async function startTranslation()

in src/contentScripts/index.ts [103:148]

• 25 lines of code
• 3 McCabe index (conditional complexity)

async function startTranslation(
  creds: TranslateClientConfig,
  source: string,
  target: string,
  startingEl: HTMLElement | null
): Promise<void> {
  if (startingEl) {
    // Crawl the DOM from the starting element and get the text pages and node map
    const { pageMap, nodeMap } = crawl(startingEl);

    const cachedTranslation = getCache(window.location.href, source, target);

    if (cachedTranslation) {
      // If the page has been translated previously and is cached, follow this logic tree
      applyCachedTranslation(pageMap, nodeMap, cachedTranslation);
    } else {
      // If the page has not been previously translated and cached, get new translation and apply it

      // Create translatable pages from the page map.
      const writtenPages = writePages(pageMap);

      // Bind the pages into documents (chunks) that can be sent to Amazon Translate
      const docs = bindPages(writtenPages);

      // Translate the documents
      const translated = await translateDocuments(creds, source, target, docs);

      // Break the translated documents back into pages
      const translatedPages = breakDocuments(translated);

      // Break the pages into tuples of the node ID and the translated text
      const translatedPageMap = breakPages(translatedPages);

      // Make a cache text map for the selected language pair
      const textMap = makeCacheTextMap(pageMap, translatedPageMap);

      // Cache the translated text map
      cacheTranslation(window.location.href, source, target, textMap);

      // Apply the translated documents to the DOM
      applyTranslation(nodeMap, translatedPages);
    }
  } else {
    throw new Error('Amazon Translate Error: The top level tag does not exist on the document.');
  }
}