/*
 * This file is part of mpv.
 *
 * mpv is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * mpv 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 mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "dmabuf_interop.h"

#include <drm_fourcc.h>
#include <EGL/egl.h>
#include "video/out/opengl/ra_gl.h"

typedef void* GLeglImageOES;
typedef void *EGLImageKHR;

// Any EGL_EXT_image_dma_buf_import definitions used in this source file.
#define EGL_LINUX_DMA_BUF_EXT             0x3270
#define EGL_LINUX_DRM_FOURCC_EXT          0x3271
#define EGL_DMA_BUF_PLANE0_FD_EXT         0x3272
#define EGL_DMA_BUF_PLANE0_OFFSET_EXT     0x3273
#define EGL_DMA_BUF_PLANE0_PITCH_EXT      0x3274
#define EGL_DMA_BUF_PLANE1_FD_EXT         0x3275
#define EGL_DMA_BUF_PLANE1_OFFSET_EXT     0x3276
#define EGL_DMA_BUF_PLANE1_PITCH_EXT      0x3277
#define EGL_DMA_BUF_PLANE2_FD_EXT         0x3278
#define EGL_DMA_BUF_PLANE2_OFFSET_EXT     0x3279
#define EGL_DMA_BUF_PLANE2_PITCH_EXT      0x327A


// Any EGL_EXT_image_dma_buf_import definitions used in this source file.
#define EGL_DMA_BUF_PLANE3_FD_EXT         0x3440
#define EGL_DMA_BUF_PLANE3_OFFSET_EXT     0x3441
#define EGL_DMA_BUF_PLANE3_PITCH_EXT      0x3442
#define EGL_DMA_BUF_PLANE0_MODIFIER_LO_EXT 0x3443
#define EGL_DMA_BUF_PLANE0_MODIFIER_HI_EXT 0x3444
#define EGL_DMA_BUF_PLANE1_MODIFIER_LO_EXT 0x3445
#define EGL_DMA_BUF_PLANE1_MODIFIER_HI_EXT 0x3446
#define EGL_DMA_BUF_PLANE2_MODIFIER_LO_EXT 0x3447
#define EGL_DMA_BUF_PLANE2_MODIFIER_HI_EXT 0x3448
#define EGL_DMA_BUF_PLANE3_MODIFIER_LO_EXT 0x3449
#define EGL_DMA_BUF_PLANE3_MODIFIER_HI_EXT 0x344A

struct vaapi_gl_mapper_priv {
    GLuint gl_textures[AV_DRM_MAX_PLANES];
    EGLImageKHR images[AV_DRM_MAX_PLANES];

    const struct ra_format *planes[AV_DRM_MAX_PLANES];

    EGLImageKHR (EGLAPIENTRY *CreateImageKHR)(EGLDisplay, EGLContext,
                                              EGLenum, EGLClientBuffer,
                                              const EGLint *);
    EGLBoolean (EGLAPIENTRY *DestroyImageKHR)(EGLDisplay, EGLImageKHR);
    void (EGLAPIENTRY *EGLImageTargetTexture2DOES)(GLenum, GLeglImageOES);
    void (EGLAPIENTRY *EGLImageTargetTexStorageEXT)(GLenum, GLeglImageOES,
                                                    const GLint *);
};

static bool gl_create_textures(struct ra_hwdec_mapper *mapper)
{
    struct dmabuf_interop_priv *p_mapper = mapper->priv;
    struct vaapi_gl_mapper_priv *p = p_mapper->interop_mapper_priv;

