#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#include <signal.h>
#include <errno.h>
#include <sys/time.h>
#include "client.h"

static int sig[2];

static void sendsig(int signum)
{
	signum=signum; /* Keep compiler quiet */
	write(sig[1], "", 1);
	return;
}

void signal_init(void)
{
	struct sigaction action;
	struct itimerval itimer;

	if (pipe(sig))
	{
		fprintf(stderr, "pipe: %s\n", strerror(errno));
		exit(1);
	}

	if (fcntl(sig[1], F_SETFL, O_NONBLOCK))
	{
		fprintf(stderr, "fcntl: %s\n", strerror(errno));
		exit(1);
	}
	action.sa_handler=sendsig;
	sigfillset(&action.sa_mask);
	action.sa_flags=SA_RESTART;
	if (sigaction(SIGALRM, &action, NULL))
	{
		fprintf(stderr, "sigaction: %s\n", strerror(errno));
		exit(1);
	}
	
	itimer.it_value.tv_sec=itimer.it_interval.tv_sec=update_interval;
	itimer.it_interval.tv_usec=itimer.it_value.tv_usec=PKT_INTERVAL_USEC;
	
	if (setitimer(ITIMER_REAL, &itimer, NULL))
	{
		fprintf(stderr, "setitimer: %s\n", strerror(errno));
		exit(1);
	}
}

void signal_preselect(int *maxfd, fd_set *fds, struct timeval *tvp)
{
	tvp=tvp; /* Keep compiler quiet */
/* 	printf(" [signal: %i]", sig[0]); */
	FD_SET(sig[0], fds);
	if (*maxfd<sig[0]) *maxfd=sig[0];
}

void signal_postselect(fd_set *fds)
{
	int bytes;
	char buf[16];

	if (!FD_ISSET(sig[0], fds)) return;
 read1:
	bytes=read(sig[0], buf, 16);
	if (bytes==-1 && errno==EINTR) goto read1;
	if (bytes==-1) goto error;
	if (bytes==0) goto eof;
	while (bytes==16)
	{
	read2:
		bytes=read(sig[0], buf, 16);
		if (bytes==-1 && errno==EINTR) goto read2;
		if (bytes==-1 && errno!=EAGAIN) goto error;
		if (bytes==0) goto eof;
	}
	packet_send(0);
	return;

 error:
	fprintf(stderr, "Huh? select said data available but read said %s\n", 
		strerror(errno));
	exit(1);
 eof:
	fprintf(stderr, "Huh? read: unexpected EOF\n");
	exit(1);
}