#define _DEFAULT_SOURCE
#define _XOPEN_SOURCE
#define _BSD_SOURCE
#include <time.h>
#include <locale.h>


void set_c_locale() {
    setlocale(LC_TIME, "C");
}


// When given invalid input, returns 0.
time_t c_parse_http_time(char* s) {
    if (s == NULL) return 0;
    struct tm dest;
    if (strptime(s, "%a, %d %b %Y %H:%M:%S GMT", &dest) == NULL) {
        return 0;
    }
    return timegm(&dest);
}

void c_format_http_time(time_t src, char* dest) {
    struct tm t;
    gmtime_r(&src, &t);
    strftime(dest, 40, "%a, %d %b %Y %H:%M:%S GMT", &t);
}

void c_format_log_time(time_t src, char* dest) {
    struct tm t;
    localtime_r(&src, &t);
    strftime(dest, 40, "%d/%b/%Y:%H:%M:%S %z", &t);
}