infoderm/healthone

export default function validateLineLength(
    parts,
    kind,
    validLengths,
    trailingSlash,
) {
    if (typeof validLengths === 'number') validLengths = [validLengths];
    let validLengthsWithTrailingSlash =
        trailingSlash === false ? [] : validLengths.map((x) => x + 1);
    validLengths = trailingSlash === true ? [] : validLengths;
    validLengths = new Set(validLengths);
    validLengthsWithTrailingSlash = new Set(validLengthsWithTrailingSlash);

    const isValidLength = validLengths.has(parts.length);
    const isValidLengthWithTrailingSlash = validLengthsWithTrailingSlash.has(
        parts.length,
    );

    if (!isValidLength && !isValidLengthWithTrailingSlash) {
        const expectedLengths = Array.from(
            new Set([...validLengths, ...validLengthsWithTrailingSlash]),
        );
        expectedLengths.sort();
        const expected = `any of ${JSON.stringify(expectedLengths)}`;
        throw new Error(
            `parse${kind}: wrong number of parts, got ${parts.length}, expected ${expected}.`,
        );
    }

    if (
        trailingSlash === true ||
        (isValidLengthWithTrailingSlash && !isValidLength)
    ) {
        // Last part MUST be empty
        const last = parts.length - 1;
        if (parts[last].trimStart() !== '') {
            throw new Error(
                `parse${kind}: wrong last part, got ${parts[last]}, expected ''.`,
            );
        }
    }
}