Invalid package"sv);
		}
		CachePolicy Policy = PolicyFromURL;

		CbObject			CacheRecord = Package.GetObject();
		AttachmentCount		Count;
		std::vector<IoHash> ValidAttachments;

		ValidAttachments.reserve(Package.GetAttachments().size());

		CacheRecord.IterateAttachments([this, &Ref, &Package, &ValidAttachments, &Count](CbFieldView HashView) {
			const IoHash Hash = HashView.AsHash();
			if (const CbAttachment* Attachment = Package.FindAttachment(Hash))
			{
				if (Attachment->IsCompressedBinary())
				{
					CompressedBuffer	   Chunk		= Attachment->AsCompressedBinary();
					CidStore::InsertResult InsertResult = m_CidStore.AddChunk(Chunk);

					ValidAttachments.emplace_back(InsertResult.DecompressedId);

					if (InsertResult.New)
					{
						Count.New++;
					}
					Count.Valid++;
				}
				else
				{
					ZEN_WARN("PUT - '{}/{}' '{}' FAILED, attachment '{}' is not compressed",
							 Ref.BucketSegment,
							 Ref.HashKey,
							 ToString(HttpContentType::kCbPackage),
							 Hash);
					Count.Invalid++;
				}
			}
			else if (m_CidStore.ContainsChunk(Hash))
			{
				ValidAttachments.emplace_back(Hash);
				Count.Valid++;
			}
			Count.Total++;
		});

		if (Count.Invalid > 0)
		{
			return Request.WriteResponse(HttpResponseCode::BadRequest, HttpContentType::kText, "Invalid attachment(s)"sv);
		}

		ZEN_DEBUG("PUT - '{}/{}' {} '{}', attachments '{}/{}/{}' (new/valid/total)",
				  Ref.BucketSegment,
				  Ref.HashKey,
				  NiceBytes(Body.GetSize()),
				  ToString(ContentType),
				  Count.New,
				  Count.Valid,
				  Count.Total);

		ZenCacheValue CacheValue;
		CacheValue.Value = CacheRecord.GetBuffer().AsIoBuffer();
		CacheValue.Value.SetContentType(ZenContentType::kCbObject);

		m_CacheStore.Put(Ref.BucketSegment, Ref.HashKey, CacheValue);

		const bool IsPartialRecord = Count.Valid != Count.Total;

		if (EnumHasAllFlags(Policy, CachePolicy::StoreRemote) && !IsPartialRecord)
		{
			m_UpstreamCache.EnqueueUpstream({.Type			  = ZenContentType::kCbPackage,
											 .Key			  = {Ref.BucketSegment, Ref.HashKey},
											 .ValueContentIds = std::move(ValidAttachments)});
		}

		Request.WriteResponse(HttpResponseCode::Created);
	}
	else
	{
		return Request.WriteResponse(HttpResponseCode::BadRequest, HttpContentType::kText, "Content-Type invalid"sv);
	}
}

void
HttpStructuredCacheService::HandleCacheValueRequest(HttpServerRequest& Request, const CacheRef& Ref, CachePolicy PolicyFromURL)
{
	switch (Request.RequestVerb())
	{
		case HttpVerb::kHead:
		case HttpVerb::kGet:
			HandleGetCacheValue(Request, Ref, PolicyFromURL);
			break;
		case HttpVerb::kPut:
			HandlePutCacheValue(Request, Ref, PolicyFromURL);
			break;
		default:
			break;
	}
}

void
HttpStructuredCacheService::HandleGetCacheValue(zen::HttpServerRequest& Request, const CacheRef& Ref, CachePolicy PolicyFromURL)
{
	IoBuffer	Value			= m_CidStore.FindChunkByCid(Ref.ValueContentId);
	bool		InUpstreamCache = false;
	CachePolicy Policy			= PolicyFromURL;
	const bool	QueryUpstream	= !Value && EnumHasAllFlags(Policy, CachePolicy::QueryRemote);

	if (QueryUpstream)
	{
		if (auto UpstreamResult = m_UpstreamCache.GetCacheValue({Ref.BucketSegment, Ref.HashKey}, Ref.ValueContentId);
			UpstreamResult.Success)
		{
			if (CompressedBuffer Compressed = CompressedBuffer::FromCompressed(SharedBuffer(UpstreamResult.Value)))
			{
				m_CidStore.AddChunk(Compressed);
				InUpstreamCache = true;
			}
			else
			{
				ZEN_WARN("got uncompressed upstream cache value");
			}
		}
	}

	if (!Value)
	{
		ZEN_DEBUG("MISS - '{}/{}/{}' '{}'", Ref.BucketSegment, Ref.HashKey, Ref.ValueContentId, ToString(Request.AcceptContentType()));
		m_CacheStats.MissCount++;
		return Request.WriteResponse(HttpResponseCode::NotFound);
	}

	ZEN_DEBUG("HIT - '{}/{}/{}' {} '{}' ({})",
			  Ref.BucketSegment,
			  Ref.HashKey,
			  Ref.ValueContentId,
			  NiceBytes(Value.Size()),
			  ToString(Value.GetContentType()),
			  InUpstreamCache ? "UPSTREAM" : "LOCAL");

	m_CacheStats.HitCount++;
	if (InUpstreamCache)
	{
		m_CacheStats.UpstreamHitCount++;
	}

	if (EnumHasAllFlags(Policy, CachePolicy::SkipData))
	{
		Request.WriteResponse(HttpResponseCode::OK);
	}
	else
	{
		Request.WriteResponse(HttpResponseCode::OK, HttpContentType::kBinary, Value);
	}
}

void
HttpStructuredCacheService::HandlePutCacheValue(zen::HttpServerRequest& Request, const CacheRef& Ref, CachePolicy PolicyFromURL)
{
	// Note: Individual cacherecord values are not propagated upstream until a valid cache record has been stored
	ZEN_UNUSED(PolicyFromURL);

	IoBuffer Body = Request.ReadPayload();

	if (!Body || Body.Size() == 0)
	{
		return Request.WriteResponse(HttpResponseCode::BadRequest);
	}

	Body.SetContentType(Request.RequestContentType());

	CompressedBuffer Compressed = CompressedBuffer::FromCompressed(SharedBuffer(Body));

	if (!Compressed)
	{
		return Request.WriteResponse(HttpResponseCode::BadRequest, HttpContentType::kText, "Attachments must be compressed"sv);
	}

	if (IoHash::FromBLAKE3(Compressed.GetRawHash()) != Ref.ValueContentId)
	{
		return Request.WriteResponse(HttpResponseCode::BadRequest,
									 HttpContentType::kText,
									 "ValueContentId does not match attachment hash"sv);
	}

	CidStore::InsertResult Result = m_CidStore.AddChunk(Compressed);

	ZEN_DEBUG("PUT - '{}/{}/{}' {} '{}' ({})",
			  Ref.BucketSegment,
			  Ref.HashKey,
			  Ref.ValueContentId,
			  NiceBytes(Body.Size()),
			  ToString(Body.GetContentType()),
			  Result.New ? "NEW" : "OLD");

	const HttpResponseCode ResponseCode = Result.New ? HttpResponseCode::Created : HttpResponseCode::OK;

	Request.WriteResponse(ResponseCode);
}

bool
HttpStructuredCacheService::ValidateKeyUri(HttpServerRequest& Request, CacheRef& OutRef)
{
	std::string_view			Key				  = Request.RelativeUri();
	std::string_view::size_type BucketSplitOffset = Key.find_first_of('/');

	if (BucketSplitOffset == std::string_view::npos)
	{
		return false;
	}

	OutRef.BucketSegment = ToLower(Key.substr(0, BucketSplitOffset));

	if (!std::all_of(begin(OutRef.BucketSegment), end(OutRef.BucketSegment), [](const char c) { return std::isalnum(c); }))
	{
		return false;
	}

	std::string_view HashSegment;
	std::string_view ValueSegment;

	std::string_view::size_type ValueSplitOffset = Key.find_last_of('/');

