/****************************************************************************
 Copyright (c) 2020-2023 Xiamen Yaji Software Co., Ltd.

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 of this software and associated documentation files (the "Software"), to deal
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 The above copyright notice and this permission notice shall be included in
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****************************************************************************/

#include "InstancedBuffer.h"
#include "Define.h"
#include "gfx-base/GFXBuffer.h"
#include "gfx-base/GFXCommandBuffer.h"
#include "gfx-base/GFXDescriptorSet.h"
#include "gfx-base/GFXDevice.h"
#include "gfx-base/GFXInputAssembler.h"

namespace cc {
namespace pipeline {

InstancedBuffer::InstancedBuffer(const scene::Pass *pass)
: _pass(pass),
  _device(gfx::Device::getInstance()) {
}

InstancedBuffer::~InstancedBuffer() {
    destroy();
}

void InstancedBuffer::destroy() {
    for (auto &instance : _instances) {
        CC_SAFE_DESTROY_AND_DELETE(instance.vb);
        CC_SAFE_DESTROY_AND_DELETE(instance.ia);
        CC_FREE(instance.data);
    }
    _instances.clear();
}

void InstancedBuffer::merge(scene::SubModel *subModel, uint32_t passIdx) {
    merge(subModel, passIdx, nullptr);
}

void InstancedBuffer::merge(scene::SubModel *subModel, uint32_t passIdx, gfx::Shader *shaderImplant) {
    auto &attrs = subModel->getInstancedAttributeBlock();

    const auto stride = attrs.buffer.length();
    if (!stride) return; // we assume per-instance attributes are always present

    auto *sourceIA = subModel->getInputAssembler();
    auto *descriptorSet = subModel->getDescriptorSet();
    auto *lightingMap = descriptorSet->getTexture(LIGHTMAPTEXTURE::BINDING);
    auto *reflectionProbeCubemap = descriptorSet->getTexture(REFLECTIONPROBECUBEMAP::BINDING);
    auto *reflectionProbePlanarMap = descriptorSet->getTexture(REFLECTIONPROBEPLANARMAP::BINDING);
    auto *reflectionProbeBlendCubemap = descriptorSet->getTexture(REFLECTIONPROBEBLENDCUBEMAP::BINDING);
    uint32_t reflectionProbeType = subModel->getReflectionProbeType();
    auto *shader = shaderImplant;
    if (!shader) {
        shader = subModel->getShader(passIdx);
    }

    for (auto &instance : _instances) {
        if (instance.ia->getIndexBuffer() != sourceIA->getIndexBuffer() || instance.drawInfo.instanceCount >= MAX_CAPACITY) {
            continue;
        }

        // check same binding
        if (instance.lightingMap != lightingMap) {
            continue;
        }

        if (instance.reflectionProbeType != reflectionProbeType) {
            continue;
        }
        if (instance.reflectionProbeCubemap != reflectionProbeCubemap) {
            continue;
        }
        if (instance.reflectionProbePlanarMap != reflectionProbePlanarMap) {
            continue;
        }
        if (instance.reflectionProbeBlendCubemap != reflectionProbeBlendCubemap) {
            continue;
        }

        if (instance.stride != stride) {
            continue;
        }
        if (instance.drawInfo.instanceCount >= instance.capacity) { // resize buffers
            instance.capacity <<= 1;
            const auto newSize = instance.stride * instance.capacity;
            instance.data = static_cast<uint8_t *>(CC_REALLOC(instance.data, newSize));
            instance.vb->resize(newSize);
        }
        if (instance.shader != shader) {
            instance.shader = shader;
        }
        if (instance.descriptorSet != descriptorSet) {
            instance.descriptorSet = descriptorSet;
        }
        memcpy(instance.data + instance.stride * instance.drawInfo.instanceCount++, attrs.buffer.buffer()->getData(), stride);
        _hasPendingModels = true;
        return;
    }

    // Create a new instance
    const auto newSize = stride * INITIAL_CAPACITY;
    auto *vb = _device->createBuffer({
        gfx::BufferUsageBit::VERTEX | gfx::BufferUsageBit::TRANSFER_DST,
        gfx::MemoryUsageBit::DEVICE,
        static_cast<uint32_t>(newSize),
        static_cast<uint32_t>(stride),
    });

    auto vertexBuffers = sourceIA->getVertexBuffers();
    auto attributes = sourceIA->getAttributes();
    auto *indexBuffer = sourceIA->getIndexBuffer();

    for (const auto &attribute : attrs.attributes) {
        attributes.emplace_back(gfx::Attribute{
            attribute.name,
            attribute.format,
            attribute.isNormalized,
            static_cast<uint32_t>(vertexBuffers.size()), // stream
            true,
            attribute.location});
    }

    auto *data = static_cast<uint8_t *>(CC_MALLOC(newSize));
    memcpy(data, attrs.buffer.buffer()->getData(), stride);
    vertexBuffers.emplace_back(vb);
    const gfx::InputAssemblerInfo iaInfo = {attributes, vertexBuffers, indexBuffer};
    auto *ia = _device->createInputAssembler(iaInfo);
    InstancedItem item = {INITIAL_CAPACITY, vb, data, ia, stride, shader, descriptorSet,
                          lightingMap, reflectionProbeCubemap, reflectionProbePlanarMap, reflectionProbeType, reflectionProbeBlendCubemap,
                          ia->getDrawInfo()};
    item.drawInfo.instanceCount = 1;
    _instances.emplace_back(item);
    _hasPendingModels = true;
}

void InstancedBuffer::uploadBuffers(gfx::CommandBuffer *cmdBuff) const {
    for (const auto &instance : _instances) {
        if (!instance.drawInfo.instanceCount) continue;

        cmdBuff->updateBuffer(instance.vb, instance.data, instance.vb->getSize());
        instance.ia->setInstanceCount(instance.drawInfo.instanceCount);
    }
}

void InstancedBuffer::clear() {
    for (auto &instance : _instances) {
        instance.drawInfo.instanceCount = 0;
    }
    _hasPendingModels = false;
}

void InstancedBuffer::setDynamicOffset(uint32_t idx, uint32_t value) {
    if (_dynamicOffsets.size() <= idx) _dynamicOffsets.resize(1 + idx);
    _dynamicOffsets[idx] = value;
}
} // namespace pipeline
} // namespace cc