import { useEffect, useState, useRef, useCallback } from "react";import { codeToHtml, resolveLang } from "../lib/shiki";import { cn } from "../lib/utils";import { IconCopy, IconCheck } from "./icons"; // Lazily loaded, cached across rendersconst highlightCache = new Map<string, string>(); function cacheKey(code: string, lang: string) { return `${lang}::${code.length}::${code.slice(0, 64)}`;} function detectLanguage(code: string, hint?: string): string { if (hint) return resolveLang(hint) ?? "json"; const trimmed = code.trimStart(); if (trimmed.startsWith("{") || trimmed.startsWith("[")) return "json"; if (trimmed.startsWith("<")) return "xml"; if (trimmed.startsWith("---")) return "yaml"; return "json";} export function CodeBlock(props: { code: string; lang?: string; className?: string;}) { const { code, lang: langHint, className } = props; const [html, setHtml] = useState<string | null>(null); const [copied, setCopied] = useState(false); const mountedRef = useRef(true); const language = detectLanguage(code, langHint); const key = cacheKey(code, language); useEffect(() => { mountedRef.current = true; return () => { mountedRef.current = false; }; }, []); useEffect(() => { const cached = highlightCache.get(key); if (cached) { setHtml(cached); return; } let cancelled = false; codeToHtml(code, { lang: language }).then((result) => { if (cancelled) return; highlightCache.set(key, result); if (mountedRef.current) setHtml(result); }); return () => { cancelled = true; }; }, [code, key, language]); const handleCopy = useCallback(() => { void navigator.clipboard.writeText(code).then(() => { setCopied(true); setTimeout(() => setCopied(false), 1500); }); }, [code]); return ( <div className={cn("group relative overflow-auto", className)}> {/* Copy button */} <button type="button" onClick={handleCopy} className="absolute right-2 top-2 z-10 rounded-md border border-border bg-card/90 p-1.5 text-muted-foreground/40 opacity-0 backdrop-blur-sm transition-all hover:text-foreground group-hover:opacity-100" title="Copy to clipboard" > {copied ? <IconCheck className="size-3" /> : <IconCopy className="size-3" />} </button> {html ? ( <div className="shiki-container text-[12px] leading-relaxed [&_pre]:!bg-transparent [&_pre]:p-3 [&_code]:font-mono" dangerouslySetInnerHTML={{ __html: html }} /> ) : ( // Fallback while shiki loads <pre className="p-3 font-mono text-[12px] leading-relaxed text-foreground/60"> {code} </pre> )} </div> );}
import { useEffect, useState, useRef, useCallback } from "react";
import { codeToHtml, resolveLang } from "../lib/shiki";
import { cn } from "../lib/utils";
import { IconCopy, IconCheck } from "./icons";
// Lazily loaded, cached across renders
const highlightCache = new Map<string, string>();
function cacheKey(code: string, lang: string) {
return `${lang}::${code.length}::${code.slice(0, 64)}`;
}
function detectLanguage(code: string, hint?: string): string {
if (hint) return resolveLang(hint) ?? "json";
const trimmed = code.trimStart();
if (trimmed.startsWith("{") || trimmed.startsWith("[")) return "json";
if (trimmed.startsWith("<")) return "xml";
if (trimmed.startsWith("---")) return "yaml";
return "json";
}
export function CodeBlock(props: {
code: string;
lang?: string;
className?: string;
}) {
const { code, lang: langHint, className } = props;
const [html, setHtml] = useState<string | null>(null);
const [copied, setCopied] = useState(false);
const mountedRef = useRef(true);
const language = detectLanguage(code, langHint);
const key = cacheKey(code, language);
useEffect(() => {
mountedRef.current = true;
return () => {
mountedRef.current = false;
};
}, []);
useEffect(() => {
const cached = highlightCache.get(key);
if (cached) {
setHtml(cached);
return;
}
let cancelled = false;
codeToHtml(code, { lang: language }).then((result) => {
if (cancelled) return;
highlightCache.set(key, result);
if (mountedRef.current) setHtml(result);
});
return () => {
cancelled = true;
};
}, [code, key, language]);
const handleCopy = useCallback(() => {
void navigator.clipboard.writeText(code).then(() => {
setCopied(true);
setTimeout(() => setCopied(false), 1500);
});
}, [code]);
return (
<div className={cn("group relative overflow-auto", className)}>
{/* Copy button */}
<button
type="button"
onClick={handleCopy}
className="absolute right-2 top-2 z-10 rounded-md border border-border bg-card/90 p-1.5 text-muted-foreground/40 opacity-0 backdrop-blur-sm transition-all hover:text-foreground group-hover:opacity-100"
title="Copy to clipboard"
>
{copied ? <IconCheck className="size-3" /> : <IconCopy className="size-3" />}
</button>
{html ? (
<div
className="shiki-container text-[12px] leading-relaxed [&_pre]:!bg-transparent [&_pre]:p-3 [&_code]:font-mono"
dangerouslySetInnerHTML={{ __html: html }}
/>
) : (
// Fallback while shiki loads
<pre className="p-3 font-mono text-[12px] leading-relaxed text-foreground/60">
{code}
</pre>
)}
</div>
);
}