	// We know there is a slash so no need to check for npos return

	if (ValueSplitOffset == BucketSplitOffset)
	{
		// Basic cache record lookup
		HashSegment = Key.substr(BucketSplitOffset + 1);
	}
	else
	{
		// Cache record + valueid lookup
		HashSegment	 = Key.substr(BucketSplitOffset + 1, ValueSplitOffset - BucketSplitOffset - 1);
		ValueSegment = Key.substr(ValueSplitOffset + 1);
	}

	if (HashSegment.size() != IoHash::StringLength)
	{
		return false;
	}

	if (!ValueSegment.empty() && ValueSegment.size() == IoHash::StringLength)
	{
		const bool IsOk = ParseHexBytes(ValueSegment.data(), ValueSegment.size(), OutRef.ValueContentId.Hash);

		if (!IsOk)
		{
			return false;
		}
	}
	else
	{
		OutRef.ValueContentId = IoHash::Zero;
	}

	const bool IsOk = ParseHexBytes(HashSegment.data(), HashSegment.size(), OutRef.HashKey.Hash);

	if (!IsOk)
	{
		return false;
	}

	return true;
}

void
HttpStructuredCacheService::HandleRpcRequest(zen::HttpServerRequest& Request)
{
	switch (Request.RequestVerb())
	{
		case HttpVerb::kPost:
			{
				const HttpContentType ContentType = Request.RequestContentType();
				const HttpContentType AcceptType  = Request.AcceptContentType();

				if ((ContentType != HttpContentType::kCbObject && ContentType != HttpContentType::kCbPackage) ||
					AcceptType != HttpContentType::kCbPackage)
				{
					return Request.WriteResponse(HttpResponseCode::BadRequest);
				}

				Request.WriteResponseAsync([this, Body = Request.ReadPayload(), ContentType](HttpServerRequest& AsyncRequest) mutable {
					CbPackage	 Package;
					CbObjectView Object;
					CbObject	 ObjectBuffer;
					if (ContentType == HttpContentType::kCbObject)
					{
						ObjectBuffer = zen::LoadCompactBinaryObject(std::move(Body));
						Object		 = ObjectBuffer;
					}
					else
					{
						Package = ParsePackageMessage(Body);
						Object	= Package.GetObject();
					}
					const std::string_view Method = Object["Method"sv].AsString();
					if (Method == "PutCacheRecords"sv)
					{
						HandleRpcPutCacheRecords(AsyncRequest, Package);
					}
					else if (Method == "GetCacheRecords"sv)
					{
						HandleRpcGetCacheRecords(AsyncRequest, Object);
					}
					else if (Method == "PutCacheValues"sv)
					{
						HandleRpcPutCacheValues(AsyncRequest, Package);
					}
					else if (Method == "GetCacheValues"sv)
					{
						HandleRpcGetCacheValues(AsyncRequest, Object);
					}
					else if (Method == "GetCacheChunks"sv)
					{
						HandleRpcGetCacheChunks(AsyncRequest, Object);
					}
					else
					{
						AsyncRequest.WriteResponse(HttpResponseCode::BadRequest);
					}
				});
			}
			break;
		default:
			Request.WriteResponse(HttpResponseCode::BadRequest);
			break;
	}
}

void
HttpStructuredCacheService::HandleRpcPutCacheRecords(zen::HttpServerRequest& Request, const CbPackage& BatchRequest)
{
	ZEN_TRACE_CPU("Z$::RpcPutCacheRecords");
	CbObjectView BatchObject = BatchRequest.GetObject();

	CbObjectView Params = BatchObject["Params"sv].AsObjectView();
	CachePolicy	 DefaultPolicy;

	ZEN_ASSERT(BatchObject["Method"sv].AsString() == "PutCacheRecords"sv);

	std::string_view PolicyText = Params["DefaultPolicy"].AsString();
	DefaultPolicy				= !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
	std::vector<bool> Results;
	for (CbFieldView RequestField : Params["Requests"sv])
	{
		CbObjectView RequestObject = RequestField.AsObjectView();
		CbObjectView RecordObject  = RequestObject["Record"sv].AsObjectView();
		CbObjectView KeyView	   = RecordObject["Key"sv].AsObjectView();
		CbFieldView	 BucketField   = KeyView["Bucket"sv];
		CbFieldView	 HashField	   = KeyView["Hash"sv];
		CacheKey	 Key		   = CacheKey::Create(BucketField.AsString(), HashField.AsHash());
		if (BucketField.HasError() || HashField.HasError() || Key.Bucket.empty())
		{
			return Request.WriteResponse(HttpResponseCode::BadRequest);
		}
		CacheRecordPolicy Policy = LoadCacheRecordPolicy(RequestObject["Policy"sv].AsObjectView(), DefaultPolicy);
		PutRequestData	  PutRequest{std::move(Key), RecordObject, std::move(Policy)};

		PutResult Result = PutCacheRecord(PutRequest, &BatchRequest);

		if (Result == PutResult::Invalid)
		{
			return Request.WriteResponse(HttpResponseCode::BadRequest);
		}
		Results.push_back(Result == PutResult::Success);
	}
	if (Results.empty())
	{
		return Request.WriteResponse(HttpResponseCode::BadRequest);
	}

	CbObjectWriter ResponseObject;
	ResponseObject.BeginArray("Result"sv);
	for (bool Value : Results)
	{
		ResponseObject.AddBool(Value);
	}
	ResponseObject.EndArray();

	CbPackage RpcResponse;
	RpcResponse.SetObject(ResponseObject.Save());

	BinaryWriter MemStream;
	RpcResponse.Save(MemStream);

	Request.WriteResponse(HttpResponseCode::OK,
						  HttpContentType::kCbPackage,
						  IoBuffer(IoBuffer::Wrap, MemStream.GetData(), MemStream.GetSize()));
}

HttpStructuredCacheService::PutResult
HttpStructuredCacheService::PutCacheRecord(PutRequestData& Request, const CbPackage* Package)
{
	std::vector<IoHash> ValidAttachments;
	AttachmentCount		Count;
	CbObjectView		Record			 = Request.RecordObject;
	uint64_t			RecordObjectSize = Record.GetSize();
	uint64_t			TransferredSize	 = RecordObjectSize;

	Request.RecordObject.IterateAttachments([this, &Request, Package, &ValidAttachments, &Count, &TransferredSize](CbFieldView HashView) {
		const IoHash ValueHash = HashView.AsHash();
		if (const CbAttachment* Attachment = Package ? Package->FindAttachment(ValueHash) : nullptr)
		{
			if (Attachment->IsCompressedBinary())
			{
				CompressedBuffer	   Chunk		= Attachment->AsCompressedBinary();
				CidStore::InsertResult InsertResult = m_CidStore.AddChunk(Chunk);

				ValidAttachments.emplace_back(InsertResult.DecompressedId);

				if (InsertResult.New)
				{
					Count.New++;
				}
				Count.Valid++;
				TransferredSize += Chunk.GetCompressedSize();
			}
			else
			{
				ZEN_WARN("PUT - '{}/{}' '{}' FAILED, attachment '{}' is not compressed",
						 Request.Key.Bucket,
						 Request.Key.Hash,
						 ToString(HttpContentType::kCbPackage),
						 ValueHash);
				Count.Invalid++;
			}
		}
		else if (m_CidStore.ContainsChunk(ValueHash))
		{
			ValidAttachments.emplace_back(ValueHash);
			Count.Valid++;
		}
		Count.Total++;
	});

	if (Count.Invalid > 0)
	{
		return PutResult::Invalid;
	}

	ZEN_DEBUG("PUT - '{}/{}' {}, attachments '{}/{}/{}' (new/valid/total)",
			  Request.Key.Bucket,
			  Request.Key.Hash,
			  NiceBytes(TransferredSize),
			  Count.New,
			  Count.Valid,
			  Count.Total);

	ZenCacheValue CacheValue;
	CacheValue.Value = IoBuffer(Record.GetSize());
	Record.CopyTo(MutableMemoryView(CacheValue.Value.MutableData(), CacheValue.Value.GetSize()));
	CacheValue.Value.SetContentType(ZenContentType::kCbObject);
	m_CacheStore.Put(Request.Key.Bucket, Request.Key.Hash, CacheValue);

	const bool IsPartialRecord = Count.Valid != Count.Total;

	if (EnumHasAllFlags(Request.Policy.GetRecordPolicy(), CachePolicy::StoreRemote) && !IsPartialRecord)
	{
		m_UpstreamCache.EnqueueUpstream(
			{.Type = ZenContentType::kCbPackage, .Key = Request.Key, .ValueContentIds = std::move(ValidAttachments)});
	}
	return PutResult::Success;
}

#if BACKWARDS_COMPATABILITY_JAN2022
void
HttpStructuredCacheService::HandleRpcGetCacheRecordsLegacy(zen::HttpServerRequest& Request, CbObjectView RpcRequest)
{
	ZEN_TRACE_CPU("Z$::RpcGetCacheRecords");

