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

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****************************************************************************/

#include "WGPUPipelineState.h"
#include <emscripten/html5_webgpu.h>
#include <algorithm>
#include <numeric>
#include "WGPUDescriptorSetLayout.h"
#include "WGPUDevice.h"
#include "WGPUObject.h"
#include "WGPUPipelineLayout.h"
#include "WGPURenderPass.h"
#include "WGPUShader.h"
#include "WGPUUtils.h"
#include "base/std/container/vector.h"

namespace cc {
namespace gfx {
ccstd::map<ccstd::hash_t, void *> CCWGPUPipelineState::pipelineMap;

namespace {
using ccstd::hash_combine;
ccstd::hash_t hash(const WGPURenderPipelineDescriptor &desc) {
    ccstd::hash_t hash = 9527;
    hash_combine(hash, desc.layout);
    hash_combine(hash, desc.vertex.module);
    hash_combine(hash, desc.vertex.entryPoint);
    hash_combine(hash, desc.vertex.constantCount);
    for (uint32_t i = 0; i < desc.vertex.constantCount; ++i) {
        hash_combine(hash, desc.vertex.constants[i].key);
        hash_combine(hash, desc.vertex.constants[i].value);
    }

    hash_combine(hash, desc.vertex.bufferCount);
    for (size_t i = 0; i < desc.vertex.bufferCount; ++i) {
        const auto &buffer = desc.vertex.buffers[i];
        hash_combine(hash, buffer.arrayStride);
        hash_combine(hash, buffer.stepMode);
        hash_combine(hash, buffer.attributeCount);
        for (size_t j = 0; j < buffer.attributeCount; ++j) {
            const auto &attribute = buffer.attributes[j];
            hash_combine(hash, attribute.shaderLocation);
            hash_combine(hash, attribute.offset);
            hash_combine(hash, attribute.format);
        }
    }

    hash_combine(hash, desc.primitive.topology);
    hash_combine(hash, desc.primitive.stripIndexFormat);
    hash_combine(hash, desc.primitive.frontFace);
    hash_combine(hash, desc.primitive.cullMode);

    if (desc.depthStencil) {
        hash_combine(hash, desc.depthStencil->format);
        hash_combine(hash, desc.depthStencil->depthWriteEnabled);
        hash_combine(hash, desc.depthStencil->depthCompare);
        hash_combine(hash, desc.depthStencil->stencilFront.compare);
        hash_combine(hash, desc.depthStencil->stencilFront.failOp);
        hash_combine(hash, desc.depthStencil->stencilFront.depthFailOp);
        hash_combine(hash, desc.depthStencil->stencilFront.passOp);
        hash_combine(hash, desc.depthStencil->stencilBack.compare);
        hash_combine(hash, desc.depthStencil->stencilBack.failOp);
        hash_combine(hash, desc.depthStencil->stencilBack.depthFailOp);
        hash_combine(hash, desc.depthStencil->stencilBack.passOp);
        hash_combine(hash, desc.depthStencil->stencilReadMask);
        hash_combine(hash, desc.depthStencil->stencilWriteMask);
        hash_combine(hash, desc.depthStencil->depthBias);
        hash_combine(hash, desc.depthStencil->depthBiasSlopeScale);
        hash_combine(hash, desc.depthStencil->depthBiasClamp);
    }

    hash_combine(hash, desc.multisample.count);
    hash_combine(hash, desc.multisample.mask);
    hash_combine(hash, desc.multisample.alphaToCoverageEnabled);

    if (desc.fragment) {
        hash_combine(hash, desc.fragment->module);
        hash_combine(hash, desc.fragment->entryPoint);
        hash_combine(hash, desc.fragment->constantCount);
        for (uint32_t i = 0; i < desc.fragment->constantCount; ++i) {
            hash_combine(hash, desc.fragment->constants[i].key);
            hash_combine(hash, desc.fragment->constants[i].value);
        }

