// Extracts each PDF's text page by page, using macOS's built-in PDFKit.
// usage: osascript -l JavaScript rag/extract.js out.json a.pdf b.pdf ...
ObjC.import('Foundation');
ObjC.import('PDFKit');
function run(argv) {
  const out = argv[0];
  const pages = [];
  for (const path of argv.slice(1)) {
    const doc = $.PDFDocument.alloc.initWithURL($.NSURL.fileURLWithPath(path));
    if (!doc.js) throw new Error('Could not open ' + path);
    const book = path.split('/').pop();
    const n = doc.pageCount;
    for (let i = 0; i < n; i++) {
      const s = doc.pageAtIndex(i).string;
      pages.push({ book, page: i + 1, label: ObjC.unwrap(doc.pageAtIndex(i).label) || '', text: s.js ? ObjC.unwrap(s) : '' });
    }
  }
  $.NSString.alloc.initWithUTF8String(JSON.stringify(pages)).writeToFileAtomicallyEncodingError(out, true, $.NSUTF8StringEncoding, null);
  return pages.length + ' pages';
}