	CbPackage			  RpcResponse;
	CbObjectView		  Params	  = RpcRequest["Params"sv].AsObjectView();
	CacheRecordPolicy	  BatchPolicy = LoadCacheRecordPolicy(Params["Policy"sv].AsObjectView());
	std::vector<CacheKey> CacheKeys;
	std::vector<IoBuffer> CacheValues;
	std::vector<size_t>	  UpstreamRequests;

	ZEN_ASSERT(RpcRequest["Method"sv].AsString() == "GetCacheRecords"sv);

	for (CbFieldView KeyView : Params["CacheKeys"sv])
	{
		CbObjectView KeyObject = KeyView.AsObjectView();
		CacheKeys.push_back(CacheKey::Create(KeyObject["Bucket"sv].AsString(), KeyObject["Hash"sv].AsHash()));
	}

	if (CacheKeys.empty())
	{
		return Request.WriteResponse(HttpResponseCode::BadRequest);
	}

	CacheValues.resize(CacheKeys.size());

	for (size_t KeyIndex = 0; const CacheKey& Key : CacheKeys)
	{
		ZenCacheValue CacheValue;
		uint32_t	  MissingCount				   = 0;
		uint32_t	  MissingReadFromUpstreamCount = 0;

		if (EnumHasAllFlags(BatchPolicy.GetRecordPolicy(), CachePolicy::QueryLocal) && m_CacheStore.Get(Key.Bucket, Key.Hash, CacheValue) &&
			CacheValue.Value.GetContentType() == ZenContentType::kCbObject)
		{
			CbObjectView CacheRecord(CacheValue.Value.Data());
			CacheRecord.IterateAttachments(
				[this, &MissingCount, &MissingReadFromUpstreamCount, &RpcResponse, &BatchPolicy](CbFieldView AttachmentHash) {
					CachePolicy ValuePolicy = BatchPolicy.GetRecordPolicy();
					if (!EnumHasAllFlags(ValuePolicy, CachePolicy::QueryLocal))
					{
						// A value that is requested without the Query flag (such as None/Disable) does not count as missing, because we
						// didn't ask for it and thus the record is complete in its absence.
						if (EnumHasAllFlags(ValuePolicy, CachePolicy::QueryRemote))
						{
							MissingReadFromUpstreamCount++;
							MissingCount++;
						}
					}
					else if (EnumHasAllFlags(ValuePolicy, CachePolicy::SkipData))
					{
						if (!m_CidStore.ContainsChunk(AttachmentHash.AsHash()))
						{
							if (EnumHasAllFlags(ValuePolicy, CachePolicy::QueryRemote))
							{
								MissingReadFromUpstreamCount++;
							}
							MissingCount++;
						}
					}
					else
					{
						if (IoBuffer Chunk = m_CidStore.FindChunkByCid(AttachmentHash.AsHash()))
						{
							ZEN_ASSERT(Chunk.GetSize() > 0);
							RpcResponse.AddAttachment(CbAttachment(CompressedBuffer::FromCompressed(SharedBuffer(Chunk))));
						}
						else
						{
							if (EnumHasAllFlags(ValuePolicy, CachePolicy::QueryRemote))
							{
								MissingReadFromUpstreamCount++;
							}
							MissingCount++;
						}
					}
				});
		}

		// Searching upstream is not implemented in this legacy support function
		if (CacheValue.Value && (MissingCount == 0 || EnumHasAllFlags(BatchPolicy.GetRecordPolicy(), CachePolicy::PartialRecord)))
		{
			ZEN_DEBUG("HIT - '{}/{}' {} '{}' (LOCAL) {}",
					  Key.Bucket,
					  Key.Hash,
					  NiceBytes(CacheValue.Value.Size()),
					  ToString(CacheValue.Value.GetContentType()),
					  MissingCount ? "(PARTIAL)" : ""sv);

			CacheValues[KeyIndex] = std::move(CacheValue.Value);
			m_CacheStats.HitCount++;
		}
		else
		{
			if (!EnumHasAnyFlags(BatchPolicy.GetRecordPolicy(), CachePolicy::Query))
			{
				// If they requested no query, do not record this as a miss
				ZEN_DEBUG("DISABLEDQUERY - '{}/{}'", Key.Bucket, Key.Hash);
			}
			else
			{
				ZEN_DEBUG("MISS - '{}/{}' {}", Key.Bucket, Key.Hash, MissingCount ? "(PARTIAL)"sv : ""sv);
				m_CacheStats.MissCount++;
			}
		}

		++KeyIndex;
	}

	CbObjectWriter ResponseObject;

	ResponseObject.BeginArray("Result"sv);
	for (const IoBuffer& Value : CacheValues)
	{
		if (Value)
		{
			CbObjectView Record(Value.Data());
			ResponseObject << Record;
		}
		else
		{
			ResponseObject.AddNull();
		}
	}
	ResponseObject.EndArray();

	RpcResponse.SetObject(ResponseObject.Save());

	BinaryWriter MemStream;
	RpcResponse.Save(MemStream);

	Request.WriteResponse(HttpResponseCode::OK,
						  HttpContentType::kCbPackage,
						  IoBuffer(IoBuffer::Wrap, MemStream.GetData(), MemStream.GetSize()));
}
#endif

void
HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& HttpRequest, CbObjectView RpcRequest)
{
#if BACKWARDS_COMPATABILITY_JAN2022
	// Backwards compatability;
	if (RpcRequest["Params"sv].AsObjectView()["CacheKeys"sv])
	{
		return HandleRpcGetCacheRecordsLegacy(HttpRequest, RpcRequest);
	}
#endif
	ZEN_TRACE_CPU("Z$::RpcGetCacheRecords");

	CbObjectView Params = RpcRequest["Params"sv].AsObjectView();
	ZEN_ASSERT(RpcRequest["Method"sv].AsString() == "GetCacheRecords"sv);

	struct ValueRequestData
	{
		Oid				 ValueId;
		IoHash			 ContentId;
		CompressedBuffer Payload;
		CachePolicy		 DownstreamPolicy;
		bool			 Exists			  = false;
		bool			 ReadFromUpstream = false;
	};
	struct RecordRequestData
	{
		CacheKeyRequest				  Upstream;
		CbObjectView				  RecordObject;
		IoBuffer					  RecordCacheValue;
		CacheRecordPolicy			  DownstreamPolicy;
		std::vector<ValueRequestData> Values;
		bool						  Complete	   = false;
		bool						  UsedUpstream = false;
	};

	std::string_view			   PolicyText	 = Params["DefaultPolicy"sv].AsString();
	CachePolicy					   DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
	std::vector<RecordRequestData> Requests;
	std::vector<size_t>			   UpstreamIndexes;
	CbArrayView					   RequestsArray = Params["Requests"sv].AsArrayView();
	Requests.reserve(RequestsArray.Num());

	auto ParseValues = [](RecordRequestData& Request) {
		CbArrayView ValuesArray = Request.RecordObject["Values"sv].AsArrayView();
		Request.Values.reserve(ValuesArray.Num());
		for (CbFieldView ValueField : ValuesArray)
		{
			CbObjectView ValueObject  = ValueField.AsObjectView();
			Oid			 ValueId	  = ValueObject["Id"sv].AsObjectId();
			CbFieldView	 RawHashField = ValueObject["RawHash"sv];
			IoHash		 RawHash	  = RawHashField.AsBinaryAttachment();
			if (ValueId && !RawHashField.HasError())
			{
				Request.Values.push_back({ValueId, RawHash});
				Request.Values.back().DownstreamPolicy = Request.DownstreamPolicy.GetValuePolicy(ValueId);
			}
		}
	};

	for (CbFieldView RequestField : RequestsArray)
	{
		RecordRequestData& Request		 = Requests.emplace_back();
		CbObjectView	   RequestObject = RequestField.AsObjectView();
		CbObjectView	   KeyObject	 = RequestObject["Key"sv].AsObjectView();
		CbFieldView		   BucketField	 = KeyObject["Bucket"sv];
		CbFieldView		   HashField	 = KeyObject["Hash"sv];
		CacheKey&		   Key			 = Request.Upstream.Key;
		Key								 = CacheKey::Create(BucketField.AsString(), HashField.AsHash());
		if (HashField.HasError() || Key.Bucket.empty())
		{
			return HttpRequest.WriteResponse(HttpResponseCode::BadRequest);
		}
		Request.DownstreamPolicy		= LoadCacheRecordPolicy(RequestObject["Policy"sv].AsObjectView(), DefaultPolicy);
		const CacheRecordPolicy& Policy = Request.DownstreamPolicy;

