#include "RenderEngine.h"

#include <gl/gl.h>

RenderEngine::RenderEngine(
	RuntimeHost& runtimeHost,
	RuntimeSnapshotProvider& runtimeSnapshotProvider,
	CRITICAL_SECTION& mutex,
	HDC hdc,
	HGLRC hglrc,
	RenderEffectCallback renderEffect,
	ScreenshotCallback screenshotReady,
	PreviewPaintCallback previewPaint) :
	mRenderer(),
	mRenderPass(mRenderer),
	mRenderPipeline(mRenderer, runtimeHost, std::move(renderEffect), std::move(screenshotReady), std::move(previewPaint)),
	mShaderPrograms(mRenderer, runtimeHost, runtimeSnapshotProvider),
	mMutex(mutex),
	mHdc(hdc),
	mHglrc(hglrc)
{
}

RenderEngine::~RenderEngine()
{
	mRenderer.DestroyResources();
}

bool RenderEngine::CompileDecodeShader(int errorMessageSize, char* errorMessage)
{
	return mShaderPrograms.CompileDecodeShader(errorMessageSize, errorMessage);
}

bool RenderEngine::CompileOutputPackShader(int errorMessageSize, char* errorMessage)
{
	return mShaderPrograms.CompileOutputPackShader(errorMessageSize, errorMessage);
}

bool RenderEngine::InitializeResources(
	unsigned inputFrameWidth,
	unsigned inputFrameHeight,
	unsigned captureTextureWidth,
	unsigned outputFrameWidth,
	unsigned outputFrameHeight,
	unsigned outputPackTextureWidth,
	std::string& error)
{
	return mRenderer.InitializeResources(
		inputFrameWidth,
		inputFrameHeight,
		captureTextureWidth,
		outputFrameWidth,
		outputFrameHeight,
		outputPackTextureWidth,
		error);
}

bool RenderEngine::CompileLayerPrograms(unsigned inputFrameWidth, unsigned inputFrameHeight, int errorMessageSize, char* errorMessage)
{
	return mShaderPrograms.CompileLayerPrograms(inputFrameWidth, inputFrameHeight, errorMessageSize, errorMessage);
}

bool RenderEngine::CommitPreparedLayerPrograms(const PreparedShaderBuild& preparedBuild, unsigned inputFrameWidth, unsigned inputFrameHeight, int errorMessageSize, char* errorMessage)
{
	return mShaderPrograms.CommitPreparedLayerPrograms(preparedBuild, inputFrameWidth, inputFrameHeight, errorMessageSize, errorMessage);
}

const std::vector<RuntimeRenderState>& RenderEngine::CommittedLayerStates() const
{
	return mShaderPrograms.CommittedLayerStates();
}

void RenderEngine::ResetTemporalHistoryState()
{
	mShaderPrograms.ResetTemporalHistoryState();
}

void RenderEngine::ResetShaderFeedbackState()
{
	mShaderPrograms.ResetShaderFeedbackState();
}

void RenderEngine::ResizeView(int width, int height)
{
	mRenderer.ResizeView(width, height);
}

bool RenderEngine::TryPresentToWindow(unsigned outputFrameWidth, unsigned outputFrameHeight)
{
	if (!TryEnterCriticalSection(&mMutex))
		return false;

	mRenderer.PresentToWindow(mHdc, outputFrameWidth, outputFrameHeight);
	LeaveCriticalSection(&mMutex);
	return true;
}

bool RenderEngine::TryUploadInputFrame(const VideoIOFrame& inputFrame, const VideoIOState& videoState)
{
	if (inputFrame.hasNoInputSource || inputFrame.bytes == nullptr)
		return true;

	const long textureSize = inputFrame.rowBytes * static_cast<long>(inputFrame.height);
	if (!TryEnterCriticalSection(&mMutex))
		return false;

	wglMakeCurrent(mHdc, mHglrc);

	glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
	glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
	glBindBuffer(GL_PIXEL_UNPACK_BUFFER, mRenderer.TextureUploadBuffer());
	glBufferData(GL_PIXEL_UNPACK_BUFFER, textureSize, inputFrame.bytes, GL_DYNAMIC_DRAW);
	glBindTexture(GL_TEXTURE_2D, mRenderer.CaptureTexture());
	if (inputFrame.pixelFormat == VideoIOPixelFormat::V210)
		glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, videoState.captureTextureWidth, videoState.inputFrameSize.height, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	else
		glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, videoState.captureTextureWidth, videoState.inputFrameSize.height, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, NULL);
	glBindTexture(GL_TEXTURE_2D, 0);
	glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);

	wglMakeCurrent(NULL, NULL);
	LeaveCriticalSection(&mMutex);
	return true;
}

bool RenderEngine::RenderOutputFrame(const RenderPipelineFrameContext& context, VideoIOOutputFrame& outputFrame)
{
	EnterCriticalSection(&mMutex);
	wglMakeCurrent(mHdc, mHglrc);
	const bool rendered = mRenderPipeline.RenderFrame(context, outputFrame);
	wglMakeCurrent(NULL, NULL);
	LeaveCriticalSection(&mMutex);
	return rendered;
}

void RenderEngine::RenderLayerStack(
	bool hasInputSource,
	const std::vector<RuntimeRenderState>& layerStates,
	unsigned inputFrameWidth,
	unsigned inputFrameHeight,
	unsigned captureTextureWidth,
	VideoIOPixelFormat inputPixelFormat,
	unsigned historyCap)
{
	mRenderPass.Render(
		hasInputSource,
		layerStates,
		inputFrameWidth,
		inputFrameHeight,
		captureTextureWidth,
		inputPixelFormat,
		historyCap,
		[this](const RuntimeRenderState& state, OpenGLRenderer::LayerProgram::TextBinding& textBinding, std::string& error) {
			return mShaderPrograms.UpdateTextBindingTexture(state, textBinding, error);
		},
		[this](const RuntimeRenderState& state, unsigned availableSourceHistoryLength, unsigned availableTemporalHistoryLength, bool feedbackAvailable) {
			return mShaderPrograms.UpdateGlobalParamsBuffer(state, availableSourceHistoryLength, availableTemporalHistoryLength, feedbackAvailable);
		});
}

bool RenderEngine::ReadOutputFrameRgba(unsigned width, unsigned height, std::vector<unsigned char>& bottomUpPixels)
{
	if (width == 0 || height == 0)
		return false;

	EnterCriticalSection(&mMutex);
	wglMakeCurrent(mHdc, mHglrc);

	bottomUpPixels.resize(static_cast<std::size_t>(width) * height * 4);
	glBindFramebuffer(GL_READ_FRAMEBUFFER, mRenderer.OutputFramebuffer());
	glReadBuffer(GL_COLOR_ATTACHMENT0);
	glPixelStorei(GL_PACK_ALIGNMENT, 1);
	glPixelStorei(GL_PACK_ROW_LENGTH, 0);
	glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, bottomUpPixels.data());
	glPixelStorei(GL_PACK_ALIGNMENT, 4);

	wglMakeCurrent(NULL, NULL);
	LeaveCriticalSection(&mMutex);
	return true;
}