        hash_combine(hash, desc.fragment->targetCount);
        for (uint32_t i = 0; i < desc.fragment->targetCount; ++i) {
            hash_combine(hash, desc.fragment->targets[i].format);
            if (desc.fragment->targets[i].blend) {
                hash_combine(hash, desc.fragment->targets[i].blend->color.operation);
                hash_combine(hash, desc.fragment->targets[i].blend->color.srcFactor);
                hash_combine(hash, desc.fragment->targets[i].blend->color.dstFactor);
                hash_combine(hash, desc.fragment->targets[i].blend->alpha.operation);
                hash_combine(hash, desc.fragment->targets[i].blend->alpha.srcFactor);
                hash_combine(hash, desc.fragment->targets[i].blend->alpha.dstFactor);
            }
            hash_combine(hash, desc.fragment->targets[i].writeMask);
        }
    }
    return hash;
}

ccstd::hash_t hash(const WGPUComputePipelineDescriptor &desc) {
    ccstd::hash_t hash = 9527;
    hash_combine(hash, desc.layout);
    // hash_combine(hash, desc.compute);
    return hash;
}

} // namespace

CCWGPUPipelineState::CCWGPUPipelineState() : PipelineState() {
}

CCWGPUPipelineState::~CCWGPUPipelineState() {
    doDestroy();
}

void CCWGPUPipelineState::doInit(const PipelineStateInfo &info) {
    _gpuPipelineStateObj = ccnew CCWGPUPipelineStateObject;
}

void CCWGPUPipelineState::check(RenderPass *renderPass, bool forceUpdate) {
    if (_renderPass != renderPass) {
        _renderPass = renderPass;
        // _forceUpdate = true;
    }
    _forceUpdate |= forceUpdate;
}

void CCWGPUPipelineState::prepare(const ccstd::set<uint8_t> &setInUse) {
    auto *pipelineLayout = static_cast<CCWGPUPipelineLayout *>(_pipelineLayout);

    const DepthStencilAttachment &dsAttachment = _renderPass->getDepthStencilAttachment();
    if (_bindPoint == PipelineBindPoint::GRAPHICS) {
        if (_gpuPipelineStateObj->wgpuRenderPipeline && !_forceUpdate) {
            return;
        }

        if (!_gpuPipelineStateObj->redundantAttr.empty()) {
            _gpuPipelineStateObj->redundantAttr.clear();
        }

        auto maxStreamAttr = std::max_element(_inputState.attributes.begin(), _inputState.attributes.end(), [&](const Attribute &lhs, const Attribute &rhs) {
            return lhs.stream < rhs.stream;
        });

        auto longestAttr = std::max_element(_inputState.attributes.begin(), _inputState.attributes.end(), [&](const Attribute &lhs, const Attribute &rhs) {
            return GFX_FORMAT_INFOS[static_cast<uint32_t>(lhs.format)].size < GFX_FORMAT_INFOS[static_cast<uint32_t>(rhs.format)].size;
        });
        uint8_t mostToleranceStream = (*longestAttr).stream;

        const uint8_t streamCount = (*maxStreamAttr).stream + 1;

        ccstd::vector<WGPUVertexBufferLayout> vbLayouts(streamCount);
        ccstd::vector<ccstd::vector<WGPUVertexAttribute>> wgpuAttrsVec(streamCount);

        const AttributeList &attrs = _shader->getAttributes();
        uint64_t offset[256] = {0};
        // ccstd::vector<WGPUVertexAttribute> wgpuAttrs;

        for (size_t i = 0; i < _inputState.attributes.size(); ++i) {
            const auto &attr = _inputState.attributes[i];
            const auto &attrName = attr.name;
            auto iter = std::find_if(attrs.begin(), attrs.end(), [attrName](const Attribute &attr) {
                return strcmp(attrName.c_str(), attr.name.c_str()) == 0;
            });
            if (iter != attrs.end()) {
                Format format = attr.format;
                WGPUVertexAttribute attrInfo = {
                    .format = toWGPUVertexFormat(format),
                    .offset = offset[attr.stream],
                    .shaderLocation = (*iter).location,
                };
                wgpuAttrsVec[attr.stream].push_back(attrInfo);
                offset[attr.stream] += GFX_FORMAT_INFOS[static_cast<uint32_t>(format)].size;
                vbLayouts[attr.stream].stepMode = attr.isInstanced ? WGPUVertexStepMode_Instance : WGPUVertexStepMode_Vertex;
            } else {
                // all none-input attr are put in 1st buffer layout with offset = 0;
                Format format = attr.format;
                offset[attr.stream] += GFX_FORMAT_INFOS[static_cast<uint32_t>(format)].size;
            }
        }