    GL *gl = ra_gl_get(mapper->ra);
    gl->GenTextures(AV_DRM_MAX_PLANES, p->gl_textures);
    for (int n = 0; n < p_mapper->num_planes; n++) {
        gl->BindTexture(GL_TEXTURE_2D, p->gl_textures[n]);
        gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        gl->BindTexture(GL_TEXTURE_2D, 0);

        struct ra_tex_params params = {
            .dimensions = 2,
            .w = mp_image_plane_w(&p_mapper->layout, n),
            .h = mp_image_plane_h(&p_mapper->layout, n),
            .d = 1,
            .format = p->planes[n],
            .render_src = true,
            .src_linear = true,
        };

        if (params.format->ctype != RA_CTYPE_UNORM)
            return false;

        p_mapper->tex[n] = ra_create_wrapped_tex(mapper->ra, &params,
                                                 p->gl_textures[n]);
        if (!p_mapper->tex[n])
            return false;
    }

    return true;
}

static void gl_delete_textures(const struct ra_hwdec_mapper *mapper)
{
    struct dmabuf_interop_priv *p_mapper = mapper->priv;
    struct vaapi_gl_mapper_priv *p = p_mapper->interop_mapper_priv;

    GL *gl = ra_gl_get(mapper->ra);
    gl->DeleteTextures(AV_DRM_MAX_PLANES, p->gl_textures);
    for (int n = 0; n < AV_DRM_MAX_PLANES; n++) {
        p->gl_textures[n] = 0;
        ra_tex_free(mapper->ra, &p_mapper->tex[n]);
    }
}

static bool vaapi_gl_mapper_init(struct ra_hwdec_mapper *mapper,
                                 const struct ra_imgfmt_desc *desc)
{
    struct dmabuf_interop_priv *p_mapper = mapper->priv;
    struct vaapi_gl_mapper_priv *p = talloc_ptrtype(NULL, p);
    p_mapper->interop_mapper_priv = p;

    *p = (struct vaapi_gl_mapper_priv) {
        // EGL_KHR_image_base
        .CreateImageKHR = (void *)eglGetProcAddress("eglCreateImageKHR"),
        .DestroyImageKHR = (void *)eglGetProcAddress("eglDestroyImageKHR"),
    };
    if (ra_gl_get(mapper->ra)->es) {
        // GL_OES_EGL_image
        p->EGLImageTargetTexture2DOES =
            (void *)eglGetProcAddress("glEGLImageTargetTexture2DOES");
    } else {
        // GL_EXT_EGL_image_storage
        p->EGLImageTargetTexStorageEXT =
            (void *)eglGetProcAddress("glEGLImageTargetTexStorageEXT");
    }

    if (!p->CreateImageKHR || !p->DestroyImageKHR ||
        (!p->EGLImageTargetTexture2DOES && !p->EGLImageTargetTexStorageEXT)) {
        return false;
    }

    static_assert(MP_ARRAY_SIZE(desc->planes) == AV_DRM_MAX_PLANES, "");
    static_assert(MP_ARRAY_SIZE(mapper->tex) == AV_DRM_MAX_PLANES, "");

    // remember format to allow texture recreation
    for (int n = 0; n < desc->num_planes; n++) {
        p->planes[n] = desc->planes[n];
    }
    if (p->EGLImageTargetTexture2DOES) {
        // created only once
        if (!gl_create_textures(mapper))
            return false;
    }

    return true;
}

static void vaapi_gl_mapper_uninit(const struct ra_hwdec_mapper *mapper)
{
    struct dmabuf_interop_priv *p_mapper = mapper->priv;
    struct vaapi_gl_mapper_priv *p = p_mapper->interop_mapper_priv;

    if (p) {
        gl_delete_textures(mapper);
        talloc_free(p);
        p_mapper->interop_mapper_priv = NULL;
    }
}

#define ADD_ATTRIB(name, value) \
    do { \
    assert(num_attribs + 3 < MP_ARRAY_SIZE(attribs)); \
    attribs[num_attribs++] = (name); \
    attribs[num_attribs++] = (value); \
    attribs[num_attribs] = EGL_NONE; \
    } while(0)

