crabmate 0.5.0

//! `read_dir` 等工具输出的体积与时间格式化（原 `file.rs` 内联辅助函数）。

pub(super) fn format_size(bytes: u64) -> String {
    const KB: u64 = 1024;
    const MB: u64 = 1024 * 1024;
    const GB: u64 = 1024 * 1024 * 1024;
    if bytes >= GB {
        format!("{:.1} GiB", bytes as f64 / GB as f64)
    } else if bytes >= MB {
        format!("{:.1} MiB", bytes as f64 / MB as f64)
    } else if bytes >= KB {
        format!("{:.1} KiB", bytes as f64 / KB as f64)
    } else {
        format!("{} B", bytes)
    }
}

pub(super) fn format_unix_timestamp(secs: u64) -> String {
    let days_since_epoch = secs / 86400;
    let time_of_day = secs % 86400;
    let hours = time_of_day / 3600;
    let minutes = (time_of_day % 3600) / 60;

    let mut y: i64 = 1970;
    let mut remaining = days_since_epoch as i64;
    loop {
        let days_in_year = if is_leap(y) { 366 } else { 365 };
        if remaining < days_in_year {
            break;
        }
        remaining -= days_in_year;
        y += 1;
    }
    let month_days = if is_leap(y) {
        [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    } else {
        [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    };
    let mut m = 0usize;
    for (i, &d) in month_days.iter().enumerate() {
        if remaining < d {
            m = i;
            break;
        }
        remaining -= d;
    }
    let day = remaining + 1;
    format!(
        "{:04}-{:02}-{:02} {:02}:{:02}",
        y,
        m + 1,
        day,
        hours,
        minutes
    )
}

fn is_leap(y: i64) -> bool {
    (y % 4 == 0 && y % 100 != 0) || y % 400 == 0
}