/*
 * Copyright © Canonical Ltd.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version 2 or 3,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MIR_GRAPHICS_GRAPHIC_BUFFER_ALLOCATOR_H_
#define MIR_GRAPHICS_GRAPHIC_BUFFER_ALLOCATOR_H_

#include "mir/graphics/buffer.h"

#include <vector>
#include <memory>
#include <functional>

struct wl_display;
struct wl_resource;

namespace mir
{
class Executor;

namespace renderer::software
{
class RWMappableBuffer;
}

namespace graphics
{

/**
 * Interface to graphic buffer allocation.
 */
class GraphicBufferAllocator
{
public:
    virtual ~GraphicBufferAllocator() = default;

    /**
     * The supported CPU-accessible buffer pixel formats.
     * \note: once the above is deprecated, this is really only (marginally) useful 
     *        for the software allocation path.
     *        (and we could probably move software/cpu buffers up to libmirserver)
     */
    virtual std::vector<MirPixelFormat> supported_pixel_formats() = 0;

    /**
     * allocates a 'software' (cpu-accessible) buffer
     * note: gbm-kms and eglstreams use ShmBuffer, android uses ANW with software usage bits.
     */
    virtual std::shared_ptr<Buffer> alloc_software_buffer(geometry::Size size, MirPixelFormat) = 0;

    /**
     * Initialise the BufferAllocator for this Wayland display
     *
     * This should do whatever setup is required for client buffer submission. For example,
     * calling eglBindWaylandDisplayWL.
     *
     * \param display [in]          The Wayland display to initialise on
     * \param wayland_executor [in] An Executor that spawns tasks on the event loop of display.
     */
    virtual void bind_display(wl_display* display, std::shared_ptr<Executor> wayland_executor) = 0;

    /**
     * Deinitialise the BufferAllocator for this Wayland display
     *
     * This should do whatever is required to clean up before the Wayland loop is stopped. For
     * example, calling eglUnbindWaylandDisplayWL.
     *
     * \param display [in] The Wayland display to unbind from
     */
    virtual void unbind_display(wl_display* display) = 0;

    virtual std::shared_ptr<Buffer> buffer_from_resource(
        wl_resource* buffer,
        std::function<void()>&& on_consumed,
        std::function<void()>&& on_release) = 0;

    virtual auto buffer_from_shm(
        std::shared_ptr<renderer::software::RWMappableBuffer> shm_data,
        std::function<void()>&& on_consumed,
        std::function<void()>&& on_release) -> std::shared_ptr<Buffer> = 0;

protected:
    GraphicBufferAllocator() = default;
    GraphicBufferAllocator(const GraphicBufferAllocator&) = delete;
    GraphicBufferAllocator& operator=(const GraphicBufferAllocator&) = delete;
};

}
}
#endif // MIR_GRAPHICS_GRAPHIC_BUFFER_ALLOCATOR_H_