		ZenCacheValue CacheValue;
		bool		  NeedUpstreamAttachment = false;
		bool		  FoundLocalInvalid		 = false;
		ZenCacheValue RecordCacheValue;

		if (EnumHasAllFlags(Policy.GetRecordPolicy(), CachePolicy::QueryLocal) && m_CacheStore.Get(Key.Bucket, Key.Hash, RecordCacheValue))
		{
			Request.RecordCacheValue = std::move(RecordCacheValue.Value);
			if (Request.RecordCacheValue.GetContentType() != ZenContentType::kCbObject)
			{
				FoundLocalInvalid = true;
			}
			else
			{
				Request.RecordObject = CbObjectView(Request.RecordCacheValue.GetData());
				ParseValues(Request);

				Request.Complete = true;
				for (ValueRequestData& Value : Request.Values)
				{
					CachePolicy ValuePolicy = Value.DownstreamPolicy;
					if (!EnumHasAllFlags(ValuePolicy, CachePolicy::QueryLocal))
					{
						// A value that is requested without the Query flag (such as None/Disable) counts as existing, because we
						// didn't ask for it and thus the record is complete in its absence.
						if (!EnumHasAllFlags(ValuePolicy, CachePolicy::QueryRemote))
						{
							Value.Exists = true;
						}
						else
						{
							NeedUpstreamAttachment = true;
							Value.ReadFromUpstream = true;
							Request.Complete	   = false;
						}
					}
					else if (EnumHasAllFlags(ValuePolicy, CachePolicy::SkipData))
					{
						if (m_CidStore.ContainsChunk(Value.ContentId))
						{
							Value.Exists = true;
						}
						else
						{
							if (EnumHasAllFlags(ValuePolicy, CachePolicy::QueryRemote))
							{
								NeedUpstreamAttachment = true;
								Value.ReadFromUpstream = true;
							}
							Request.Complete = false;
						}
					}
					else
					{
						if (IoBuffer Chunk = m_CidStore.FindChunkByCid(Value.ContentId))
						{
							ZEN_ASSERT(Chunk.GetSize() > 0);
							Value.Payload = CompressedBuffer::FromCompressed(SharedBuffer(Chunk));
							Value.Exists  = true;
						}
						else
						{
							if (EnumHasAllFlags(ValuePolicy, CachePolicy::QueryRemote))
							{
								NeedUpstreamAttachment = true;
								Value.ReadFromUpstream = true;
							}
							Request.Complete = false;
						}
					}
				}
			}
		}
		if (!Request.Complete)
		{
			bool NeedUpstreamRecord =
				!Request.RecordObject && !FoundLocalInvalid && EnumHasAllFlags(Policy.GetRecordPolicy(), CachePolicy::QueryRemote);
			if (NeedUpstreamRecord || NeedUpstreamAttachment)
			{
				UpstreamIndexes.push_back(Requests.size() - 1);
			}
		}
	}
	if (Requests.empty())
	{
		return HttpRequest.WriteResponse(HttpResponseCode::BadRequest);
	}

	if (!UpstreamIndexes.empty())
	{
		std::vector<CacheKeyRequest*> UpstreamRequests;
		UpstreamRequests.reserve(UpstreamIndexes.size());
		for (size_t Index : UpstreamIndexes)
		{
			RecordRequestData& Request = Requests[Index];
			UpstreamRequests.push_back(&Request.Upstream);

			if (Request.Values.size())
			{
				// We will be returning the local object and know all the value Ids that exist in it
				// Convert all their Downstream Values to upstream values, and add SkipData to any ones that we already have.
				CachePolicy UpstreamBasePolicy = ConvertToUpstream(Request.DownstreamPolicy.GetBasePolicy()) | CachePolicy::SkipMeta;
				CacheRecordPolicyBuilder Builder(UpstreamBasePolicy);
				for (ValueRequestData& Value : Request.Values)
				{
					CachePolicy UpstreamPolicy = ConvertToUpstream(Value.DownstreamPolicy);
					UpstreamPolicy |= !Value.ReadFromUpstream ? CachePolicy::SkipData : CachePolicy::None;
					Builder.AddValuePolicy(Value.ValueId, UpstreamPolicy);
				}
				Request.Upstream.Policy = Builder.Build();
			}
			else
			{
				// We don't know which Values exist in the Record; ask the upstrem for all values that the client wants,
				// and convert the CacheRecordPolicy to an upstream policy
				Request.Upstream.Policy = Request.DownstreamPolicy.ConvertToUpstream();
			}
		}

		const auto OnCacheRecordGetComplete = [this, &ParseValues](CacheRecordGetCompleteParams&& Params) {
			if (!Params.Record)
			{
				return;
			}

			RecordRequestData& Request =
				*reinterpret_cast<RecordRequestData*>(reinterpret_cast<char*>(&Params.Request) - offsetof(RecordRequestData, Upstream));
			const CacheKey& Key = Request.Upstream.Key;
			if (!Request.RecordObject)
			{
				CbObject ObjectBuffer	 = CbObject::Clone(Params.Record);
				Request.RecordCacheValue = ObjectBuffer.GetBuffer().AsIoBuffer();
				Request.RecordCacheValue.SetContentType(ZenContentType::kCbObject);
				Request.RecordObject = ObjectBuffer;
				if (EnumHasAllFlags(Request.DownstreamPolicy.GetRecordPolicy(), CachePolicy::StoreLocal))
				{
					m_CacheStore.Put(Key.Bucket, Key.Hash, {.Value = {Request.RecordCacheValue}});
				}
				ParseValues(Request);
				Request.UsedUpstream = true;
			}

			Request.Complete = true;
			for (ValueRequestData& Value : Request.Values)
			{
				if (Value.Exists)
				{
					continue;
				}
				CachePolicy ValuePolicy = Value.DownstreamPolicy;
				if (!EnumHasAllFlags(ValuePolicy, CachePolicy::QueryRemote))
				{
					Request.Complete = false;
					continue;
				}
				if (!EnumHasAllFlags(ValuePolicy, CachePolicy::SkipData) || EnumHasAllFlags(ValuePolicy, CachePolicy::StoreLocal))
				{
					if (const CbAttachment* Attachment = Params.Package.FindAttachment(Value.ContentId))
					{
						if (CompressedBuffer Compressed = Attachment->AsCompressedBinary())
						{
							Request.UsedUpstream = true;
							Value.Exists		 = true;
							if (EnumHasAllFlags(ValuePolicy, CachePolicy::StoreLocal))
							{
								m_CidStore.AddChunk(Compressed);
							}
							if (!EnumHasAllFlags(ValuePolicy, CachePolicy::SkipData))
							{
								Value.Payload = Compressed;
							}
						}
						else
						{
							ZEN_DEBUG("Uncompressed value '{}' from upstream cache record '{}/{}'", Value.ContentId, Key.Bucket, Key.Hash);
						}
					}
					if (!Value.Exists && !EnumHasAllFlags(ValuePolicy, CachePolicy::SkipData))
					{
						Request.Complete = false;
					}
					// Request.Complete does not need to be set to false for upstream SkipData attachments.
					// In the PartialRecord==false case, the upstream will have failed the entire record if any SkipData attachment
					// didn't exist and we will not get here. In the PartialRecord==true case, we do not need to inform the client of
					// any missing SkipData attachments.
				}
			}
		};

		m_UpstreamCache.GetCacheRecords(UpstreamRequests, std::move(OnCacheRecordGetComplete));
	}

	CbPackage	   ResponsePackage;
	CbObjectWriter ResponseObject;

	ResponseObject.BeginArray("Result"sv);
	for (RecordRequestData& Request : Requests)
	{
		const CacheKey& Key = Request.Upstream.Key;
		if (Request.Complete ||
			(Request.RecordObject && EnumHasAllFlags(Request.DownstreamPolicy.GetRecordPolicy(), CachePolicy::PartialRecord)))
		{
			ResponseObject << Request.RecordObject;
			for (ValueRequestData& Value : Request.Values)
			{
				if (!EnumHasAllFlags(Value.DownstreamPolicy, CachePolicy::SkipData) && Value.Payload)
				{
					ResponsePackage.AddAttachment(CbAttachment(Value.Payload));
				}
			}

