// SPDX-License-Identifier: MPL-2.0
// Copyright © 2021 Skyline Team and Contributors (https://github.com/skyline-emu/)

#include <range/v3/algorithm.hpp>
#include <boost/functional/hash.hpp>
#include <gpu.h>
#include <common/settings.h>
#include <shader_compiler/common/settings.h>
#include <shader_compiler/common/log.h>
#include <shader_compiler/frontend/maxwell/translate_program.h>
#include <shader_compiler/backend/spirv/emit_spirv.h>
#include <vulkan/vulkan_raii.hpp>
#include "shader_manager.h"

static constexpr bool DumpShaders{false};

namespace Shader::Log {
    void Debug(const std::string &message) {
        skyline::Logger::Write(skyline::Logger::LogLevel::Debug, message);
    }

    void Warn(const std::string &message) {
        skyline::Logger::Write(skyline::Logger::LogLevel::Warn, message);
    }

    void Error(const std::string &message) {
        skyline::Logger::Write(skyline::Logger::LogLevel::Error, message);
    }
}

namespace skyline::gpu {
    void ShaderManager::LoadShaderReplacements(std::string_view replacementDir) {
        std::filesystem::path replacementDirPath{replacementDir};
        if (std::filesystem::exists(replacementDirPath)) {
            for (const auto &entry : std::filesystem::directory_iterator{replacementDirPath}) {
                if (entry.is_regular_file()) {
                    // Parse hash from filename
                    auto path{entry.path()};
                    auto &replacementMap{path.extension().string() == ".spv" ? hostShaderReplacements : guestShaderReplacements};
                    u64 hash{std::stoull(path.stem().string(), nullptr, 16)};
                    auto it{replacementMap.insert({hash, {}})};

                    // Read file into map entry
                    std::ifstream file{entry.path(), std::ios::binary | std::ios::ate};
                    it.first->second.resize(static_cast<size_t>(file.tellg()));
                    file.seekg(0, std::ios::beg);
                    file.read(reinterpret_cast<char *>(it.first->second.data()), static_cast<std::streamsize>(it.first->second.size()));
                }
            }
        }
    }

    span<u8> ShaderManager::ProcessShaderBinary(bool spv, u64 hash, span<u8> binary) {
        auto &replacementMap{spv ? hostShaderReplacements : guestShaderReplacements};
        auto it{replacementMap.find(hash)};
        if (it != replacementMap.end()) {
            Logger::Info("Replacing shader with hash: 0x{:X}", hash);
            return it->second;
        }

        if (DumpShaders) {
            std::scoped_lock lock{dumpMutex};

            auto shaderPath{dumpPath / fmt::format("{:016X}{}", hash, spv ? ".spv" : "")};
            if (!std::filesystem::exists(shaderPath)) {
                std::ofstream file{shaderPath, std::ios::binary};
                file.write(reinterpret_cast<const char *>(binary.data()), static_cast<std::streamsize>(binary.size()));
            }
        }

        return binary;
    }

    ShaderManager::ShaderManager(const DeviceState &state, GPU &gpu, std::string_view replacementDir, std::string_view dumpDir) : gpu{gpu}, dumpPath{dumpDir} {
        LoadShaderReplacements(replacementDir);

        if constexpr (DumpShaders) {
            if (!std::filesystem::exists(dumpPath))
                std::filesystem::create_directories(dumpPath);
        }

        auto &traits{gpu.traits};
        hostTranslateInfo = Shader::HostTranslateInfo{
            .support_float16 = traits.supportsFloat16,
            .support_int64 = traits.supportsInt64,
            .needs_demote_reorder = false,
            .support_snorm_render_buffer = true,
            .support_viewport_index_layer = gpu.traits.supportsShaderViewportIndexLayer,
            .min_ssbo_alignment = traits.minimumStorageBufferAlignment,
            .support_geometry_shader_passthrough = false
        };

