#include <rfb/rfb.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <sys/mman.h>

#include <xf86drm.h>
#include <libdrm/drm_fourcc.h>
#include <xf86drmMode.h>

#include <EGL/egl.h>
#include <EGL/eglext.h>
#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>


// #define APIENTRY
// #define APIENTRYP APIENTRY *
// #define GLAPI extern
// // FIXME integrate into glad
// typedef void(APIENTRYP PFNGLEGLIMAGETARGETTEXTURE2DOESPROC)(
// 	GLenum target, GLeglImageOES image);
// GLAPI PFNGLEGLIMAGETARGETTEXTURE2DOESPROC glad_glEGLImageTargetTexture2DOES;
// typedef void(APIENTRYP PFNGLEGLIMAGETARGETRENDERBUFFERSTORAGEOESPROC)(
// 	GLenum target, GLeglImageOES image);
// GLAPI PFNGLEGLIMAGETARGETRENDERBUFFERSTORAGEOESPROC
// 	glad_glEGLImageTargetRenderbufferStorageOES;

// // FIXME glad
// static PFNGLEGLIMAGETARGETTEXTURE2DOESPROC glEGLImageTargetTexture2DOES;
// extern void glEGLImageTargetTexture2DOES(GLenum target, GLeglImageOES image);

int main(int argc, const char **argv)
{
    if (argc < 2) {
        printf("not enough arguments\n");
        return 1;
    }

    const char *card = argv[1];
    const int drmfd = open(card, O_RDONLY);
    if (drmfd < 0) {
        fprintf(stderr, "card %s open failed: %s\n", card, strerror(errno));
        return 1;
    }
    int err;
    int source_plane = 0;
    int source_crtc = 0;
    err = drmSetClientCap(drmfd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
    if (err < 0) {
        perror("Failed to set universal planes capability: primary planes will not be usable");
	}
    drmModePlane *plane = NULL;
    drmModePlaneRes *plane_res = NULL;
    drmModeFB2 *fb = NULL;
    if (source_plane > 0) {
        plane = drmModeGetPlane(drmfd, source_plane);
        if (!plane) {
            fprintf(stderr, "Failed to get plane %d: %s\n", source_plane, strerror(errno));
            goto cleanup;
        }
        if (plane->fb_id == 0) {
            fprintf(stderr, "Place %d does not have an attached framebuffer\n", source_plane);
        }
    }
    else {
        plane_res = drmModeGetPlaneResources(drmfd);
        if (!plane_res) {
            perror("Failed to get plane resources");
            goto cleanup;
        }
        int i;
        for (i = 0; i < plane_res->count_planes; i++) {
            plane = drmModeGetPlane(drmfd, plane_res->planes[i]);
            if (!plane) {
                fprintf(stderr, "Failed to get plane %u: %s\n", plane_res->planes[i], strerror(errno));
                continue;
            }
            printf("Plane %u CRTC %u FB %u\n", plane->plane_id, plane->crtc_id, plane->fb_id);
            if ((source_crtc > 0 && plane->crtc_id != source_crtc) || plane->fb_id == 0) {
                // Either not connected to the target source CRTC
                // or not active.
                drmModeFreePlane(plane);
                plane = NULL;
                continue;
            }
            break;
        }
        if (i == plane_res->count_planes) {
            if (source_crtc > 0) {
                fprintf(stderr, "No usable planes found on CRTC %d\n", source_crtc);
            } else {
                fprintf(stderr, "No usable planes found\n");
            }
            goto cleanup;
        }
        printf("Using plane %u to locate framebuffers\n", plane->plane_id);
    }
    uint32_t plane_id = plane->plane_id;

    fb = drmModeGetFB2(drmfd, plane->fb_id);
    if (!fb) {
        fprintf(stderr, "Failed to get framebuffer %u: %s\n", plane->fb_id, strerror(errno));
        goto cleanup;
    }
    //printf("Template framebuffer is %u: %ux%u %ubpp %ub depth %u pitch\n", fb->fb_id, fb->width, fb->height, fb->bpp, fb->depth, fb->pitch);
    printf("Template framebuffer is %u: %ux%u fourcc:%u mod:%u flags:%u\n", fb->fb_id, fb->width, fb->height, fb->pixel_format, fb->modifier, fb->flags);
    printf("handles %u %u %u %u\n", fb->handles[0], fb->handles[1], fb->handles[2], fb->handles[3]);
    printf("offsets %u %u %u %u\n", fb->offsets[0], fb->offsets[1], fb->offsets[2], fb->offsets[3]);
    printf("pitches %u %u %u %u\n", fb->pitches[0], fb->pitches[1], fb->pitches[2], fb->pitches[3]);
    printf("format %s, modifier %s:%s\n", drmGetFormatName(fb->pixel_format), drmGetFormatModifierVendor(fb->modifier), drmGetFormatModifierName(fb->modifier));