			ZEN_DEBUG("HIT - '{}/{}' {}{}{}",
					  Key.Bucket,
					  Key.Hash,
					  NiceBytes(Request.RecordCacheValue.Size()),
					  Request.Complete ? ""sv : " (PARTIAL)"sv,
					  Request.UsedUpstream ? " (UPSTREAM)"sv : ""sv);
			m_CacheStats.HitCount++;
			m_CacheStats.UpstreamHitCount += Request.UsedUpstream ? 1 : 0;
		}
		else
		{
			ResponseObject.AddNull();

			if (!EnumHasAnyFlags(Request.DownstreamPolicy.GetRecordPolicy(), CachePolicy::Query))
			{
				// If they requested no query, do not record this as a miss
				ZEN_DEBUG("DISABLEDQUERY - '{}/{}'", Key.Bucket, Key.Hash);
			}
			else
			{
				ZEN_DEBUG("MISS - '{}/{}' {}", Key.Bucket, Key.Hash, Request.RecordObject ? ""sv : "(PARTIAL)"sv);
				m_CacheStats.MissCount++;
			}
		}
	}
	ResponseObject.EndArray();
	ResponsePackage.SetObject(ResponseObject.Save());

	BinaryWriter MemStream;
	ResponsePackage.Save(MemStream);

	HttpRequest.WriteResponse(HttpResponseCode::OK,
							  HttpContentType::kCbPackage,
							  IoBuffer(IoBuffer::Wrap, MemStream.GetData(), MemStream.GetSize()));
}

void
HttpStructuredCacheService::HandleRpcPutCacheValues(zen::HttpServerRequest& Request, const CbPackage& BatchRequest)
{
	ZEN_TRACE_CPU("Z$::RpcPutCacheValues");
	CbObjectView BatchObject = BatchRequest.GetObject();

	CbObjectView Params = BatchObject["Params"sv].AsObjectView();

	ZEN_ASSERT(BatchObject["Method"sv].AsString() == "PutCacheValues"sv);

	std::string_view  PolicyText	= Params["DefaultPolicy"].AsString();
	CachePolicy		  DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
	std::vector<bool> Results;
	for (CbFieldView RequestField : Params["Requests"sv])
	{
		CbObjectView RequestObject = RequestField.AsObjectView();
		CbObjectView KeyView	   = RequestObject["Key"sv].AsObjectView();
		CbFieldView	 BucketField   = KeyView["Bucket"sv];
		CbFieldView	 HashField	   = KeyView["Hash"sv];
		CacheKey	 Key		   = CacheKey::Create(BucketField.AsString(), HashField.AsHash());
		if (BucketField.HasError() || HashField.HasError() || Key.Bucket.empty())
		{
			return Request.WriteResponse(HttpResponseCode::BadRequest);
		}
		PolicyText					= RequestObject["Policy"sv].AsString();
		CachePolicy Policy			= !PolicyText.empty() ? ParseCachePolicy(PolicyText) : DefaultPolicy;
		IoHash		RawHash			= RequestObject["RawHash"sv].AsBinaryAttachment();
		bool		Succeeded		= false;
		uint64_t	TransferredSize = 0;

		if (const CbAttachment* Attachment = BatchRequest.FindAttachment(RawHash))
		{
			if (Attachment->IsCompressedBinary())
			{
				CompressedBuffer Chunk = Attachment->AsCompressedBinary();
				if (EnumHasAllFlags(Policy, CachePolicy::StoreRemote))
				{
					// TODO: Implement upstream puts of CacheValues with StoreLocal == false.
					// Currently ProcessCacheRecord requires that the value exist in the local cache to put it upstream.
					Policy |= CachePolicy::StoreLocal;
				}

				if (EnumHasAllFlags(Policy, CachePolicy::StoreLocal))
				{
					IoBuffer Value = Chunk.GetCompressed().Flatten().AsIoBuffer();
					Value.SetContentType(ZenContentType::kCompressedBinary);
					m_CacheStore.Put(Key.Bucket, Key.Hash, {.Value = Value});
					TransferredSize = Chunk.GetCompressedSize();
				}
				Succeeded = true;
			}
			else
			{
				ZEN_WARN("PUTCACHEVALUES - '{}/{}/{}' FAILED, value is not compressed", Key.Bucket, Key.Hash, RawHash);
				return Request.WriteResponse(HttpResponseCode::BadRequest);
			}
		}
		else if (EnumHasAllFlags(Policy, CachePolicy::QueryLocal))
		{
			ZenCacheValue ExistingValue;
			if (m_CacheStore.Get(Key.Bucket, Key.Hash, ExistingValue) && IsCompressedBinary(ExistingValue.Value.GetContentType()))
			{
				Succeeded = true;
			}
		}
		// We do not search the Upstream. No data in a put means the caller is probing for whether they need to do a heavy put.
		// If it doesn't exist locally they should do the heavy put rather than having us fetch it from upstream.

		if (Succeeded && EnumHasAllFlags(Policy, CachePolicy::StoreRemote))
		{
			m_UpstreamCache.EnqueueUpstream({.Type = ZenContentType::kCompressedBinary, .Key = Key});
		}
		Results.push_back(Succeeded);
		ZEN_DEBUG("PUTCACHEVALUES - '{}/{}' {}, '{}'", Key.Bucket, Key.Hash, NiceBytes(TransferredSize), Succeeded ? "Added"sv : "Invalid");
	}
	if (Results.empty())
	{
		return Request.WriteResponse(HttpResponseCode::BadRequest);
	}

	CbObjectWriter ResponseObject;
	ResponseObject.BeginArray("Result"sv);
	for (bool Value : Results)
	{
		ResponseObject.AddBool(Value);
	}
	ResponseObject.EndArray();

	CbPackage RpcResponse;
	RpcResponse.SetObject(ResponseObject.Save());

	BinaryWriter MemStream;
	RpcResponse.Save(MemStream);

	Request.WriteResponse(HttpResponseCode::OK,
						  HttpContentType::kCbPackage,
						  IoBuffer(IoBuffer::Wrap, MemStream.GetData(), MemStream.GetSize()));
}

void
HttpStructuredCacheService::HandleRpcGetCacheValues(zen::HttpServerRequest& HttpRequest, CbObjectView RpcRequest)
{
#if BACKWARDS_COMPATABILITY_JAN2022
	if (RpcRequest["Params"sv].AsObjectView()["ChunkRequests"])
	{
		return HandleRpcGetCacheChunks(HttpRequest, RpcRequest);
	}
#endif

	ZEN_TRACE_CPU("Z$::RpcGetCacheValues");

	CbObjectView	 Params		   = RpcRequest["Params"sv].AsObjectView();
	std::string_view PolicyText	   = Params["DefaultPolicy"sv].AsString();
	CachePolicy		 DefaultPolicy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : CachePolicy::Default;
	struct RequestData
	{
		CacheKey		 Key;
		CachePolicy		 Policy;
		CompressedBuffer Result;
	};
	std::vector<RequestData> Requests;

	ZEN_ASSERT(RpcRequest["Method"sv].AsString() == "GetCacheValues"sv);

	for (CbFieldView RequestField : Params["Requests"sv])
	{
		RequestData& Request	   = Requests.emplace_back();
		CbObjectView RequestObject = RequestField.AsObjectView();
		CbObjectView KeyObject	   = RequestObject["Key"sv].AsObjectView();
		CbFieldView	 BucketField   = KeyObject["Bucket"sv];
		CbFieldView	 HashField	   = KeyObject["Hash"sv];
		Request.Key				   = CacheKey::Create(BucketField.AsString(), HashField.AsHash());
		if (BucketField.HasError() || HashField.HasError() || Request.Key.Bucket.empty())
		{
			return HttpRequest.WriteResponse(HttpResponseCode::BadRequest);
		}
		PolicyText	   = RequestObject["Policy"sv].AsString();
		Request.Policy = !PolicyText.empty() ? ParseCachePolicy(PolicyText) : DefaultPolicy;

		CacheKey&		  Key	 = Request.Key;
		CachePolicy		  Policy = Request.Policy;
		CompressedBuffer& Result = Request.Result;

