From 13cbe429cc487d93b47d446c41c3ef9707772fab Mon Sep 17 00:00:00 2001
From: Theodore Kruczek <theodore.kruczek@gmail.com>
Date: Sun, 14 Jan 2024 07:51:36 -0500
Subject: [PATCH] feat: add related blog posts component

---
 src/components/blog/RelatedPosts.astro | 28 ++++++++++++++++++++++
 src/config.yaml                        |  2 ++
 src/pages/[...blog]/index.astro        |  2 ++
 src/utils/blog.ts                      | 33 ++++++++++++++++++++++++++
 src/utils/config.ts                    |  2 ++
 5 files changed, 67 insertions(+)
 create mode 100644 src/components/blog/RelatedPosts.astro

diff --git a/src/components/blog/RelatedPosts.astro b/src/components/blog/RelatedPosts.astro
new file mode 100644
index 0000000..e193baf
--- /dev/null
+++ b/src/components/blog/RelatedPosts.astro
@@ -0,0 +1,28 @@
+---
+import { APP_BLOG } from "~/utils/config";
+
+import { fetchPosts, getRelatedPosts } from "~/utils/blog";
+import BlogHighlightedPosts from "../widgets/BlogHighlightedPosts.astro";
+import type { Post } from "~/types";
+import { getBlogPermalink } from "~/utils/permalinks";
+
+export interface Props {
+  post: Post;
+}
+
+const { post } = Astro.props;
+const fetchedPosts = await fetchPosts();
+const relatedPosts = post.tags ? getRelatedPosts(fetchedPosts, post.slug, post.tags) : [];
+---
+
+{
+  APP_BLOG.isRelatedPostsEnabled ? (
+    <BlogHighlightedPosts
+      classes={{ container: "pt-0 lg:pt-0 md:pt-0" }}
+      title="Related Posts"
+      linkText="View All Posts"
+      linkUrl={getBlogPermalink()}
+      postIds={relatedPosts.map((post) => post.id)}
+    />
+  ) : null
+}
diff --git a/src/config.yaml b/src/config.yaml
index 97f086c..e25340b 100644
--- a/src/config.yaml
+++ b/src/config.yaml
@@ -35,6 +35,8 @@ apps:
   blog:
     isEnabled: true
     postsPerPage: 6
+    isRelatedPostsEnabled: true
+    relatedPostsCount: 4
 
     post:
       isEnabled: true
diff --git a/src/pages/[...blog]/index.astro b/src/pages/[...blog]/index.astro
index 87ef541..ffeedcb 100644
--- a/src/pages/[...blog]/index.astro
+++ b/src/pages/[...blog]/index.astro
@@ -11,6 +11,7 @@ import { getCanonical, getPermalink } from '~/utils/permalinks';
 import { getStaticPathsBlogPost, blogPostRobots } from '~/utils/blog';
 import { findImage } from '~/utils/images';
 import type { MetaData } from '~/types';
+import RelatedPosts from '~/components/blog/RelatedPosts.astro';
 
 export const prerender = true;
 
@@ -45,4 +46,5 @@ const metadata = merge(
 <Layout metadata={metadata}>
   <SinglePost post={{ ...post, image: image }} url={url} />
   <ToBlogLink />
+  <RelatedPosts post={post} />
 </Layout>
diff --git a/src/utils/blog.ts b/src/utils/blog.ts
index 5bdd676..f0ef94f 100644
--- a/src/utils/blog.ts
+++ b/src/utils/blog.ts
@@ -90,6 +90,18 @@ const getNormalizedPost = async (post: CollectionEntry<'post'>): Promise<Post> =
   };
 };
 
+const getRandomizedPosts = (array: Post[], num: number) => {
+  const newArray: Post[] = [];
+
+  while (newArray.length < num && array.length > 0) {
+    const randomIndex = Math.floor(Math.random() * array.length);
+    newArray.push(array[randomIndex]);
+    array.splice(randomIndex, 1);
+  }
+
+  return newArray;
+};
+
 const load = async function (): Promise<Array<Post>> {
   const posts = await getCollection('post');
   const normalizedPosts = posts.map(async (post) => await getNormalizedPost(post));
@@ -105,6 +117,7 @@ let _posts: Array<Post>;
 
 /** */
 export const isBlogEnabled = APP_BLOG.isEnabled;
+export const isRelatedPostsEnabled = APP_BLOG.isRelatedPostsEnabled;
 export const isBlogListRouteEnabled = APP_BLOG.list.isEnabled;
 export const isBlogPostRouteEnabled = APP_BLOG.post.isEnabled;
 export const isBlogCategoryRouteEnabled = APP_BLOG.category.isEnabled;
@@ -225,3 +238,23 @@ export const getStaticPathsBlogTag = async ({ paginate }: { paginate: PaginateFu
     )
   );
 };
+
+/** */
+export function getRelatedPosts(allPosts: Post[], currentSlug: string, currentTags: string[]) {
+  if (!isBlogEnabled || !isRelatedPostsEnabled) return [];
+
+  const relatedPosts = getRandomizedPosts(
+    allPosts.filter((post) => post.slug !== currentSlug && post.tags?.some((tag) => currentTags.includes(tag))),
+    APP_BLOG.relatedPostsCount
+  );
+
+  if (relatedPosts.length < APP_BLOG.relatedPostsCount) {
+    const morePosts = getRandomizedPosts(
+      allPosts.filter((post) => post.slug !== currentSlug && !post.tags?.some((tag) => currentTags.includes(tag))),
+      APP_BLOG.relatedPostsCount - relatedPosts.length
+    );
+    relatedPosts.push(...morePosts);
+  }
+
+  return relatedPosts;
+}
diff --git a/src/utils/config.ts b/src/utils/config.ts
index bbeb7a2..6e2a2e7 100644
--- a/src/utils/config.ts
+++ b/src/utils/config.ts
@@ -25,6 +25,8 @@ export interface I18NConfig {
 export interface AppBlogConfig {
   isEnabled: boolean;
   postsPerPage: number;
+  isRelatedPostsEnabled: boolean;
+  relatedPostsCount: number;
   post: {
     isEnabled: boolean;
     permalink: string;