SolarEnergy/central_backend/src/utils/time_utils.rs

use chrono::prelude::*;
use std::time::{SystemTime, UNIX_EPOCH};

/// Get the current time since epoch
pub fn time_secs() -> u64 {
    SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .unwrap()
        .as_secs()
}

/// Get the current time since epoch
pub fn time_millis() -> u128 {
    SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .unwrap()
        .as_millis()
}

/// Get the number of the day since 01-01-1970 of a given UNIX timestamp (UTC)
pub fn day_number(time: u64) -> u64 {
    time / (3600 * 24)
}

/// Get current day number
pub fn curr_day_number() -> u64 {
    day_number(time_secs())
}

/// Get current hour, 00 => 23 (local time)
pub fn curr_hour() -> u32 {
    let local: DateTime<Local> = Local::now();
    local.hour()
}

/// Get the first second of the day (local time)
pub fn time_start_of_day() -> anyhow::Result<u64> {
    let local: DateTime<Local> = Local::now()
        .with_time(NaiveTime::from_hms_opt(0, 0, 0).unwrap())
        .unwrap();
    Ok(local.timestamp() as u64)
}

#[cfg(test)]
mod test {
    use crate::utils::time_utils::day_number;

    #[test]
    fn test_time_of_day() {
        assert_eq!(day_number(500), 0);
        assert_eq!(day_number(1726592301), 19983);
        assert_eq!(day_number(1726592401), 19983);
        assert_eq!(day_number(1726498701), 19982);
    }
}