/*
 * Copyright (c) 2014, NORDUnet A/S.
 * See LICENSE for licensing information.
 */

#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "net_read_write.h"
#include "erlport.h"

static ssize_t
read_length(size_t length_size)
{
    unsigned char buf[2];

    if (length_size != 2) {
        return -1;
    }

    if (length_size > sizeof(buf)) {
        return -1;
    }

    ssize_t ret;

    ret = net_read(0, (char *)buf, length_size);

    if (ret != (ssize_t) length_size) {
        return -1;
    }

    return (ssize_t)(((unsigned long)buf[0] << 8) | (unsigned long)buf[1]);
}

ssize_t
read_command(char *buf, size_t maxlen)
{
    ssize_t len;

    len = read_length(2);

    if (len < 0) {
        return -1;
    }

    if (len > (ssize_t) maxlen) {
        return -1;
    }
    return net_read(0, buf, (size_t)len);
}

static int
write_length(size_t len, size_t length_size)
{
    unsigned char buf[2];

    if (length_size != 2) {
        return -1;
    }

    buf[0] = (len >> 8) & 0xff;
    buf[1] = len & 0xff;

    ssize_t ret;

    ret = net_write(1, (char *)buf, length_size);

    if (ret < 0) {
        return -1;
    }

    if (ret != (ssize_t) length_size) {
        return -1;
    }

    return 0;
}

static int
write_reply(char *msg, size_t len)
{
    ssize_t ret;

    ret = write_length(len, 2);
    if (ret < 0) {
        return -1;
    }
    ret = net_write(1, msg, len);
    if (ret < 0) {
        return -1;
    }

    return 0;
}

int
write_status(char *msg)
{
    return write_reply(msg, strlen(msg));
}