package vocabletrainer.heinecke.aron.vocabletrainer.lib;

import java.io.File;
import java.text.DecimalFormat;

/**
 * Formatter
 */
public class Formatter {
    private final DecimalFormat formatBytes = new DecimalFormat("#,##0.#");
    private final String[] units = new String[]{"B", "KB", "MB", "GB", "TB"};
    private final String[] unit_si = new String[]{"B", "KiB", "MiB", "GiB", "TiB"};
    private boolean USE_SI = true;

    /**
     * Format bytes to human readable string
     *
     * @param i bytes amount
     * @return String, for ex. 5,4MiB
     */
    public String formatBytes(long i) {
        if (i <= 0)
            return "0";
        int digitGroups = (int) (Math.log10(i) / Math.log10(USE_SI ? 1024 : 1000));
        return formatBytes.format(i / Math.pow(1024, digitGroups)) + " " + (USE_SI ? unit_si[digitGroups] : units[digitGroups]);
    }

    /**
     * Format file length
     *
     * @param file
     * @return (empty) String with the file length
     */
    public String formatFileLength(final File file) {
        if (file.exists() && file.isFile()) {
            return formatBytes(file.length());
        } else {
            return "";
        }
    }

    /**
     * Change SI notation usage
     *
     * @param use_si
     */
    public void changeSI(boolean use_si) {
        USE_SI = use_si;
    }
}

@@ -775,20 +775,36 @@
 ath.pow(
-1024
+USE_SI ? 1024 : 1000
 , digitG

fix missing SI handling in formatBytes