#include "OpenGLVideoIOBridge.h"

#include "OpenGLRenderer.h"
#include "RuntimeHost.h"

#include <chrono>
#include <gl/gl.h>

OpenGLVideoIOBridge::OpenGLVideoIOBridge(
	VideoIODevice& videoIO,
	OpenGLRenderer& renderer,
	RuntimeHost& runtimeHost,
	CRITICAL_SECTION& mutex,
	HDC hdc,
	HGLRC hglrc,
	RenderEffectCallback renderEffect,
	OutputReadyCallback outputReady,
	PaintCallback paint) :
	mVideoIO(videoIO),
	mRenderer(renderer),
	mRuntimeHost(runtimeHost),
	mMutex(mutex),
	mHdc(hdc),
	mHglrc(hglrc),
	mRenderEffect(renderEffect),
	mOutputReady(outputReady),
	mPaint(paint)
{
}

void OpenGLVideoIOBridge::RecordFramePacing(VideoIOCompletionResult completionResult)
{
	const auto now = std::chrono::steady_clock::now();
	if (mLastPlayoutCompletionTime != std::chrono::steady_clock::time_point())
	{
		mCompletionIntervalMilliseconds = std::chrono::duration_cast<std::chrono::duration<double, std::milli>>(now - mLastPlayoutCompletionTime).count();
		if (mSmoothedCompletionIntervalMilliseconds <= 0.0)
			mSmoothedCompletionIntervalMilliseconds = mCompletionIntervalMilliseconds;
		else
			mSmoothedCompletionIntervalMilliseconds = mSmoothedCompletionIntervalMilliseconds * 0.9 + mCompletionIntervalMilliseconds * 0.1;
		if (mCompletionIntervalMilliseconds > mMaxCompletionIntervalMilliseconds)
			mMaxCompletionIntervalMilliseconds = mCompletionIntervalMilliseconds;
	}
	mLastPlayoutCompletionTime = now;

	if (completionResult == VideoIOCompletionResult::DisplayedLate)
		++mLateFrameCount;
	else if (completionResult == VideoIOCompletionResult::Dropped)
		++mDroppedFrameCount;
	else if (completionResult == VideoIOCompletionResult::Flushed)
		++mFlushedFrameCount;

	mRuntimeHost.TrySetFramePacingStats(
		mCompletionIntervalMilliseconds,
		mSmoothedCompletionIntervalMilliseconds,
		mMaxCompletionIntervalMilliseconds,
		mLateFrameCount,
		mDroppedFrameCount,
		mFlushedFrameCount);
}

void OpenGLVideoIOBridge::VideoFrameArrived(const VideoIOFrame& inputFrame)
{
	const VideoIOState& state = mVideoIO.State();
	mRuntimeHost.TrySetSignalStatus(!inputFrame.hasNoInputSource, state.inputFrameSize.width, state.inputFrameSize.height, state.inputDisplayModeName);

	if (inputFrame.hasNoInputSource || inputFrame.bytes == nullptr)
		return;							// don't transfer texture when there's no input

	const long textureSize = inputFrame.rowBytes * static_cast<long>(inputFrame.height);

	EnterCriticalSection(&mMutex);

	wglMakeCurrent(mHdc, mHglrc);		// make OpenGL context current in this thread

	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());

	// NULL for last arg indicates use current GL_PIXEL_UNPACK_BUFFER target as texture data.
	if (inputFrame.pixelFormat == VideoIOPixelFormat::V210)
		glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, state.captureTextureWidth, state.inputFrameSize.height, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	else
		glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, state.captureTextureWidth, state.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);
}

void OpenGLVideoIOBridge::PlayoutFrameCompleted(const VideoIOCompletion& completion)
{
	RecordFramePacing(completion.result);

	EnterCriticalSection(&mMutex);

	VideoIOOutputFrame outputFrame;
	if (!mVideoIO.BeginOutputFrame(outputFrame))
	{
		LeaveCriticalSection(&mMutex);
		return;
	}
	const VideoIOState& state = mVideoIO.State();
	RenderPipelineFrameContext frameContext;
	frameContext.videoState = state;
	frameContext.completion = completion;