        // printf("cr shname %s %d\n", _shader->getName().c_str(), streamCount);
        // wgpuAttrsVec[0] ∪ wgpuAttrsVec[1] ∪ ... ∪ wgpuAttrsVec[n] == shader.attrs
        for (size_t i = 0; i < attrs.size(); i++) {
            ccstd::string attrName = attrs[i].name;
            auto iter = std::find_if(_inputState.attributes.begin(), _inputState.attributes.end(), [attrName](const Attribute &attr) {
                return strcmp(attrName.c_str(), attr.name.c_str()) == 0;
            });

            if (iter == _inputState.attributes.end()) {
                // all none-input attr are put in 1st buffer layout with offset = 0;
                Format format = attrs[i].format;
                WGPUVertexAttribute attr = {
                    .format = toWGPUVertexFormat(format),
                    .offset = 0,
                    .shaderLocation = attrs[i].location,
                };

                if (GFX_FORMAT_INFOS[static_cast<uint32_t>(format)].size > GFX_FORMAT_INFOS[static_cast<uint32_t>((*longestAttr).format)].size) {
                    // printf("found attr %s %s in shader exceed size of longest attr %s %s\n", attrName.c_str(), GFX_FORMAT_INFOS[static_cast<uint32_t>(format)].name.c_str(),
                    //        (*longestAttr).name.c_str(), GFX_FORMAT_INFOS[static_cast<uint32_t>((*longestAttr).format)].name.c_str());
                    _gpuPipelineStateObj->redundantAttr.push_back(attr);
                    if (GFX_FORMAT_INFOS[static_cast<uint32_t>(format)].size > _gpuPipelineStateObj->maxAttrLength) {
                        _gpuPipelineStateObj->maxAttrLength = GFX_FORMAT_INFOS[static_cast<uint32_t>(format)].size;
                    }
                } else {
                    wgpuAttrsVec[mostToleranceStream].push_back(attr);
                }
            }

            // printf("sl %s, %d, %d\n", attrName.c_str(), attrs[i].location, attrs[i].stream);
        }

        if (_gpuPipelineStateObj->maxAttrLength > 0) {
            wgpuAttrsVec.push_back(_gpuPipelineStateObj->redundantAttr);
            vbLayouts.resize(vbLayouts.size() + 1);
        }
        // _gpuPipelineStateObj->slotCount = vbLayouts.size();

        // std::set<uint32_t> locSet;
        for (size_t i = 0; i < wgpuAttrsVec.size(); ++i) {
            vbLayouts[i].arrayStride = offset[i];
            vbLayouts[i].attributeCount = static_cast<uint32_t>(wgpuAttrsVec[i].size());
            vbLayouts[i].attributes = wgpuAttrsVec[i].data();
            // for (size_t j = 0; j < wgpuAttrsVec[i].size(); ++j) {
            //     printf("wg %d, %llu, %d\n", wgpuAttrsVec[i][j].shaderLocation, wgpuAttrsVec[i][j].offset, wgpuAttrsVec[i][j].format);

            //     // if (locSet.find(wgpuAttrsVec[i][j].shaderLocation) != locSet.end() && wgpuAttrsVec[i][j].shaderLocation != 0) {
            //     //     printf("duplicate location %d\n", wgpuAttrsVec[i][j].shaderLocation);
            //     //     while (1) {
            //     //     }
            //     // }
            //     // locSet.insert(wgpuAttrsVec[i][j].shaderLocation);
            // }
        }

        WGPUVertexState vertexState = {
            .nextInChain = nullptr,
            .module = static_cast<CCWGPUShader *>(_shader)->gpuShaderObject()->wgpuShaderVertexModule,
            .entryPoint = "main",
            .bufferCount = vbLayouts.size(),
            .buffers = vbLayouts.data(),
        };

        bool stripTopology = (_primitive == PrimitiveMode::LINE_STRIP || _primitive == PrimitiveMode::TRIANGLE_STRIP);