        constexpr u32 TegraX1WarpSize{32}; //!< The amount of threads in a warp on the Tegra X1
        profile = Shader::Profile{
            .supported_spirv = traits.supportsSpirv14 ? 0x00010400U : 0x00010000U,
            .unified_descriptor_binding = true,
            .support_descriptor_aliasing = !traits.quirks.brokenDescriptorAliasing,
            .support_int8 = traits.supportsInt8,
            .support_int16 = traits.supportsInt16,
            .support_int64 = traits.supportsInt64,
            .support_vertex_instance_id = false,
            .support_float_controls = traits.supportsFloatControls,
            .support_separate_denorm_behavior = traits.floatControls.denormBehaviorIndependence == vk::ShaderFloatControlsIndependence::eAll,
            .support_separate_rounding_mode = traits.floatControls.roundingModeIndependence == vk::ShaderFloatControlsIndependence::eAll,
            .support_fp16_denorm_preserve = static_cast<bool>(traits.floatControls.shaderDenormPreserveFloat16),
            .support_fp32_denorm_preserve = static_cast<bool>(traits.floatControls.shaderDenormPreserveFloat32),
            .support_fp16_denorm_flush = static_cast<bool>(traits.floatControls.shaderDenormFlushToZeroFloat16),
            .support_fp32_denorm_flush = static_cast<bool>(traits.floatControls.shaderDenormFlushToZeroFloat32),
            .support_fp16_signed_zero_nan_preserve = static_cast<bool>(traits.floatControls.shaderSignedZeroInfNanPreserveFloat16),
            .support_fp32_signed_zero_nan_preserve = static_cast<bool>(traits.floatControls.shaderSignedZeroInfNanPreserveFloat32),
            .support_fp64_signed_zero_nan_preserve = static_cast<bool>(traits.floatControls.shaderSignedZeroInfNanPreserveFloat64),
            .support_explicit_workgroup_layout = false,
            .support_vote = traits.supportsSubgroupVote,
            .support_viewport_index_layer_non_geometry = traits.supportsShaderViewportIndexLayer,
            .support_viewport_mask = false,
            .support_typeless_image_loads = traits.supportsImageReadWithoutFormat,
            .support_demote_to_helper_invocation = traits.supportsShaderDemoteToHelper,
            .support_int64_atomics = traits.supportsAtomicInt64,
            .support_derivative_control = true,
            .support_geometry_shader_passthrough = false,
            .support_native_ndc = false,
            .warp_size_potentially_larger_than_guest = TegraX1WarpSize < traits.subgroupSize,
            .lower_left_origin_mode = false,
            .need_declared_frag_colors = false,
            .has_broken_spirv_position_input = traits.quirks.brokenSpirvPositionInput,
            .has_broken_spirv_subgroup_mask_vector_extract_dynamic = traits.quirks.brokenSubgroupMaskExtractDynamic,
            .has_broken_spirv_subgroup_shuffle = traits.quirks.brokenSubgroupShuffle,
            .max_subgroup_size = traits.subgroupSize,
            .disable_subgroup_shuffle = *state.settings->disableSubgroupShuffle
        };

        Shader::Settings::values = {
            #ifdef NDEBUG
            .renderer_debug = false,
            .disable_shader_loop_safety_checks = false,
            #else
            .renderer_debug = true,
            .disable_shader_loop_safety_checks = true,
            #endif
            .resolution_info = {
                .active = false,
            },
        };
    }

    /**
     * @brief A shader environment for all graphics pipeline stages
     */
    class GraphicsEnvironment : public Shader::Environment {
      private:
        span<u8> binary;
        u32 baseOffset;
        u32 textureBufferIndex;
        bool viewportTransformEnabled;
        ShaderManager::ConstantBufferRead constantBufferRead;
        ShaderManager::GetTextureType getTextureType;

      public:
        GraphicsEnvironment(const std::array<u32, 8> &postVtgShaderAttributeSkipMask,
                            Shader::Stage pStage,
                            span<u8> pBinary, u32 baseOffset,
                            u32 textureBufferIndex,
                            bool viewportTransformEnabled,
                            ShaderManager::ConstantBufferRead constantBufferRead, ShaderManager::GetTextureType getTextureType)
            : binary{pBinary}, baseOffset{baseOffset},
              textureBufferIndex{textureBufferIndex},
              viewportTransformEnabled{viewportTransformEnabled},
              constantBufferRead{std::move(constantBufferRead)}, getTextureType{std::move(getTextureType)} {
            gp_passthrough_mask = postVtgShaderAttributeSkipMask;
            stage = pStage;
            sph = *reinterpret_cast<Shader::ProgramHeader *>(binary.data());
            start_address = baseOffset;
            is_propietary_driver = textureBufferIndex == 2;
        }

        [[nodiscard]] u64 ReadInstruction(u32 address) final {
            address -= baseOffset;
            if (binary.size() < (address + sizeof(u64)))
                throw exception("Out of bounds instruction read: 0x{:X}", address);
            return *reinterpret_cast<u64 *>(binary.data() + address);
        }

        [[nodiscard]] u32 ReadCbufValue(u32 index, u32 offset) final {
            return constantBufferRead(index, offset);
        }

        [[nodiscard]] Shader::TexturePixelFormat ReadTexturePixelFormat(u32 handle) final {
            throw exception("ReadTexturePixelFormat not implemented");
        }

        [[nodiscard]] Shader::TextureType ReadTextureType(u32 handle) final {
            return getTextureType(handle);
        }

        [[nodiscard]] u32 ReadViewportTransformState() final {
            return viewportTransformEnabled ? 1 : 0; // Only relevant for graphics shaders
        }

        [[nodiscard]] u32 TextureBoundBuffer() const final {
            return textureBufferIndex;
        }

