background.js

chrome.runtime.onMessage.addListener((msg, _sender, sendResponse) => {
  if (msg.type !== 'BOOKMARK_IMAGE') return;

  const { src } = msg;

  try {
    chrome.storage.local.get(['bookmarks'], ({ bookmarks = [] }) => {
      if (chrome.runtime.lastError) {
        sendResponse({ status: 'error' });
        return;
      }

      if (bookmarks.some(b => b.src === src)) {
        sendResponse({ status: 'already' });
        return;
      }

      fetchAsBase64(src)
        .then(data => {
          bookmarks.push({ src, data, savedAt: Date.now() });
          chrome.storage.local.set({ bookmarks }, () => {
            if (chrome.runtime.lastError) {
              sendResponse({ status: 'error' });
              return;
            }
            sendResponse({ status: 'saved' });
          });
        })
        .catch(() => {
          sendResponse({ status: 'error' });
        });
    });
  } catch {
    sendResponse({ status: 'error' });
  }

  return true;
});

async function fetchAsBase64(url) {
  const response = await fetch(url);
  if (!response.ok) throw new Error(`HTTP ${response.status}`);
  const blob = await response.blob();
  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.onload  = () => resolve(reader.result);
    reader.onerror = () => reject(new Error('FileReader failed'));
    reader.readAsDataURL(blob);
  });
}