import { Marked } from 'marked';

const marked = new Marked({ breaks: true, gfm: true });

const CODE_OPEN = '';
const CODE_CLOSE = '';

export function processLatex(text: string): string {
	const placeholders: string[] = [];
	const stash = (match: string) => {
		const token = `${CODE_OPEN}${placeholders.length}${CODE_CLOSE}`;
		placeholders.push(match);
		return token;
	};

	const protectedText = text.replace(/```[\s\S]*?```/g, stash).replace(/`[^`\n]*`/g, stash);

	const rendered = protectedText
		.replace(/\$\$(.*?)\$\$/gs, (_, tex) => {
			const encoded = encodeURIComponent(tex.trim());
			return `<img src="/service/latex?tex=${encoded}&display=1" alt="LaTeX" class="block my-1 max-h-12" />`;
		})
		.replace(/\$(.+?)\$/g, (_, tex) => {
			const encoded = encodeURIComponent(tex.trim());
			return `<img src="/service/latex?tex=${encoded}" alt="LaTeX" class="inline-block align-middle max-h-4" />`;
		});

	return rendered.replace(
		new RegExp(`${CODE_OPEN}(\\d+)${CODE_CLOSE}`, 'g'),
		(_, i) => placeholders[Number(i)]
	);
}

export function processContent(text: string): string {
	return marked.parse(processLatex(text)) as string;
}