        [[nodiscard]] u32 LocalMemorySize() const final {
            return static_cast<u32>(sph.LocalMemorySize()) + sph.common3.shader_local_memory_crs_size;
        }

        [[nodiscard]] u32 SharedMemorySize() const final {
            return 0; // Only relevant for compute shaders
        }

        [[nodiscard]] std::array<u32, 3> WorkgroupSize() const final {
            return {0, 0, 0}; // Only relevant for compute shaders
        }

        [[nodiscard]] bool HasHLEMacroState() const final {
            return false;
        }

        [[nodiscard]] std::optional<Shader::ReplaceConstant> GetReplaceConstBuffer(u32 bank, u32 offset) final {
            return std::nullopt;
        }

        void Dump(u64 hash) final {}
    };

    /**
     * @brief A shader environment for all compute pipeline stages
     */
    class ComputeEnvironment : public Shader::Environment {
      private:
        span<u8> binary;
        u32 baseOffset;
        u32 textureBufferIndex;
        u32 localMemorySize;
        u32 sharedMemorySize;
        std::array<u32, 3> workgroupDimensions;
        ShaderManager::ConstantBufferRead constantBufferRead;
        ShaderManager::GetTextureType getTextureType;

      public:
        ComputeEnvironment(span<u8> pBinary,
                           u32 baseOffset,
                           u32 textureBufferIndex,
                           u32 localMemorySize, u32 sharedMemorySize,
                           std::array<u32, 3> workgroupDimensions,
                           ShaderManager::ConstantBufferRead constantBufferRead, ShaderManager::GetTextureType getTextureType)
            : binary{pBinary},
              baseOffset{baseOffset},
              textureBufferIndex{textureBufferIndex},
              localMemorySize{localMemorySize},
              sharedMemorySize{sharedMemorySize},
              workgroupDimensions{workgroupDimensions},
              constantBufferRead{std::move(constantBufferRead)},
              getTextureType{std::move(getTextureType)} {
            stage = Shader::Stage::Compute;
            start_address = baseOffset;
            is_propietary_driver = textureBufferIndex == 2;
        }

        [[nodiscard]] u64 ReadInstruction(u32 address) final {
            address -= baseOffset;
            if (binary.size() < (address + sizeof(u64)))
                throw exception("Out of bounds instruction read: 0x{:X}", address);
            return *reinterpret_cast<u64 *>(binary.data() + address);
        }

        [[nodiscard]] u32 ReadCbufValue(u32 index, u32 offset) final {
            return constantBufferRead(index, offset);
        }

        [[nodiscard]] Shader::TexturePixelFormat ReadTexturePixelFormat(u32 handle) final {
            throw exception("ReadTexturePixelFormat not implemented");
        }

        [[nodiscard]] Shader::TextureType ReadTextureType(u32 handle) final {
            return getTextureType(handle);
        }

        [[nodiscard]] u32 ReadViewportTransformState() final {
            return 0; // Only relevant for graphics shaders
        }

        [[nodiscard]] u32 TextureBoundBuffer() const final {
            return textureBufferIndex;
        }

        [[nodiscard]] u32 LocalMemorySize() const final {
            return localMemorySize;
        }

        [[nodiscard]] u32 SharedMemorySize() const final {
            return sharedMemorySize;
        }

        [[nodiscard]] std::array<u32, 3> WorkgroupSize() const final {
            return workgroupDimensions;
        }

        [[nodiscard]] bool HasHLEMacroState() const final {
            return false;
        }

        [[nodiscard]] std::optional<Shader::ReplaceConstant> GetReplaceConstBuffer(u32 bank, u32 offset) final {
            return std::nullopt;
        }

        void Dump(u64 hash) final {}
    };


    /**
     * @brief A shader environment for VertexB during combination as it only requires the shader header and no higher level context
     */
    class VertexBEnvironment : public Shader::Environment {
      public:
        explicit VertexBEnvironment(span<u8> binary) {
            sph = *reinterpret_cast<Shader::ProgramHeader *>(binary.data());
            stage = Shader::Stage::VertexB;
        }

        [[nodiscard]] u64 ReadInstruction(u32 address) final {
            throw exception("Not implemented");
        }

        [[nodiscard]] u32 ReadCbufValue(u32 index, u32 offset) final {
            throw exception("Not implemented");
        }

        [[nodiscard]] Shader::TextureType ReadTextureType(u32 handle) final {
            throw exception("Not implemented");
        }

        [[nodiscard]] Shader::TexturePixelFormat ReadTexturePixelFormat(u32 handle) final {
            throw exception("Not implemented");
        }

        [[nodiscard]] u32 ReadViewportTransformState() final {
            throw exception("Not implemented");
        }

        [[nodiscard]] u32 TextureBoundBuffer() const final {
            throw exception("Not implemented");
        }

