//
//  RenderDeferredTask.cpp
//  render-utils/src/
//
//  Created by Sam Gateau on 5/29/15.
//  Copyright 2016 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#include "RenderDeferredTask.h"

#include <PerfStat.h>
#include <PathUtils.h>
#include <RenderArgs.h>
#include <ViewFrustum.h>
#include <gpu/Context.h>

#include <render/CullTask.h>
#include <render/SortTask.h>
#include <render/DrawTask.h>
#include <render/DrawStatus.h>
#include <render/DrawSceneOctree.h>
#include <render/BlurTask.h>

#include "DebugDeferredBuffer.h"
#include "DeferredLightingEffect.h"
#include "SurfaceGeometryPass.h"
#include "FramebufferCache.h"
#include "HitEffect.h"
#include "TextureCache.h"

#include "AmbientOcclusionEffect.h"
#include "AntialiasingEffect.h"
#include "ToneMappingEffect.h"
#include "SubsurfaceScattering.h"

using namespace render;

extern void initStencilPipeline(gpu::PipelinePointer& pipeline);
extern void initOverlay3DPipelines(render::ShapePlumber& plumber);
extern void initDeferredPipelines(render::ShapePlumber& plumber);

void PrepareDeferred::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext) {
    DependencyManager::get<DeferredLightingEffect>()->prepare(renderContext->args);
}

void RenderDeferred::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext) {
    DependencyManager::get<DeferredLightingEffect>()->render(renderContext);
}

RenderDeferredTask::RenderDeferredTask(CullFunctor cullFunctor) {
    cullFunctor = cullFunctor ? cullFunctor : [](const RenderArgs*, const AABox&){ return true; };

    // Prepare the ShapePipelines
    ShapePlumberPointer shapePlumber = std::make_shared<ShapePlumber>();
    initDeferredPipelines(*shapePlumber);

    // CPU jobs:
    // Fetch and cull the items from the scene
    auto spatialFilter = ItemFilter::Builder::visibleWorldItems().withoutLayered();
    const auto spatialSelection = addJob<FetchSpatialTree>("FetchSceneSelection", spatialFilter);
    const auto culledSpatialSelection = addJob<CullSpatialSelection>("CullSceneSelection", spatialSelection, cullFunctor, RenderDetails::ITEM, spatialFilter);

    // Overlays are not culled
    const auto nonspatialSelection = addJob<FetchNonspatialItems>("FetchOverlaySelection");

    // Multi filter visible items into different buckets
    const int NUM_FILTERS = 3;
    const int OPAQUE_SHAPE_BUCKET = 0;
    const int TRANSPARENT_SHAPE_BUCKET = 1;
    const int LIGHT_BUCKET = 2;
    const int BACKGROUND_BUCKET = 2;
    MultiFilterItem<NUM_FILTERS>::ItemFilterArray spatialFilters = { {
            ItemFilter::Builder::opaqueShape(),
            ItemFilter::Builder::transparentShape(),
            ItemFilter::Builder::light()
    } };
    MultiFilterItem<NUM_FILTERS>::ItemFilterArray nonspatialFilters = { {
            ItemFilter::Builder::opaqueShape(),
            ItemFilter::Builder::transparentShape(),
            ItemFilter::Builder::background()
    } };
    const auto filteredSpatialBuckets = addJob<MultiFilterItem<NUM_FILTERS>>("FilterSceneSelection", culledSpatialSelection, spatialFilters).get<MultiFilterItem<NUM_FILTERS>::ItemBoundsArray>();
    const auto filteredNonspatialBuckets = addJob<MultiFilterItem<NUM_FILTERS>>("FilterOverlaySelection", nonspatialSelection, nonspatialFilters).get<MultiFilterItem<NUM_FILTERS>::ItemBoundsArray>();

    // Extract / Sort opaques / Transparents / Lights / Overlays
    const auto opaques = addJob<DepthSortItems>("DepthSortOpaque", filteredSpatialBuckets[OPAQUE_SHAPE_BUCKET]);
    const auto transparents = addJob<DepthSortItems>("DepthSortTransparent", filteredSpatialBuckets[TRANSPARENT_SHAPE_BUCKET], DepthSortItems(false));
    const auto lights = filteredSpatialBuckets[LIGHT_BUCKET];

    const auto overlayOpaques = addJob<DepthSortItems>("DepthSortOverlayOpaque", filteredNonspatialBuckets[OPAQUE_SHAPE_BUCKET]);
    const auto overlayTransparents = addJob<DepthSortItems>("DepthSortOverlayTransparent", filteredNonspatialBuckets[TRANSPARENT_SHAPE_BUCKET], DepthSortItems(false));
    const auto background = filteredNonspatialBuckets[BACKGROUND_BUCKET];

