#include "Descriptor.h"
#include "Buffer.h"
#include "CRC.h"
#include "Command.h"
#include "Graphics.h"
#include "Texture.h"


using namespace Seele;
using namespace Seele::Vulkan;

DescriptorLayout::DescriptorLayout(PGraphics graphics, const std::string& name)
    : Gfx::DescriptorLayout(name), graphics(graphics), layoutHandle(VK_NULL_HANDLE) {}

DescriptorLayout::~DescriptorLayout() {
    graphics->getDestructionManager()->queueResourceForDestruction(std::move(pool));
    if (layoutHandle != VK_NULL_HANDLE) {
        vkDestroyDescriptorSetLayout(graphics->getDevice(), layoutHandle, nullptr);
    }
}

void DescriptorLayout::create() {
    if (layoutHandle != VK_NULL_HANDLE) {
        return;
    }
    bindings.resize(descriptorBindings.size());
    Array<VkDescriptorBindingFlags> bindingFlags(descriptorBindings.size());
    for (size_t i = 0; i < descriptorBindings.size(); ++i) {
        const Gfx::DescriptorBinding& gfxBinding = descriptorBindings[i];
        bindings[i] = {
            .binding = gfxBinding.binding,
            .descriptorType = cast(gfxBinding.descriptorType),
            .descriptorCount = gfxBinding.descriptorCount,
            .stageFlags = gfxBinding.shaderStages,
            .pImmutableSamplers = nullptr,
        };
        bindingFlags[i] = gfxBinding.bindingFlags;
    }
    VkDescriptorSetLayoutBindingFlagsCreateInfo bindingFlagsInfo = {
        .sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_BINDING_FLAGS_CREATE_INFO,
        .pNext = nullptr,
        .bindingCount = static_cast<uint32>(bindingFlags.size()),
        .pBindingFlags = bindingFlags.data(),
    };
    VkDescriptorSetLayoutCreateInfo createInfo = {
        .sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO,
        .pNext = &bindingFlagsInfo,
        .flags = 0,
        .bindingCount = (uint32)bindings.size(),
        .pBindings = bindings.data(),
    };
    VK_CHECK(vkCreateDescriptorSetLayout(graphics->getDevice(), &createInfo, nullptr, &layoutHandle));

    pool = new DescriptorPool(graphics, this);

    hash = CRC::Calculate(bindings.data(), sizeof(VkDescriptorSetLayoutBinding) * bindings.size(), CRC::CRC_32());
}

DescriptorPool::DescriptorPool(PGraphics graphics, PDescriptorLayout layout)
    : CommandBoundResource(graphics), graphics(graphics), layout(layout) {
    for (uint32 i = 0; i < cachedHandles.size(); ++i) {
        cachedHandles[i] = nullptr;
    }

    uint32 perTypeSizes[VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT]; // TODO: FIX ENUM
    std::memset(perTypeSizes, 0, sizeof(perTypeSizes));
    for (uint32 i = 0; i < layout->getBindings().size(); ++i) {
        auto& binding = layout->getBindings()[i];
        int typeIndex = binding.descriptorType;
        perTypeSizes[typeIndex] += 512;
    }
    Array<VkDescriptorPoolSize> poolSizes;
    for (uint32 i = 0; i < VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT; ++i) {
        if (perTypeSizes[i] > 0) {
            VkDescriptorPoolSize size;
            size.descriptorCount = perTypeSizes[i];
            size.type = (VkDescriptorType)i;
            poolSizes.add(size);
        }
    }
    VkDescriptorPoolCreateInfo createInfo = {
        .sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO,
        .pNext = nullptr,
        .flags = 0,
        .maxSets = maxSets * Gfx::numFramesBuffered,
        .poolSizeCount = (uint32)poolSizes.size(),
        .pPoolSizes = poolSizes.data(),
    };
    VK_CHECK(vkCreateDescriptorPool(graphics->getDevice(), &createInfo, nullptr, &poolHandle));
}

DescriptorPool::~DescriptorPool() {
    for (size_t i = 0; i < maxSets; ++i) {
        if (cachedHandles[i] != nullptr) {
            cachedHandles[i] = nullptr;
        }
    }
    vkDestroyDescriptorPool(graphics->getDevice(), poolHandle, nullptr);
    if (nextAlloc) {
        delete nextAlloc;
    }
}

