V2Wizard: Add checkRepositoriesAvailability

This adds checkRepositoriesAvailability.ts to a newly created `utilities` folder.

src/Components/CreateImageWizardV2/utilities/checkRepositoriesAvailability.ts

@@ -0,0 +1,74 @@
+import { useMemo } from 'react';
+
+import { useFormApi } from '@data-driven-forms/react-form-renderer';
+
+import { releaseToVersion } from './releaseToVersion';
+
+import { useListRepositoriesQuery } from '../store/contentSourcesApi';
+
+/**
+ * This checks the list of the payload repositories against a list of repos freshly
+ * fetched from content source API and returns true whether there are some
+ * repositories that are no longer available in the Repositories service.
+ *
+ * (The payload repositories are comming from the useFormApi hook).
+ */
+export const useCheckRepositoriesAvailability = () => {
+  const { getState } = useFormApi();
+
+  const arch = getState().values?.arch;
+  const release = getState().values?.release;
+  const version = releaseToVersion(release);
+
+  // There needs to be two requests because the default limit for the
+  // useListRepositoriesQuery is a 100 elements, and a first request is
+  // necessary to know the total amount of elements to fetch.
+  const firstRequest = useListRepositoriesQuery({
+    availableForArch: arch,
+    availableForVersion: version,
+    contentType: 'rpm',
+    origin: 'external',
+  });
+
+  const skip =
+    firstRequest?.data?.meta?.count === undefined ||
+    firstRequest?.data?.meta?.count <= 100;
+
+  // Fetch *all* repositories if there are more than 100
+  const followupRequest = useListRepositoriesQuery(
+    {
+      availableForArch: arch,
+      availableForVersion: version,
+      contentType: 'rpm',
+      origin: 'external',
+      limit: firstRequest?.data?.meta?.count,
+      offset: 0,
+    },
+    {
+      skip: skip,
+    }
+  );
+
+  const { data: freshRepos, isSuccess } = useMemo(() => {
+    if (firstRequest?.data?.meta?.count > 100) {
+      return { ...followupRequest };
+    }
+    return { ...firstRequest };
+  }, [firstRequest, followupRequest]);
+
+  const payloadRepositories = getState()?.values?.['payload-repositories'];
+  // payloadRepositories existing === we came here from Recreate
+  if (isSuccess && payloadRepositories) {
+    // Transform the fresh repos array into a Set to access its elements in O(1)
+    // complexity later in the for loop.
+    const freshReposUrls = new Set(
+      freshRepos.data.map((freshRepo) => freshRepo.url)
+    );
+    for (const payloadRepo of payloadRepositories) {
+      if (!freshReposUrls.has(payloadRepo.baseurl)) {
+        return true;
+      }
+    }
+  }
+  return false;
+};