refactor(services, types): reorganize GraphQL fetchers and data types

The Typescript mapped types was useful for autocompletion in fetchers
but their are harder to maintain. I think it's better to keep each
query close to its fetcher to have a better understanding of the
fetched data. So I:
* colocate queries with their own fetcher
* colocate mutations with their own mutator
* remove Typescript mapped types for queries and mutations
* move data convertors inside graphql services
* rename most of data types and fetchers

1 files changed, 43 insertions, 0 deletions

diff --git a/src/services/graphql/fetchers/posts/fetch-posts-count.ts b/src/services/graphql/fetchers/posts/fetch-posts-count.ts
new file mode 100644
index 0000000..a72af52
--- /dev/null
+++ b/src/services/graphql/fetchers/posts/fetch-posts-count.ts
@@ -0,0 +1,43 @@
+import type {
+  GraphQLPageInfo,
+  GraphQLPostWhere,
+  Nullable,
+} from '../../../../types';
+import { fetchGraphQL, getGraphQLUrl } from '../../../../utils/helpers';
+
+type PostsCountResponse = {
+  posts: Nullable<{
+    pageInfo: Pick<GraphQLPageInfo, 'total'>;
+  }>;
+};
+
+const postsCountQuery = `query PostsCount($authorName: String, $search: String, $title: String) {
+  posts(where: {authorName: $authorName, search: $search, title: $title}) {
+    pageInfo {
+      total
+    }
+  }
+}`;
+
+/**
+ * Retrieve the total of WordPress posts.
+ *
+ * @param {GraphQLPostWhere} [input] - The input to filter the posts.
+ * @returns {Promise<number>} The total number of posts.
+ */
+export const fetchPostsCount = async (
+  input?: GraphQLPostWhere
+): Promise<number> => {
+  const response = await fetchGraphQL<PostsCountResponse>({
+    query: postsCountQuery,
+    url: getGraphQLUrl(),
+    variables: { ...input },
+  });
+
+  if (!response.posts)
+    return Promise.reject(
+      new Error('Unable to find the total number of posts.')
+    );
+
+  return response.posts.pageInfo.total;
+};