import { Markers } from '../../primitives.js';
/**
 * Makes no changes to `spec.lines[].tokens` but joins them into `spec.description`
 * following given spacing srtategy
 * @param {Spacing} spacing tells how to handle the whitespace
 */
export default function descriptionTokenizer(spacing = 'compact') {
    const join = getJoiner(spacing);
    return (spec) => {
        spec.description = join(spec.source);
        return spec;
    };
}
export function getJoiner(spacing) {
    if (spacing === 'compact')
        return compactJoiner;
    if (spacing === 'preserve')
        return preserveJoiner;
    return spacing;
}
function compactJoiner(lines) {
    return lines
        .map(({ tokens: { description } }) => description.trim())
        .filter((description) => description !== '')
        .join(' ');
}
const lineNo = (num, { tokens }, i) => tokens.type === '' ? num : i;
const getDescription = ({ tokens }) => (tokens.delimiter === '' ? tokens.start : tokens.postDelimiter.slice(1)) +
    tokens.description;
function preserveJoiner(lines) {
    if (lines.length === 0)
        return '';
    // skip the opening line with no description
    if (lines[0].tokens.description === '' &&
        lines[0].tokens.delimiter === Markers.start)
        lines = lines.slice(1);
    // skip the closing line with no description
    const lastLine = lines[lines.length - 1];
    if (lastLine !== undefined &&
        lastLine.tokens.description === '' &&
        lastLine.tokens.end.endsWith(Markers.end))
        lines = lines.slice(0, -1);
    // description starts at the last line of type definition
    lines = lines.slice(lines.reduce(lineNo, 0));
    return lines.map(getDescription).join('\n');
}