chore: created a utility function for creating platform URLs

Includes some additional constants needed for future work. Don't forget
to remove the `FIXME` stuff!

src/data/constants.js

@@ -10,3 +10,12 @@ export const SPLIT_TRACKING_EVENTS = {
 
 export const SDK_BASE_URL =
   'https://d1zobbh8kytrtv.cloudfront.net/platform/doc-app';
+
+// FIXME: update this to production URL when deployed / launched
+export const NR1_LOGIN_URL = 'https://staging-login.newrelic.com/login';
+
+// FIXME: update this to production URL when deployed / launched
+export const NR1_BASE_URL = 'https://dev-one.newrelic.com';
+
+export const NR1_PACK_DETAILS_NERDLET =
+  'catalog-pack-details.catalog-pack-details';

src/utils/get-pack-nr1-url.js

@@ -0,0 +1,30 @@
+import { NR1_BASE_URL, NR1_PACK_DETAILS_NERDLET } from '../data/constants';
+
+const NERDLET_PATH = `nerdlet/${NR1_PACK_DETAILS_NERDLET}`;
+
+/**
+ * @param {string} packId The ID for an observability pack.
+ * @param {boolean} [debug] If set to true, this will add `packages=local`.
+ * @returns {string} The URL for the pack details within the platform.
+ */
+const getPackNr1Url = (packId, debug = false) => {
+  const pane = JSON.stringify({
+    nerdletId: NR1_PACK_DETAILS_NERDLET,
+    packId,
+  });
+
+  // Note: this works differently depending on whether or not we have access
+  // to the window object (and the btoa function).
+  const hash =
+    window && window.btoa
+      ? btoa(pane)
+      : Buffer.from(pane, 'utf-8').toString('base64');
+
+  const local = debug ? 'packages=local&' : '';
+
+  const url = new URL(`${NERDLET_PATH}?${local}pane=${hash}`, NR1_BASE_URL);
+
+  return url.href;
+};
+
+export default getPackNr1Url;