#define ADD_PLANE_ATTRIBS(nplane) \
    do { \
    const AVDRMPlaneDescriptor *plane = &p_mapper->desc.layers[i].planes[j]; \
    const AVDRMObjectDescriptor *object = \
        &p_mapper->desc.objects[plane->object_index]; \
    ADD_ATTRIB(EGL_DMA_BUF_PLANE ## nplane ## _FD_EXT, object->fd); \
    ADD_ATTRIB(EGL_DMA_BUF_PLANE ## nplane ## _OFFSET_EXT, plane->offset); \
    ADD_ATTRIB(EGL_DMA_BUF_PLANE ## nplane ## _PITCH_EXT, plane->pitch); \
    uint64_t drm_format_modifier = object->format_modifier; \
    if (dmabuf_interop->use_modifiers && \
        drm_format_modifier != DRM_FORMAT_MOD_INVALID) { \
        ADD_ATTRIB(EGL_DMA_BUF_PLANE ## nplane ## _MODIFIER_LO_EXT, \
            drm_format_modifier & 0xfffffffful); \
        ADD_ATTRIB(EGL_DMA_BUF_PLANE ## nplane ## _MODIFIER_HI_EXT, \
            drm_format_modifier >> 32); \
    } \
    } while (0)

static bool vaapi_gl_map(struct ra_hwdec_mapper *mapper,
                         struct dmabuf_interop *dmabuf_interop,
                         bool probing)
{
    struct dmabuf_interop_priv *p_mapper = mapper->priv;
    struct vaapi_gl_mapper_priv *p = p_mapper->interop_mapper_priv;

    GL *gl = ra_gl_get(mapper->ra);

    if (p->EGLImageTargetTexStorageEXT) {
        if (!gl_create_textures(mapper))
            return false;
    }

    for (int i = 0, n = 0; i < p_mapper->desc.nb_layers; i++) {
        /*
         * As we must map surfaces as one texture per plane, we can only support
         * a subset of possible multi-plane layer formats. This is due to having
         * to manually establish what DRM format each synthetic layer should
         * have.
         */
        uint32_t format[AV_DRM_MAX_PLANES] = {
            p_mapper->desc.layers[i].format,
        };

        if (p_mapper->desc.layers[i].nb_planes > 1) {
            switch (p_mapper->desc.layers[i].format) {
            case DRM_FORMAT_NV12:
            case DRM_FORMAT_NV16:
                format[0] = DRM_FORMAT_R8;
                format[1] = DRM_FORMAT_GR88;
                break;
            case DRM_FORMAT_YUV420:
                format[0] = DRM_FORMAT_R8;
                format[1] = DRM_FORMAT_R8;
                format[2] = DRM_FORMAT_R8;
                break;
            case DRM_FORMAT_P010:
            case DRM_FORMAT_P210:
#ifdef DRM_FORMAT_P030 /* Format added in a newer libdrm version than minimum */
            case DRM_FORMAT_P030:
#endif
                format[0] = DRM_FORMAT_R16;
                format[1] = DRM_FORMAT_GR1616;
                break;
            default:
                mp_msg(mapper->log, probing ? MSGL_DEBUG : MSGL_ERR,
                       "Cannot map unknown multi-plane format: 0x%08X\n",
                       p_mapper->desc.layers[i].format);
                return false;
            }
        } else {
            /*
             * As OpenGL only has one guaranteed rgba format (rgba8), drivers
             * that support importing dmabuf formats with different channel
             * orders do implicit swizzling to get to rgba. However, we look at
             * the original imgfmt to decide channel order, and we then swizzle
             * based on that. So, we can get into a situation where we swizzle
             * twice and end up with a mess.
             *
             * The simplest way to avoid that is to lie to OpenGL and say that
             * the surface we are importing is in the natural channel order, so
             * that our swizzling does the right thing.
             *
             * DRM ABGR corresponds to OpenGL RGBA due to different naming
             * conventions.
             */
            switch (format[0]) {
            case DRM_FORMAT_ARGB8888:
            case DRM_FORMAT_RGBA8888:
            case DRM_FORMAT_BGRA8888:
                format[0] = DRM_FORMAT_ABGR8888;
                break;
            case DRM_FORMAT_XRGB8888:
                format[0] = DRM_FORMAT_XBGR8888;
                break;
            case DRM_FORMAT_RGBX8888:
            case DRM_FORMAT_BGRX8888:
                // Logically, these two formats should be handled as above,
                // but there appear to be additional problems that make the
                // format change here insufficient or incorrect, so we're
                // doing nothing for now.
                break;
            }
        }

        for (int j = 0; j < p_mapper->desc.layers[i].nb_planes; j++, n++) {
            int attribs[48] = {EGL_NONE};
            int num_attribs = 0;

