user-docs

import { resolveUrl } from "./http.js";

export interface RemoteImageCandidate {
  url: string;
  altText?: string;
  sourceId?: string;
  sourceKind?: string;
}

export function parseRemoteImageRefsFromChunk(
  chunkContent: string,
  metadata: Record<string, unknown> | undefined
): RemoteImageCandidate[] {
  const refs: RemoteImageCandidate[] = [];
  const seen = new Set<string>();
  const baseUrl = typeof metadata?.baseUrl === "string" ? metadata.baseUrl : undefined;
  const sourceId = typeof metadata?.documentPath === "string" ? metadata.documentPath : undefined;
  const sourceKind = typeof metadata?.sourceKind === "string" ? metadata.sourceKind : undefined;

  function add(url: string | null, altText?: string): void {
    if (!url || seen.has(url)) return;
    seen.add(url);
    refs.push({ url, altText, sourceId, sourceKind });
  }

  const markdownImage = /!\[([^\]]*)\]\((<([^>]+)>|[^)\s]+)(?:\s+"[^"]*")?\)/g;
  let md: RegExpExecArray | null;
  while ((md = markdownImage.exec(chunkContent)) !== null) {
    const raw = (md[3] ?? md[2]).replace(/^<|>$/g, "").trim();
    if (/^data:/i.test(raw)) continue;
    if (/^https?:\/\//i.test(raw)) add(raw, md[1]?.trim() || undefined);
    else if (baseUrl) add(resolveUrl(raw, baseUrl), md[1]?.trim() || undefined);
  }

  const htmlImage = /<img\b[^>]*>/gi;
  let img: RegExpExecArray | null;
  while ((img = htmlImage.exec(chunkContent)) !== null) {
    const tag = img[0];
    const src = attr(tag, "src");
    const alt = attr(tag, "alt") || undefined;
    if (src) add(/^https?:\/\//i.test(src) ? src : baseUrl ? resolveUrl(src, baseUrl) : null, alt);
  }

  return refs;
}

function attr(tag: string, name: string): string | null {
  const re = new RegExp(`${name}=["']([^"']+)["']`, "i");
  return re.exec(tag)?.[1] ?? null;
}