#include "AnimQueue.h"
#include "UtilityLibrary.h"

FlxAnimationStep::FlxAnimationStep(uint64 hash, std::string_view body) {
	Finished = false;
	Hash = hash;
	Body.SetNum(body.size());
	memcpy(Body.GetData(), body.data(), body.size());
	Blueprint = UlxAnimationStepLibrary::AnimationStepGetString(*this, "bp");
}

static void ClearProperties(const FString& prefix, UObject* obj, FProperty *except) {
	UClass* uclass = obj->GetClass();
	FName prefixlo(prefix);
	FName prefixhi(prefix + TEXT("\xFFFF"));
	for (TFieldIterator<FProperty> It(uclass); It; ++It)
	{
		FProperty* fprop = *It;
		if (fprop == except) continue;
		bool match1 = (fprop->GetFName().Compare(prefixlo) > 0);
		bool match2 = (fprop->GetFName().Compare(prefixhi) < 0);
		if (match1 && match2) {
			uint8* pptr = fprop->ContainerPtrToValuePtr<uint8>(obj);
			fprop->ClearValue(pptr);
		}
	}
}

#pragma optimize("", off)

static bool SetProperty(const FString& prefix, UObject* obj, const FlxAnimationField& field) {
	UClass* uclass = obj->GetClass();
	FString sname(field.Name.size(), (const UTF8CHAR*)field.Name.data());
	FName nname(prefix + sname);
	switch (field.Type) {
		case SimpleDynamicTag::STRING: {
			FStrProperty* fprop = FindFProperty<FStrProperty>(uclass, nname);
			if (fprop == nullptr) return false;
			FString* pptr = fprop->ContainerPtrToValuePtr<FString>(obj);
			*pptr = FString(field.S.size(), (const UTF8CHAR*)field.S.data());
			return true;
		}
		case SimpleDynamicTag::NUMBER: {
			FDoubleProperty* fprop = FindFProperty<FDoubleProperty>(uclass, nname);
			if (fprop == nullptr) return false;
			double* pptr = fprop->ContainerPtrToValuePtr<double>(obj);
			*pptr = field.X;
			return true;
		}
		case SimpleDynamicTag::BOOLEAN: {
			FBoolProperty* fprop = FindFProperty<FBoolProperty>(uclass, nname);
			if (fprop == nullptr) return false;
			uint8* pptr = fprop->ContainerPtrToValuePtr<uint8>(obj);
			fprop->SetPropertyValue(pptr, (field.X == 1.0));
			return true;
		}
		case SimpleDynamicTag::VECTOR: {
			FStructProperty* fprop = FindFProperty<FStructProperty>(uclass, nname);
			if (fprop == nullptr) return false;
			if (fprop->Struct != TBaseStructure<FVector>::Get()) return false;
			FVector* pptr = fprop->ContainerPtrToValuePtr<FVector>(obj);
			*pptr = FVector(field.X, field.Y, field.Z);
			return true;
		}
	}
	return false;
}

#pragma optimize("", off)
static FStructProperty *FindAnimationStepProperty(UClass *uclass, const FString &prefix) {
	FName nname(prefix + TEXT("Animation Step"));
	FStructProperty* fprop = FindFProperty<FStructProperty>(uclass, nname);
	if (fprop == nullptr) return nullptr;
	if (fprop->Struct != TBaseStructure<FlxAnimationStep>::Get()) return nullptr;
	return fprop;
}

#pragma optimize("", off)
void UlxAnimationStepLibrary::UnpackAnimationStep(bool &bChanged, FString &Action, const FlxAnimationStep& step, UObject* target, const FString& prefix) {
	bChanged = false;
	Action = TEXT("");

	if (prefix.IsEmpty())
	{
		UE_LOG(LogBlueprint, Error, TEXT("UnpackAnimationStep: You may not pass an empty string for prefix"));
		return;
	}

	UClass* uclass = target->GetClass();
	std::string_view body((const char*)(step.Body.GetData()), step.Body.Num());
	FlxAnimationStepDecoder decoder(body);

	FStructProperty* stepproperty = FindAnimationStepProperty(uclass, prefix);
	if (stepproperty == nullptr) {
		UE_LOG(LogBlueprint, Error, TEXT("UnpackAnimationStep: Target object does not have a variable named: '%s Animation Step'"), *prefix);
		return;
	}

