/**
* Markdown parsing utilities using micromark via mdast
* Provides robust markdown tokenization for PDF rendering
*/
import { fromMarkdown } from 'mdast-util-from-markdown';
import type { Node } from 'unist';
import { visit } from 'unist-util-visit';
/**
* Token types for styled text segments
*/
export type Token = { type: 'text'; text: string } | { type: 'bold'; text: string } | { type: 'italic'; text: string } | { type: 'boldItalic'; text: string } | { type: 'link'; text: string; url: string };
/**
* Tokenize markdown text into styled tokens using micromark
*
* Supports:
* - **bold** or __bold__
* - *italic* or _italic_
* - ***bold+italic*** or ___bold+italic___
* - [link text](url)
*
* @param markdown - Text with markdown syntax
* @returns Array of tokens
*/
export function tokenizeMarkdown(markdown: string): Token[] {
const tree = fromMarkdown(markdown);
const tokens: Token[] = [];
// Helper to extract text recursively from node
const extractText = (node: Node): string => {
if ('value' in node && typeof node.value === 'string') {
return node.value;
}
if ('children' in node && Array.isArray(node.children)) {
return node.children.map(extractText).join('');
}
return '';
};
visit(tree, (node: Node, _index, parent: Node | undefined) => {
// Skip text nodes that are children of styled nodes (link, strong, emphasis)
if (node.type === 'text') {
// Only add text if parent is not a styled node
if (parent?.type !== 'link' && parent?.type !== 'strong' && parent?.type !== 'emphasis') {
if ('value' in node && typeof node.value === 'string') {
tokens.push({ type: 'text', text: node.value });
}
}
return;
}
// link
if (node.type === 'link') {
const text = extractText(node);
const url = 'url' in node && typeof node.url === 'string' ? node.url : '';
tokens.push({ type: 'link', text, url });
return;
}
// bold / italic / bold+italic
if (node.type === 'strong' || node.type === 'emphasis') {
// Skip if parent is also a styled node (we want the outermost one)
if (parent?.type === 'strong' || parent?.type === 'emphasis') {
return;
}
const text = extractText(node);
const children = 'children' in node && Array.isArray(node.children) ? node.children : [];
const hasStrong = children.some((c) => c.type === 'strong');
const hasEm = children.some((c) => c.type === 'emphasis');
tokens.push({
type: (node.type === 'strong' && hasEm) || (node.type === 'emphasis' && hasStrong) ? 'boldItalic' : node.type === 'strong' ? 'bold' : 'italic',
text,
});
}
});
return tokens;
}
/**
* Styled segment for PDF rendering
*/
export interface StyledSegment {
type: 'text' | 'link';
content: string;
bold: boolean;
italic: boolean;
url?: string;
}
/**
* Convert markdown tokens to styled segments for PDF rendering
*
* @param tokens - Markdown tokens from tokenizeMarkdown
* @returns Array of segments with styling information
*/
export function tokensToStyledSegments(tokens: Token[]): StyledSegment[] {
return tokens.map((token) => {
const segment: StyledSegment = {
type: token.type === 'link' ? 'link' : 'text',
content: token.text,
bold: token.type === 'bold' || token.type === 'boldItalic',
italic: token.type === 'italic' || token.type === 'boldItalic',
url: token.type === 'link' ? token.url : undefined,
};
return segment;
});
}