		ZenCacheValue	 CacheValue;
		std::string_view Source;
		if (EnumHasAllFlags(Policy, CachePolicy::QueryLocal))
		{
			if (m_CacheStore.Get(Key.Bucket, Key.Hash, CacheValue) && IsCompressedBinary(CacheValue.Value.GetContentType()))
			{
				Result = CompressedBuffer::FromCompressed(SharedBuffer(CacheValue.Value));
				if (Result)
				{
					Source = "LOCAL"sv;
				}
			}
		}
		if (!Result && EnumHasAllFlags(Policy, CachePolicy::QueryRemote))
		{
			GetUpstreamCacheResult UpstreamResult = m_UpstreamCache.GetCacheRecord({Key.Bucket, Key.Hash}, ZenContentType::kBinary);
			if (UpstreamResult.Success && IsCompressedBinary(UpstreamResult.Value.GetContentType()))
			{
				Result = CompressedBuffer::FromCompressed(SharedBuffer(UpstreamResult.Value));
				if (Result)
				{
					UpstreamResult.Value.SetContentType(ZenContentType::kCompressedBinary);
					Source = "UPSTREAM"sv;
					// TODO: Respect the StoreLocal flag once we have upstream existence-only checks. For now the requirement
					// that we copy data from upstream even when SkipData and !StoreLocal are true means that it is too expensive
					// for us to keep the data only on the upstream server.
					// if (EnumHasAllFlags(Policy, CachePolicy::StoreLocal))
					{
						m_CacheStore.Put(Key.Bucket, Key.Hash, ZenCacheValue{UpstreamResult.Value});
					}
				}
			}
		}

		if (Result)
		{
			ZEN_DEBUG("GETCACHEVALUES HIT - '{}/{}' {} ({})", Key.Bucket, Key.Hash, NiceBytes(Result.GetCompressed().GetSize()), Source);
			m_CacheStats.HitCount++;
		}
		else if (!EnumHasAnyFlags(Policy, CachePolicy::Query))
		{
			// If they requested no query, do not record this as a miss
			ZEN_DEBUG("GETCACHEVALUES DISABLEDQUERY - '{}/{}'", Key.Bucket, Key.Hash);
		}
		else
		{
			ZEN_DEBUG("GETCACHEVALUES MISS - '{}/{}'", Key.Bucket, Key.Hash);
			m_CacheStats.MissCount++;
		}
	}
	if (Requests.empty())
	{
		return HttpRequest.WriteResponse(HttpResponseCode::BadRequest);
	}

	CbPackage	   RpcResponse;
	CbObjectWriter ResponseObject;
	ResponseObject.BeginArray("Result"sv);
	for (const RequestData& Request : Requests)
	{
		ResponseObject.BeginObject();
		{
			const CompressedBuffer& Result = Request.Result;
			if (Result)
			{
				ResponseObject.AddHash("RawHash"sv, IoHash::FromBLAKE3(Result.GetRawHash()));
				if (!EnumHasAllFlags(Request.Policy, CachePolicy::SkipData))
				{
					RpcResponse.AddAttachment(CbAttachment(Result));
				}
				else
				{
					ResponseObject.AddInteger("RawSize"sv, Result.GetRawSize());
				}
			}
		}
		ResponseObject.EndObject();
	}
	ResponseObject.EndArray();

	RpcResponse.SetObject(ResponseObject.Save());

	BinaryWriter MemStream;
	RpcResponse.Save(MemStream);

	HttpRequest.WriteResponse(HttpResponseCode::OK,
							  HttpContentType::kCbPackage,
							  IoBuffer(IoBuffer::Wrap, MemStream.GetData(), MemStream.GetSize()));
}

namespace GetCacheChunks::detail {

	struct ValueData
	{
		Oid		 ValueId;
		IoHash	 ContentId;
		uint64_t RawSize;
	};
	struct KeyRequestData
	{
		CacheKeyRequest		   Upstream;
		IoBuffer			   CacheValue;
		std::vector<ValueData> Values;
		CachePolicy			   DownstreamRecordPolicy;
		CachePolicy			   DownstreamPolicy;
		std::string_view	   Source;
		bool				   Exists			= false;
		bool				   HasRequest		= false;
		bool				   HasRecordRequest = false;
		bool				   HasValueRequest	= false;
		bool				   ValuesRead		= false;
	};
	struct ChunkRequestData
	{
		CacheChunkRequest Upstream;
		KeyRequestData*	  KeyRequest;
		size_t			  KeyRequestIndex;
		CachePolicy		  DownstreamPolicy;
		CompressedBuffer  Value;
		std::string_view  Source;
		uint64_t		  TotalSize		  = 0;
		bool			  Exists		  = false;
		bool			  IsRecordRequest = false;
		bool			  TotalSizeKnown  = false;
	};

}  // namespace GetCacheChunks::detail

void
HttpStructuredCacheService::HandleRpcGetCacheChunks(zen::HttpServerRequest& HttpRequest, CbObjectView RpcRequest)
{
	using namespace GetCacheChunks::detail;

	ZEN_TRACE_CPU("Z$::RpcGetCacheChunks");

	std::vector<KeyRequestData>	  KeyRequests;
	std::vector<ChunkRequestData> Chunks;
	BACKWARDS_COMPATABILITY_JAN2022_CODE(bool SendValueOnly = false;)
	if (!TryGetCacheChunks_Parse(KeyRequests, Chunks BACKWARDS_COMPATABILITY_JAN2022_CODE(, SendValueOnly), RpcRequest))
	{
		return HttpRequest.WriteResponse(HttpResponseCode::BadRequest);
	}
	GetCacheChunks_LoadKeys(KeyRequests);
	GetCacheChunks_LoadChunks(Chunks);
	GetCacheChunks_SendResults(Chunks, HttpRequest BACKWARDS_COMPATABILITY_JAN2022_CODE(, SendValueOnly));
}

bool
HttpStructuredCacheService::TryGetCacheChunks_Parse(std::vector<GetCacheChunks::detail::KeyRequestData>&					 KeyRequests,
													std::vector<GetCacheChunks::detail::ChunkRequestData>&					 Chunks,
													BACKWARDS_COMPATABILITY_JAN2022_CODE(bool& SendValueOnly, ) CbObjectView RpcRequest)
{
	using namespace GetCacheChunks::detail;

#if BACKWARDS_COMPATABILITY_JAN2022
	SendValueOnly = RpcRequest["MethodVersion"sv].AsInt32() < 1;
#else
	ZEN_ASSERT(RpcRequest["Method"sv].AsString() == "GetCacheChunks"sv);
#endif

	CbObjectView	 Params			   = RpcRequest["Params"sv].AsObjectView();
	std::string_view DefaultPolicyText = Params["DefaultPolicy"sv].AsString();
	CachePolicy		 DefaultPolicy	   = !DefaultPolicyText.empty() ? ParseCachePolicy(DefaultPolicyText) : CachePolicy::Default;

	KeyRequestData* PreviousKeyRequest = nullptr;
	CbArrayView		ChunkRequestsArray = Params["ChunkRequests"sv].AsArrayView();
	Chunks.reserve(ChunkRequestsArray.Num());
	for (CbFieldView RequestView : ChunkRequestsArray)
	{
		ChunkRequestData& Chunk			= Chunks.emplace_back();
		CbObjectView	  RequestObject = RequestView.AsObjectView();

		CbObjectView KeyObject = RequestObject["Key"sv].AsObjectView();
		CbFieldView	 HashField = KeyObject["Hash"sv];
		Chunk.Upstream.Key	   = CacheKey::Create(KeyObject["Bucket"sv].AsString(), HashField.AsHash());
		if (Chunk.Upstream.Key.Bucket.empty() || HashField.HasError())
		{
			ZEN_WARN("GetCacheChunks: Invalid key in ChunkRequest.");
			return false;
		}

		KeyRequestData* KeyRequest = nullptr;
		if (!PreviousKeyRequest || PreviousKeyRequest->Upstream.Key < Chunk.Upstream.Key)
		{
			KeyRequest				 = &KeyRequests.emplace_back();
			KeyRequest->Upstream.Key = Chunk.Upstream.Key;
			PreviousKeyRequest		 = KeyRequest;
		}
		else if (!(Chunk.Upstream.Key < PreviousKeyRequest->Upstream.Key))
		{
			KeyRequest = PreviousKeyRequest;
		}
		else
		{
			ZEN_WARN("GetCacheChunks: Keys in ChunkRequest are not sorted: {}/{} came after {}/{}.",
					 Chunk.Upstream.Key.Bucket,
					 Chunk.Upstream.Key.Hash,
					 PreviousKeyRequest->Upstream.Key.Bucket,
					 PreviousKeyRequest->Upstream.Key.Hash);
			return false;
		}
		Chunk.KeyRequestIndex = std::distance(KeyRequests.data(), KeyRequest);