        WGPUPrimitiveState primitiveState = {
            .nextInChain = nullptr,
            .topology = toWGPUPrimTopology(_primitive),
            .stripIndexFormat = stripTopology ? WGPUIndexFormat_Uint16 : WGPUIndexFormat_Undefined, // TODO_Zeqiang: ???
            .frontFace = _rasterizerState.isFrontFaceCCW ? WGPUFrontFace::WGPUFrontFace_CCW : WGPUFrontFace::WGPUFrontFace_CW,
            .cullMode = _rasterizerState.cullMode == CullMode::FRONT  ? WGPUCullMode::WGPUCullMode_Front
                        : _rasterizerState.cullMode == CullMode::BACK ? WGPUCullMode::WGPUCullMode_Back
                                                                      : WGPUCullMode::WGPUCullMode_None,
        };

        WGPUStencilFaceState stencilFront = {
            .compare = toWGPUCompareFunction(_depthStencilState.stencilFuncFront),
            .failOp = toWGPUStencilOperation(_depthStencilState.stencilFailOpFront),
            .depthFailOp = toWGPUStencilOperation(_depthStencilState.stencilZFailOpFront),
            .passOp = toWGPUStencilOperation(_depthStencilState.stencilPassOpFront),
        };
        WGPUStencilFaceState stencilBack = {
            .compare = toWGPUCompareFunction(_depthStencilState.stencilFuncBack),
            .failOp = toWGPUStencilOperation(_depthStencilState.stencilFailOpBack),
            .depthFailOp = toWGPUStencilOperation(_depthStencilState.stencilZFailOpBack),
            .passOp = toWGPUStencilOperation(_depthStencilState.stencilPassOpBack),
        };

        WGPUDepthStencilState dsState = {
            .nextInChain = nullptr,
            .format = toWGPUTextureFormat(dsAttachment.format),
            .depthWriteEnabled = _depthStencilState.depthWrite != 0,
            .depthCompare = _depthStencilState.depthTest ? toWGPUCompareFunction(_depthStencilState.depthFunc) : WGPUCompareFunction_Always,
            .stencilFront = stencilFront,
            .stencilBack = stencilBack,
            .stencilReadMask = _depthStencilState.stencilReadMaskFront,
            .stencilWriteMask = _depthStencilState.stencilWriteMaskFront,
            .depthBias = static_cast<int32_t>(_rasterizerState.depthBias),
            .depthBiasSlopeScale = _rasterizerState.depthBiasSlop,
            .depthBiasClamp = _rasterizerState.depthBiasClamp,
        };

        WGPUMultisampleState msState = {
            .count = static_cast<CCWGPURenderPass *>(_renderPass)->gpuRenderPassObject()->sampleCount,
            .mask = 0xFFFFFFFF,
            .alphaToCoverageEnabled = _blendState.isA2C != 0,
        };

        const ColorAttachmentList &colors = _renderPass->getColorAttachments();
        ccstd::vector<WGPUColorTargetState> colorTargetStates(colors.size());

        ccstd::vector<WGPUBlendState> blendState(colors.size());

        for (size_t i = 0, targetIndex = 0; i < colors.size(); i++) {
            colorTargetStates[i].format = toWGPUTextureFormat(colors[i].format);
            auto colorBO = _blendState.targets[targetIndex].blendEq;
            blendState[i].color = {
                .operation = toWGPUBlendOperation(colorBO),
                .srcFactor = toWGPUBlendFactor(colorBO == BlendOp::MAX ? BlendFactor::ONE : _blendState.targets[targetIndex].blendSrc),
                .dstFactor = toWGPUBlendFactor(colorBO == BlendOp::MAX ? BlendFactor::ONE : _blendState.targets[targetIndex].blendDst),
            };
            auto alphaBO = _blendState.targets[targetIndex].blendAlphaEq;
            blendState[i].alpha = {
                .operation = toWGPUBlendOperation(alphaBO),
                .srcFactor = toWGPUBlendFactor(alphaBO == BlendOp::MAX ? BlendFactor::ONE : _blendState.targets[targetIndex].blendSrcAlpha),
                .dstFactor = toWGPUBlendFactor(alphaBO == BlendOp::MAX ? BlendFactor::ONE : _blendState.targets[targetIndex].blendDstAlpha),
            };
            // only textureSampleType with float can be blended.
            colorTargetStates[i].blend = (_blendState.targets[targetIndex].blend && (textureSampleTypeTrait(colors[i].format) == WGPUTextureSampleType_Float)) ? &blendState[i] : nullptr;
            colorTargetStates[i].writeMask = toWGPUColorWriteMask(_blendState.targets[targetIndex].blendColorMask);
            if (targetIndex < _blendState.targets.size() - 1) {
                ++targetIndex;
            }
        }

