hermes-agent/web/src/components/Markdown.tsx

279 lines
8.7 KiB
TypeScript

import { useMemo } from "react";
/**
* Lightweight markdown renderer for LLM output.
* Handles: code blocks, inline code, bold, italic, headers, links, lists, horizontal rules.
* NOT a full CommonMark parser — optimized for typical assistant message patterns.
*/
export function Markdown({ content, highlightTerms }: { content: string; highlightTerms?: string[] }) {
const blocks = useMemo(() => parseBlocks(content), [content]);
return (
<div className="text-sm text-foreground leading-relaxed space-y-2">
{blocks.map((block, i) => (
<Block key={i} block={block} highlightTerms={highlightTerms} />
))}
</div>
);
}
/* ------------------------------------------------------------------ */
/* Types */
/* ------------------------------------------------------------------ */
type BlockNode =
| { type: "code"; lang: string; content: string }
| { type: "heading"; level: number; content: string }
| { type: "hr" }
| { type: "list"; ordered: boolean; items: string[] }
| { type: "paragraph"; content: string };
/* ------------------------------------------------------------------ */
/* Block parser */
/* ------------------------------------------------------------------ */
function parseBlocks(text: string): BlockNode[] {
const lines = text.split("\n");
const blocks: BlockNode[] = [];
let i = 0;
while (i < lines.length) {
const line = lines[i];
// Fenced code block
const fenceMatch = line.match(/^```(\w*)/);
if (fenceMatch) {
const lang = fenceMatch[1] || "";
const codeLines: string[] = [];
i++;
while (i < lines.length && !lines[i].startsWith("```")) {
codeLines.push(lines[i]);
i++;
}
i++; // skip closing ```
blocks.push({ type: "code", lang, content: codeLines.join("\n") });
continue;
}
// Heading
const headingMatch = line.match(/^(#{1,4})\s+(.+)/);
if (headingMatch) {
blocks.push({ type: "heading", level: headingMatch[1].length, content: headingMatch[2] });
i++;
continue;
}
// Horizontal rule
if (/^[-*_]{3,}\s*$/.test(line)) {
blocks.push({ type: "hr" });
i++;
continue;
}
// Unordered list
if (/^[-*+]\s/.test(line)) {
const items: string[] = [];
while (i < lines.length && /^[-*+]\s/.test(lines[i])) {
items.push(lines[i].replace(/^[-*+]\s/, ""));
i++;
}
blocks.push({ type: "list", ordered: false, items });
continue;
}
// Ordered list
if (/^\d+[.)]\s/.test(line)) {
const items: string[] = [];
while (i < lines.length && /^\d+[.)]\s/.test(lines[i])) {
items.push(lines[i].replace(/^\d+[.)]\s/, ""));
i++;
}
blocks.push({ type: "list", ordered: true, items });
continue;
}
// Empty line
if (line.trim() === "") {
i++;
continue;
}
// Paragraph — collect consecutive non-empty, non-special lines
const paraLines: string[] = [];
while (
i < lines.length &&
lines[i].trim() !== "" &&
!lines[i].match(/^```/) &&
!lines[i].match(/^#{1,4}\s/) &&
!lines[i].match(/^[-*+]\s/) &&
!lines[i].match(/^\d+[.)]\s/) &&
!lines[i].match(/^[-*_]{3,}\s*$/)
) {
paraLines.push(lines[i]);
i++;
}
if (paraLines.length > 0) {
blocks.push({ type: "paragraph", content: paraLines.join("\n") });
}
}
return blocks;
}
/* ------------------------------------------------------------------ */
/* Block renderer */
/* ------------------------------------------------------------------ */
function Block({ block, highlightTerms }: { block: BlockNode; highlightTerms?: string[] }) {
switch (block.type) {
case "code":
return (
<pre className="bg-secondary/60 border border-border px-3 py-2.5 text-xs font-mono leading-relaxed overflow-x-auto">
<code>{block.content}</code>
</pre>
);
case "heading": {
const Tag = `h${Math.min(block.level, 4)}` as "h1" | "h2" | "h3" | "h4";
const sizes: Record<string, string> = {
h1: "text-base font-bold",
h2: "text-sm font-bold",
h3: "text-sm font-semibold",
