import type { MarkdownConfig } from '@lezer/markdown';
import { styleTags, tags } from '@lezer/highlight';

export const callout: MarkdownConfig = {
    defineNodes: [
      'CalloutBlock',
      'CalloutMarker',
      'CalloutMark', 
      'CalloutType',
      'CalloutTitle',
      'CalloutLine',
      'CalloutContent',
    ],
    parseBlock: [{
        name: 'Callout',
        before: 'Blockquote',
        parse(cx, line) {
            const match = /^>\s*\[!(\w+)\](?:\s+(.*))?/.exec(line.text);
            if (!match || !match[1]) return false; //No match
            
            const start = cx.lineStart, children = [];
            
            const quoteEnd = start + line.text.indexOf('[!');
            const typeStart = quoteEnd + 2;
            const typeEnd = typeStart + match[1].length;
            const bracketEnd = typeEnd + 1;
            
            children.push(cx.elt('CalloutMarker', start, bracketEnd, [ cx.elt('CalloutMark', start, quoteEnd), cx.elt('CalloutType', typeStart, typeEnd) ]));
            
            if(match[2]) children.push(cx.elt('CalloutTitle', bracketEnd + 1, start + line.text.length));
            
            while (cx.nextLine() && line.text.startsWith('>')) 
            {
                const pos = line.text.substring(1).search(/\S/) + 1;
                children.push(cx.elt('CalloutLine', cx.lineStart, cx.lineStart + line.text.length, [
                    cx.elt('CalloutMark', cx.lineStart, cx.lineStart + pos),
                    cx.elt('CalloutContent', cx.lineStart + pos, cx.lineStart + line.text.length),
                ]))
            }

            cx.addElement(cx.elt('CalloutBlock', start, cx.lineStart - 1, children));

            return true;
        }
    }],
    props: [
        styleTags({
            'CalloutBlock': tags.special(tags.quote),
            'CalloutMarker': tags.meta,
            'CalloutMark': tags.meta,
            'CalloutType': tags.keyword,
            'CalloutTitle': tags.heading,
            'CalloutLine': tags.content,
            'CalloutContent': tags.content,
        })
    ]
};