/*
 * X11 video grab interface
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg integration:
 * Copyright (C) 2006 Clemens Fruhwirth <clemens@endorphin.org>
 *                    Edouard Gomez <ed.gomez@free.fr>
 *
 * This file contains code from grab.c:
 * Copyright (c) 2000-2001 Fabrice Bellard 
 *
 * This file contains code from the xvidcap project:
 * Copyright (C) 1997-1998 Rasca, Berlin
 *               2003-2004 Karl H. Beckers, Frankfurt
 *
 * FFmpeg is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * FFmpeg 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 General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "avformat.h"
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/time.h>
#define _LINUX_TIME_H 1
#include <time.h>
#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xlibint.h>
#include <X11/Xproto.h>
#include <X11/Xutil.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <X11/extensions/XShm.h>

typedef struct
{
	Display *dpy;
	int frame_format;
	int frame_size;
	int frame_rate;
	int frame_rate_base;
	int64_t time_frame;

	int height;
	int width;
	int x_off;
	int y_off;
	XImage *image;
	int use_shm;
	XShmSegmentInfo shminfo;
	int mouse_wanted;
} X11Grab;

static int
x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
{
	X11Grab *x11grab = s1->priv_data;
	Display *dpy;
	AVStream *st = NULL;
	int width, height;
	int frame_rate, frame_rate_base, frame_size;
	int input_pixfmt;
	XImage *image;
	int x_off=0; int y_off = 0;
	int use_shm;

	dpy = XOpenDisplay(NULL);
	if(!dpy) {
		goto fail;
	}

	sscanf(ap->device, "x11:%d,%d", &x_off, &y_off);
	av_log(s1, AV_LOG_INFO, "device: %s -> x: %d y: %d width: %d height: %d\n", ap->device, x_off, y_off, ap->width, ap->height);
  
	if (!ap || ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
		av_log(s1, AV_LOG_ERROR, "AVParameters don't have any video size. Use -s.\n");
		return AVERROR_IO;  
	}

	width = ap->width;
	height = ap->height;
	frame_rate = ap->time_base.den;
	frame_rate_base = ap->time_base.num;

	st = av_new_stream(s1, 0);
	if (!st) {
		return -ENOMEM;
	}
	av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */

	use_shm = XShmQueryExtension(dpy);
	av_log(s1, AV_LOG_INFO, "shared memory extension %s\n", use_shm ? "found" : "not found");

	if(use_shm) {
		int scr = XDefaultScreen(dpy);
		image = XShmCreateImage(dpy,
					DefaultVisual(dpy, scr),
					DefaultDepth(dpy, scr),
					ZPixmap,
					NULL,
					&x11grab->shminfo,
					ap->width, ap->height);
		x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
						image->bytes_per_line * image->height,
						IPC_CREAT|0777);
		if (x11grab->shminfo.shmid == -1) {
			av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
			return -ENOMEM;
		}
		x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
		x11grab->shminfo.readOnly = False;
            
		if (!XShmAttach(dpy, &x11grab->shminfo)) {
			av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
			/* needs some better error subroutine :) */
			return AVERROR_IO;  
		}
	} else {
		image = XGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)),
				  x_off,y_off,
				  ap->width,ap->height,
				  AllPlanes, ZPixmap); 
	}
  
	switch (image->bits_per_pixel) {
	case 8:
		av_log (s1, AV_LOG_DEBUG, "8 bit pallete\n");
		input_pixfmt = PIX_FMT_PAL8;
		break;
	case 16:
		if ( image->red_mask == 0xF800 && image->green_mask == 0x07E0
		     && image->blue_mask == 0x1F ) {
			av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
			input_pixfmt = PIX_FMT_RGB565;
		} else if ( image->red_mask == 0x7C00 && 
			    image->green_mask == 0x03E0 && 
			    image->blue_mask == 0x1F ) {
			av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
			input_pixfmt = PIX_FMT_RGB555;
		} else {
			av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
			av_log(s1, AV_LOG_ERROR, "color masks: r 0x%.6lx g 0x%.6lx b 0x%.6lx\n", image->red_mask, image->green_mask, image->blue_mask);
			return AVERROR_IO;  
		}
		break;
	case 24:
		if ( image->red_mask == 0xFF0000 && 
		     image->green_mask == 0xFF00
		     && image->blue_mask == 0xFF ) {
			input_pixfmt = PIX_FMT_BGR24;
		} else if ( image->red_mask == 0xFF && image->green_mask == 0xFF00
			    && image->blue_mask == 0xFF0000 ) {
			input_pixfmt = PIX_FMT_RGB24;
		} else {
			av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
			av_log(s1, AV_LOG_ERROR, "color masks: r 0x%.6lx g 0x%.6lx b 0x%.6lx\n", image->red_mask, image->green_mask, image->blue_mask);
			return AVERROR_IO;  
		}
		break;
	case 32:
#if 0
		GetColorInfo (image, &c_info);
		if ( c_info.alpha_mask == 0xFF000000 && image->green_mask == 0xFF00 ) {
			/* byte order is relevant here, not endianness
			 * endianness is handled by avcodec, but atm no such thing
			 * as having ABGR, instead of ARGB in a word. Since we
			 * need this for Solaris/SPARC, but need to do the conversion
			 * for every frame we do it outside of this loop, cf. below
			 * this matches both ARGB32 and ABGR32 */
			input_pixfmt = PIX_FMT_ARGB32;
		}  else {
			av_log(s1, AV_LOG_ERROR,"image depth %i not supported ... aborting\n", image->bits_per_pixel);
			return AVERROR_IO;  
		}
#endif
		input_pixfmt = PIX_FMT_RGBA32;
		break;
	default:
		av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
		return -1;
	}

