#include "BsBansheeRenderer.h"
#include "BsCamera.h"
#include "BsSceneObject.h"
#include "BsSceneManager.h"
#include "BsRenderable.h"
#include "BsMaterial.h"
#include "BsMesh.h"
#include "BsPass.h"
#include "BsBlendState.h"
#include "BsRasterizerState.h"
#include "BsDepthStencilState.h"
#include "BsCoreApplication.h"
#include "BsViewport.h"
#include "BsRenderTarget.h"
#include "BsRenderOperation.h"
#include "BsDefaultRenderQueue.h"
#include "BsOverlayManager.h"
#include "BsDrawHelper2D.h"
#include "BsDrawHelper3D.h"
#include "BsGUIManager.h"
#include "BsCoreThread.h"
#include "BsProfilerCPU.h"
#include "BsDrawList.h"

using namespace std::placeholders;

namespace BansheeEngine
{
	BansheeRenderer::BansheeRenderer()
	{
		mRenderableRemovedConn = gBsSceneManager().onRenderableRemoved.connect(std::bind(&BansheeRenderer::renderableRemoved, this, _1));
	}

	BansheeRenderer::~BansheeRenderer()
	{
		assert(false); // TODO - Delete all renderable proxies

		mRenderableRemovedConn.disconnect();
	}

	const String& BansheeRenderer::getName() const
	{
		static String name = "BansheeRenderer";
		return name;
	}

	void BansheeRenderer::addRenderableProxy(RenderableProxy* proxy)
	{
		for (auto& subProxy : proxy->subProxies)
		{
			mRenderableProxies.push_back(subProxy);
			mWorldTransforms.push_back(subProxy->worldTransform);
			mWorldBounds.push_back(subProxy->calculateWorldBounds());
			subProxy->markBoundsClean();

			subProxy->id = (UINT32)(mRenderableProxies.size() - 1);
			subProxy->mesh->addRenderableProxy(subProxy);
		}
	}

	void BansheeRenderer::removeRenderableProxy(RenderableProxy* proxy)
	{
		for (auto& subProxy : proxy->subProxies)
		{
			assert(mRenderableProxies.size() > subProxy->id && subProxy->id >= 0);

			if (mRenderableProxies.size() == 0)
				mRenderableProxies.erase(mRenderableProxies.begin());
			else
			{
				std::swap(mRenderableProxies[subProxy->id], mRenderableProxies.back());
				mRenderableProxies.erase(mRenderableProxies.end() - 1);

				mRenderableProxies[subProxy->id]->id = subProxy->id;
			}

			subProxy->mesh->removeRenderableProxy(subProxy);
			bs_delete(subProxy);
		}

		bs_delete(proxy);
	}

	void BansheeRenderer::updateRenderableProxy(RenderableProxy* proxy, Matrix4 localToWorld)
	{
		for (auto& subProxy : proxy->subProxies)
		{
			subProxy->worldTransform = localToWorld;

			mWorldTransforms[subProxy->id] = localToWorld;
			mWorldBounds[subProxy->id] = subProxy->calculateWorldBounds();
			subProxy->markBoundsClean();
		}
	}

	void BansheeRenderer::renderableRemoved(const HRenderable& renderable)
	{
		if (renderable->_getActiveProxy() != nullptr)
		{
			mDeletedProxies.push_back(renderable->_getActiveProxy());
		}
	}

	void BansheeRenderer::renderAll() 
	{
		gProfilerCPU().beginSample("renderA");

		gBsSceneManager().updateRenderableTransforms();

		// Remove proxies from deleted Renderable
		for (auto& proxy : mDeletedProxies)
		{
			if (proxy != nullptr)
				gCoreAccessor().queueCommand(std::bind(&BansheeRenderer::removeRenderableProxy, this, proxy));
		}

		// Add or update Renderable proxies
		const Vector<HRenderable>& allRenderables = gBsSceneManager().getAllRenderables();
		for (auto& renderable : allRenderables)
		{
			if (!renderable->_isRenderDataDirty())
			{
				RenderableProxy* proxy = renderable->_getActiveProxy();

				if (proxy != nullptr)
					gCoreAccessor().queueCommand(std::bind(&BansheeRenderer::removeRenderableProxy, this, proxy));

				proxy = renderable->_createProxy(gCoreThread().getFrameAlloc());
				renderable->_setActiveProxy(proxy);

				gCoreAccessor().queueCommand(std::bind(&BansheeRenderer::addRenderableProxy, this, proxy));

				renderable->_markRenderDataClean();
				renderable->SO()->_markRenderDataUpToDate();
			}
			else if (!renderable->SO()->_isRenderDataUpToDate())
			{
				RenderableProxy* proxy = renderable->_getActiveProxy();
				assert(proxy != nullptr);

