#include "RuntimeLayerModel.h"

#include <utility>

namespace RenderCadenceCompositor
{
bool RuntimeLayerModel::InitializeSingleLayer(const SupportedShaderCatalog& shaderCatalog, const std::string& shaderId, std::string& error)
{
	Clear();
	if (shaderId.empty())
	{
		error.clear();
		return true;
	}

	const ShaderPackage* shaderPackage = shaderCatalog.FindPackage(shaderId);
	if (!shaderPackage)
	{
		error = "Shader '" + shaderId + "' is not in the supported shader catalog.";
		return false;
	}

	Layer layer;
	layer.id = AllocateLayerId();
	layer.shaderId = shaderPackage->id;
	layer.shaderName = shaderPackage->displayName.empty() ? shaderPackage->id : shaderPackage->displayName;
	layer.buildState = RuntimeLayerBuildState::Pending;
	layer.message = "Runtime Slang build is waiting to start.";
	mLayers.push_back(std::move(layer));
	error.clear();
	return true;
}

bool RuntimeLayerModel::AddLayer(const SupportedShaderCatalog& shaderCatalog, const std::string& shaderId, std::string& layerId, std::string& error)
{
	const ShaderPackage* shaderPackage = shaderCatalog.FindPackage(shaderId);
	if (!shaderPackage)
	{
		error = "Shader '" + shaderId + "' is not in the supported shader catalog.";
		return false;
	}

	Layer layer;
	layer.id = AllocateLayerId();
	layer.shaderId = shaderPackage->id;
	layer.shaderName = shaderPackage->displayName.empty() ? shaderPackage->id : shaderPackage->displayName;
	layer.buildState = RuntimeLayerBuildState::Pending;
	layer.message = "Runtime Slang build is waiting to start.";
	layerId = layer.id;
	mLayers.push_back(std::move(layer));
	error.clear();
	return true;
}

bool RuntimeLayerModel::RemoveLayer(const std::string& layerId, std::string& error)
{
	for (auto layerIt = mLayers.begin(); layerIt != mLayers.end(); ++layerIt)
	{
		if (layerIt->id != layerId)
			continue;

		mLayers.erase(layerIt);
		error.clear();
		return true;
	}

	error = "Unknown runtime layer id: " + layerId;
	return false;
}

void RuntimeLayerModel::Clear()
{
	mLayers.clear();
}

bool RuntimeLayerModel::MarkBuildStarted(const std::string& layerId, const std::string& message, std::string& error)
{
	Layer* layer = FindLayer(layerId);
	if (!layer)
	{
		error = "Unknown runtime layer id: " + layerId;
		return false;
	}

	layer->buildState = RuntimeLayerBuildState::Pending;
	layer->message = message;
	layer->renderReady = false;
	layer->artifact = RuntimeShaderArtifact();
	error.clear();
	return true;
}

bool RuntimeLayerModel::MarkBuildReady(const RuntimeShaderArtifact& artifact, std::string& error)
{
	Layer* layer = artifact.layerId.empty() ? FindFirstLayerForShader(artifact.shaderId) : FindLayer(artifact.layerId);
	if (!layer)
	{
		error = artifact.layerId.empty()
			? "No runtime layer is waiting for shader artifact: " + artifact.shaderId
			: "No runtime layer is waiting for shader artifact on layer: " + artifact.layerId;
		return false;
	}

	layer->shaderName = artifact.displayName.empty() ? artifact.shaderId : artifact.displayName;
	layer->buildState = RuntimeLayerBuildState::Ready;
	layer->message = artifact.message;
	layer->renderReady = true;
	layer->artifact = artifact;
	error.clear();
	return true;
}

bool RuntimeLayerModel::MarkBuildFailedForShader(const std::string& shaderId, const std::string& message)
{
	Layer* layer = FindFirstLayerForShader(shaderId);
	if (!layer)
		return false;

	std::string error;
	return MarkBuildFailed(layer->id, message, error);
}

bool RuntimeLayerModel::MarkBuildFailed(const std::string& layerId, const std::string& message, std::string& error)
{
	Layer* layer = FindLayer(layerId);
	if (!layer)
	{
		error = "Unknown runtime layer id: " + layerId;
		return false;
	}

	layer->buildState = RuntimeLayerBuildState::Failed;
	layer->message = message;
	layer->renderReady = false;
	layer->artifact = RuntimeShaderArtifact();
	error.clear();
	return true;
}

bool RuntimeLayerModel::MarkRenderCommitFailed(const std::string& layerId, const std::string& message, std::string& error)
{
	return MarkBuildFailed(layerId, message, error);
}

RuntimeLayerModelSnapshot RuntimeLayerModel::Snapshot() const
{
	RuntimeLayerModelSnapshot snapshot;
	snapshot.compileSucceeded = true;

	for (const Layer& layer : mLayers)
	{
		snapshot.displayLayers.push_back(ToReadModel(layer));
		if (!layer.message.empty() && snapshot.compileMessage.empty())
			snapshot.compileMessage = layer.message;
		if (layer.buildState == RuntimeLayerBuildState::Failed)
			snapshot.compileSucceeded = false;
		if (layer.renderReady)
		{
			RuntimeRenderLayerModel renderLayer;
			renderLayer.id = layer.id;
			renderLayer.shaderId = layer.shaderId;
			renderLayer.artifact = layer.artifact;
			snapshot.renderLayers.push_back(std::move(renderLayer));
		}
	}

	if (snapshot.compileMessage.empty())
		snapshot.compileMessage = mLayers.empty() ? "Runtime shader build disabled." : "Runtime shader build has not completed yet.";
	return snapshot;
}

std::string RuntimeLayerModel::FirstLayerId() const
{
	return mLayers.empty() ? std::string() : mLayers.front().id;
}

RuntimeLayerModel::Layer* RuntimeLayerModel::FindLayer(const std::string& layerId)
{
	for (Layer& layer : mLayers)
	{
		if (layer.id == layerId)
			return &layer;
	}
	return nullptr;
}

const RuntimeLayerModel::Layer* RuntimeLayerModel::FindLayer(const std::string& layerId) const
{
	for (const Layer& layer : mLayers)
	{
		if (layer.id == layerId)
			return &layer;
	}
	return nullptr;
}

RuntimeLayerModel::Layer* RuntimeLayerModel::FindFirstLayerForShader(const std::string& shaderId)
{
	for (Layer& layer : mLayers)
	{
		if (layer.shaderId == shaderId)
			return &layer;
	}
	return nullptr;
}

std::string RuntimeLayerModel::AllocateLayerId()
{
	return "runtime-layer-" + std::to_string(mNextLayerNumber++);
}

RuntimeLayerReadModel RuntimeLayerModel::ToReadModel(const Layer& layer)
{
	RuntimeLayerReadModel readModel;
	readModel.id = layer.id;
	readModel.shaderId = layer.shaderId;
	readModel.shaderName = layer.shaderName;
	readModel.bypass = layer.bypass;
	readModel.buildState = layer.buildState;
	readModel.message = layer.message;
	readModel.renderReady = layer.renderReady;
	return readModel;
}
}