	FlxAnimationStep* stepstorage = stepproperty->ContainerPtrToValuePtr<FlxAnimationStep>(target);
	uint64 oldhash = stepstorage->Hash;

	FlxAnimationField actionfield;
	actionfield.Name = "action";
	actionfield.Persistent = false;
	actionfield.Type = SimpleDynamicTag::STRING;
	actionfield.S = "unknown";

	// Decode everything.  If an action field is found, save it for later.
	ClearProperties(prefix, target, stepproperty);
	while (!decoder.AtEOF()) {
		FlxAnimationField field = decoder.ReadField();
		if ((field.Type == SimpleDynamicTag::STRING) && (field.Name == "action")) {
			actionfield.S = field.S;
			continue;
		}
		if (step.Finished && !field.Persistent) continue;
		SetProperty(prefix, target, field);
	}

	// Store the action field.
	if (step.Finished) actionfield.S = "idle";
	SetProperty(prefix, target, actionfield);

	// Store the whole step.
	*stepstorage = step;
	
	// Return the correct values.
	Action = FString(actionfield.S.size(), (const UTF8CHAR*)actionfield.S.data());
	bChanged = (step.Hash != oldhash);
}

FString UlxAnimationStepLibrary::AnimationStepDebugString(const FlxAnimationStep& step) {
	std::string_view body((const char*)(step.Body.GetData()), step.Body.Num());
	return FlxAnimationStepDecoder::DebugString(step.Finished, step.Finished, step.Hash, body);
}

static FlxAnimationField FindAnimationFieldLL(const FlxAnimationStep& step, std::string_view name) {
	std::string_view body((const char*)(step.Body.GetData()), step.Body.Num());
	FlxAnimationStepDecoder decoder(body);
	FlxAnimationField result;
	while (!decoder.AtEOF()) {
		result = decoder.ReadField();
		if (result.Name == name) {
			return result;
		}
	}
	result.Type = SimpleDynamicTag::UNINITIALIZED;
	return result;
}

static FlxAnimationField FindAnimationField(const FlxAnimationStep& step, const FString& name) {
	FTCHARToUTF8 utf8name(name);
	std::string_view uname(utf8name.Get(), utf8name.Length());
	return FindAnimationFieldLL(step, uname);
}

void FlxAnimationStep::AutoUpdateXYZ(AActor *actor) const {
	FlxAnimationField xyz = FindAnimationFieldLL(*this, "xyz");
	if (xyz.Type == SimpleDynamicTag::VECTOR) {
		actor->SetActorLocation(FVector(xyz.X, xyz.Y, xyz.Z));
	}
}

void FlxAnimationStep::AutoUpdateFacing(AActor *actor) const {
	FlxAnimationField facing = FindAnimationFieldLL(*this, "facing");
	if (facing.Type == SimpleDynamicTag::NUMBER) {
		actor->SetActorRotation(FRotator(0, facing.X, 0));
	}
}

void FlxAnimationStep::AutoUpdatePlane(FName *planep) const {
	FlxAnimationField plane = FindAnimationFieldLL(*this, "plane");
	if (plane.Type == SimpleDynamicTag::STRING) {
		FString pname(plane.S.size(), (const UTF8CHAR*)(plane.S.data()));
		*planep = FName(pname);
	}
}

bool UlxAnimationStepLibrary::AnimationStepEqual(const FlxAnimationStep &stepa, const FlxAnimationStep &stepb) {
	return (stepa.Finished == stepb.Finished) && (stepa.Hash == stepb.Hash);
}

bool UlxAnimationStepLibrary::AnimationStepIsIdle(const FlxAnimationStep &step) {
	return step.Finished;
}

FVector UlxAnimationStepLibrary::AnimationStepGetVector(const FlxAnimationStep& step, const FString& name) {
	FlxAnimationField field = FindAnimationField(step, name);
	if (field.Type != SimpleDynamicTag::VECTOR) return FVector(0, 0, 0);
	return FVector(field.X, field.Y, field.Z);
}

double UlxAnimationStepLibrary::AnimationStepGetFloat(const FlxAnimationStep& step, const FString& name) {
	FlxAnimationField field = FindAnimationField(step, name);
	if (field.Type != SimpleDynamicTag::NUMBER) return 0.0;
	return field.X;
}