				gCoreAccessor().queueCommand(std::bind(&BansheeRenderer::updateRenderableProxy, this, proxy, renderable->SO()->getWorldTfrm()));

				renderable->SO()->_markRenderDataUpToDate();
			}
		}

		// Create frame data
		const Vector<HCamera>& allCameras = gBsSceneManager().getAllCameras();
		Vector<RenderQueuePtr> renderQueues;

		std::shared_ptr<FrameData> frameData = bs_shared_ptr<FrameData>();

		for (auto& camera : allCameras)
		{
			RenderTargetPtr target = camera->getViewport()->getTarget();
			auto findIter = std::find_if(begin(frameData->renderTargets), end(frameData->renderTargets), 
				[&target](const RenderTargetData& x) { return x.target == target; });

			if (findIter == frameData->renderTargets.end())
			{
				frameData->renderTargets.push_back(RenderTargetData());
				RenderTargetData& renderTargetData = frameData->renderTargets.back();

				renderTargetData.target = target;
				renderTargetData.cameras.push_back(CameraData());

				CameraData& camData = renderTargetData.cameras.back();
				camData.cameraProxy = camera->_createProxy();
				camData.renderQueue = bs_shared_ptr<DefaultRenderQueue>();

				renderQueues.push_back(camData.renderQueue);
			}
			else
			{
				findIter->cameras.push_back(CameraData());

				CameraData& camData = findIter->cameras.back();
				camData.cameraProxy = camera->_createProxy();
				camData.renderQueue = bs_shared_ptr<DefaultRenderQueue>();

				renderQueues.push_back(camData.renderQueue);
			}
		}

		// Sort everything based on priority
		auto cameraComparer = [&](const CameraData& a, const CameraData& b) { return a.cameraProxy.priority > b.cameraProxy.priority; };
		auto renderTargetInfoComparer = [&](const RenderTargetData& a, const RenderTargetData& b) { return a.target->getPriority() > b.target->getPriority(); };
		std::sort(begin(frameData->renderTargets), end(frameData->renderTargets), renderTargetInfoComparer);

		for (auto& camerasPerTarget : frameData->renderTargets)
		{
			Vector<CameraData>& cameras = camerasPerTarget.cameras;

			std::sort(begin(cameras), end(cameras), cameraComparer);
		}

		// Populate direct draw lists
		UINT32 idx = 0;
		for (auto& camera : allCameras)
		{
			DrawList drawList;

			// Get GUI render operations
			GUIManager::instance().render(camera->getViewport(), drawList);

			// Get overlay render operations
			OverlayManager::instance().render(camera->getViewport(), drawList);

			// Get debug render operations
			DrawHelper3D::instance().render(camera, drawList);
			DrawHelper2D::instance().render(camera, drawList);

			// Get any operations from hooked up callbacks
			const Viewport* viewportRawPtr = camera->getViewport().get();
			auto callbacksForViewport = mRenderCallbacks[viewportRawPtr];

			for (auto& callback : callbacksForViewport)
				callback(viewportRawPtr, drawList);

			RenderQueuePtr renderQueue = renderQueues[idx];

			const Vector<DrawOperation>& drawOps = drawList.getDrawOperations();
			for (auto& drawOp : drawOps)
			{
				// TODO - Will I need to check if materials match renderer?

				renderQueue->add(drawOp.material->_createProxy(gCoreThread().getFrameAlloc()),
					&drawOp.mesh->_getMeshProxy(drawOp.submeshIdx), drawOp.worldPosition);
			}

			idx++;
		}

		gCoreAccessor().queueCommand(std::bind(&BansheeRenderer::renderAllCore, this, frameData));
	}

	void BansheeRenderer::renderAllCore(std::shared_ptr<FrameData> frameData)
	{
		// Render everything, target by target
		for (auto& renderTargetData : frameData->renderTargets)
		{
			RenderTargetPtr target = renderTargetData.target;
			Vector<CameraData>& cameraData = renderTargetData.cameras;

			RenderSystem::instance().beginFrame();

			for(auto& data : cameraData)
			{
				Viewport& viewport = data.cameraProxy.viewport;
				RenderSystem::instance().setViewport(viewport);