	frame_size = width * height * image->bits_per_pixel/8;
	x11grab->frame_size = frame_size;
	x11grab->dpy = dpy;
	x11grab->width = ap->width;
	x11grab->height = ap->height;
	x11grab->frame_rate      = frame_rate;
	x11grab->frame_rate_base = frame_rate_base;
	x11grab->time_frame = av_gettime() * frame_rate / frame_rate_base;
	x11grab->x_off = x_off;
	x11grab->y_off = y_off;
	x11grab->image = image;
	x11grab->use_shm = use_shm;
	x11grab->mouse_wanted = 1;

	st->codec->codec_type = CODEC_TYPE_VIDEO;
	st->codec->codec_id = CODEC_ID_RAWVIDEO;
	st->codec->width = width;
	st->codec->height = height;
	st->codec->pix_fmt = input_pixfmt;
	st->codec->time_base.den = frame_rate;
	st->codec->time_base.num = frame_rate_base;
	st->codec->bit_rate = frame_size * 1/av_q2d(st->codec->time_base) * 8;
  
	return 0;
fail:
	av_free(st);
	return AVERROR_IO;  
}

static void
getCurrentPointer(AVFormatContext *s1, X11Grab *s, int *x, int *y)
{
	Window mrootwindow, childwindow;
	int dummy;
	Display *dpy = s->dpy;
  
	mrootwindow = DefaultRootWindow(dpy);
  
	if (XQueryPointer(dpy, mrootwindow, &mrootwindow, &childwindow,
			  x, y, &dummy, &dummy, (unsigned int*)&dummy)) {
	} else {
		av_log(s1, AV_LOG_INFO, "couldn't find mouse pointer\n");
		*x = -1;
		*y = -1;
	}
}

#define DRAW_CURSOR_TEMPLATE(type_t) \
do { \
type_t *cursor; \
int width_cursor; \
uint16_t bm_b, bm_w, mask; \
\
for (line = 0; line < min(20, (y_off + height) - *y); line++ ) { \
	if (s->mouse_wanted == 1) { \
		bm_b = mousePointerBlack[line]; \
		bm_w = mousePointerWhite[line]; \
	} else { \
		bm_b = mousePointerWhite[line]; \
		bm_w = mousePointerBlack[line]; \
	} \
	mask = ( 0x0001 << 15 ); \
\
	for (cursor = (type_t*) im_data, width_cursor = 0; \
	     ((width_cursor + *x) < (width + x_off) && width_cursor < 16); \
	     cursor++, width_cursor++) { \
		if ( ( bm_b & mask ) > 0 ) { \
			*cursor &= ((~ image->red_mask) & (~ image->green_mask) & (~image->blue_mask )); \
		} else if ( ( bm_w & mask ) > 0 ) { \
			*cursor |= (image->red_mask | image->green_mask | image->blue_mask ); \
		} \
		mask >>= 1; \
	} \
	im_data += image->bytes_per_line; \
} \
} while (0)

static void
paintMousePointer(AVFormatContext *s1, X11Grab *s, int *x, int *y, XImage *image)
{
	static const uint16_t const mousePointerBlack[] =
		{
			0, 49152, 40960, 36864, 34816,
			33792, 33280, 33024, 32896, 32832,
			33728, 37376, 43264, 51456, 1152,
			1152, 576, 576, 448, 0
		};

