#include "net.h"

#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <unistd.h>

#define NET_TIMEOUT_SEC 10

int net_connect(const char *host, int port, char *err, size_t errlen)
{
    char portstr[16];
    snprintf(portstr, sizeof(portstr), "%d", port);

    struct addrinfo hints;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;

    struct addrinfo *res = NULL;
    int rc = getaddrinfo(host, portstr, &hints, &res);
    if (rc != 0) {
        snprintf(err, errlen, "cannot resolve %s: %s", host, gai_strerror(rc));
        return -1;
    }

    int fd = -1;
    for (struct addrinfo *ai = res; ai != NULL; ai = ai->ai_next) {
        fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
        if (fd < 0)
            continue;

        struct timeval tv;
        tv.tv_sec = NET_TIMEOUT_SEC;
        tv.tv_usec = 0;
        setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
        setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));

        if (connect(fd, ai->ai_addr, ai->ai_addrlen) == 0) {
            break;
        }
        close(fd);
        fd = -1;
    }
    freeaddrinfo(res);

    if (fd < 0) {
        snprintf(err, errlen, "cannot connect to %s:%d: %s", host, port, strerror(errno));
        return -1;
    }

    return fd;
}