duration_calculation.rs

use chrono::{DateTime, Duration, FixedOffset, Local, Utc};
use std::time::Instant;

/// Get the elapsed time between two code sections
///
/// # Arguments
///
/// * `callback` - A closure that contains the code sections to measure the elapsed time
///
/// # Example
///
/// ```
/// use date_time::get_two_code_sections_elapsed_time;
///
/// let result = get_two_code_sections_elapsed_time(|| {
///    let mut _sum: u64 = 0;
///    for i in 0..200000000 {
///       _sum += i;
///    }
/// });
/// print!("{}", result);
/// ```
pub fn get_two_code_sections_elapsed_time(callback: fn()) -> String {
    let start = Instant::now();
    callback();
    let duration = start.elapsed();
    format!("Elapsed time: {:?}", duration)
}

/// Check the number of days from a given date time
///
/// # Arguments
///
/// * `date_time` - A date time to check the number of days from
///
/// # Example
///
/// ```
/// use chrono::{Duration, Utc};
/// use date_time::check_days_from_date_time;
///
/// let date_time = Utc::now() + Duration::days(2);
/// let result = check_days_from_date_time(date_time);
/// assert_eq!(result, "1 days ahead");
/// ```
pub fn check_days_from_date_time(date_time: DateTime<Utc>) -> String {
    let now = Utc::now();
    let duration = now - date_time;
    let num_days = duration.num_days();

    match num_days {
        n if n < 0 => format!("{} days ahead", -n),
        0 => String::from("Today"),
        1 => String::from("Yesterday"),
        2..=7 => String::from("This week"),
        8..=14 => String::from("Last week"),
        _ => format!("{} days ago", num_days),
    }
}

/// Offset the date time to a specific time zone
///
/// # Arguments
///
/// * `local_datetime` - A local date time to offset
/// * `offset_hours` - The offset hours to adjust the date time
///
/// # Returns
///
/// A tuple of the adjusted date time and the new offset
///
/// # Example
///
/// ```
/// use date_time::offset_date_timezone;
/// use chrono::{DateTime, Local};
///
/// let date_time = Local::now();
/// let (adjusted_datetime, ..) = offset_date_timezone(date_time, 2);
/// println!("Adjusted datetime: {:?}", adjusted_datetime);
/// ```
pub fn offset_date_timezone(
    local_datetime: DateTime<Local>,
    offset_hours: i64,
) -> (DateTime<FixedOffset>, FixedOffset) {
    let naive_utc = local_datetime.naive_utc();
    let offset_duration = Duration::hours(offset_hours);
    let offset_datetime = naive_utc + offset_duration;
    let new_offset = FixedOffset::east_opt(offset_hours as i32 * 3600).unwrap();
    let adjusted_datetime = DateTime::from_naive_utc_and_offset(offset_datetime, new_offset);
    (adjusted_datetime, new_offset)
}