            ADD_ATTRIB(EGL_LINUX_DRM_FOURCC_EXT, format[j]);
            ADD_ATTRIB(EGL_WIDTH,  p_mapper->tex[n]->params.w);
            ADD_ATTRIB(EGL_HEIGHT, p_mapper->tex[n]->params.h);
            ADD_PLANE_ATTRIBS(0);

            p->images[n] = p->CreateImageKHR(eglGetCurrentDisplay(),
                EGL_NO_CONTEXT, EGL_LINUX_DMA_BUF_EXT, NULL, attribs);
            if (!p->images[n]) {
                mp_msg(mapper->log, probing ? MSGL_DEBUG : MSGL_ERR,
                    "Failed to import surface in EGL: %u\n", eglGetError());
                return false;
            }

            gl->BindTexture(GL_TEXTURE_2D, p->gl_textures[n]);
            if (p->EGLImageTargetTexStorageEXT) {
                p->EGLImageTargetTexStorageEXT(GL_TEXTURE_2D, p->images[n], NULL);
            } else {
                p->EGLImageTargetTexture2DOES(GL_TEXTURE_2D, p->images[n]);
            }

            mapper->tex[n] = p_mapper->tex[n];
        }
    }

    gl->BindTexture(GL_TEXTURE_2D, 0);
    return true;
}

static void vaapi_gl_unmap(struct ra_hwdec_mapper *mapper)
{
    struct dmabuf_interop_priv *p_mapper = mapper->priv;
    struct vaapi_gl_mapper_priv *p = p_mapper->interop_mapper_priv;

    if (!p)
        return;

    if (p->EGLImageTargetTexStorageEXT) {
        // textures are immutable, can't reuse
        gl_delete_textures(mapper);
    }

    for (int n = 0; n < AV_DRM_MAX_PLANES; n++) {
        if (p->images[n])
            p->DestroyImageKHR(eglGetCurrentDisplay(), p->images[n]);
        p->images[n] = 0;
    }
}

bool dmabuf_interop_gl_init(const struct ra_hwdec *hw,
                            struct dmabuf_interop *dmabuf_interop)
{
    if (!ra_is_gl(hw->ra_ctx->ra)) {
        // This is not an OpenGL RA.
        return false;
    }

    if (!eglGetCurrentContext())
        return false;

    const char *exts = eglQueryString(eglGetCurrentDisplay(), EGL_EXTENSIONS);
    if (!exts)
        return false;

    GL *gl = ra_gl_get(hw->ra_ctx->ra);
    const char *imageext = gl->es ? "GL_OES_EGL_image" : "GL_EXT_EGL_image_storage";
    if (!gl_check_extension(exts, "EGL_EXT_image_dma_buf_import") ||
        !gl_check_extension(exts, "EGL_KHR_image_base") ||
        !gl_check_extension(gl->extensions, imageext) ||
        !(gl->mpgl_caps & MPGL_CAP_TEX_RG)) {
        return false;
    }

    dmabuf_interop->use_modifiers =
        gl_check_extension(exts, "EGL_EXT_image_dma_buf_import_modifiers");

    MP_VERBOSE(hw, "Using EGL dmabuf interop via %s\n", imageext);

    dmabuf_interop->interop_init = vaapi_gl_mapper_init;
    dmabuf_interop->interop_uninit = vaapi_gl_mapper_uninit;
    dmabuf_interop->interop_map = vaapi_gl_map;
    dmabuf_interop->interop_unmap = vaapi_gl_unmap;

    return true;
}