#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include "morse.h"

static char *progname;

void
usage(void)
{
	fprintf(stderr, "usage: %s PID\n", progname);
	exit(1);
}

/*
** We need this empty handler because ignored signals don't interrupt pause().
*/
void
feedbackhandler(int sig)
{
	if (signal(SIGINT, feedbackhandler) == SIG_ERR) {
		_exit(1);
	}
}

/*
** Convenience wrapper: Send signal, check errors and wait for confirmation.
*/
void
xkill(pid_t pid, int sig)
{
	if (kill(pid, sig) < 0) {
		perror("kill");
		exit(2);
	}
	pause();
}

void
send(pid_t pid, char *str)
{
	char *cp;  /* pointer to human-readable characters */
	char *mp;  /* pointer to morse code signals of one character */

	for (cp=str; *cp; cp++) {
		if (!(mp = encode(*cp))) {
			/* unknown character */
			continue;
		}

		for (; *mp; mp++) {
			xkill(pid, (*mp == '.') ? SIGUSR1 : SIGUSR2);
		}
		/* end of character */
		xkill(pid, SIGTERM);
	}
	xkill(pid, SIGTERM);
}

int
main(int argc, char *argv[])
{
	int pid;
	char ch;
	char buf[BUFSIZ];

	progname = *argv;

	if (argc != 2) {
		usage();
	}

	if (signal(SIGINT, feedbackhandler) == SIG_ERR) {
		perror("signal(SIGINT)");
		_exit(1);
	}

	while (fgets(buf, sizeof buf, stdin)) {
		send(atoi(argv[1]), buf);
	}

	return 0;
}