h4: "text-sm font-medium",
};
return <Tag className={sizes[Tag]}><InlineContent text={block.content} highlightTerms={highlightTerms} /></Tag>;
}
case "hr":
return <hr className="border-border" />;
case "list": {
const Tag = block.ordered ? "ol" : "ul";
return (
<Tag className={`space-y-0.5 ${block.ordered ? "list-decimal" : "list-disc"} pl-5 text-sm`}>
{block.items.map((item, i) => (
<li key={i}><InlineContent text={item} highlightTerms={highlightTerms} /></li>
))}
</Tag>
);
}
case "paragraph":
return <p><InlineContent text={block.content} highlightTerms={highlightTerms} /></p>;
}
}
/* ------------------------------------------------------------------ */
/* Inline parser + renderer */
/* ------------------------------------------------------------------ */
type InlineNode =
| { type: "text"; content: string }
| { type: "code"; content: string }
| { type: "bold"; content: string }
| { type: "italic"; content: string }
| { type: "link"; text: string; href: string }
| { type: "br" };
function parseInline(text: string): InlineNode[] {
const nodes: InlineNode[] = [];
// Pattern priority: code > link > bold > italic > bare URL > line break
const pattern = /(`[^`]+`)|(\[([^\]]+)\]\(([^)]+)\))|(\*\*([^*]+)\*\*)|(\*([^*]+)\*)|(\bhttps?:\/\/[^\s<>)\]]+)|(\n)/g;
let lastIndex = 0;
let match: RegExpExecArray | null;
while ((match = pattern.exec(text)) !== null) {
if (match.index > lastIndex) {
nodes.push({ type: "text", content: text.slice(lastIndex, match.index) });
}
if (match[1]) {
// Inline code
nodes.push({ type: "code", content: match[1].slice(1, -1) });
} else if (match[2]) {
// [text](url) link
nodes.push({ type: "link", text: match[3], href: match[4] });
} else if (match[5]) {
// **bold**
nodes.push({ type: "bold", content: match[6] });
} else if (match[7]) {
// *italic*
nodes.push({ type: "italic", content: match[8] });
} else if (match[9]) {
// Bare URL
nodes.push({ type: "link", text: match[9], href: match[9] });
} else if (match[10]) {
// Line break within paragraph
nodes.push({ type: "br" });
}
lastIndex = match.index + match[0].length;
}
if (lastIndex < text.length) {
nodes.push({ type: "text", content: text.slice(lastIndex) });
}
return nodes;
}
function InlineContent({ text, highlightTerms }: { text: string; highlightTerms?: string[] }) {
const nodes = useMemo(() => parseInline(text), [text]);
return (
<>
{nodes.map((node, i) => {
switch (node.type) {
case "text":
return <HighlightedText key={i} text={node.content} terms={highlightTerms} />;
case "code":
return (
<code key={i} className="bg-secondary/60 px-1.5 py-0.5 text-xs font-mono text-primary/90">
{node.content}
</code>
);
case "bold":
return <strong key={i} className="font-semibold"><HighlightedText text={node.content} terms={highlightTerms} /></strong>;
case "italic":
return <em key={i}><HighlightedText text={node.content} terms={highlightTerms} /></em>;
case "link":
return (
<a
key={i}
href={node.href}
target="_blank"
rel="noreferrer"
className="text-primary underline underline-offset-2 decoration-primary/30 hover:decoration-primary/60 transition-colors"
>
{node.text}
</a>
);
case "br":
return <br key={i} />;
}
})}
</>
);
}
/** Highlight search terms within a plain text string. */
function HighlightedText({ text, terms }: { text: string; terms?: string[] }) {
if (!terms || terms.length === 0) return <>{text}</>;
// Build a regex that matches any of the search terms (case-insensitive)
const escaped = terms.map((t) => t.replace(/[.*+?^${}()|[\]\\]/g, "\\$&"));
const regex = new RegExp(`(${escaped.join("|")})`, "gi");
const parts = text.split(regex);
return (
<>
{parts.map((part, i) =>
regex.test(part) ? (
<mark key={i} className="bg-warning/30 text-warning px-0.5">{part}</mark>
) : (
<span key={i}>{part}</span>
)
)}
</>
);
}