vision.js

import config from './config.js';

const IMAGE_URL_RE =
  /(https?:\/\/\S+\.(?:png|jpe?g|gif|webp)(?:\?\S*)?)|(\/uploads\/attachments\/[^\s)]+\.(?:png|jpe?g|gif|webp)(?:\?\S*)?)/gi;

const FETCH_TIMEOUT_MS = 8_000;

export function extractImageUrls(text) {
  if (!text) return [];
  const matches = text.match(IMAGE_URL_RE) || [];
  return [...new Set(matches)].map((url) =>
    url.startsWith('/uploads/') ? `${config.apiUrl}${url}` : url,
  );
}

function mediaTypeFromUrl(url) {
  const lower = url.toLowerCase().split('?')[0];
  if (lower.endsWith('.png')) return 'image/png';
  if (lower.endsWith('.gif')) return 'image/gif';
  if (lower.endsWith('.webp')) return 'image/webp';
  return 'image/jpeg';
}

export async function fetchImageAsBlock(url) {
  try {
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), FETCH_TIMEOUT_MS);
    const res = await fetch(url, { signal: controller.signal });
    clearTimeout(timeout);

    if (!res.ok) return null;

    const buffer = await res.arrayBuffer();

    return {
      type: 'image',
      source: {
        type: 'base64',
        media_type: mediaTypeFromUrl(url),
        data: Buffer.from(buffer).toString('base64'),
      },
    };
  } catch {
    return null;
  }
}

export async function fetchImagesFromText(text, maxImages = 5) {
  const urls = extractImageUrls(text);
  if (!urls.length) return [];

  const blocks = await Promise.all(
    urls.slice(0, maxImages).map((u) => fetchImageAsBlock(u)),
  );
  return blocks.filter(Boolean);
}