		Chunk.Upstream.ChunkId		= RequestObject["ChunkId"sv].AsHash();
		Chunk.Upstream.ValueId		= RequestObject["ValueId"sv].AsObjectId();
		Chunk.Upstream.RawOffset	= RequestObject["RawOffset"sv].AsUInt64();
		Chunk.Upstream.RawSize		= RequestObject["RawSize"sv].AsUInt64(UINT64_MAX);
		std::string_view PolicyText = RequestObject["Policy"sv].AsString();
		Chunk.DownstreamPolicy		= !PolicyText.empty() ? ParseCachePolicy(PolicyText) : DefaultPolicy;
#if BACKWARDS_COMPATABILITY_JAN2022
		if (SendValueOnly)
		{
			Chunk.DownstreamPolicy = Chunk.DownstreamPolicy & (~CachePolicy::SkipData);
		}
#endif
		Chunk.IsRecordRequest = (bool)Chunk.Upstream.ValueId;

		if (!Chunk.IsRecordRequest || Chunk.Upstream.ChunkId == IoHash::Zero)
		{
			KeyRequest->DownstreamPolicy =
				KeyRequest->HasRequest ? Union(KeyRequest->DownstreamPolicy, Chunk.DownstreamPolicy) : Chunk.DownstreamPolicy;
			KeyRequest->HasRequest																 = true;
			(Chunk.IsRecordRequest ? KeyRequest->HasRecordRequest : KeyRequest->HasValueRequest) = true;
		}
	}
	if (Chunks.empty())
	{
		return false;
	}
	for (ChunkRequestData& Chunk : Chunks)
	{
		Chunk.KeyRequest = &KeyRequests[Chunk.KeyRequestIndex];
	}
	return true;
}

void
HttpStructuredCacheService::GetCacheChunks_LoadKeys(std::vector<GetCacheChunks::detail::KeyRequestData>& KeyRequests)
{
	using namespace GetCacheChunks::detail;

	std::vector<CacheKeyRequest*> UpstreamRecordRequests;
	std::vector<KeyRequestData*>  UpstreamValueRequests;
	for (KeyRequestData& KeyRequest : KeyRequests)
	{
		if (KeyRequest.HasRequest)
		{
			if (KeyRequest.HasRecordRequest)
			{
				KeyRequest.DownstreamRecordPolicy = KeyRequest.DownstreamPolicy | CachePolicy::SkipData | CachePolicy::SkipMeta;
			}

			if (!KeyRequest.Exists && EnumHasAllFlags(KeyRequest.DownstreamPolicy, CachePolicy::QueryLocal))
			{
				// There's currently no interface for checking only whether a CacheValue exists without loading it,
				// so we load it here even if SkipData is true and its a CacheValue request.
				ZenCacheValue CacheValue;
				if (m_CacheStore.Get(KeyRequest.Upstream.Key.Bucket, KeyRequest.Upstream.Key.Hash, CacheValue))
				{
					KeyRequest.Exists	  = true;
					KeyRequest.CacheValue = std::move(CacheValue.Value);
					KeyRequest.Source	  = "LOCAL"sv;
				}
			}
			if (!KeyRequest.Exists)
			{
				// At most one of RecordRequest or ValueRequest will succeed for the upstream request of the key a given key, but we don't
				// know which,
				// and if the requests (from arbitrary Unreal Class code) includes both types of request for a key, we want to ask for both
				// kinds and pass the request that uses the one that succeeds.
				if (KeyRequest.HasRecordRequest && EnumHasAllFlags(KeyRequest.DownstreamRecordPolicy, CachePolicy::QueryRemote))
				{
					KeyRequest.Upstream.Policy = CacheRecordPolicy(ConvertToUpstream(KeyRequest.DownstreamRecordPolicy));
					UpstreamRecordRequests.push_back(&KeyRequest.Upstream);
				}
				if (KeyRequest.HasValueRequest && EnumHasAllFlags(KeyRequest.DownstreamPolicy, CachePolicy::QueryRemote))
				{
					UpstreamValueRequests.push_back(&KeyRequest);
				}
			}
		}
	}

	if (!UpstreamRecordRequests.empty())
	{
		const auto OnCacheRecordGetComplete = [this](CacheRecordGetCompleteParams&& Params) {
			if (!Params.Record)
			{
				return;
			}

			KeyRequestData& KeyRequest =
				*reinterpret_cast<KeyRequestData*>(reinterpret_cast<char*>(&Params.Request) - offsetof(KeyRequestData, Upstream));
			const CacheKey& Key	  = KeyRequest.Upstream.Key;
			KeyRequest.Exists	  = true;
			CbObject ObjectBuffer = CbObject::Clone(Params.Record);
			KeyRequest.CacheValue = ObjectBuffer.GetBuffer().AsIoBuffer();
			KeyRequest.CacheValue.SetContentType(ZenContentType::kCbObject);
			KeyRequest.Source = "UPSTREAM"sv;

			if (EnumHasAllFlags(KeyRequest.DownstreamPolicy, CachePolicy::StoreLocal))
			{
				m_CacheStore.Put(Key.Bucket, Key.Hash, {.Value = KeyRequest.CacheValue});
			}
		};
		m_UpstreamCache.GetCacheRecords(UpstreamRecordRequests, std::move(OnCacheRecordGetComplete));
	}

	if (!UpstreamValueRequests.empty())
	{
		for (KeyRequestData* KeyRequestPtr : UpstreamValueRequests)
		{
			KeyRequestData&		   KeyRequest	  = *KeyRequestPtr;
			CacheKey&			   Key			  = KeyRequest.Upstream.Key;
			GetUpstreamCacheResult UpstreamResult = m_UpstreamCache.GetCacheRecord({Key.Bucket, Key.Hash}, ZenContentType::kBinary);
			if (UpstreamResult.Success && IsCompressedBinary(UpstreamResult.Value.GetContentType()))
			{
				CompressedBuffer Result = CompressedBuffer::FromCompressed(SharedBuffer(UpstreamResult.Value));
				if (Result)
				{
					KeyRequest.CacheValue = std::move(UpstreamResult.Value);
					KeyRequest.CacheValue.SetContentType(ZenContentType::kCompressedBinary);
					KeyRequest.Exists = true;
					KeyRequest.Source = "UPSTREAM"sv;
					// TODO: Respect the StoreLocal flag once we have upstream existence-only checks. For now the requirement
					// that we copy data from upstream even when SkipData and !StoreLocal are true means that it is too expensive
					// for us to keep the data only on the upstream server.
					// if (EnumHasAllFlags(KeyRequest->DownstreamValuePolicy, CachePolicy::StoreLocal))
					{
						m_CacheStore.Put(Key.Bucket, Key.Hash, {.Value = KeyRequest.CacheValue});
					}
				}
			}
		}
	}
}

void
HttpStructuredCacheService::GetCacheChunks_LoadChunks(std::vector<GetCacheChunks::detail::ChunkRequestData>& Chunks)
{
	using namespace GetCacheChunks::detail;

	std::vector<CacheChunkRequest*> UpstreamPayloadRequests;
	for (ChunkRequestData& Chunk : Chunks)
	{
		if (Chunk.IsRecordRequest)
		{
			if (Chunk.Upstream.ChunkId == IoHash::Zero)
			{
				// Unreal uses a 12 byte ID to address cache record values. When the uncompressed hash (ChunkId)
				// is missing, parse the cache record and try to find the raw hash from the ValueId.
				KeyRequestData& KeyRequest = *Chunk.KeyRequest;
				if (!KeyRequest.ValuesRead)
				{
					KeyRequest.ValuesRead = true;
					if (KeyRequest.CacheValue && KeyRequest.CacheValue.GetContentType() == ZenContentType::kCbObject)
					{
						CbObjectView RecordObject = CbObjectView(KeyRequest.CacheValue.GetData());
						CbArrayView	 ValuesArray  = RecordObject["Values"sv].AsArrayView();
						KeyRequest.Values.reserve(ValuesArray.Num());
						for (CbFieldView ValueField : ValuesArray)
						{
							CbObjectView ValueObject  = ValueField.AsObjectView();
							Oid			 ValueId	  = ValueObject["Id"sv].AsObjectId();
							CbFieldView	 RawHashField = ValueObject["RawHash"sv];
							IoHash		 RawHash	  = RawHashField.AsBinaryAttachment();
							if (ValueId && !RawHashField.HasError())
							{
								KeyRequest.Values.push_back({ValueId, RawHash, ValueObject["RawSize"sv].AsUInt64()});
							}
						}
					}
				}

				for (const ValueData& Value : KeyRequest.Values)
				{
					if (Value.ValueId == Chunk.Upstream.ValueId)
					{
						Chunk.Upstream.ChunkId = Value.ContentId;
						Chunk.TotalSize		   = Value.RawSize;
						Chunk.TotalSizeKnown   = true;
						break;
					}
				}
			}

