use std::ops::Add;
use std::time::Duration;

pub(crate) fn truncate_with_dots(to_truncate: String, new_size: usize) -> String {
    let mut new_string = to_truncate.clone();
    let dots = "...";
    if new_size as isize - 3 > 0 {
        new_string.truncate(new_size - 3);
        new_string.add(dots)
    } else {
        let mut dots_to_ret = String::new();
        for _i in 0..new_size {
            dots_to_ret.push('.');
        }
        return dots_to_ret;
    }
}

pub(crate) fn human_readable_duration(duration: Duration) -> String {
    let total_duration = duration.as_secs();
    let mut minutes = total_duration / 60;
    let seconds = total_duration % 60;

    if minutes >= 60 {
        let hours = minutes / 60;
        minutes = minutes % 60;
        return format!(
            "{} hour(s), {} minute(s) and {} second(s)",
            hours, minutes, seconds
        );
    }
    format!("{} minute(s) and {} second(s)", minutes, seconds)
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn should_truncate_short_string_as_expected() {
        let example_string = "example";
        let expected_string = "..";

        assert_eq!(
            expected_string,
            truncate_with_dots(example_string.to_string(), 2)
        )
    }

    #[test]
    fn should_truncate_long_string_as_expected() {
        let example_string = "this is a very long string";
        let expected_string = "this i...";

        assert_eq!(
            expected_string,
            truncate_with_dots(example_string.to_string(), 9)
        )
    }

    #[test]
    fn should_print_correct_duration_into_human_readable_format() {
        let duration: Duration = Duration::new(124, 0);
        let got = human_readable_duration(duration);

        assert_eq!("2 minute(s) and 4 second(s)", got)
    }

    #[test]
    fn should_handle_duration_in_hours() {
        let duration1 = Duration::new(3621, 0);
        let got1 = human_readable_duration(duration1);

        assert_eq!("1 hour(s), 0 minute(s) and 21 second(s)", got1);

        let duration2 = Duration::new(5021, 0);
        let got2 = human_readable_duration(duration2);

        assert_eq!("1 hour(s), 23 minute(s) and 41 second(s)", got2);
    }
}