	static const uint16_t const mousePointerWhite[] =
		{
			0, 0, 16384, 24576, 28672,
			30720, 31744, 32256, 32512, 32640,
			31744, 27648, 17920, 1536, 768,
			768, 384, 384, 0, 0
		};

	int x_off = s->x_off;
	int y_off = s->y_off;
	int width = s->width;
	int height = s->height;

	if (   (*x - x_off) >= 0 && *x < (width + x_off)
	    && (*y - y_off) >= 0 && *y < (height + y_off) ) { 
		int line;
		uint8_t *im_data = (uint8_t*)image->data;
    
		im_data += (image->bytes_per_line * (*y - y_off)); // shift to right line
		im_data += (image->bits_per_pixel / 8 * (*x - x_off)); // shift to right pixel
    
		switch(image->bits_per_pixel) {
		case 32:
			DRAW_CURSOR_TEMPLATE(uint32_t);
			break;
		case 16:
			DRAW_CURSOR_TEMPLATE(uint16_t);
			break;
		default:
			/* XXX: How do we deal with 24bit and 8bit modes ? */
			break;
		}
	}
}


/*
 * just read new data in the image structure, the image
 * structure inclusive the data area must be allocated before
 */
static int
XGetZPixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
{
	xGetImageReply rep;
	xGetImageReq *req;
	long nbytes;
  
	if (!image) {
		return False;
	}

	LockDisplay(dpy);
	GetReq(GetImage, req);

	/* First set up the standard stuff in the request */
	req->drawable = d;
	req->x = x;
	req->y = y;
	req->width = image->width;
	req->height = image->height;
	req->planeMask = (unsigned int)AllPlanes;
	req->format = ZPixmap;
  
	if (!_XReply(dpy, (xReply *) &rep, 0, xFalse) || !rep.length) {
		UnlockDisplay(dpy);
		SyncHandle();
		return False;
	}
  
	nbytes = (long)rep.length << 2;
	_XReadPad(dpy, image->data, nbytes);
  
	UnlockDisplay(dpy);
	SyncHandle();
	return True;
}

static int x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
{
	X11Grab *s = s1->priv_data;
	Display *dpy = s->dpy;
	XImage *image = s->image;
	int x_off = s->x_off;
	int y_off = s->y_off;

	int64_t curtime, delay;
	struct timespec ts;
  
	/* Calculate the time of the next frame */
	s->time_frame += int64_t_C(1000000);
  
	/* wait based on the frame rate */
	for(;;) {
		curtime = av_gettime();
		delay = s->time_frame  * s->frame_rate_base / s->frame_rate - curtime;
		if (delay <= 0) {
			if (delay < int64_t_C(-1000000) * s->frame_rate_base / s->frame_rate) {
				s->time_frame += int64_t_C(1000000);
			}
			break;
		}    
		ts.tv_sec = delay / 1000000;
		ts.tv_nsec = (delay % 1000000) * 1000;
		nanosleep(&ts, NULL);
	}
  
	if (av_new_packet(pkt, s->frame_size) < 0) {
		return AVERROR_IO;
	}
  
	pkt->pts = curtime & ((1LL << 48) - 1);
  
	if(s->use_shm) {
		if (!XShmGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off, AllPlanes)) {
			av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
		}
	} else {
		if (!XGetZPixmap(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off)) {
			av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
		}
	}

	{
		int pointer_x, pointer_y;
		getCurrentPointer(s1, s, &pointer_x, &pointer_y);
		paintMousePointer(s1, s, &pointer_x, &pointer_y, image);
	}


	/* XXX: avoid memcpy */
	memcpy(pkt->data, image->data, s->frame_size);
	return s->frame_size;
}

static int x11grab_read_close(AVFormatContext *s1)
{
	X11Grab *x11grab = s1->priv_data;

	/* Detach cleanly from shared mem */
	if (x11grab->use_shm) {
		XShmDetach(x11grab->dpy, &x11grab->shminfo);
		shmdt(x11grab->shminfo.shmaddr);
		shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
	}

	/* Destroy X11 image */
	if (x11grab->image) {
		XDestroyImage(x11grab->image);
		x11grab->image = NULL;
	}

	/* Free X11 display */
	XCloseDisplay(x11grab->dpy);
	return 0;
}

AVInputFormat x11_grab_device_demuxer =
{
	"x11grab",
	"X11grab",
	sizeof(X11Grab),
	NULL,
	x11grab_read_header,
	x11grab_read_packet,
	x11grab_read_close,
	.flags = AVFMT_NOFILE,
};