Gfx::PDescriptorSet DescriptorPool::allocateDescriptorSet() {
    VkDescriptorSetLayout layoutHandle = layout->getHandle();
    VkDescriptorSetVariableDescriptorCountAllocateInfo setCounts = {
        .sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_VARIABLE_DESCRIPTOR_COUNT_ALLOCATE_INFO,
        .pNext = nullptr,
        .descriptorSetCount = 1,
    };
    VkDescriptorSetAllocateInfo allocInfo = {
        .sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO,
        .pNext = nullptr,
        .descriptorPool = poolHandle,
        .descriptorSetCount = 1,
        .pSetLayouts = &layoutHandle,
    };
    uint32 counts = 0;
    for (const auto& binding : layout->bindings) {
        if (binding.descriptorCount > 0) {
            counts = binding.descriptorCount;
        }
    }
    if (layout->bindings.size() > 0) {
        setCounts.pDescriptorCounts = &counts;
        allocInfo.pNext = &setCounts;
    }
    for (uint32 setIndex = 0; setIndex < cachedHandles.size(); ++setIndex) {
        if (cachedHandles[setIndex] == nullptr) {
            cachedHandles[setIndex] = new DescriptorSet(graphics, this);
        }
        if (cachedHandles[setIndex]->isCurrentlyBound() || cachedHandles[setIndex]->isCurrentlyInUse()) {
            // Currently in use, skip
            continue;
        }
        if (cachedHandles[setIndex]->getHandle() == VK_NULL_HANDLE) {
            // If it hasnt been initialized, allocate it
            VK_CHECK(vkAllocateDescriptorSets(graphics->getDevice(), &allocInfo, &cachedHandles[setIndex]->setHandle));
        }
        cachedHandles[setIndex]->allocate();

        PDescriptorSet vulkanSet = cachedHandles[setIndex];

        // Found set, stop searching
        return vulkanSet;
    }
    if (nextAlloc == nullptr) {
        nextAlloc = new DescriptorPool(graphics, layout);
    }
    // std::cout << "Out of descriptors, forwarding" << std::endl;
    return nextAlloc->allocateDescriptorSet();
    // throw std::logic_error("Out of descriptor sets");
}

void DescriptorPool::reset() {
    for (uint32 i = 0; i < cachedHandles.size(); ++i) {
        if (cachedHandles[i] == nullptr) {
            return;
        }
        cachedHandles[i]->free();
    }
    if (nextAlloc != nullptr) {
        nextAlloc->reset();
    }
}

DescriptorSet::DescriptorSet(PGraphics graphics, PDescriptorPool owner)
    : Gfx::DescriptorSet(owner->getLayout()), CommandBoundResource(graphics), setHandle(VK_NULL_HANDLE), graphics(graphics), owner(owner),
      bindCount(0), currentlyInUse(false) {
    boundResources.resize(owner->getLayout()->getBindings().size());
}

DescriptorSet::~DescriptorSet() {}

void DescriptorSet::updateBuffer(uint32_t binding, Gfx::PUniformBuffer uniformBuffer) {
    PUniformBuffer vulkanBuffer = uniformBuffer.cast<UniformBuffer>();
    if (boundResources[binding] == vulkanBuffer->getAlloc()) {
        return;
    }

    bufferInfos.add(VkDescriptorBufferInfo{
        .buffer = vulkanBuffer->getHandle(),
        .offset = 0,
        .range = vulkanBuffer->getSize(),
    });

    writeDescriptors.add(VkWriteDescriptorSet{
        .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
        .pNext = nullptr,
        .dstSet = setHandle,
        .dstBinding = binding,
        .dstArrayElement = 0,
        .descriptorCount = 1,
        .descriptorType = cast(layout->getBindings()[binding].descriptorType),
        .pBufferInfo = &bufferInfos.back(),
    });

    boundResources[binding] = vulkanBuffer->getAlloc();
}

void DescriptorSet::updateBuffer(uint32_t binding, Gfx::PShaderBuffer shaderBuffer) {
    PShaderBuffer vulkanBuffer = shaderBuffer.cast<ShaderBuffer>();
    if (boundResources[binding] == vulkanBuffer->getAlloc()) {
        return;
    }

    bufferInfos.add(VkDescriptorBufferInfo{
        .buffer = vulkanBuffer->getHandle(),
        .offset = 0,
        .range = vulkanBuffer->getSize(),
    });
    writeDescriptors.add(VkWriteDescriptorSet{
        .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
        .pNext = nullptr,
        .dstSet = setHandle,
        .dstBinding = binding,
        .dstArrayElement = 0,
        .descriptorCount = 1,
        .descriptorType = cast(layout->getBindings()[binding].descriptorType),
        .pBufferInfo = &bufferInfos.back(),
    });

    boundResources[binding] = vulkanBuffer->getAlloc();
}

void DescriptorSet::updateBuffer(uint32_t binding, uint32 index, Gfx::PShaderBuffer shaderBuffer) {
    PShaderBuffer vulkanBuffer = shaderBuffer.cast<ShaderBuffer>();
    if (boundResources[binding] == vulkanBuffer->getAlloc()) {
        return;
    }