			// Now load the ContentId from the local ContentIdStore or from the upstream
			if (Chunk.Upstream.ChunkId != IoHash::Zero)
			{
				if (EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::QueryLocal))
				{
					if (EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::SkipData) && Chunk.TotalSizeKnown)
					{
						if (m_CidStore.ContainsChunk(Chunk.Upstream.ChunkId))
						{
							Chunk.Exists = true;
							Chunk.Source = "LOCAL"sv;
						}
					}
					else if (IoBuffer Payload = m_CidStore.FindChunkByCid(Chunk.Upstream.ChunkId))
					{
						CompressedBuffer Compressed = CompressedBuffer::FromCompressed(SharedBuffer(Payload));
						if (Compressed)
						{
							if (!EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::SkipData))
							{
								Chunk.Value = Compressed;
							}
							Chunk.Exists		 = true;
							Chunk.TotalSize		 = Compressed.GetRawSize();
							Chunk.TotalSizeKnown = true;
							Chunk.Source		 = "LOCAL"sv;
						}
					}
				}
				if (!Chunk.Exists && EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::QueryRemote))
				{
					Chunk.Upstream.Policy = ConvertToUpstream(Chunk.DownstreamPolicy);
					UpstreamPayloadRequests.push_back(&Chunk.Upstream);
				}
			}
		}
		else
		{
			if (Chunk.KeyRequest->Exists)
			{
				if (Chunk.KeyRequest->CacheValue && IsCompressedBinary(Chunk.KeyRequest->CacheValue.GetContentType()))
				{
					CompressedBuffer Compressed = CompressedBuffer::FromCompressed(SharedBuffer(Chunk.KeyRequest->CacheValue));
					if (Compressed)
					{
						if (!EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::SkipData))
						{
							Chunk.Value = Compressed;
						}
						Chunk.Exists		   = true;
						Chunk.TotalSize		   = Compressed.GetRawSize();
						Chunk.TotalSizeKnown   = true;
						Chunk.Source		   = Chunk.KeyRequest->Source;
						Chunk.Upstream.ChunkId = IoHash::FromBLAKE3(Compressed.GetRawHash());
					}
				}
			}
		}
	}

	if (!UpstreamPayloadRequests.empty())
	{
		const auto OnCacheValueGetComplete = [this](CacheValueGetCompleteParams&& Params) {
			if (Params.RawHash == Params.RawHash.Zero)
			{
				return;
			}

			ChunkRequestData& Chunk =
				*reinterpret_cast<ChunkRequestData*>(reinterpret_cast<char*>(&Params.Request) - offsetof(ChunkRequestData, Upstream));
			if (EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::StoreLocal) ||
				!EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::SkipData))
			{
				CompressedBuffer Compressed = CompressedBuffer::FromCompressed(SharedBuffer(Params.Value));
				if (!Compressed || Compressed.GetRawSize() != Params.RawSize)
				{
					return;
				}

				if (EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::StoreLocal))
				{
					m_CidStore.AddChunk(Compressed);
				}
				if (!EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::SkipData))
				{
					Chunk.Value = std::move(Compressed);
				}
			}
			Chunk.Exists		 = true;
			Chunk.TotalSize		 = Params.RawSize;
			Chunk.TotalSizeKnown = true;
			Chunk.Source		 = "UPSTREAM"sv;

			m_CacheStats.UpstreamHitCount++;
		};

		m_UpstreamCache.GetCacheValues(UpstreamPayloadRequests, std::move(OnCacheValueGetComplete));
	}
}

void
HttpStructuredCacheService::GetCacheChunks_SendResults(std::vector<GetCacheChunks::detail::ChunkRequestData>& Chunks,
													   zen::HttpServerRequest& HttpRequest
														   BACKWARDS_COMPATABILITY_JAN2022_CODE(, bool SendValueOnly))
{
	using namespace GetCacheChunks::detail;

	CbPackage	   RpcResponse;
	CbObjectWriter Writer;

	Writer.BeginArray("Result"sv);
	for (ChunkRequestData& Chunk : Chunks)
	{
#if BACKWARDS_COMPATABILITY_JAN2022
		if (SendValueOnly)
		{
			if (Chunk.Value)
			{
				Writer << Chunk.Upstream.ChunkId;
				RpcResponse.AddAttachment(CbAttachment(Chunk.Value));
			}
			else
			{
				Writer << IoHash::Zero;
			}
		}
		else
#endif
		{
			Writer.BeginObject();
			{
				if (Chunk.Exists)
				{
					Writer.AddHash("RawHash"sv, Chunk.Upstream.ChunkId);
					if (Chunk.Value && !EnumHasAllFlags(Chunk.DownstreamPolicy, CachePolicy::SkipData))
					{
						RpcResponse.AddAttachment(CbAttachment(Chunk.Value));
					}
					else
					{
						Writer.AddInteger("RawSize"sv, Chunk.TotalSize);
					}

					ZEN_DEBUG("CHUNKHIT - '{}/{}/{}' {} '{}' ({})",
							  Chunk.Upstream.Key.Bucket,
							  Chunk.Upstream.Key.Hash,
							  Chunk.Upstream.ValueId,
							  NiceBytes(Chunk.TotalSize),
							  Chunk.IsRecordRequest ? "Record"sv : "Value"sv,
							  Chunk.Source);
					m_CacheStats.HitCount++;
				}
				else if (!EnumHasAnyFlags(Chunk.DownstreamPolicy, CachePolicy::Query))
				{
					ZEN_DEBUG("CHUNKSKIP - '{}/{}/{}'", Chunk.Upstream.Key.Bucket, Chunk.Upstream.Key.Hash, Chunk.Upstream.ValueId);
				}
				else
				{
					ZEN_DEBUG("MISS - '{}/{}/{}'", Chunk.Upstream.Key.Bucket, Chunk.Upstream.Key.Hash, Chunk.Upstream.ValueId);
					m_CacheStats.MissCount++;
				}
			}
			Writer.EndObject();
		}
	}
	Writer.EndArray();

	RpcResponse.SetObject(Writer.Save());

	BinaryWriter MemStream;
	RpcResponse.Save(MemStream);

	HttpRequest.WriteResponse(HttpResponseCode::OK,
							  HttpContentType::kCbPackage,
							  IoBuffer(IoBuffer::Wrap, MemStream.GetData(), MemStream.GetSize()));
}

void
HttpStructuredCacheService::HandleStatsRequest(zen::HttpServerRequest& Request)
{
	CbObjectWriter Cbo;

	EmitSnapshot("requests", m_HttpRequests, Cbo);
	EmitSnapshot("upstream_gets", m_UpstreamGetRequestTiming, Cbo);

	const uint64_t HitCount			= m_CacheStats.HitCount;
	const uint64_t UpstreamHitCount = m_CacheStats.UpstreamHitCount;
	const uint64_t MissCount		= m_CacheStats.MissCount;
	const uint64_t TotalCount		= HitCount + MissCount;

	const CasStoreSize	CasSize	  = m_CidStore.CasSize();
	const GcStorageSize CacheSize = m_CacheStore.StorageSize();

	Cbo.BeginObject("cache");
	Cbo.BeginObject("size");
	Cbo << "disk" << CacheSize.DiskSize;
	Cbo << "memory" << CacheSize.MemorySize;
	Cbo.EndObject();
	Cbo << "upstream_ratio" << (HitCount > 0 ? (double(UpstreamHitCount) / double(HitCount)) : 0.0);
	Cbo << "hits" << HitCount << "misses" << MissCount;
	Cbo << "hit_ratio" << (TotalCount > 0 ? (double(HitCount) / double(TotalCount)) : 0.0);
	Cbo << "upstream_hits" << m_CacheStats.UpstreamHitCount;
	Cbo << "upstream_ratio" << (HitCount > 0 ? (double(UpstreamHitCount) / double(HitCount)) : 0.0);
	Cbo.EndObject();
	Cbo.BeginObject("upstream");
	m_UpstreamCache.GetStatus(Cbo);
	Cbo.EndObject();

	Cbo.BeginObject("cas");
	Cbo.BeginObject("size");
	Cbo << "tiny" << CasSize.TinySize;
	Cbo << "small" << CasSize.SmallSize;
	Cbo << "large" << CasSize.LargeSize;
	Cbo << "total" << CasSize.TotalSize;
	Cbo.EndObject();
	Cbo.EndObject();

	Request.WriteResponse(HttpResponseCode::OK, Cbo.Save());
}

void
HttpStructuredCacheService::HandleStatusRequest(zen::HttpServerRequest& Request)
{
	CbObjectWriter Cbo;
	Cbo << "ok" << true;
	Request.WriteResponse(HttpResponseCode::OK, Cbo.Save());
}

}  // namespace zen