// Copyright (c) 2012-2023 Wojciech Figat. All rights reserved.

#pragma once

#include "Engine/Graphics/GPUSwapChain.h"
#include "GPUDeviceVulkan.h"
#include "GPUTextureVulkan.h"

#if GRAPHICS_API_VULKAN

/// <summary>
/// Represents a Vulkan swap chain back buffer wrapper object.
/// </summary>
class BackBufferVulkan : public ResourceOwnerVulkan
{
public:

    /// <summary>
    /// The device.
    /// </summary>
    GPUDeviceVulkan* Device;

    /// <summary>
    /// The image acquired semaphore handle.
    /// </summary>
    SemaphoreVulkan* ImageAcquiredSemaphore;

    /// <summary>
    /// The rendering done semaphore handle.
    /// </summary>
    SemaphoreVulkan* RenderingDoneSemaphore;

    /// <summary>
    /// The render target surface handle.
    /// </summary>
    GPUTextureViewVulkan Handle;

public:

    void Setup(GPUSwapChainVulkan* window, VkImage backbuffer, PixelFormat format, VkExtent3D extent);
    void Release();

public:

    // [ResourceOwnerVulkan]
    GPUResource* AsGPUResource() const override
    {
        return nullptr;
    }
};

/// <summary>
/// Window swap chain for Vulkan backend.
/// </summary>
class GPUSwapChainVulkan : public GPUResourceVulkan<GPUSwapChain>, public ResourceOwnerVulkan
{
    friend class GPUContextVulkan;
    friend GPUDeviceVulkan;

private:

    VkSurfaceKHR _surface;
    VkSwapchainKHR _swapChain;
    int32 _currentImageIndex;
    int32 _semaphoreIndex;
    int32 _acquiredImageIndex;
    Array<BackBufferVulkan, FixedAllocation<VULKAN_BACK_BUFFERS_COUNT_MAX>> _backBuffers;
    SemaphoreVulkan* _acquiredSemaphore;

public:

    GPUSwapChainVulkan(GPUDeviceVulkan* device, Window* window);

public:

    /// <summary>
    /// Gets the Vulkan surface.
    /// </summary>
    /// <returns>The surface object.</returns>
    FORCE_INLINE VkSurfaceKHR GetSurface() const
    {
        return _surface;
    }

    /// <summary>
    /// Gets the Vulkan surface swap chain.
    /// </summary>
    /// <returns>The swap chain object.</returns>
    FORCE_INLINE VkSwapchainKHR GetSwapChain() const
    {
        return _swapChain;
    }

public:

    enum class Status
    {
        Ok = 0,
        Outdated = -1,
        LostSurface = -2,
    };

    Status Present(QueueVulkan* presentQueue, SemaphoreVulkan* backBufferRenderingDoneSemaphore);

    static int32 DoAcquireImageIndex(GPUSwapChainVulkan* viewport, void* customData);
    static int32 DoPresent(GPUSwapChainVulkan* viewport, void* customData);
    int32 TryPresent(Function<int32(GPUSwapChainVulkan*, void*)> job, void* customData = nullptr, bool skipOnOutOfDate = false);
    int32 AcquireNextImage(SemaphoreVulkan** outSemaphore);

private:

    void ReleaseBackBuffer();
    bool CreateSwapChain(int32 width, int32 height);

public:

    // [GPUSwapChain]
    bool IsFullscreen() override;
    void SetFullscreen(bool isFullscreen) override;
    GPUTextureView* GetBackBufferView() override;
    void Present(bool vsync) override;
    bool Resize(int32 width, int32 height) override;
    void CopyBackbuffer(GPUContext* context, GPUTexture* dst) override;

    // [ResourceOwnerVulkan]
    GPUResource* AsGPUResource() const override
    {
        return (GPUResource*)this;
    }

protected:

    // [GPUResourceVulkan]
    void OnReleaseGPU() override;
};

#endif