				UINT32 clearBuffers = 0;
				if(viewport.getRequiresColorClear())
					clearBuffers |= FBT_COLOR;

				if(viewport.getRequiresDepthClear())
					clearBuffers |= FBT_DEPTH;

				if(viewport.getRequiresStencilClear())
					clearBuffers |= FBT_STENCIL;

				if(clearBuffers != 0)
					RenderSystem::instance().clearViewport(clearBuffers, viewport.getClearColor(), viewport.getClearDepthValue(), viewport.getClearStencilValue());

				render(data.cameraProxy, data.renderQueue);
			}

			RenderSystem::instance().endFrame();
			RenderSystem::instance().swapBuffers(target);
		}
	}

	void BansheeRenderer::render(const CameraProxy& cameraProxy, const RenderQueuePtr& renderQueue) 
	{
		RenderSystem& rs = RenderSystem::instance();

		if (!cameraProxy.ignoreSceneRenderables)
		{
			// TODO - Do frustum culling
			for (auto& renderableProxy : mRenderableProxies)
			{
				// TODO - Apply world-view-proj matrix

				renderQueue->add(renderableProxy->material, renderableProxy->mesh, mWorldBounds[renderableProxy->id].getSphere().getCenter());
				
			}
		}

		Matrix4 projMatrixCstm = cameraProxy.projMatrix;
		Matrix4 viewMatrixCstm = cameraProxy.viewMatrix;

		Matrix4 viewProjMatrix = projMatrixCstm * viewMatrixCstm;

		renderQueue->sort();
		const Vector<SortedRenderOp>& sortedROps = renderQueue->getSortedRenderOps();

		for(auto iter = sortedROps.begin(); iter != sortedROps.end(); ++iter)
		{
			const RenderOperation& renderOp = *iter->baseOperation;
			const MaterialProxy& materialProxy = renderOp.material;

			setPass(materialProxy.passes[iter->passIdx]);

			// TODO - Call rs.render() - I need to refactor it so it accepts vertex and index data instead of mesh,
			// but I need to find a way to notify mesh when it is used on GPU. (Notify the proxy?)

			SubMesh subMesh = renderOp.mesh->getSubMesh();
			//rs.render(renderOp.mesh->getVertexData(), renderOp.mesh->getIndexBuffer(), subMesh.indexOffset, subMesh.indexCount, true, subMesh.drawOp);
		}
	}

	void BansheeRenderer::setPass(const MaterialProxy::PassData& pass)
	{
		RenderSystem& rs = RenderSystem::instance();

		if (pass.vertexProg)
		{
			rs.bindGpuProgram(pass.vertexProg);
			rs.bindGpuParams(GPT_VERTEX_PROGRAM, *pass.vertexProgParams);
		}
		else
			rs.unbindGpuProgram(GPT_VERTEX_PROGRAM);

		if (pass.fragmentProg)
		{
			rs.bindGpuProgram(pass.fragmentProg);
			rs.bindGpuParams(GPT_FRAGMENT_PROGRAM, *pass.geometryProgParams);
		}
		else
			rs.unbindGpuProgram(GPT_FRAGMENT_PROGRAM);

		if (pass.geometryProg)
		{
			rs.bindGpuProgram(pass.geometryProg);
			rs.bindGpuParams(GPT_GEOMETRY_PROGRAM, *pass.geometryProgParams);
		}
		else
			rs.unbindGpuProgram(GPT_GEOMETRY_PROGRAM);

		if (pass.hullProg)
		{
			rs.bindGpuProgram(pass.hullProg);
			rs.bindGpuParams(GPT_HULL_PROGRAM, *pass.hullProgParams);
		}
		else
			rs.unbindGpuProgram(GPT_HULL_PROGRAM);

		if (pass.domainProg)
		{
			rs.bindGpuProgram(pass.domainProg);
			rs.bindGpuParams(GPT_DOMAIN_PROGRAM, *pass.domainProgParams);
		}
		else
			rs.unbindGpuProgram(GPT_DOMAIN_PROGRAM);

		if (pass.computeProg)
		{
			rs.bindGpuProgram(pass.computeProg);
			rs.bindGpuParams(GPT_COMPUTE_PROGRAM, *pass.computeProgParams);
		}
		else
			rs.unbindGpuProgram(GPT_COMPUTE_PROGRAM);

		// TODO - Try to limit amount of state changes, if previous state is already the same

		// Set up non-texture related pass settings
		if (pass.blendState != nullptr)
			rs.setBlendState(pass.blendState.getInternalPtr());
		else
			rs.setBlendState(BlendState::getDefault());

		if (pass.depthStencilState != nullptr)
			rs.setDepthStencilState(pass.depthStencilState.getInternalPtr(), pass.stencilRefValue);
		else
			rs.setDepthStencilState(DepthStencilState::getDefault(), pass.stencilRefValue);

		if (pass.rasterizerState != nullptr)
			rs.setRasterizerState(pass.rasterizerState.getInternalPtr());
		else
			rs.setRasterizerState(RasterizerState::getDefault());
	}
}