	// make GL context current in this thread
	wglMakeCurrent(mHdc, mHglrc);

	// Draw the effect output to the off-screen framebuffer.
	const auto renderStartTime = std::chrono::steady_clock::now();
	glBindFramebuffer(GL_FRAMEBUFFER, mRenderer.CompositeFramebuffer());
	mRenderEffect();
	glBindFramebuffer(GL_READ_FRAMEBUFFER, mRenderer.CompositeFramebuffer());
	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, mRenderer.OutputFramebuffer());
	glBlitFramebuffer(0, 0, state.inputFrameSize.width, state.inputFrameSize.height, 0, 0, state.outputFrameSize.width, state.outputFrameSize.height, GL_COLOR_BUFFER_BIT, GL_LINEAR);
	glBindFramebuffer(GL_FRAMEBUFFER, mRenderer.OutputFramebuffer());
	if (mOutputReady)
		mOutputReady();
	if (state.outputPixelFormat == VideoIOPixelFormat::V210)
	{
		glBindFramebuffer(GL_FRAMEBUFFER, mRenderer.OutputPackFramebuffer());
		glViewport(0, 0, state.outputPackTextureWidth, state.outputFrameSize.height);
		glDisable(GL_SCISSOR_TEST);
		glDisable(GL_BLEND);
		glDisable(GL_DEPTH_TEST);
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, mRenderer.OutputTexture());
		glBindVertexArray(mRenderer.FullscreenVertexArray());
		glUseProgram(mRenderer.OutputPackProgram());
		const GLint outputResolutionLocation = glGetUniformLocation(mRenderer.OutputPackProgram(), "uOutputVideoResolution");
		const GLint activeWordsLocation = glGetUniformLocation(mRenderer.OutputPackProgram(), "uActiveV210Words");
		if (outputResolutionLocation >= 0)
			glUniform2f(outputResolutionLocation, static_cast<float>(state.outputFrameSize.width), static_cast<float>(state.outputFrameSize.height));
		if (activeWordsLocation >= 0)
			glUniform1f(activeWordsLocation, static_cast<float>(ActiveV210WordsForWidth(state.outputFrameSize.width)));
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glUseProgram(0);
		glBindVertexArray(0);
		glBindTexture(GL_TEXTURE_2D, 0);
	}
	glFlush();
	const auto renderEndTime = std::chrono::steady_clock::now();
	const double frameBudgetMilliseconds = state.frameBudgetMilliseconds;
	const double renderMilliseconds = std::chrono::duration_cast<std::chrono::duration<double, std::milli>>(renderEndTime - renderStartTime).count();
	mRuntimeHost.TrySetPerformanceStats(frameBudgetMilliseconds, renderMilliseconds);
	mRuntimeHost.TryAdvanceFrame();

	glPixelStorei(GL_PACK_ALIGNMENT, 4);
	glPixelStorei(GL_PACK_ROW_LENGTH, 0);
	if (state.outputPixelFormat == VideoIOPixelFormat::V210)
	{
		glBindFramebuffer(GL_READ_FRAMEBUFFER, mRenderer.OutputPackFramebuffer());
		glReadPixels(0, 0, state.outputPackTextureWidth, state.outputFrameSize.height, GL_RGBA, GL_UNSIGNED_BYTE, outputFrame.bytes);
	}
	else
	{
		glBindFramebuffer(GL_READ_FRAMEBUFFER, mRenderer.OutputFramebuffer());
		glReadPixels(0, 0, state.outputFrameSize.width, state.outputFrameSize.height, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, outputFrame.bytes);
	}
	mPaint();

	mVideoIO.EndOutputFrame(outputFrame);

	mVideoIO.AccountForCompletionResult(completion.result);

	// Schedule the next frame for playout
	mVideoIO.ScheduleOutputFrame(outputFrame);

	wglMakeCurrent(NULL, NULL);

	LeaveCriticalSection(&mMutex);
}