#include <stdint.h>
#include <string.h>
#include <stdbool.h>
#include <fcntl.h>
#include <errno.h>
#include <assert.h>

#include "common_utils/utils.h"

char *append(char *buf, const char *appended, size_t *pcap)
{
    char c;
    char *buf0 = buf;
    size_t cap = *pcap;

    if (buf0 == NULL) return NULL;
    if (appended == NULL || appended[0] == 0) return buf0;

    if (*pcap < strlen(appended)+1) {
        return NULL;
    }

    while (cap > 1 && 0 != (c = *appended++)) {
        *buf++ = c;
        cap--;
    }
    assert(cap > 0);

    *pcap = cap;
    *buf = 0;
    return buf;
}

bool append_realloc(char **head, size_t *cap, const char *appended) {
    if (!head) return NULL;
    if (!*head) return NULL;
    if (!cap) return NULL;
    if (!appended) return NULL;

    size_t cursize = strlen(*head);
    size_t needed = strlen(appended) + 1;
    size_t remains = *cap - cursize;

    if (remains < needed) {
        size_t need_extra = needed - remains;
        size_t newsize = *cap + need_extra;
        char *new = realloc(*head, newsize);
        if (!new) return false;
        *head = new;
        *cap = newsize;
    }

    strcpy(*head + cursize, appended);
    return true;
}

bool fd_is_valid(int fd)
{
    return fcntl(fd, F_GETFD) != -1 || errno != EBADF;
}

bool parse_boolean_arg(const char *str)
{
    if (0 == strcasecmp(str, "on")) return true;
    if (0 == strcmp(str, "1")) return true;
    if (0 == strcasecmp(str, "yes")) return true;
    if (0 == strcasecmp(str, "enable")) return true;
    if (0 == strcasecmp(str, "en")) return true;
    if (0 == strcasecmp(str, "y")) return true;
    if (0 == strcasecmp(str, "a")) return true;

    return false;
}

bool parse_boolean_arg_false(const char *str)
{
    if (0 == strcasecmp(str, "off")) return true;
    if (0 == strcmp(str, "0")) return true;
    if (0 == strcasecmp(str, "no")) return true;
    if (0 == strcasecmp(str, "disable")) return true;
    if (0 == strcasecmp(str, "dis")) return true;
    if (0 == strcasecmp(str, "n")) return true;

    return false;
}