feat: add pagination in tag posts (#201)

* feat: add pagination in tag posts

Implement pagination in tag posts. Refactor and extract pagination logic and pagination component.

Closes: #152

* fix: update breadcrumbs for updated tag pagination

src/utils/getPagination.ts

@@ -0,0 +1,35 @@
+import { SITE } from "@config";
+import getPageNumbers from "./getPageNumbers";
+
+interface GetPaginationProps<T> {
+  posts: T;
+  page: string | number;
+  isIndex?: boolean;
+}
+
+const getPagination = <T>({
+  posts,
+  page,
+  isIndex = false,
+}: GetPaginationProps<T[]>) => {
+  const totalPagesArray = getPageNumbers(posts.length);
+  const totalPages = totalPagesArray.length;
+
+  const currentPage = isIndex
+    ? 1
+    : page && !isNaN(Number(page)) && totalPagesArray.includes(Number(page))
+      ? Number(page)
+      : 0;
+
+  const lastPost = isIndex ? SITE.postPerPage : currentPage * SITE.postPerPage;
+  const startPost = isIndex ? 0 : lastPost - SITE.postPerPage;
+  const paginatedPosts = posts.slice(startPost, lastPost);
+
+  return {
+    totalPages,
+    currentPage,
+    paginatedPosts,
+  };
+};
+
+export default getPagination;

src/utils/getPostsByTag.ts

@@ -1,7 +1,10 @@
-import { slugifyAll } from "./slugify";
 import type { CollectionEntry } from "astro:content";
+import getSortedPosts from "./getSortedPosts";
+import { slugifyAll } from "./slugify";
 
 const getPostsByTag = (posts: CollectionEntry<"blog">[], tag: string) =>
-  posts.filter(post => slugifyAll(post.data.tags).includes(tag));
+  getSortedPosts(
+    posts.filter(post => slugifyAll(post.data.tags).includes(tag))
+  );
 
 export default getPostsByTag;