FString UlxAnimationStepLibrary::AnimationStepGetString(const FlxAnimationStep& step, const FString& name) {
	if (step.Finished && (name == TEXT("action"))) {
		return TEXT("idle");
	}
	FlxAnimationField field = FindAnimationField(step, name);
	if (field.Type != SimpleDynamicTag::STRING) return TEXT("");
	return FString(field.S.size(), (const UTF8CHAR*)(field.S.data()));
}

bool UlxAnimationStepLibrary::AnimationStepGetBool(const FlxAnimationStep& step, const FString& name) {
	FlxAnimationField field = FindAnimationField(step, name);
	if (field.Type != SimpleDynamicTag::BOOLEAN) return false;
	return field.X == 1.0;
}


FlxAnimationField FlxAnimationStepDecoder::ReadField() {
	FlxAnimationField result;
	result.Name = Decoder.read_string_view();
	result.Persistent = Decoder.read_bool();
	result.Type = (SimpleDynamicTag)Decoder.read_uint8();
	switch (result.Type) {
		case SimpleDynamicTag::STRING: {
			result.S = Decoder.read_string_view();
			break;
		}
		case SimpleDynamicTag::NUMBER: {
			result.X = Decoder.read_double();
			break;
		}
		case SimpleDynamicTag::BOOLEAN: {
			result.X = Decoder.read_bool() ? 1.0 : 0.0;
			break;
		}
		case SimpleDynamicTag::VECTOR: {
			result.X = Decoder.read_double();
			result.Y = Decoder.read_double();
			result.Z = Decoder.read_double();
			break;
		}
		default: {
			Decoder.read_bytes(Decoder.fill());
			result.Type = SimpleDynamicTag::UNINITIALIZED;
			break;
		}
	}
	return result;
}

FString FlxAnimationStepDecoder::DebugString(bool injectidle, bool persistentonly, uint64 hash, std::string_view body) {
	FString result;
	FlxAnimationStepDecoder decoder(body);
	result.Appendf(TEXT("Hash=%016llx"), hash);
	if (injectidle) {
		result.Appendf(TEXT(" action=idle"));
	}
	while (!decoder.AtEOF()) {
		FlxAnimationField field = decoder.ReadField();
		if (persistentonly && !field.Persistent) continue;
		result.Append(TEXT(" "));
		result.Append(FString(field.Name.size(), (const UTF8CHAR*)field.Name.data()));
		result.Append(field.Persistent ? TEXT("=") : TEXT(":"));
		switch (field.Type) {
		case SimpleDynamicTag::STRING:
			result.Append(FString(field.S.size(), (const UTF8CHAR*)field.S.data()));
			break;
		case SimpleDynamicTag::NUMBER:
			result.Appendf(TEXT("%lf"), field.X);
			break;
		case SimpleDynamicTag::BOOLEAN:
			result.Append((field.X) == 1.0 ? TEXT("true") : TEXT("false"));
			break;
		case SimpleDynamicTag::VECTOR:
			result.Appendf(TEXT("%lf,%lf,%lf"), field.X, field.Y, field.Z);
			break;
		}
	}
	return result;
}

FlxAnimationStepView FlxAnimQueueDecoder::ReadStep() {
	FlxAnimationStepView result;
	result.Hash = Decoder.read_uint64();
	result.Body = Decoder.read_string_view();
	return result;
}

uint64 FlxAnimQueueDecoder::PeekHash() {
	int64_t read_count = Decoder.total_reads();
	uint64 result = Decoder.read_uint64();
	Decoder.unread_to(read_count);
	return result;
}

FlxAnimQueueDecoder::FlxAnimQueueDecoder(std::string_view queue) : Decoder(queue) {
	SizeLimit = Decoder.read_uint8();
	ActualSize = Decoder.read_uint8();
}

FString FlxAnimQueueDecoder::DebugString(std::string_view queue) {
	FString result;
	FlxAnimQueueDecoder decoder(queue);
	while (!decoder.AtEOF()) {
		FlxAnimationStepView step = decoder.ReadStep();
		FString stepdebug = FlxAnimationStepDecoder::DebugString(false, false, step.Hash, step.Body);
		result.Appendf(TEXT("%s\n"), *stepdebug);
	}
	return result;
}

