random wiki article cloudflare worker

index.js

export default {
  async fetch(request) {
    // Define the topics and corresponding Wikipedia random URLs
    const topics = [
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Data_structures",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Algorithms",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Computer_science",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Cognitive_biases",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Mathematics",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Data_structures",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Algorithms",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Computer_science",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Cognitive_biases",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Mathematics",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Data_structures",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Algorithms",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Computer_science",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Cognitive_biases",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Mathematics",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Data_structures",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Algorithms",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Computer_science",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Cognitive_biases",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Mathematics",
      // -- i like these less but i want them
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Philosophy",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Engineering",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Linguistics",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Psychology",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Sociology",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/Astronomy",
      "https://en.wikipedia.org/wiki/Special:RandomInCategory/The_arts",
    ];

    // Function to get a random topic URL
    function getRandomTopicUrl() {
      const randomIndex = Math.floor(Math.random() * topics.length);
      const randomUrl = topics[randomIndex];
      console.log(`Selected random topic URL: ${randomUrl}`);
      return randomUrl;
    }

    // Function to check if the URL is a category page
    function isCategoryPage(url) {
      const isCategory = url.includes("/wiki/Category:");
      console.log(`Checking if URL is a category: ${url} -> ${isCategory}`);
      return isCategory;
    }

    // Follow redirects and resolve to an article or retry within a category
    async function resolveToArticle(url) {
      let currentUrl = url;
      while (true) {
        console.log(`Fetching URL: ${currentUrl}`);
        const response = await fetch(currentUrl, { redirect: "manual" });
        console.log(`Response status: ${response.status}`);

        if (response.status === 302) {
          currentUrl = response.headers.get("Location");
          console.log(`Redirected to: ${currentUrl}`);
          if (!currentUrl) {
            console.error("Redirect URL is missing, stopping resolution.");
            break;
          }
          if (!isCategoryPage(currentUrl)) {
            console.log(`Resolved to article: ${currentUrl}`);
            return currentUrl;
          } else {
            console.log(`Still in category, navigating deeper with Special:RandomInCategory.`);
            const categoryName = currentUrl.split("/wiki/Category:")[1];
            currentUrl = `https://en.wikipedia.org/wiki/Special:RandomInCategory/${categoryName}`;
          }
        } else if (response.status === 200) {
          console.log(`Loaded content successfully from: ${currentUrl}`);
          const html = await response.text();
          if (!html.includes("/wiki/Category:")) {
            console.log(`Resolved to article: ${currentUrl}`);
            return currentUrl;
          } else {
            console.log(`Still in category, extracting random link.`);
            const match = html.match(/href="(\/wiki\/[^:]+)"/);
            if (match) {
              currentUrl = "https://en.wikipedia.org" + match[1];
              console.log(`Navigating to extracted link: ${currentUrl}`);
            } else {
              console.error("No valid links found in category page, stopping resolution.");
              break;
            }
          }
        } else {
          console.error(`Failed to fetch URL: ${currentUrl} with status: ${response.status}`);
          break;
        }
      }
      console.log("Fallback to a truly random page: https://en.wikipedia.org/wiki/Special:Random");
      return "https://en.wikipedia.org/wiki/Special:Random"; // Fallback to a truly random page
    }

    // Get a random topic URL and resolve it
    const randomUrl = getRandomTopicUrl();
    console.log(`Starting resolution for random URL: ${randomUrl}`);
    const resolvedUrl = await resolveToArticle(randomUrl);
    console.log(`Final resolved URL: ${resolvedUrl}`);
    console.log("--------------------------------------")
    return Response.redirect(resolvedUrl, 302);
  }
};