#include <QString>

#include "vaapi.h"
#include <streaming/streamutils.h>

#include <SDL_syswm.h>

VAAPIRenderer::VAAPIRenderer()
    : m_HwContext(nullptr)
{

}

VAAPIRenderer::~VAAPIRenderer()
{
    if (m_HwContext != nullptr) {
        AVHWDeviceContext* deviceContext = (AVHWDeviceContext*)m_HwContext->data;
        AVVAAPIDeviceContext* vaDeviceContext = (AVVAAPIDeviceContext*)deviceContext->hwctx;

        // Hold onto this VADisplay since we'll need it to uninitialize VAAPI
        VADisplay display = vaDeviceContext->display;

        av_buffer_unref(&m_HwContext);

        if (display) {
            vaTerminate(display);
        }
    }
}

bool
VAAPIRenderer::initialize(PDECODER_PARAMETERS params)
{
    int err;
    SDL_SysWMinfo info;

    m_VideoWidth = params->width;
    m_VideoHeight = params->height;

    SDL_GetWindowSize(params->window, &m_DisplayWidth, &m_DisplayHeight);

    SDL_VERSION(&info.version);

    if (!SDL_GetWindowWMInfo(params->window, &info)) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                     "SDL_GetWindowWMInfo() failed: %s",
                     SDL_GetError());
        return false;
    }

    m_HwContext = av_hwdevice_ctx_alloc(AV_HWDEVICE_TYPE_VAAPI);
    if (!m_HwContext) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                    "Failed to allocate VAAPI context");
        return false;
    }

    AVHWDeviceContext* deviceContext = (AVHWDeviceContext*)m_HwContext->data;
    AVVAAPIDeviceContext* vaDeviceContext = (AVVAAPIDeviceContext*)deviceContext->hwctx;

    m_WindowSystem = info.subsystem;
    if (info.subsystem == SDL_SYSWM_X11) {
#ifdef HAVE_LIBVA_X11
        m_XWindow = info.info.x11.window;
        vaDeviceContext->display = vaGetDisplay(info.info.x11.display);
        if (!vaDeviceContext->display) {
            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                         "Unable to open X11 display for VAAPI");
            return false;
        }
#else
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                     "Moonlight not compiled with VAAPI X11 support!");
        return false;
#endif
    }
    else if (info.subsystem == SDL_SYSWM_WAYLAND) {
#ifdef HAVE_LIBVA_WAYLAND
        vaDeviceContext->display = vaGetDisplayWl(info.info.wl.display);
        if (!vaDeviceContext->display) {
            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                         "Unable to open Wayland display for VAAPI");
            return false;
        }
#else
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                     "Moonlight not compiled with VAAPI Wayland support!");
        return false;
#endif
    }
    else {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                     "Unsupported VAAPI rendering subsystem: %d",
                     info.subsystem);
        return false;
    }

    int major, minor;
    VAStatus status;
    status = vaInitialize(vaDeviceContext->display, &major, &minor);
    if (status != VA_STATUS_SUCCESS) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                     "Failed to initialize VAAPI: %d",
                     status);
        return false;
    }

    SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
                "Initialized VAAPI %d.%d",
                major, minor);

    const char* vendorString = vaQueryVendorString(vaDeviceContext->display);
    SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
                "Driver: %s",
                vendorString ? vendorString : "<unknown>");

    // AMD's Gallium VAAPI driver has a nasty memory leak
    // that causes memory to be leaked for each submitted frame.
    // The Flatpak runtime has a VDPAU driver in place that works
    // well, so use that instead on AMD systems.
    if (vendorString && qgetenv("FORCE_VAAPI") != "1") {
        QString vendorStr(vendorString);
        if (vendorStr.contains("AMD", Qt::CaseInsensitive) ||
                vendorStr.contains("Radeon", Qt::CaseInsensitive)) {
            // Fail and let VDPAU pick this up
            SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
                        "Avoiding VAAPI on AMD driver");
            return false;
        }
    }

    // This will populate the driver_quirks
    err = av_hwdevice_ctx_init(m_HwContext);
    if (err < 0) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                     "Failed to initialize VAAPI context: %d",
                     err);
        return false;
    }

    // This quirk is set for the VDPAU wrapper which doesn't work with our VAAPI renderer
    if (vaDeviceContext->driver_quirks & AV_VAAPI_DRIVER_QUIRK_SURFACE_ATTRIBUTES) {
        // Fail and let our VDPAU renderer pick this up
        SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
                    "Avoiding VDPAU wrapper for VAAPI decoding");
        return false;
    }

    return true;
}

bool
VAAPIRenderer::prepareDecoderContext(AVCodecContext* context)
{
    context->hw_device_ctx = av_buffer_ref(m_HwContext);

    SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
                "Using VAAPI accelerated renderer on %s",
                m_WindowSystem == SDL_SYSWM_X11 ? "X11" : "Wayland");

    return true;
}

bool
VAAPIRenderer::needsTestFrame()
{
    // We need a test frame to see if this VAAPI driver
    // supports the profile used for streaming
    return true;
}

bool
VAAPIRenderer::isDirectRenderingSupported()
{
    // Many Wayland renderers don't support YUV surfaces, so use
    // another frontend renderer to draw our frames.
    return m_WindowSystem == SDL_SYSWM_X11;
}

void
VAAPIRenderer::renderFrame(AVFrame* frame)
{
    VASurfaceID surface = (VASurfaceID)(uintptr_t)frame->data[3];
    AVHWDeviceContext* deviceContext = (AVHWDeviceContext*)m_HwContext->data;
    AVVAAPIDeviceContext* vaDeviceContext = (AVVAAPIDeviceContext*)deviceContext->hwctx;

    SDL_Rect src, dst;
    src.x = src.y = 0;
    src.w = m_VideoWidth;
    src.h = m_VideoHeight;
    dst.x = dst.y = 0;
    dst.w = m_DisplayWidth;
    dst.h = m_DisplayHeight;

    StreamUtils::scaleSourceToDestinationSurface(&src, &dst);

    if (m_WindowSystem == SDL_SYSWM_X11) {
#ifdef HAVE_LIBVA_X11
        vaPutSurface(vaDeviceContext->display,
                     surface,
                     m_XWindow,
                     0, 0,
                     m_VideoWidth, m_VideoHeight,
                     dst.x, dst.y,
                     dst.w, dst.h,
                     NULL, 0, 0);
#endif
    }
    else if (m_WindowSystem == SDL_SYSWM_WAYLAND) {
        // We don't support direct rendering on Wayland, so we should
        // never get called there. Many common Wayland compositors don't
        // support YUV surfaces, so direct rendering would fail.
        SDL_assert(false);
    }
    else {
        // We don't accept anything else in initialize().
        SDL_assert(false);
    }
}