        [[nodiscard]] u32 LocalMemorySize() const final {
            return static_cast<u32>(sph.LocalMemorySize()) + sph.common3.shader_local_memory_crs_size;
        }

        [[nodiscard]] u32 SharedMemorySize() const final {
            return 0; // Only relevant for compute shaders
        }

        [[nodiscard]] std::array<u32, 3> WorkgroupSize() const final {
            return {0, 0, 0}; // Only relevant for compute shaders
        }

        [[nodiscard]] bool HasHLEMacroState() const final {
            return false;
        }

        [[nodiscard]] std::optional<Shader::ReplaceConstant> GetReplaceConstBuffer(u32 bank, u32 offset) final {
            return std::nullopt;
        }

        void Dump(u64 hash) final {}
    };

    Shader::IR::Program ShaderManager::ParseGraphicsShader(const std::array<u32, 8> &postVtgShaderAttributeSkipMask,
                                                           Shader::Stage stage,
                                                           u64 hash, span<u8> binary, u32 baseOffset,
                                                           u32 textureConstantBufferIndex,
                                                           bool viewportTransformEnabled,
                                                           const ConstantBufferRead &constantBufferRead, const GetTextureType &getTextureType) {
        binary = ProcessShaderBinary(false, hash, binary);

        std::scoped_lock lock{poolMutex};

        GraphicsEnvironment environment{postVtgShaderAttributeSkipMask, stage, binary, baseOffset, textureConstantBufferIndex, viewportTransformEnabled, constantBufferRead, getTextureType};
        Shader::Maxwell::Flow::CFG cfg{environment, flowBlockPool, Shader::Maxwell::Location{static_cast<u32>(baseOffset + sizeof(Shader::ProgramHeader))}};
        return  Shader::Maxwell::TranslateProgram(instructionPool, blockPool, environment, cfg, hostTranslateInfo);
    }

    Shader::IR::Program ShaderManager::CombineVertexShaders(Shader::IR::Program &vertexA, Shader::IR::Program &vertexB, span<u8> vertexBBinary) {
        std::scoped_lock lock{poolMutex};

        VertexBEnvironment env{vertexBBinary};
        return Shader::Maxwell::MergeDualVertexPrograms(vertexA, vertexB, env);
    }

    Shader::IR::Program ShaderManager::GenerateGeometryPassthroughShader(Shader::IR::Program &layerSource, Shader::OutputTopology topology) {
        std::scoped_lock lock{poolMutex};

        return Shader::Maxwell::GenerateGeometryPassthrough(instructionPool, blockPool, hostTranslateInfo, layerSource, topology);
    }

    Shader::IR::Program ShaderManager::ParseComputeShader(u64 hash, span<u8> binary, u32 baseOffset,
                                                          u32 textureConstantBufferIndex,
                                                          u32 localMemorySize, u32 sharedMemorySize,
                                                          std::array<u32, 3> workgroupDimensions,
                                                          const ConstantBufferRead &constantBufferRead, const GetTextureType &getTextureType) {
        binary = ProcessShaderBinary(false, hash, binary);

        std::scoped_lock lock{poolMutex};

        ComputeEnvironment environment{binary, baseOffset, textureConstantBufferIndex, localMemorySize, sharedMemorySize, workgroupDimensions, constantBufferRead, getTextureType};
        Shader::Maxwell::Flow::CFG cfg{environment, flowBlockPool, Shader::Maxwell::Location{static_cast<u32>(baseOffset)}};
        return Shader::Maxwell::TranslateProgram(instructionPool, blockPool, environment, cfg, hostTranslateInfo);
    }

    vk::ShaderModule ShaderManager::CompileShader(const Shader::RuntimeInfo &runtimeInfo, Shader::IR::Program &program, Shader::Backend::Bindings &bindings, u64 hash) {
        std::scoped_lock lock{poolMutex};

        if (program.info.loads.Legacy() || program.info.stores.Legacy())
            Shader::Maxwell::ConvertLegacyToGeneric(program, runtimeInfo);

        auto spirvEmitted{Shader::Backend::SPIRV::EmitSPIRV(profile, runtimeInfo, program, bindings)};
        auto spirv{ProcessShaderBinary(true, hash, span<u32>{spirvEmitted}.cast<u8>()).cast<u32>()};

        vk::ShaderModuleCreateInfo createInfo{
            .pCode = spirv.data(),
            .codeSize = spirv.size_bytes(),
        };

        return (*gpu.vkDevice).createShaderModule(createInfo, nullptr, *gpu.vkDevice.getDispatcher());
    }

    void ShaderManager::ResetPools() {
        std::scoped_lock lock{poolMutex};

        instructionPool.ReleaseContents();
        blockPool.ReleaseContents();
        flowBlockPool.ReleaseContents();
    }
}