/*
 * X11 video grab interface
 * Copyright (c) 2006 Clemens Fruhwirth
 * 
 * A quick note on licensing. This file is a mixture of LGPL code
 * (ffmpeg) and GPL code (xvidcap). The result is a file that must
 * abid both licenses. As they are compatible and GPL is more
 * strict, this code has an "effective" GPL license.
 * 
 * This file contains code from grab.c:
 * Copyright (c) 2000,2001 Fabrice Bellard 
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * This file contains code from the xvidcap project:
 * Copyright (C) 1997-98 Rasca, Berlin
 * Copyright (C) 2003,04 Karl H. Beckers, Frankfurt
 *
 * This program 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.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, 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 <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;
  int width, height;
  int frame_rate, frame_rate_base, frame_size;
  int input_pixfmt;
  XImage *image;
  int x_off=0; int y_off = 0;
  char *device_parsing = strdup(ap->device);
  int use_shm;

  dpy = XOpenDisplay(NULL);

  if(!dpy)
    goto fail;

  sscanf(device_parsing,"x11:%d,%d",&x_off, &y_off);
  fprintf(stderr,"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) {
    fprintf(stderr,"x11grab: 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, 48, 1, 1000000); /* 48 bits pts in us */

  use_shm = XShmQueryExtension(dpy);
  fprintf(stderr,"x11grab: 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) {
      fprintf(stderr,"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) == 0) {
      fprintf(stderr,"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:
    fprintf (stderr, "x11grab: 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 ) {
      fprintf (stderr, "x11grab: 16 bit RGB565\n");
      input_pixfmt = PIX_FMT_RGB565;
    } else if ( image->red_mask == 0x7C00 && 
		image->green_mask == 0x03E0 && 
		image->blue_mask == 0x1F ) {
      fprintf (stderr, "x11grab: 16 bit RGB555\n");
      input_pixfmt = PIX_FMT_RGB555;
    } else {
      fprintf (stderr, "x11grab: RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
      fprintf (stderr, "x11grab: color masks: r 0x%.6X g 0x%.6X b 0x%.6X\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 {
      fprintf (stderr, "xtoffmpeg.XImageToFFMPEG(): rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
      fprintf (stderr, "xtoffmpeg.XImageToFFMPEG(): color masks: r 0x%.6X g 0x%.6X b 0x%.6X\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 {
      fprintf (stderr, "xtoffmpeg.XImageToFFMPEG(): image depth %i not supported ... aborting\n", image->bits_per_pixel);
      return AVERROR_IO;  
    }
#endif
    input_pixfmt = PIX_FMT_RGBA32;
    break;
  default:
    fprintf (stderr, "xtoffmpeg.XImageToFFMPEG(): 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);
  av_free(device_parsing);
  return AVERROR_IO;  
}

uint16_t mousePointerBlack[] = { 0, 49152, 40960, 36864, 34816, 33792, 33280, 33024, 32896, 32832,
33728, 37376, 43264, 51456, 1152, 1152, 576, 576, 448, 0 };
uint16_t mousePointerWhite[] = { 0, 0, 16384, 24576, 28672, 30720, 31744, 32256, 32512, 32640, 31744,
27648, 17920, 1536, 768, 768, 384, 384, 0, 0 };

static void getCurrentPointer(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, &dummy)) {
  } else {
    fprintf(stderr,"couldn't find mouse pointer\n");
    *x = -1;
    *y = -1;
  }
}

static void paintMousePointer(X11Grab *s, int *x, int *y, XImage *image) {
  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 = 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: 
    {
	uint32_t *cursor;
	int width_cursor;
	uint16_t bm_b, bm_w, mask;
      
	for (line = 0; line < 20; 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 = (uint32_t*) im_data, width_cursor = 0; 
	       ((width_cursor + *x) < (width + x_off) && width_cursor < 16);
	       cursor++, width_cursor++) {
	    //							Boolean pointer_b_bit, pointer_w_bit;	  
	    //							pointer_b_bit = ( ( bm_b & mask ) > 0 );
	    //							pointer_w_bit = ( ( bm_w & mask ) > 0 );
	    //							printf("%i ", pointer_b_bit, pointer_w_bit );
	    
