holllo-org/source/ts/re-nav/share.ts

import {Base64} from "js-base64";

const fragmentPrefix = "#json=";

const exampleRedirect: Redirect = {
  matcherType: "hostname",
  matcherValue: "example.com",
  redirectType: "hostname",
  redirectValue: "example.org",
};

function decodeBase64<T>(base64: string): T {
  return JSON.parse(Base64.decode(base64)) as T;
}

function encodeBase64(source: any): string {
  return Base64.encode(JSON.stringify(source), true);
}

window.addEventListener("DOMContentLoaded", () => {
  window["Re-Nav"] = {
    decodeBase64,
    encodeBase64,
    share,
  };

  console.log(
    "Want to manually create a share link? Use the window['Re-Nav'].share",
    "function, where redirect is an object with matcherType, matcherValue,",
    "redirectType and redirectValue properties. Like this:",
  );
  console.log(JSON.stringify(exampleRedirect, undefined, 2));
  console.log(window["Re-Nav"].share);

  if (!location.hash.startsWith(fragmentPrefix)) {
    return;
  }

  const decoded = decodeBase64<Redirect>(
    location.hash.slice(fragmentPrefix.length),
  );
  for (const [key, value] of Object.entries(decoded)) {
    insertText(key as keyof Redirect, value);
  }

  for (const element of document.querySelectorAll(".hidden-by-default")) {
    element.classList.remove("hidden-by-default");
  }

  document.querySelector(".subtitle")!.textContent =
    "Someone shared a redirect with you!";
});

function insertText(key: keyof Redirect, value: string): void {
  const insert = (selector: string, text: string) => {
    document.querySelector(selector)!.textContent = text;
  };

  // eslint-disable-next-line unicorn/prefer-switch
  if (key === "matcherType") {
    insert(".matcher-type", value);
  } else if (key === "matcherValue") {
    insert(".matcher-value", value);
  } else if (key === "redirectType") {
    insert(".redirect-type", value);
  } else if (key === "redirectValue") {
    insert(".redirect-value", value);
  } else {
    console.warn(`Unknown key: ${key as string}`);
  }
}

function share(redirect: Redirect): string {
  const encoded = encodeBase64(redirect);
  const url = new URL(window.location.href);
  url.hash = `${fragmentPrefix}${encoded}`;
  return url.href;
}