    // Prepare deferred, generate the shared Deferred Frame Transform
    const auto deferredFrameTransform = addJob<GenerateDeferredFrameTransform>("EvalDeferredFrameTransform");

    // GPU jobs: Start preparing the deferred and lighting buffer
    addJob<PrepareDeferred>("PrepareDeferred");

    // Render opaque objects in DeferredBuffer
    addJob<DrawStateSortDeferred>("DrawOpaqueDeferred", opaques, shapePlumber);

    // Once opaque is all rendered create stencil background
    addJob<DrawStencilDeferred>("DrawOpaqueStencil");

    // Use Stencil and start drawing background in Lighting buffer
    addJob<DrawBackgroundDeferred>("DrawBackgroundDeferred", background);

    // Opaque all rendered, generate surface geometry buffers
    const auto curvatureFramebufferAndDepth = addJob<SurfaceGeometryPass>("SurfaceGeometry", deferredFrameTransform);

    addJob<render::BlurGaussianDepthAware>("DiffuseCurvature", curvatureFramebufferAndDepth);

    const auto diffusedCurvatureFramebuffer = addJob<render::BlurGaussianDepthAware>("DiffuseCurvature2", curvatureFramebufferAndDepth, true);
    
    // AO job
    addJob<AmbientOcclusionEffect>("AmbientOcclusion");

    // Draw Lights just add the lights to the current list of lights to deal with. NOt really gpu job for now.
    addJob<DrawLight>("DrawLight", lights);

    const auto scatteringInputs = render::Varying(SubsurfaceScattering::Inputs(deferredFrameTransform, curvatureFramebufferAndDepth[0]));
    const auto scatteringFramebuffer = addJob<SubsurfaceScattering>("Scattering", scatteringInputs);

    // DeferredBuffer is complete, now let's shade it into the LightingBuffer
    addJob<RenderDeferred>("RenderDeferred");


    // AA job to be revisited
    addJob<Antialiasing>("Antialiasing");

    // Render transparent objects forward in LightingBuffer
    addJob<DrawDeferred>("DrawTransparentDeferred", transparents, shapePlumber);
    
    // Lighting Buffer ready for tone mapping
    addJob<ToneMappingDeferred>("ToneMapping");

    // Overlays
    addJob<DrawOverlay3D>("DrawOverlay3DOpaque", overlayOpaques, true);
    addJob<DrawOverlay3D>("DrawOverlay3DTransparent", overlayTransparents, false);

    
    // Debugging stages
    {
        // Debugging Deferred buffer job
        addJob<DebugDeferredBuffer>("DebugDeferredBuffer", scatteringFramebuffer);

        // Scene Octree Debuging job
        {
            addJob<DrawSceneOctree>("DrawSceneOctree", spatialSelection);
            addJob<DrawItemSelection>("DrawItemSelection", spatialSelection);
        }

        // Status icon rendering job
        {
            // Grab a texture map representing the different status icons and assign that to the drawStatsuJob
            auto iconMapPath = PathUtils::resourcesPath() + "icons/statusIconAtlas.svg";
            auto statusIconMap = DependencyManager::get<TextureCache>()->getImageTexture(iconMapPath);
            addJob<DrawStatus>("DrawStatus", opaques, DrawStatus(statusIconMap));
        }
    }

    // FIXME: Hit effect is never used, let's hide it for now, probably a more generic way to add custom post process effects
    // addJob<HitEffect>("HitEffect");

    // Blit!
    addJob<Blit>("Blit");
}

void RenderDeferredTask::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext) {
    // sanity checks
    assert(sceneContext);
    if (!sceneContext->_scene) {
        return;
    }


