#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <pthread.h>

#define PORT 8889
#define BUFF_SIZE 8192
#define MAX_CLIENTS 125

typedef struct {
	int fd;
	struct sockaddr_in clients[MAX_CLIENTS + 1];
} DATA;

void *process_clients(void *p) {
	DATA *data = (DATA *)p;
	char buf[BUFF_SIZE];

	while (1) {
		off_t ret = read(STDIN_FILENO, buf, sizeof(buf));
		if (ret <= 0)
			continue;

		socklen_t len = sizeof(struct sockaddr_in);
		for (size_t i = 0; i < MAX_CLIENTS; i++)
			sendto(data->fd, buf, ret, 0, (struct sockaddr *)&data->clients[i], len);
	}
}

int main(void) {
	signal(SIGPIPE, SIG_IGN);

	int fd = socket(AF_INET, SOCK_DGRAM, 0);
	if (fd < 0)
		goto ERROR_WITHOUTCLOSE;

	struct timeval tv = {.tv_sec = 0, .tv_usec = 50};
	if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) < 0)
		goto ERROR;

	if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) < 0)
		goto ERROR;

	int reuse = 1;
	if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &reuse, sizeof(int)) < 0)
		goto ERROR;

	static struct sockaddr_in addr;
	addr.sin_family = AF_INET;
	addr.sin_port = htons(PORT);
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
		goto ERROR;

	static DATA data;
	data.fd = fd;

	pthread_t td;
	pthread_create(&td, NULL, process_clients, (void *)&data);

	int last = 0;
	char buf[1];

	socklen_t len = sizeof(struct sockaddr_in);
	while (1) {
		if (last <= MAX_CLIENTS) {
			if (recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *)&data.clients[last], &len) > 0)
				last++;
		}

		else
			last = 0;
	}

ERROR:
	close(fd);

ERROR_WITHOUTCLOSE:
	fprintf(stderr, "streamer: %s\n", strerror(errno));
	return 1;
}