        WGPUFragmentState fragmentState = {
            .module = static_cast<CCWGPUShader *>(_shader)->gpuShaderObject()->wgpuShaderFragmentModule,
            .entryPoint = "main",
            .targetCount = colorTargetStates.size(),
            .targets = colorTargetStates.data(),
        };

        // pipelineLayout->prepare(setInUse);

        WGPURenderPipelineDescriptor piplineDesc = {
            .nextInChain = nullptr,
            .label = static_cast<CCWGPUShader *>(_shader)->getName().c_str(),
            .layout = pipelineLayout->gpuPipelineLayoutObject()->wgpuPipelineLayout,
            .vertex = vertexState,
            .primitive = primitiveState,
            .depthStencil = dsState.format == WGPUTextureFormat_Undefined ? nullptr : &dsState,
            .multisample = msState,
            .fragment = &fragmentState,
        };

        auto hashVal = hash(piplineDesc);
        _hash = hashVal;

        auto iter = pipelineMap.find(hashVal);
        if (iter == pipelineMap.end()) {
            _gpuPipelineStateObj->wgpuRenderPipeline = wgpuDeviceCreateRenderPipeline(CCWGPUDevice::getInstance()->gpuDeviceObject()->wgpuDevice, &piplineDesc);
            printf("ppl %s\n", static_cast<CCWGPUShader *>(_shader)->getName().c_str());
            pipelineMap[hashVal] = _gpuPipelineStateObj->wgpuRenderPipeline;
        } else {
            _gpuPipelineStateObj->wgpuRenderPipeline = static_cast<WGPURenderPipeline>(iter->second);
        }
        _ppl = pipelineLayout;
        _forceUpdate = false;
    } else if (_bindPoint == PipelineBindPoint::COMPUTE) {
        if (_gpuPipelineStateObj->wgpuComputePipeline && !_forceUpdate)
            return;
        WGPUProgrammableStageDescriptor psDesc = {
            .module = static_cast<CCWGPUShader *>(_shader)->gpuShaderObject()->wgpuShaderComputeModule,
            .entryPoint = "main",
        };
        // pipelineLayout->prepare(setInUse);
        WGPUComputePipelineDescriptor piplineDesc = {
            .layout = pipelineLayout->gpuPipelineLayoutObject()->wgpuPipelineLayout,
            .compute = psDesc,
        };
        auto hashVal = hash(piplineDesc);
        _hash = hashVal;

        auto iter = pipelineMap.find(hashVal);
        if (iter == pipelineMap.end()) {
            _gpuPipelineStateObj->wgpuComputePipeline = wgpuDeviceCreateComputePipeline(CCWGPUDevice::getInstance()->gpuDeviceObject()->wgpuDevice, &piplineDesc);
            printf("ppl %s\n", static_cast<CCWGPUShader *>(_shader)->getName().c_str());
            pipelineMap[hashVal] = _gpuPipelineStateObj->wgpuComputePipeline;
        } else {
            _gpuPipelineStateObj->wgpuComputePipeline = static_cast<WGPUComputePipeline>(iter->second);
        }
        _ppl = pipelineLayout;
        _forceUpdate = false;
    } else {
        printf("unsupport pipeline bind point");
    }
}

void CCWGPUPipelineState::doDestroy() {
    if (_gpuPipelineStateObj) {
        if (_gpuPipelineStateObj->wgpuRenderPipeline) {
            wgpuRenderPipelineRelease(_gpuPipelineStateObj->wgpuRenderPipeline);
        }
        if (_gpuPipelineStateObj->wgpuComputePipeline) {
            wgpuComputePipelineRelease(_gpuPipelineStateObj->wgpuComputePipeline);
        }

        delete _gpuPipelineStateObj;
        _gpuPipelineStateObj = nullptr;
    }
}

} // namespace gfx
} // namespace cc