/* wxpaste.c- paste contents of cutbuffer to stdout
 *
 *  Copyright (c) 1997-2003 Alfredo K. Kojima
 *
 *  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, see <https://www.gnu.org/licenses/>.
 */

#include "../config.h"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <sys/time.h>
#include <sys/types.h>
#ifdef HAVE_SYS_SELECT_H
# include <sys/select.h>
#endif

#define MAXDATA		(4*1024*1024)

static const char *prog_name;

static void print_help(void)
{
	printf("Usage: %s [OPTIONS]\n", prog_name);
	puts("Copies data from X selection or cutbuffer to stdout.");
	puts("");
	puts("  -display display         display to use");
	puts("  --cutbuffer number       cutbuffer number to get data from");
	puts("  --selection [selection]  reads data from named selection instead of cutbuffer");
	puts("  -h, --help               display this help and exit");
	puts("  -v, --version            output version information and exit");
}

static Time getTimestamp(Display * dpy, Window win)
{
	XEvent ev;

	/* So we do this trickery to get a time stamp:
	 *
	 * 1. Grab the server because we are paranoid and don't want to
	 * get in a race with another instance of wxpaste being ran at the
	 * same time.
	 *
	 * 2. Set a dummy property in our window.
	 *
	 * 3. Get the PropertyNotify event and get its timestamp.
	 *
	 * 4. Ungrab the server.
	 */

	XSelectInput(dpy, win, PropertyChangeMask);

	/* Generate a PropertyNotify event */
	XStoreName(dpy, win, "shit");

	/* wait for the event */
	while (1) {
		XNextEvent(dpy, &ev);
		if (ev.type == PropertyNotify)
			break;
	}

	return ev.xproperty.time;
}

static char *fetchSelection(Display *dpy, const char *selection)
{
	Atom selatom = XInternAtom(dpy, selection, False);
	Atom clipatom = XInternAtom(dpy, "CLIPBOARD", False);
	Time now;
	XEvent ev;
	Window win;
	int ok = 0;
	struct timeval timeout;
	fd_set fdset;

	win = XCreateSimpleWindow(dpy, DefaultRootWindow(dpy), 0, 0, 1, 1, 0, 0, 0);
	/*
	 * The ICCCM says that we can't pass CurrentTime as the timestamp
	 * for XConvertSelection(), but we don't have anything to use as
	 * a timestamp...
	 */
	now = getTimestamp(dpy, win);

	XConvertSelection(dpy, selatom, XA_STRING, clipatom, win, now);

	timeout.tv_sec = 1;
	timeout.tv_usec = 0;

	/* wait for the convertion */
	while (0) {
		int res;

		if (XPending(dpy) == 0) {
			FD_ZERO(&fdset);
			FD_SET(ConnectionNumber(dpy), &fdset);
			res = select(ConnectionNumber(dpy) + 1, &fdset, NULL, NULL, &timeout);
			if (res <= 0) {
				ok = 0;
				break;
			}
		}
		if (res > 0 || XPending(dpy) > 0) {
			XNextEvent(dpy, &ev);
			if (ev.type == SelectionNotify && ev.xany.window == win) {
				ok = 1;
				break;
			}
		}
	}

	/* if success, return the data */
	if (ok) {
		Atom rtype;
		int bits;
		unsigned long len, bytes;
		unsigned char *data;

		if (XGetWindowProperty(dpy, win, clipatom, 0, MAXDATA / 4, False,
				       XA_STRING, &rtype, &bits, &len, &bytes, &data) != 0)
			return NULL;

		if ((rtype != XA_STRING) || (bits != 8)) {
			return NULL;
		} else {
			return (char *)data;
		}
	}
	return NULL;
}

int main(int argc, char **argv)
{
	Display *dpy;
	int i, l;
	int buffer = 0;
	char *buf;
	int status;
	char *display_name = "";
	char *selection_name = NULL;

	prog_name = argv[0];
	for (i = 1; i < argc; i++) {
		if (argv[i][0] == '-') {
			if (argv[i][1] == 'h' || strcmp(argv[i], "--help") == 0) {
				print_help();
				exit(0);
			} else if (argv[i][1] == 'v' || strcmp(argv[i], "--version") == 0) {
				printf("%s (Window Maker %s)\n", prog_name, VERSION);
				exit(0);
			} else if (strcmp(argv[i], "-selection") == 0 || strcmp(argv[i], "--selection") == 0) {
				if (i < argc - 1) {
					selection_name = argv[++i];
				} else {
					selection_name = "PRIMARY";
				}
			} else if (strcmp(argv[i], "-display") == 0) {
				if (i < argc - 1) {
					display_name = argv[++i];
				} else {
					print_help();
					exit(0);
				}
			} else if (strcmp(argv[i], "-cutbuffer") == 0 || strcmp(argv[i], "--cutbuffer") == 0) {
				if (i < argc - 1) {
					i++;
					if (sscanf(argv[i], "%i", &buffer) != 1) {
						fprintf(stderr, "%s: could not convert \"%s\" to int\n",
						        prog_name, argv[i]);
						exit(1);
					}
					if (buffer < 0 || buffer > 7) {
						fprintf(stderr, "%s: invalid buffer number %i\n", prog_name, buffer);
						exit(1);
					}
				} else {
					fprintf(stderr, "%s: invalid argument '%s'\n", prog_name, argv[i]);
					fprintf(stderr, "Try '%s --help' for more information.\n", prog_name);
					exit(1);
				}
			}
		} else {
			fprintf(stderr, "%s: invalid argument '%s'\n", prog_name, argv[i]);
			fprintf(stderr, "Try '%s --help' for more information.\n", prog_name);
			exit(1);
		}
	}
	dpy = XOpenDisplay(display_name);
	if (!dpy) {
		fprintf(stderr, "%s: could not open display \"%s\"\n", prog_name, XDisplayName(display_name));
		exit(1);
	}

	if (selection_name) {
		buf = fetchSelection(dpy, selection_name);
	} else {
		buf = NULL;
	}

	if (buf == NULL) {
		buf = XFetchBuffer(dpy, &l, buffer);
	}

	if (buf == NULL) {
		status = 1;
	} else {
		if (write(STDOUT_FILENO, buf, l) == -1)
			status = errno;
		else
			status = 0;
	}
	XCloseDisplay(dpy);
	exit(status);
}
