// 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/NativeSwapChainImplVk.h"

#include <limits>

#include "dawn/native/vulkan/DeviceVk.h"
#include "dawn/native/vulkan/FencedDeleter.h"
#include "dawn/native/vulkan/TextureVk.h"

namespace dawn::native::vulkan {

namespace {

bool chooseSwapPresentMode(const std::vector<VkPresentModeKHR>& availablePresentModes,
                           bool turnOffVsync,
                           VkPresentModeKHR* presentMode) {
    if (turnOffVsync) {
        for (const auto& availablePresentMode : availablePresentModes) {
            if (availablePresentMode == VK_PRESENT_MODE_IMMEDIATE_KHR) {
                *presentMode = availablePresentMode;
                return true;
            }
        }
        return false;
    }

    *presentMode = VK_PRESENT_MODE_FIFO_KHR;
    return true;
}

bool ChooseSurfaceConfig(const VulkanSurfaceInfo& info,
                         NativeSwapChainImpl::ChosenConfig* config,
                         bool turnOffVsync) {
    VkPresentModeKHR presentMode;
    if (!chooseSwapPresentMode(info.presentModes, turnOffVsync, &presentMode)) {
        return false;
    }
    // TODO(crbug.com/dawn/269): For now this is hardcoded to what works with one NVIDIA
    // driver. Need to generalize
    config->nativeFormat = VK_FORMAT_B8G8R8A8_UNORM;
    config->colorSpace = VK_COLOR_SPACE_SRGB_NONLINEAR_KHR;
    config->format = wgpu::TextureFormat::BGRA8Unorm;
    config->minImageCount = 3;
    // TODO(crbug.com/dawn/269): This is upside down compared to what we want, at least
    // on Linux
    config->preTransform = info.capabilities.currentTransform;
    config->presentMode = presentMode;
    config->compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;

    return true;
}
}  // anonymous namespace

NativeSwapChainImpl::NativeSwapChainImpl(Device* device, VkSurfaceKHR surface)
    : mSurface(surface), mDevice(device) {
    // Call this immediately, so that BackendBinding::GetPreferredSwapChainTextureFormat
    // will return a correct result before a SwapChain is created.
    UpdateSurfaceConfig();
}

NativeSwapChainImpl::~NativeSwapChainImpl() {
    if (mSwapChain != VK_NULL_HANDLE) {
        mDevice->GetFencedDeleter()->DeleteWhenUnused(mSwapChain);
        mSwapChain = VK_NULL_HANDLE;
    }
    if (mSurface != VK_NULL_HANDLE) {
        mDevice->GetFencedDeleter()->DeleteWhenUnused(mSurface);
        mSurface = VK_NULL_HANDLE;
    }
}

void NativeSwapChainImpl::UpdateSurfaceConfig() {
    if (mDevice->ConsumedError(GatherSurfaceInfo(*ToBackend(mDevice->GetAdapter()), mSurface),
                               &mInfo)) {
        ASSERT(false);
    }

    if (!ChooseSurfaceConfig(mInfo, &mConfig, mDevice->IsToggleEnabled(Toggle::TurnOffVsync))) {
        ASSERT(false);
    }
}

void NativeSwapChainImpl::Init(DawnWSIContextVulkan* /*context*/) {
    UpdateSurfaceConfig();
}

DawnSwapChainError NativeSwapChainImpl::Configure(WGPUTextureFormat format,
                                                  WGPUTextureUsage usage,
                                                  uint32_t width,
                                                  uint32_t height) {
    UpdateSurfaceConfig();

    ASSERT(mInfo.capabilities.minImageExtent.width <= width);
    ASSERT(mInfo.capabilities.maxImageExtent.width >= width);
    ASSERT(mInfo.capabilities.minImageExtent.height <= height);
    ASSERT(mInfo.capabilities.maxImageExtent.height >= height);

    ASSERT(format == static_cast<WGPUTextureFormat>(GetPreferredFormat()));
    // TODO(crbug.com/dawn/269): need to check usage works too