    // Is it possible that we render without a viewFrustum ?
    if (!(renderContext->args && renderContext->args->hasViewFrustum())) {
        return;
    }

    for (auto job : _jobs) {
        job.run(sceneContext, renderContext);
    }
}

void DrawDeferred::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext, const ItemBounds& inItems) {
    assert(renderContext->args);
    assert(renderContext->args->hasViewFrustum());

    auto config = std::static_pointer_cast<Config>(renderContext->jobConfig);

    RenderArgs* args = renderContext->args;

    gpu::doInBatch(args->_context, [&](gpu::Batch& batch) {
        args->_batch = &batch;
        batch.setViewportTransform(args->_viewport);
        batch.setStateScissorRect(args->_viewport);

        glm::mat4 projMat;
        Transform viewMat;
        args->getViewFrustum().evalProjectionMatrix(projMat);
        args->getViewFrustum().evalViewTransform(viewMat);

        batch.setProjectionTransform(projMat);
        batch.setViewTransform(viewMat);

        renderShapes(sceneContext, renderContext, _shapePlumber, inItems, _maxDrawn);
        args->_batch = nullptr;
    });

    config->setNumDrawn((int)inItems.size());
}

void DrawStateSortDeferred::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext, const ItemBounds& inItems) {
    assert(renderContext->args);
    assert(renderContext->args->hasViewFrustum());

    auto config = std::static_pointer_cast<Config>(renderContext->jobConfig);

    RenderArgs* args = renderContext->args;

    gpu::doInBatch(args->_context, [&](gpu::Batch& batch) {
        args->_batch = &batch;
        batch.setViewportTransform(args->_viewport);
        batch.setStateScissorRect(args->_viewport);

        glm::mat4 projMat;
        Transform viewMat;
        args->getViewFrustum().evalProjectionMatrix(projMat);
        args->getViewFrustum().evalViewTransform(viewMat);

        batch.setProjectionTransform(projMat);
        batch.setViewTransform(viewMat);

        if (_stateSort) {
            renderStateSortShapes(sceneContext, renderContext, _shapePlumber, inItems, _maxDrawn);
        } else {
            renderShapes(sceneContext, renderContext, _shapePlumber, inItems, _maxDrawn);
        }
        args->_batch = nullptr;
    });

    config->setNumDrawn((int)inItems.size());
}

DrawOverlay3D::DrawOverlay3D(bool opaque) :
    _shapePlumber(std::make_shared<ShapePlumber>()),
    _opaquePass(opaque) {
    initOverlay3DPipelines(*_shapePlumber);
}

void DrawOverlay3D::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext, const render::ItemBounds& inItems) {
    assert(renderContext->args);
    assert(renderContext->args->hasViewFrustum());

    auto config = std::static_pointer_cast<Config>(renderContext->jobConfig);

    config->setNumDrawn((int)inItems.size());
    emit config->numDrawnChanged();

    if (!inItems.empty()) {
        RenderArgs* args = renderContext->args;

        // Clear the framebuffer without stereo
        // Needs to be distinct from the other batch because using the clear call 
        // while stereo is enabled triggers a warning
        if (_opaquePass) {
            gpu::Batch batch;
            batch.enableStereo(false);
            batch.clearFramebuffer(gpu::Framebuffer::BUFFER_DEPTH, glm::vec4(), 1.f, 0, true);
            args->_context->render(batch);
        }

        // Render the items
        gpu::doInBatch(args->_context, [&](gpu::Batch& batch) {
            args->_batch = &batch;
            batch.setViewportTransform(args->_viewport);
            batch.setStateScissorRect(args->_viewport);

            glm::mat4 projMat;
            Transform viewMat;
            args->getViewFrustum().evalProjectionMatrix(projMat);
            args->getViewFrustum().evalViewTransform(viewMat);

            batch.setProjectionTransform(projMat);
            batch.setViewTransform(viewMat);

            renderShapes(sceneContext, renderContext, _shapePlumber, inItems, _maxDrawn);
            args->_batch = nullptr;
        });
    }
}

gpu::PipelinePointer DrawStencilDeferred::_opaquePipeline;
const gpu::PipelinePointer& DrawStencilDeferred::getOpaquePipeline() {
    if (!_opaquePipeline) {
        initStencilPipeline(_opaquePipeline);
    }
    return _opaquePipeline;
}

void DrawStencilDeferred::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext) {
    assert(renderContext->args);
    assert(renderContext->args->hasViewFrustum());

