#include <err.h>
#include <errno.h>
#include <poll.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>

#define SOCK_PATH "/tmp/kissbot"

int
read_print(int s) {
	char buf[100];
	ssize_t n;
	while ((n = recv(s, buf, sizeof buf, 0)) > 0)
		write(1, buf, n);
	if (n < 0)
		perror("recv");
	return 0;
}

int
start_listening(void) {
	struct sockaddr_un my_addr = {.sun_family = AF_UNIX};
	int s = socket(AF_UNIX, SOCK_STREAM, 0);
	if (s == -1)
		err(1, "socket");
	unlink(SOCK_PATH);
	strlcpy(my_addr.sun_path, SOCK_PATH,
		sizeof(my_addr.sun_path)-1);
	if (bind(s, (struct sockaddr *)&my_addr,
		sizeof(struct sockaddr_un)) == -1)
		err(1, "bind");
	if (listen(s, 10) == -1)
		err(1, "listen");
	return s;
}

int
accept_one(int s) {
	struct sockaddr_un peer_addr;
	socklen_t slen = sizeof(peer_addr);
	return accept(s, (struct sockaddr *)&peer_addr, &slen);
}

int
main(void) {
	struct pollfd fds[3]; /* UNIX socket, IRC socket, client on UNIX socket */
	fds[0].fd = start_listening();
	fds[0].events = POLLIN;
	fds[1].fd = -1;
	fds[2].fd = -1;

	while (1) {
		fds[0].revents = 0;
		fds[1].revents = 0;
		fds[2].revents = 0;
		
		if (poll(fds, 3, -1) < 0) {
			if (errno == EAGAIN)
				continue;
			err(1, "poll");
		}

		if ((fds[0].revents & POLLIN)
			&& fds[2].fd == -1) {
			int s_recv = accept_one(fds[0].fd);
			if (s_recv != -1) {
				fds[0].events = 0; /* don't want to accept any more currently */
				fds[2].fd = s_recv;
				fds[2].events = POLLIN;
			}
		}
		if (fds[2].revents & POLLIN) {
			read_print(fds[2].fd);
			close(fds[2].fd);
			fds[2].fd = -1;
			fds[0].events = POLLIN;
		}
		if (fds[2].revents & POLLHUP) {
			close(fds[2].fd);
			fds[2].fd = -1;
			fds[0].events = POLLIN;
		}
	}
	close(fds[0].fd);
}