    // Create the swapchain with the configuration we chose
    VkSwapchainKHR oldSwapchain = mSwapChain;
    VkSwapchainCreateInfoKHR createInfo;
    createInfo.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
    createInfo.pNext = nullptr;
    createInfo.flags = 0;
    createInfo.surface = mSurface;
    createInfo.minImageCount = mConfig.minImageCount;
    createInfo.imageFormat = mConfig.nativeFormat;
    createInfo.imageColorSpace = mConfig.colorSpace;
    createInfo.imageExtent.width = width;
    createInfo.imageExtent.height = height;
    createInfo.imageArrayLayers = 1;
    createInfo.imageUsage = VulkanImageUsage(static_cast<wgpu::TextureUsage>(usage),
                                             mDevice->GetValidInternalFormat(mConfig.format));
    createInfo.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
    createInfo.queueFamilyIndexCount = 0;
    createInfo.pQueueFamilyIndices = nullptr;
    createInfo.preTransform = mConfig.preTransform;
    createInfo.compositeAlpha = mConfig.compositeAlpha;
    createInfo.presentMode = mConfig.presentMode;
    createInfo.clipped = false;
    createInfo.oldSwapchain = oldSwapchain;

    if (mDevice->fn.CreateSwapchainKHR(mDevice->GetVkDevice(), &createInfo, nullptr,
                                       &*mSwapChain) != VK_SUCCESS) {
        ASSERT(false);
    }

    // Gather the swapchain's images. Implementations are allowed to return more images than the
    // number we asked for.
    uint32_t count = 0;
    if (mDevice->fn.GetSwapchainImagesKHR(mDevice->GetVkDevice(), mSwapChain, &count, nullptr) !=
        VK_SUCCESS) {
        ASSERT(false);
    }

    ASSERT(count >= mConfig.minImageCount);
    mSwapChainImages.resize(count);
    if (mDevice->fn.GetSwapchainImagesKHR(mDevice->GetVkDevice(), mSwapChain, &count,
                                          AsVkArray(mSwapChainImages.data())) != VK_SUCCESS) {
        ASSERT(false);
    }

    if (oldSwapchain != VK_NULL_HANDLE) {
        mDevice->GetFencedDeleter()->DeleteWhenUnused(oldSwapchain);
    }

    return DAWN_SWAP_CHAIN_NO_ERROR;
}

DawnSwapChainError NativeSwapChainImpl::GetNextTexture(DawnSwapChainNextTexture* nextTexture) {
    // Transiently create a semaphore that will be signaled when the presentation engine is done
    // with the swapchain image. Further operations on the image will wait for this semaphore.
    VkSemaphore semaphore = VK_NULL_HANDLE;
    {
        VkSemaphoreCreateInfo createInfo;
        createInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
        createInfo.pNext = nullptr;
        createInfo.flags = 0;
        if (mDevice->fn.CreateSemaphore(mDevice->GetVkDevice(), &createInfo, nullptr,
                                        &*semaphore) != VK_SUCCESS) {
            ASSERT(false);
        }
    }

    if (mDevice->fn.AcquireNextImageKHR(mDevice->GetVkDevice(), mSwapChain,
                                        std::numeric_limits<uint64_t>::max(), semaphore, VkFence{},
                                        &mLastImageIndex) != VK_SUCCESS) {
        ASSERT(false);
    }

    nextTexture->texture.u64 =
#if DAWN_PLATFORM_IS(64_BIT)
        reinterpret_cast<uint64_t>
#endif
        (*mSwapChainImages[mLastImageIndex]);
    mDevice->GetPendingRecordingContext()->waitSemaphores.push_back(semaphore);

    return DAWN_SWAP_CHAIN_NO_ERROR;
}

DawnSwapChainError NativeSwapChainImpl::Present() {
    // This assumes that the image has already been transitioned to the PRESENT layout and
    // writes were made available to the stage.

    // Assuming that the present queue is the same as the graphics queue, the proper
    // synchronization has already been done on the queue so we don't need to wait on any
    // semaphores.
    VkPresentInfoKHR presentInfo;
    presentInfo.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
    presentInfo.pNext = nullptr;
    presentInfo.waitSemaphoreCount = 0;
    presentInfo.pWaitSemaphores = nullptr;
    presentInfo.swapchainCount = 1;
    presentInfo.pSwapchains = &*mSwapChain;
    presentInfo.pImageIndices = &mLastImageIndex;
    presentInfo.pResults = nullptr;

    VkQueue queue = mDevice->GetQueue();
    if (mDevice->fn.QueuePresentKHR(queue, &presentInfo) != VK_SUCCESS) {
        ASSERT(false);
    }

    return DAWN_SWAP_CHAIN_NO_ERROR;
}

wgpu::TextureFormat NativeSwapChainImpl::GetPreferredFormat() const {
    return mConfig.format;
}

}  // namespace dawn::native::vulkan