    // from the touched pixel generate the stencil buffer 
    RenderArgs* args = renderContext->args;
    doInBatch(args->_context, [&](gpu::Batch& batch) {
        args->_batch = &batch;

        auto deferredFboColorDepthStencil = DependencyManager::get<FramebufferCache>()->getDeferredFramebufferDepthColor();

        batch.enableStereo(false);

        batch.setFramebuffer(deferredFboColorDepthStencil);
        batch.setViewportTransform(args->_viewport);
        batch.setStateScissorRect(args->_viewport);

        batch.setPipeline(getOpaquePipeline());

        batch.draw(gpu::TRIANGLE_STRIP, 4);
        batch.setResourceTexture(0, nullptr);

    });
    args->_batch = nullptr;
}

void DrawBackgroundDeferred::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext, const ItemBounds& inItems) {
    assert(renderContext->args);
    assert(renderContext->args->hasViewFrustum());

    RenderArgs* args = renderContext->args;
    doInBatch(args->_context, [&](gpu::Batch& batch) {
        args->_batch = &batch;
        _gpuTimer.begin(batch);

        auto lightingFBO = DependencyManager::get<FramebufferCache>()->getLightingFramebuffer();

        batch.enableSkybox(true);

        batch.setFramebuffer(lightingFBO);

        batch.setViewportTransform(args->_viewport);
        batch.setStateScissorRect(args->_viewport);

        glm::mat4 projMat;
        Transform viewMat;
        args->getViewFrustum().evalProjectionMatrix(projMat);
        args->getViewFrustum().evalViewTransform(viewMat);

        batch.setProjectionTransform(projMat);
        batch.setViewTransform(viewMat);

        renderItems(sceneContext, renderContext, inItems);
        _gpuTimer.end(batch);
    });
    args->_batch = nullptr;

    std::static_pointer_cast<Config>(renderContext->jobConfig)->gpuTime = _gpuTimer.getAverage();
}

void Blit::run(const SceneContextPointer& sceneContext, const RenderContextPointer& renderContext) {
    assert(renderContext->args);
    assert(renderContext->args->_context);

    RenderArgs* renderArgs = renderContext->args;
    auto blitFbo = renderArgs->_blitFramebuffer;

    if (!blitFbo) {
        return;
    }

    // Determine size from viewport
    int width = renderArgs->_viewport.z;
    int height = renderArgs->_viewport.w;

    // Blit primary to blit FBO
    auto framebufferCache = DependencyManager::get<FramebufferCache>();
    auto primaryFbo = framebufferCache->getPrimaryFramebuffer();

    gpu::doInBatch(renderArgs->_context, [&](gpu::Batch& batch) {
        batch.setFramebuffer(blitFbo);

        if (renderArgs->_renderMode == RenderArgs::MIRROR_RENDER_MODE) {
            if (renderArgs->_context->isStereo()) {
                gpu::Vec4i srcRectLeft;
                srcRectLeft.z = width / 2;
                srcRectLeft.w = height;

                gpu::Vec4i srcRectRight;
                srcRectRight.x = width / 2;
                srcRectRight.z = width;
                srcRectRight.w = height;

                gpu::Vec4i destRectLeft;
                destRectLeft.x = srcRectLeft.z;
                destRectLeft.z = srcRectLeft.x;
                destRectLeft.y = srcRectLeft.y;
                destRectLeft.w = srcRectLeft.w;

                gpu::Vec4i destRectRight;
                destRectRight.x = srcRectRight.z;
                destRectRight.z = srcRectRight.x;
                destRectRight.y = srcRectRight.y;
                destRectRight.w = srcRectRight.w;

                // Blit left to right and right to left in stereo
                batch.blit(primaryFbo, srcRectRight, blitFbo, destRectLeft);
                batch.blit(primaryFbo, srcRectLeft, blitFbo, destRectRight);
            } else {
                gpu::Vec4i srcRect;
                srcRect.z = width;
                srcRect.w = height;

                gpu::Vec4i destRect;
                destRect.x = width;
                destRect.y = 0;
                destRect.z = 0;
                destRect.w = height;

                batch.blit(primaryFbo, srcRect, blitFbo, destRect);
            }
        } else {
            gpu::Vec4i rect;
            rect.z = width;
            rect.w = height;

            batch.blit(primaryFbo, rect, blitFbo, rect);
        }
    });
}