import toNumber from '../lang/toNumber';

/**
 * Converts number into currency format
 */
function currencyFormat(
    val: number,
    nDecimalDigits?: number,
    decimalSeparator?: string,
    thousandsSeparator?: string
) {
    val = toNumber(val);
    nDecimalDigits = nDecimalDigits == null ? 2 : nDecimalDigits;
    decimalSeparator = decimalSeparator == null ? '.' : decimalSeparator;
    thousandsSeparator = thousandsSeparator == null ? ',' : thousandsSeparator;

    // can't use enforce precision since it returns a number and we are
    // doing a RegExp over the string
    const fixed = val.toFixed(nDecimalDigits);
    // separate begin [$1], middle [$2] and decimal digits [$4]
    const parts = new RegExp(`^(-?\\d{1,3})((?:\\d{3})+)(\\.(\\d{${nDecimalDigits}}))?$`).exec(
        fixed
    );

    if (parts) {
        // val >= 1000 || val <= -1000
        return (
            parts[1] +
            parts[2].replace(/\d{3}/g, `${thousandsSeparator}$&`) +
            (parts[4] ? decimalSeparator + parts[4] : '')
        );
    } else {
        return fixed.replace('.', decimalSeparator);
    }
}

export default currencyFormat;