FlxAnimTracker::FlxAnimTracker() {
	Clear();
}

void FlxAnimTracker::Clear() {
	AQ.Empty();
	Changed = true;
	AutoFinish = false;
	AutoFinishAction.Empty();
	AutoFinishXYZ.Set(0,0,0);
}

void FlxAnimTracker::FinishedAnimation(uint64 hash) {
	for (int i = 0; i < AQ.Num(); i++) {
		if (AQ[i].Hash == hash) {
			AQ[i].Finished = true;
			Changed = true;
		}
	}
}

void FlxAnimTracker::SkipToEnd() {
	for (int i = 0; i < AQ.Num(); i++) {
		if (!AQ[i].Finished) {
			AQ[i].Finished = true;
			Changed = true;
		}
	}
}

void FlxAnimTracker::Update(std::string_view encqueue) {
	check(!encqueue.empty());
	
	// If the first hash matches, we don't bother updating at all.
	//
	FlxAnimQueueDecoder decoder(encqueue);
	if (!AQ.IsEmpty()) {
		if (decoder.PeekHash() == AQ.Last().Hash) {
			return;
		}
	}


	// The Changed flag is set whenever there is any change to
	// the animation queue of any kind.
	//
	Changed = true;

	// Build a map indexing the steps in AQ.
	//
	TMap<uint64, int32> HashToIndex;
	for (int i = 0; i < AQ.Num(); i++) {
		HashToIndex.Emplace(AQ[i].Hash, i);
	}

	// Search for a Luprex animation record that matches
	// something that we already have.  Yields the sequence
	// number of the most recent matching record.
	//
	// At the same time, push all non-matching records
	// after the matching record onto a stack of new records.
	//
	TArray<FlxAnimationStepView> newsteps;
	int32 matchingindex = -1;
	while (!decoder.AtEOF()) {
		FlxAnimationStepView step = decoder.ReadStep();
		int32* indexp = HashToIndex.Find(step.Hash);
		if (indexp == nullptr) {
			newsteps.Emplace(step);
		} else {
			matchingindex = *indexp;
			break;
		}
	}

	// Remove all animations after the most recent matching
	// record.
	// 
	int32 nremove = (AQ.Num() - (matchingindex + 1));
	check((nremove >= 0) && (nremove <= AQ.Num()));
	for (int32 i = 0; i < nremove; i++) {
		AQ.PopLast();
	}

	// Transfer the new animations onto the queue.
	//
	while (!newsteps.IsEmpty()) {
		FlxAnimationStepView step = newsteps.Pop();
		AQ.EmplaceLast(step.Hash, step.Body);
	}

	// If there are too many animations in AQ, discard
	// any very old ones.
	//
	// TODO: this is hardwired to keep 10.  Instead, we
	// should keep the number specified in the queue.
	//
	int limit = 10;
	int ndiscard = AQ.Num() - limit;
	if (ndiscard > 0) {
		for (int i = 0; i < ndiscard; i++) {
			AQ.PopFirst();
		}
	}

	// Autofinish up to one animation.
	//
	if (AutoFinish) {
		for (int i = 0; i < AQ.Num(); i++) {
			if (!AQ[i].Finished) {
				if (MatchesAutoFinish(AQ[i])) {
					AQ[i].Finished = true;
				}
				break;
			}
		}
		AutoFinish = false;
		AutoFinishAction.Empty();
		AutoFinishXYZ.Set(0,0,0);
	}
}

void FlxAnimTracker::SetAutoFinish(const FString &action, const FVector &xyz) {
	AutoFinish = true;
	AutoFinishAction = action;
	AutoFinishXYZ = xyz;
}

bool FlxAnimTracker::MatchesAutoFinish(const FlxAnimationStep &step) {
	FVector xyz = UlxAnimationStepLibrary::AnimationStepGetVector(step, TEXT("xyz"));
	if (xyz != AutoFinishXYZ) return false;
	FString action = UlxAnimationStepLibrary::AnimationStepGetString(step, TEXT("action"));
	if (action != AutoFinishAction) return false;
	return true;
}

FString FlxAnimTracker::GetCurrentBlueprintName() {
	for (int i = 0; i < AQ.Num(); i++) {
		if (!AQ[i].Finished) {
			return AQ[i].Blueprint;
		}
	}
	return AQ.Last().Blueprint;
}

FlxAnimationStep FlxAnimTracker::GetCurrentAnimation() {
	FlxAnimationStep result;
	for (int i = 0; i < AQ.Num(); i++) {
		if (!AQ[i].Finished) {
			return AQ[i];
		}
	}
	result = AQ.Last();
	// This next line is a hack.  We need the idle step to have a unique
	// hash.  This is a passable way to get a unique hash value.
	result.Hash += 1;
	return result;
}