/*
    KWin - the KDE window manager
    This file is part of the KDE project.

    SPDX-FileCopyrightText: 2017 Martin Flöser <mgraesslin@kde.org>

    SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "gbm_surface.h"

#include <gbm.h>
#include <errno.h>

#include "abstract_egl_backend.h"
#include "drm_gpu.h"
#include "logging.h"

namespace KWin
{

GbmSurface::GbmSurface(DrmGpu *gpu, const QSize &size, uint32_t format, uint32_t flags)
    : m_surface(gbm_surface_create(gpu->gbmDevice(), size.width(), size.height(), format, flags))
    , m_gpu(gpu)
{
    if (!m_surface) {
        qCCritical(KWIN_DRM) << "Could not create gbm surface!" << strerror(errno);
        return;
    }
    m_eglSurface = eglCreatePlatformWindowSurfaceEXT(m_gpu->eglDisplay(), m_gpu->eglBackend()->config(), (void *)(m_surface), nullptr);
    if (m_eglSurface == EGL_NO_SURFACE) {
        qCCritical(KWIN_DRM) << "Creating EGL surface failed!" << eglGetError();
    }
}

GbmSurface::~GbmSurface()
{
    auto buffers = m_lockedBuffers;
    for (auto buffer : buffers) {
        buffer->releaseBuffer();
    }
    if (m_eglSurface != EGL_NO_SURFACE) {
        eglDestroySurface(m_gpu->eglDisplay(), m_eglSurface);
    }
    if (m_surface) {
        gbm_surface_destroy(m_surface);
    }
}

QSharedPointer<DrmGbmBuffer> GbmSurface::swapBuffersForDrm()
{
    auto error = eglSwapBuffers(m_gpu->eglDisplay(), m_eglSurface);
    if (error != EGL_TRUE) {
        qCCritical(KWIN_DRM) << "an error occurred while swapping buffers" << error;
        return nullptr;
    }
    auto bo = gbm_surface_lock_front_buffer(m_surface);
    if (!bo) {
        return nullptr;
    }
    auto buffer = QSharedPointer<DrmGbmBuffer>::create(m_gpu, this, bo);
    m_currentBuffer = buffer;
    m_lockedBuffers << m_currentBuffer.get();
    if (!buffer->bufferId()) {
        return nullptr;
    }
    m_currentDrmBuffer = buffer;
    return buffer;
}

QSharedPointer<GbmBuffer> GbmSurface::swapBuffers()
{
    auto error = eglSwapBuffers(m_gpu->eglDisplay(), m_eglSurface);
    if (error != EGL_TRUE) {
        qCCritical(KWIN_DRM) << "an error occurred while swapping buffers" << error;
        return nullptr;
    }
    auto bo = gbm_surface_lock_front_buffer(m_surface);
    if (!bo) {
        return nullptr;
    }
    m_currentBuffer = QSharedPointer<GbmBuffer>::create(this, bo);
    m_lockedBuffers << m_currentBuffer.get();
    return m_currentBuffer;
}

void GbmSurface::releaseBuffer(GbmBuffer *buffer)
{
    gbm_surface_release_buffer(m_surface, buffer->getBo());
    m_lockedBuffers.removeOne(buffer);
}

QSharedPointer<GbmBuffer> GbmSurface::currentBuffer() const
{
    return m_currentBuffer;
}

QSharedPointer<DrmGbmBuffer> GbmSurface::currentDrmBuffer() const
{
    return m_currentDrmBuffer;
}

}