    bufferInfos.add(VkDescriptorBufferInfo{
        .buffer = vulkanBuffer->getHandle(),
        .offset = 0,
        .range = vulkanBuffer->getSize(),
    });

    writeDescriptors.add(VkWriteDescriptorSet{
        .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
        .pNext = nullptr,
        .dstSet = setHandle,
        .dstBinding = binding,
        .dstArrayElement = index,
        .descriptorCount = 1,
        .descriptorType = cast(layout->getBindings()[binding].descriptorType),
        .pBufferInfo = &bufferInfos.back(),
    });

    boundResources[binding] = vulkanBuffer->getAlloc();
}

void DescriptorSet::updateSampler(uint32_t binding, Gfx::PSampler samplerState) {
    PSampler vulkanSampler = samplerState.cast<Sampler>();
    if (boundResources[binding] == vulkanSampler->getHandle()) {
        return;
    }

    imageInfos.add(VkDescriptorImageInfo{
        .sampler = vulkanSampler->getSampler(),
        .imageView = VK_NULL_HANDLE,
        .imageLayout = VK_IMAGE_LAYOUT_UNDEFINED,
    });

    writeDescriptors.add(VkWriteDescriptorSet{
        .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
        .pNext = nullptr,
        .dstSet = setHandle,
        .dstBinding = binding,
        .dstArrayElement = 0,
        .descriptorCount = 1,
        .descriptorType = VK_DESCRIPTOR_TYPE_SAMPLER,
        .pImageInfo = &imageInfos.back(),
    });

    boundResources[binding] = vulkanSampler->getHandle();
}

void DescriptorSet::updateSampler(uint32_t binding, uint32 dstArrayIndex, Gfx::PSampler samplerState)
{
    PSampler vulkanSampler = samplerState.cast<Sampler>();
    if (boundResources[binding] == vulkanSampler->getHandle()) {
        return;
    }

    imageInfos.add(VkDescriptorImageInfo{
        .sampler = vulkanSampler->getSampler(),
        .imageView = VK_NULL_HANDLE,
        .imageLayout = VK_IMAGE_LAYOUT_UNDEFINED,
    });

    writeDescriptors.add(VkWriteDescriptorSet{
        .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
        .pNext = nullptr,
        .dstSet = setHandle,
        .dstBinding = binding,
        .dstArrayElement = dstArrayIndex,
        .descriptorCount = 1,
        .descriptorType = VK_DESCRIPTOR_TYPE_SAMPLER,
        .pImageInfo = &imageInfos.back(),
    });

    boundResources[binding] = vulkanSampler->getHandle();
}


void DescriptorSet::updateTexture(uint32_t binding, Gfx::PTexture texture, Gfx::PSampler samplerState) {
    TextureBase* vulkanTexture = texture.cast<TextureBase>().getHandle();
    if (boundResources[binding] == vulkanTexture->getHandle()) {
        return;
    }

    // It is assumed that the image is in the correct layout
    imageInfos.add(VkDescriptorImageInfo{
        .sampler = samplerState != nullptr ? samplerState.cast<Sampler>()->getSampler() : VK_NULL_HANDLE,
        .imageView = vulkanTexture->getView(),
        .imageLayout = cast(vulkanTexture->getLayout()),
    });
    VkDescriptorType descriptorType = VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE;
    if (samplerState != nullptr) {
        descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
    } else if (vulkanTexture->getUsage() & VK_IMAGE_USAGE_STORAGE_BIT) {
        descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
    }
    writeDescriptors.add(VkWriteDescriptorSet{
        .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
        .pNext = nullptr,
        .dstSet = setHandle,
        .dstBinding = binding,
        .dstArrayElement = 0,
        .descriptorCount = 1,
        .descriptorType = descriptorType,
        .pImageInfo = &imageInfos.back(),
    });

    boundResources[binding] = vulkanTexture->getHandle();
}

void DescriptorSet::updateTexture(uint32 binding, uint32 dstArrayIndex, Gfx::PTexture texture)
{
    TextureBase* vulkanTexture = texture.cast<TextureBase>().getHandle();
    if (boundResources[binding] == vulkanTexture->getHandle()) {
        return;
    }

