// Markdown-Renderer fuer Chat-Messages.
// Kompakter Wrapper um marked + Custom Code-Block-Renderer.
// Wird aus Message.svelte (Phase 8) und ChatPanel (legacy) verwendet.

import { marked, type Tokens } from 'marked';

const renderer = new marked.Renderer();
renderer.code = function ({ text, lang }: Tokens.Code): string {
	const language = lang || '';
	const escapedCode = text
		.replace(/&/g, '&')
		.replace(/</g, '&lt;')
		.replace(/>/g, '&gt;');
	return `<div class="code-block-wrapper" data-lang="${language}"><pre><code class="language-${language}">${escapedCode}</code></pre></div>`;
};

marked.setOptions({ breaks: true, gfm: true, renderer });

/**
 * Erkennt "Denk-Bloecke" im Text und zeigt sie als kompakte Inline-Elemente.
 * Zwei Quellen:
 *   1. SDK Extended-Thinking (kommt als <div class="thinking-inline"> aus der Bridge)
 *   2. Text-basierte Patterns (Lass mich analysieren..., Ich schaue mir...)
 */
function collapseThinkingBlocks(text: string): string {
	if (text.includes('<div class="thinking-inline">')) return text;

	if (text.includes('<details class="thinking-block">')) {
		return text.replace(
			/<details class="thinking-block">.*?<div class="thinking-content">([\s\S]*?)<\/div><\/details>/g,
			(_m, content) => `<div class="thinking-inline"><span class="thinking-label">\u{1F4AD}</span><span class="thinking-text">${content}</span></div>`
		);
	}

	const thinkingPatterns = [
		/^((?:(?:Lass mich|Let me|Ich (?:schaue|prüfe|analysiere|untersuche|überleg|werde)|OK,? (?:lass|ich)|Gut,? (?:lass|ich)|Hmm|Also,? |Zunächst|Zuerst|Schauen wir|Jetzt (?:schaue|prüfe|check)).*?\n(?:.*\n)*?))((?:\n(?:#{1,3} |(?:\*\*|Die |Das |Hier |Zusammen|Fertig|Erledigt|Done|✅|---)).*[\s\S]*))/m,
	];

	for (const pattern of thinkingPatterns) {
		const match = text.match(pattern);
		if (match && match[1] && match[1].split('\n').length > 5) {
			const thinkingPart = match[1].trim().replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
			const answerPart = match[2].trim();
			return `<div class="thinking-inline"><span class="thinking-label">\u{1F4AD}</span><span class="thinking-text">${thinkingPart}</span></div>\n\n${answerPart}`;
		}
	}
	return text;
}

export function renderMarkdown(text: string): string {
	try {
		return marked.parse(collapseThinkingBlocks(text)) as string;
	} catch {
		return text;
	}
}