    if (!fb->handles[0]) {
        fprintf(stderr, "No handle set on framebuffer: maybe you need some additional capabilities?\n");
        goto cleanup;
    }

    int fd = -1;
    err = drmPrimeHandleToFD(drmfd, fb->handles[0], O_RDONLY, &fd);
    if (err < 0 || fd < 0) {
        perror("Failed to get PRIME fd from framebuffer handle");
    }

    // //size_t buflen = fb->width * fb->height * fb->bpp / 8;
    // size_t buflen = fb->width * fb->height * 32 / 8;
    // char *buf = malloc(buflen);
    // char *mapped = mmap(NULL, buflen, PROT_READ, MAP_SHARED, fd, 0);
    // if (mapped == MAP_FAILED) {
    //     perror("mmap");
    //     goto cleanup;
    // }
    // memcpy(buf, mapped, buflen);

    //unlink("/tmp/1.raw");
    //write(open("/tmp/1.raw", O_WRONLY | O_CREAT, 00644), buf, buflen);

    // EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
    // eglInitialize(display, NULL, NULL);
    // EGLContext context = eglCreateContext(display, NULL, EGL_NO_CONTEXT, NULL);
    // eglMakeCurrent(display, EGL_NO_SURFACE, EGL_NO_SURFACE, context);
    EGLAttrib attrs[] = {
        EGL_WIDTH, fb->width,
        EGL_HEIGHT, fb->height,
        EGL_LINUX_DRM_FOURCC_EXT, DRM_FORMAT_ARGB8888,
        EGL_DMA_BUF_PLANE0_FD_EXT, fd,
        EGL_DMA_BUF_PLANE0_OFFSET_EXT, 0,
        EGL_DMA_BUF_PLANE0_MODIFIER_LO_EXT, 1,
        EGL_DMA_BUF_PLANE0_MODIFIER_HI_EXT, 1 >> 32,
        EGL_NONE,
    };
    EGLImage image = eglCreateImage(EGL_NO_DISPLAY, EGL_NO_CONTEXT, EGL_LINUX_DMA_BUF_EXT, NULL, attrs);
    if (glGetError() != GL_NO_ERROR) {
        fprintf(stderr, "eglCreateImage\n");
    }

    // Create an OpenGL texture and bind it to the EGL image
    GLuint texture;
    glGenTextures(1, &texture);
    if (glGetError() != GL_NO_ERROR) {
        fprintf(stderr, "glGenTextures\n");
    }

    glBindTexture(GL_TEXTURE_EXTERNAL_OES, texture);
    if (glGetError() != GL_NO_ERROR) {
        fprintf(stderr, "glBindTexture\n");
    }

    PFNGLEGLIMAGETARGETTEXTURE2DOESPROC glEGLImageTargetTexture2DOES =
        (PFNGLEGLIMAGETARGETTEXTURE2DOESPROC)eglGetProcAddress("glEGLImageTargetTexture2DOES");
    glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES, image);
    if (glGetError() != GL_NO_ERROR) {
        fprintf(stderr, "glEGLImageTargetTexture2DOES\n");
    }

    // Read the pixel data from the texture
    GLubyte *buf = malloc(fb->width * fb->height * 4);
    glReadPixels(0, 0, fb->width, fb->height, GL_RGB, GL_UNSIGNED_BYTE, buf);
    if (glGetError() != GL_NO_ERROR) {
        fprintf(stderr, "glReadPixels\n");
    }

    // write(open("/tmp/1.raw", O_WRONLY | O_CREAT, 00644), buf, fb->width * fb->height * 4);

    rfbScreenInfoPtr server=rfbGetScreen(0,NULL,fb->width,fb->height,8,3,32/8);
    if(!server)
        return 1;
    server->frameBuffer=buf;
    rfbInitServer(server);
    rfbRunEventLoop(server,-1,FALSE);
    return(0);

    cleanup:
        close(drmfd);
        return 1;

}