    // It is assumed that the image is in the correct layout
    imageInfos.add(VkDescriptorImageInfo{
        .sampler = VK_NULL_HANDLE,
        .imageView = vulkanTexture->getView(),
        .imageLayout = cast(vulkanTexture->getLayout()),
    });
    writeDescriptors.add(VkWriteDescriptorSet{
        .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
        .pNext = nullptr,
        .dstSet = setHandle,
        .dstBinding = binding,
        .dstArrayElement = dstArrayIndex,
        .descriptorCount = 1,
        .descriptorType = VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE,
        .pImageInfo = &imageInfos.back(),
    });

    boundResources[binding] = vulkanTexture->getHandle();
}


void DescriptorSet::updateTextureArray(uint32_t binding, Array<Gfx::PTexture> textures) {
    // maybe make this a parameter?
    uint32 arrayElement = 0;
    boundResources.resize(binding + textures.size());
    for (auto& gfxTexture : textures) {
        TextureBase* vulkanTexture = gfxTexture.cast<TextureBase>().getHandle();
        if (boundResources[binding + arrayElement] == vulkanTexture->getHandle()) {
            continue;
        }
        imageInfos.add(VkDescriptorImageInfo{
            .sampler = VK_NULL_HANDLE,
            .imageView = vulkanTexture->getView(),
            .imageLayout = cast(vulkanTexture->getLayout()),
        });

        VkDescriptorType descriptorType = VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE;
        if (vulkanTexture->getUsage() & VK_IMAGE_USAGE_STORAGE_BIT) {
            descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
        }
        boundResources[binding + arrayElement] = vulkanTexture->getHandle();
        writeDescriptors.add(VkWriteDescriptorSet{
            .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
            .pNext = nullptr,
            .dstSet = setHandle,
            .dstBinding = binding,
            .dstArrayElement = arrayElement++,
            .descriptorCount = 1,
            .descriptorType = descriptorType,
            .pImageInfo = &imageInfos.back(),
        });
        vulkanTexture->getHandle()->bind();
    }
}

void DescriptorSet::writeChanges() {
    if (writeDescriptors.size() > 0) {
        if (isCurrentlyBound()) {
            std::cout << "Descriptor currently bound, allocate a new one instead" << std::endl;
            assert(!isCurrentlyBound());
        }
        vkUpdateDescriptorSets(graphics->getDevice(), (uint32)writeDescriptors.size(), writeDescriptors.data(), 0, nullptr);
        writeDescriptors.clear();
        imageInfos.clear();
        bufferInfos.clear();
    }
}

PipelineLayout::PipelineLayout(PGraphics graphics, const std::string& name, Gfx::PPipelineLayout baseLayout)
    : Gfx::PipelineLayout(name, baseLayout), graphics(graphics), layoutHandle(VK_NULL_HANDLE) {}

PipelineLayout::~PipelineLayout() {}

std::mutex layoutLock;
Map<uint32, VkPipelineLayout> cachedLayouts;

void PipelineLayout::create() {
    for (auto [name, desc] : descriptorSetLayouts) {
        PDescriptorLayout layout = desc.cast<DescriptorLayout>();
        layout->create();
        uint32 parameterIndex = parameterMapping[layout->getName()];
        if (parameterIndex >= vulkanDescriptorLayouts.size()) {
            vulkanDescriptorLayouts.resize(parameterIndex + 1);
        }
        vulkanDescriptorLayouts[parameterIndex] = layout->getHandle();
    }

    Array<VkPushConstantRange> vkPushConstants(pushConstants.size());
    for (size_t i = 0; i < pushConstants.size(); i++) {
        vkPushConstants[i].offset = pushConstants[i].offset;
        vkPushConstants[i].size = pushConstants[i].size;
        vkPushConstants[i].stageFlags = pushConstants[i].stageFlags;
    }

    VkPipelineLayoutCreateInfo createInfo = {
        .sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO,
        .pNext = nullptr,
        .flags = 0,
        .setLayoutCount = (uint32)vulkanDescriptorLayouts.size(),
        .pSetLayouts = vulkanDescriptorLayouts.data(),
        .pushConstantRangeCount = (uint32)vkPushConstants.size(),
        .pPushConstantRanges = vkPushConstants.data(),
    };

    layoutHash =
        CRC::Calculate(createInfo.pPushConstantRanges, sizeof(VkPushConstantRange) * createInfo.pushConstantRangeCount, CRC::CRC_32());
    layoutHash =
        CRC::Calculate(createInfo.pSetLayouts, sizeof(VkDescriptorSetLayout) * createInfo.setLayoutCount, CRC::CRC_32(), layoutHash);

    std::unique_lock l(layoutLock);
    if (cachedLayouts.contains(layoutHash)) {
        //  std::cout << "New Layout" << std::endl;
        layoutHandle = cachedLayouts[layoutHash];
        return;
    }

    VK_CHECK(vkCreatePipelineLayout(graphics->getDevice(), &createInfo, nullptr, &layoutHandle));
    cachedLayouts[layoutHash] = layoutHandle;
}