// Formatting helpers for byte counts and transfer rates.

const UNITS = ['B', 'KB', 'MB', 'GB', 'TB', 'PB'];
const SHORT_UNITS = ['', 'K', 'M', 'G', 'T', 'P'];

function scale(n) {
    n = Number(n) || 0;
    let i = 0;
    while (n >= 1024 && i < UNITS.length - 1) {
        n /= 1024;
        i += 1;
    }
    return [n, i];
}

// "2.4 MB", human readable with a space.
export function formatBytes(n) {
    const [v, i] = scale(n);
    const digits = i === 0 ? 0 : v < 10 ? 1 : v < 100 ? 1 : 0;
    return `${v.toFixed(digits)} ${UNITS[i]}`;
}

// Compact for the panel: "2.4M", "120K", "0".
export function formatBytesShort(n) {
    const [v, i] = scale(n);
    if (i === 0)
        return `${Math.round(v)}`;
    const digits = v < 10 ? 1 : 0;
    return `${v.toFixed(digits)}${SHORT_UNITS[i]}`;
}

// "2.4 MB/s" for the menu.
export function formatSpeed(bytesPerSec) {
    return `${formatBytes(bytesPerSec)}/s`;
}

// "2.4M" for the panel (no /s, arrow provides context).
export function formatSpeedShort(bytesPerSec) {
    return formatBytesShort(bytesPerSec);
}