// SPDX-License-Identifier: GPL-2.0

#include <subcmd/parse-options.h>
#include <stdio.h>
#include <time.h>
#include <strings.h>
#include <linux/time64.h>
#include "debug.h"
#include "clockid.h"
#include "record.h"

struct clockid_map {
        const char *name;
        int clockid;
};

#define CLOCKID_MAP(n, c)       \
        { .name = n, .clockid = (c), }

#define CLOCKID_END     { .name = NULL, }


/*
 * Add the missing ones, we need to build on many distros...
 */
#ifndef CLOCK_MONOTONIC_RAW
#define CLOCK_MONOTONIC_RAW 4
#endif
#ifndef CLOCK_BOOTTIME
#define CLOCK_BOOTTIME 7
#endif
#ifndef CLOCK_TAI
#define CLOCK_TAI 11
#endif

static const struct clockid_map clockids[] = {
        /* available for all events, NMI safe */
        CLOCKID_MAP("monotonic", CLOCK_MONOTONIC),
        CLOCKID_MAP("monotonic_raw", CLOCK_MONOTONIC_RAW),

        /* available for some events */
        CLOCKID_MAP("realtime", CLOCK_REALTIME),
        CLOCKID_MAP("boottime", CLOCK_BOOTTIME),
        CLOCKID_MAP("tai", CLOCK_TAI),

        /* available for the lazy */
        CLOCKID_MAP("mono", CLOCK_MONOTONIC),
        CLOCKID_MAP("raw", CLOCK_MONOTONIC_RAW),
        CLOCKID_MAP("real", CLOCK_REALTIME),
        CLOCKID_MAP("boot", CLOCK_BOOTTIME),

        CLOCKID_END,
};

static int get_clockid_res(clockid_t clk_id, u64 *res_ns)
{
        struct timespec res;

        *res_ns = 0;
        if (!clock_getres(clk_id, &res))
                *res_ns = res.tv_nsec + res.tv_sec * NSEC_PER_SEC;
        else
                pr_warning("WARNING: Failed to determine specified clock resolution.\n");

        return 0;
}

int parse_clockid(const struct option *opt, const char *str, int unset)
{
        struct record_opts *opts = (struct record_opts *)opt->value;
        const struct clockid_map *cm;
        const char *ostr = str;

        if (unset) {
                opts->use_clockid = 0;
                return 0;
        }

        /* no arg passed */
        if (!str)
                return 0;

        /* no setting it twice */
        if (opts->use_clockid)
                return -1;

        opts->use_clockid = true;

        /* if its a number, we're done */
        if (sscanf(str, "%d", &opts->clockid) == 1)
                return get_clockid_res(opts->clockid, &opts->clockid_res_ns);

        /* allow a "CLOCK_" prefix to the name */
        if (!strncasecmp(str, "CLOCK_", 6))
                str += 6;

        for (cm = clockids; cm->name; cm++) {
                if (!strcasecmp(str, cm->name)) {
                        opts->clockid = cm->clockid;
                        return get_clockid_res(opts->clockid,
                                               &opts->clockid_res_ns);
                }
        }

        opts->use_clockid = false;
        ui__warning("unknown clockid %s, check man page\n", ostr);
        return -1;
}

const char *clockid_name(clockid_t clk_id)
{
        const struct clockid_map *cm;

        for (cm = clockids; cm->name; cm++) {
                if (cm->clockid == clk_id)
                        return cm->name;
        }
        return "(not found)";
}