	    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;
	  }
	  //						printf("\n");
	  im_data += image->bytes_per_line;
	}
      }
      break;
#if 0
            case 24: // not sure this can occur at all ..........
                fprintf(stderr,"input image bits_per_pixel %i not implemented with mouse pointer capture ... aborting!\n",
                image->bits_per_pixel);
                fprintf(stderr,"Please file a bug at http://www.sourceforge.net/projects/xvidcap/\n");
                exit(1);
                break;
            case 16: {
                uint16_t *cursor;
                int width;
                uint16_t bm_b, bm_w, mask;
                
                for (line = 0; line < 16; line++ ) {
                    if (mjob->mouseWanted == 1) {
                        bm_b = mousePointerBlack[line];
                        bm_w = mousePointerWhite[line];
                    } else {
                        bm_b = mousePointerWhite[line];
                        bm_w = mousePointerBlack[line];
                    }
                    mask = ( 0x0001 << 15 );
                    
                    for (cursor = (uint16_t*) im_data, width = 0;
                    ((width + *x) < (mjob->area->width + mjob->area->x)&&width < 6);
                    cursor++, width++) {
                        //							Boolean pointer_b_bit, pointer_w_bit;
                        
                        //							pointer_b_bit = ( ( bm_b & mask ) > 0 );
                        //							pointer_w_bit = ( ( bm_w & mask ) > 0 );
                        //							printf("%i ", pointer_b_bit, pointer_w_bit );
                        
                        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;
                        
                    }
                    //						printf("\n");
                    
                    im_data += image->bytes_per_line;
                }
            }
            break;
            case 8: {
                uint8_t *cursor;
                int width;
                uint16_t bm_b, bm_w, mask;
                
                for (line = 0; line < 16; line++ ) {
                    if (mjob->mouseWanted == 1) {
                        bm_b = mousePointerBlack[line];
                        bm_w = mousePointerWhite[line];
                    } else {
                        bm_b = mousePointerWhite[line];
                        bm_w = mousePointerBlack[line];
                    }
                    mask = ( 0x0001 << 15 );
                    
                    for (cursor = im_data, width = 0;
                    ((width + *x) < (mjob->area->width + mjob->area->x)&&width < 6);
                    cursor++, width++) {
                        //							Boolean pointer_b_bit, pointer_w_bit;
                        
                        //							pointer_b_bit = ( ( bm_b & mask ) > 0 );
                        //							pointer_w_bit = ( ( bm_w & mask ) > 0 );
                        //							printf("%i ", pointer_b_bit, pointer_w_bit );
                        
                        if ( ( bm_b & mask ) > 0 ) {
                            *cursor = 0;
                        } else if ( ( bm_w & mask ) > 0 ) {
                            *cursor = 1;
                        }
                        mask >>= 1;
                        
                    }
                    //						printf("\n");
                    
                    im_data += image->bytes_per_line;
                }
            }
            break;
            default:
                fprintf(stderr,"input image bits_per_pixel %i not supported with mouse pointer capture ... aborting!\n",
                image->bits_per_pixel);
                exit(1);
                
#endif        
    }
  }
}


/*
 * 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 = AllPlanes;
  req->format = ZPixmap;
  
  if (_XReply(dpy, (xReply *) &rep, 0, xFalse) == 0 ||
      rep.length == 0) {
    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) {
	/* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
	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)) {
      fprintf(stderr,"XShmGetImage() failed\n");
    }
  } 
  else {
    XGetZPixmap(dpy,
		RootWindow(dpy, DefaultScreen(dpy)),
		image, x_off, y_off); 
  };
  {
    int pointer_x, pointer_y;
    getCurrentPointer(s, &pointer_x, &pointer_y);
    paintMousePointer(s, &pointer_x, &pointer_y, image);
  }

#warning FIXME - 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;
  
  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,
};