// Copyright 2018 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "dawn_native/vulkan/ShaderModuleVk.h"

#include "dawn_native/vulkan/DeviceVk.h"
#include "dawn_native/vulkan/FencedDeleter.h"
#include "dawn_native/vulkan/VulkanError.h"

#include <spirv_cross.hpp>

// Tint include must be after spirv_hlsl.hpp, because spirv-cross has its own
// version of spirv_headers. We also need to undef SPV_REVISION because SPIRV-Cross
// is at 3 while spirv-headers is at 4.
#undef SPV_REVISION
#include <tint/tint.h>

namespace dawn_native { namespace vulkan {

    // static
    ResultOrError<ShaderModule*> ShaderModule::Create(Device* device,
                                                      const ShaderModuleDescriptor* descriptor,
                                                      ShaderModuleParseResult* parseResult) {
        Ref<ShaderModule> module = AcquireRef(new ShaderModule(device, descriptor));
        if (module == nullptr) {
            return DAWN_VALIDATION_ERROR("Unable to create ShaderModule");
        }
        DAWN_TRY(module->Initialize(parseResult));
        return module.Detach();
    }

    ShaderModule::ShaderModule(Device* device, const ShaderModuleDescriptor* descriptor)
        : ShaderModuleBase(device, descriptor) {
    }

    MaybeError ShaderModule::Initialize(ShaderModuleParseResult* parseResult) {
        std::vector<uint32_t> spirv;
        const std::vector<uint32_t>* spirvPtr;

        if (GetDevice()->IsToggleEnabled(Toggle::UseTintGenerator)) {
            std::ostringstream errorStream;
            errorStream << "Tint SPIR-V writer failure:" << std::endl;

            tint::transform::Manager transformManager;
            transformManager.append(std::make_unique<tint::transform::BoundArrayAccessors>());
            transformManager.append(std::make_unique<tint::transform::EmitVertexPointSize>());
            transformManager.append(std::make_unique<tint::transform::Spirv>());

            tint::Program program;
            DAWN_TRY_ASSIGN(program,
                            RunTransforms(&transformManager, parseResult->tintProgram.get()));

            tint::writer::spirv::Generator generator(&program);
            if (!generator.Generate()) {
                errorStream << "Generator: " << generator.error() << std::endl;
                return DAWN_VALIDATION_ERROR(errorStream.str().c_str());
            }

            spirv = generator.result();
            spirvPtr = &spirv;

            ShaderModuleParseResult transformedParseResult;
            transformedParseResult.tintProgram =
                std::make_unique<tint::Program>(std::move(program));
            transformedParseResult.spirv = spirv;

            DAWN_TRY(InitializeBase(&transformedParseResult));
        } else {
            DAWN_TRY(InitializeBase(parseResult));
            spirvPtr = &GetSpirv();
        }

        VkShaderModuleCreateInfo createInfo;
        createInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
        createInfo.pNext = nullptr;
        createInfo.flags = 0;
        std::vector<uint32_t> vulkanSource;
        createInfo.codeSize = spirvPtr->size() * sizeof(uint32_t);
        createInfo.pCode = spirvPtr->data();

        Device* device = ToBackend(GetDevice());
        return CheckVkSuccess(
            device->fn.CreateShaderModule(device->GetVkDevice(), &createInfo, nullptr, &*mHandle),
            "CreateShaderModule");
    }

    ShaderModule::~ShaderModule() {
        Device* device = ToBackend(GetDevice());

        if (mHandle != VK_NULL_HANDLE) {
            device->GetFencedDeleter()->DeleteWhenUnused(mHandle);
            mHandle = VK_NULL_HANDLE;
        }
    }

    VkShaderModule ShaderModule::GetHandle() const {
        return mHandle;
    }

}}  // namespace dawn_native::vulkan