biblioteca-nacional.js

const downloadURI = (uri, name) => {
  const link = document.createElement("a");
  link.download = name;
  link.href = uri;
  document.body.appendChild(link);
  link.click();
  document.body.removeChild(link);
}

const downloaded = new Set()

function downloadAndLoadNext() {
  const title = document.getElementById('PastaTxt')
    .innerText
    .replaceAll('\\', '-')
    .replaceAll(' ', '-')

  const [currentMatch, lastMatch] = document.getElementById('OcorNroLbl')
    .innerText
    .split('/')
    .map(Number);

  const currentUrl = document.getElementById('DocumentoImg').src
  const nextPage = document.getElementById('OcorPosBtn')

  if (!downloaded.has(currentUrl)) {
    downloaded.add(currentUrl)

    const currentPage = document.getElementById('PagAtualTxt').value
    downloadURI(currentUrl, `${title}-Página-${currentPage}.jpg`)
  }

  if (currentMatch === lastMatch) {
    alert('Terminou!')
  } else {
    nextPage.click()

    function waitUntilLoaded() {
      const newUrl = document.getElementById('DocumentoImg').src

      if (newUrl === currentUrl) {
        setTimeout(waitUntilLoaded, 0)
      } else {
        setTimeout(downloadAndLoadNext, 0)
      }
    }

    waitUntilLoaded()
  }
}

downloadAndLoadNext()