#ifndef _CTRLSTATUS_FMT_H_
#define _CTRLSTATUS_FMT_H_

/* ctrlstatus_fmt.h — render a responder snapshot timestamp (epoch-millis) in
 * the EXACT wall-clock string the controller logger emits, so the test client's
 * `ctrlstatus` output is byte-comparable against ctrl-N.log (controller-status
 * task 6.3, Req 11.2/11.3).
 *
 * The tlog prefix (vendored tinylog, _tlog_root_default_format) is built inline
 * as:
 *
 *   snprintf(... "[%.4d-%.2d-%.2d %.2d:%.2d:%.2d,%.3d]...",
 *            tm->year, tm->mon, tm->mday, tm->hour, tm->min, tm->sec,
 *            tm->usec / 1000, ...);
 *
 * where the broken-down time comes from gettimeofday() + localtime_r() — i.e.
 * LOCAL time, with sub-second precision rendered as zero-padded MILLISECONDS
 * (usec / 1000). tlog exposes no reusable formatter for callers, so this helper
 * REPLICATES that construction: localtime_r + strftime("%Y-%m-%d %H:%M:%S")
 * (byte-identical to "%.4d-%.2d-%.2d %.2d:%.2d:%.2d") then ",%03u" for the
 * millisecond fraction. Both the logger and this helper use local time, so the
 * rendered value matches the log line under the same TZ. */

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

/* Render `ms` (epoch milliseconds, e.g. xce_ctrlstatus_t.responder_time_ms)
 * into `buf` as local-time "YYYY-MM-DD HH:MM:SS,mmm". Needs at least 24 bytes.
 * Returns `buf` on success, NULL if buf is NULL / too small / time conversion
 * fails. */
static inline char* ctrlstatus_format_time_ms(uint64_t ms, char* buf, size_t n)
{
    /* "YYYY-MM-DD HH:MM:SS,mmm" + NUL == 24 bytes. */
    if (buf == NULL || n < 24) {
        return NULL;
    }

    time_t    secs = (time_t)(ms / 1000u);
    unsigned  msec = (unsigned)(ms % 1000u);
    struct tm tm;

    if (localtime_r(&secs, &tm) == NULL) {
        return NULL;
    }

    char datetime[20]; /* "YYYY-MM-DD HH:MM:SS" + NUL */
    if (strftime(datetime, sizeof(datetime), "%Y-%m-%d %H:%M:%S", &tm) == 0) {
        return NULL;
    }

    /* Match tlog's ",%.3d" millisecond fraction (zero-padded to 3 digits). */
    if (snprintf(buf, n, "%s,%03u", datetime, msec) < 0) {
        return NULL;
    }

    return buf;
}

#endif /* _CTRLSTATUS_FMT_H_ */