/*
 * gnome-exe-handler.c: Invoked when the user double clicks on an ELF
 * file, we need to figure out what to do with it.
 *
 * Author:
 *   Miguel de Icaza (miguel@ximian.com)
 */
#include <config.h>
#include <gnome.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

enum {
	OK_DIALOG = 0,
	YESNO_DIALOG = 1,

	WARNING_DIALOG = TRUE,
	ERROR_DIALOG = FALSE,

	WINDOW_CLOSE = -1,
	OK_BUTTON = 0,
	YES_BUTTON = 0,
	NO_BUTTON = 1
};

static int
message (const char *msg, int type, gboolean warning)
{
	GtkWidget *box;
	char *b1, *b2, *b3;
	int help_button = 0;
	int ret;
	
	if (type == YESNO_DIALOG) {
		b1 = GNOME_STOCK_BUTTON_YES;
		b2 = GNOME_STOCK_BUTTON_NO;
		b3 = GNOME_STOCK_BUTTON_HELP;
		help_button = 2;
	} else /* type == OK_DIALOG */ {
		b1 = GNOME_STOCK_BUTTON_OK;
		b2 = GNOME_STOCK_BUTTON_HELP;
		help_button = 1;
		b3 = NULL;
	}
	
	box = gnome_message_box_new (msg,
				     warning ?
				       GNOME_MESSAGE_BOX_WARNING :
				       GNOME_MESSAGE_BOX_ERROR,
				     b1, b2, b3, NULL);
	gnome_dialog_set_close (GNOME_DIALOG (box), FALSE);
	while ((ret = gnome_dialog_run (GNOME_DIALOG (box))) == help_button) {
		GnomeHelpMenuEntry ref
			= {"gnome-exe-handler", "index.html"};
		gnome_help_display (NULL, &ref);
	}

	gnome_dialog_close (GNOME_DIALOG (box));

	return ret;
}

static void
error (const char *msg)
{
	message (msg, OK_DIALOG, ERROR_DIALOG);
	exit (1);
}

static void
execute (const char *file)
{
	char *msg = g_strdup_printf (
		_("Executing arbitrary programs that you downloaded from the network "
		  "might be dangerous.\n\nAre you sure you want to run `%s'?"), file);
	struct stat s;
	
	switch (message (msg, YESNO_DIALOG, WARNING_DIALOG)){
	case YES_BUTTON:
		if (stat (file, &s) == -1){
			error (_("Could not access file permissions"));
		}
		
		if (chmod (file, s.st_mode | 00100) == -1){
			msg = g_strdup_printf (
				_("Could not execute the file `%s' due to a permission problem"),
				file);
			
			error (msg);
		}

		{
			char *argv [2];

			argv [0] = (char *)file;
			argv [1] = NULL;

			
			execv (file, argv);
		}

		msg = g_strdup_printf (_("Failure at executing `%s'"), file);
		error (msg);

	case NO_BUTTON:
	case WINDOW_CLOSE:
	default:
		exit (0);
	}
}

static void
launch (const char *file)
{
	char buffer [64];
	int n;
	int fd = open (file, O_RDONLY);
	
	if (fd == -1){
		char *msg = g_strdup_printf (
			_("It was not possible to open the file `%s'"),
			file);
		
		error (msg); 
	}

	n = read (fd, &buffer, sizeof (buffer));

	if (n == 0){
		char *msg = g_strdup_printf (_("The file `%s' is empty"), file);
		error (msg);
	}

	if (n < 0){
		char *msg = g_strdup_printf (_("There was an error. `%s' is empty"), file);
		error (msg);
	}

	if (buffer [0] == 0x7f &&
	    buffer [1] == 'E' &&
	    buffer [2] == 'L' &&
	    buffer [3] == 'F'){
		unsigned char processor;
		
		/* We got an ELF file, check to see what kind it is */

		switch (buffer [16]){
		case 1:
		case 0:
			error (_("This is a library and can not be executed"));
			
		case 2:
			break;
			
		case 4:
			error (_("The file is a core file and can not be executed"));

			
		default:
			error (_("This is an unknown kind of executable"));
		}

		/*
		 * This handles executables
		 */
		processor = buffer [18];

		if (
#if defined(__i386__)
			(processor == 3)
#elif defined(sparc) || defined(__sparc__) || defined(__sparcv9__)
			(processor == 2) || (processor == 18) || (processor == 43)
#elif defined(parisc) || defined (__parisc__)
			(processor == 15)
#elif defined(ppc) || defined(__ppc__)
			(processor == 20)
#elif defined(__alpha__)
			(processor == 41) || (processor == 0x9026)
#elif defined(__superh__)
			(processor == 42)
#elif defined(__ia64__)
			(processor == 50)
#else
			/* On other platforms just assume we're fine */
			TRUE
#endif
			) {
			execute (file);
		} else {
			error (_("The executable is for a different platform and can not be executed on this system"));
		}

	}
	error (_("This is an unknown kind of executable"));
}

int
main (int argc, char *argv [])
{
	poptContext ctx;
	const char **files;
	
	/* Initialize the i18n stuff */
	bindtextdomain (PACKAGE, GNOMELOCALEDIR);
	textdomain (PACKAGE);

	gnome_init_with_popt_table ("gnome-exe-handler", VERSION, argc, argv, NULL, 0, &ctx);

	files = poptGetArgs (ctx);

	while (files && *files){
		launch (*files);
		files++;
	}
	
	return 0;
}