chore: display comments as a tree

I was displaying comments without the parent/children link. Now, each
child is displayed under its parent. I also remove the reply button for
children to avoid too many child depth.

5 files changed, 51 insertions, 9 deletions

diff --git a/src/components/Comment/Comment.module.scss b/src/components/Comment/Comment.module.scss
index 8f17bfa..46c0249 100644
--- a/src/components/Comment/Comment.module.scss
+++ b/src/components/Comment/Comment.module.scss
@@ -44,6 +44,10 @@
   position: relative;
 }
 
+.author {
+  text-align: center;
+}
+
 .date {
   color: var(--color-fg-secondary);
   font-size: var(--font-size-sm);
diff --git a/src/components/Comment/Comment.tsx b/src/components/Comment/Comment.tsx
index ad6875c..7214abe 100644
--- a/src/components/Comment/Comment.tsx
+++ b/src/components/Comment/Comment.tsx
@@ -6,16 +6,22 @@ import Link from 'next/link';
 import { useRouter } from 'next/router';
 import styles from './Comment.module.scss';
 
-const Comment = ({ comment }: { comment: CommentData }) => {
+const Comment = ({
+  comment,
+  isNested = false,
+}: {
+  comment: CommentData;
+  isNested?: boolean;
+}) => {
   const router = useRouter();
 
   const getCommentAuthor = () => {
     return comment.author.url ? (
       <Link href={comment.author.url}>
-        <a>{comment.author.name}</a>
+        <a className={styles.author}>{comment.author.name}</a>
       </Link>
     ) : (
-      <span>{comment.author.name}</span>
+      <span className={styles.author}>{comment.author.name}</span>
     );
   };
 
@@ -59,14 +65,16 @@ const Comment = ({ comment }: { comment: CommentData }) => {
             className={styles.body}
             dangerouslySetInnerHTML={{ __html: comment.content }}
           ></div>
-          <footer className={styles.footer}>
-            <Button clickHandler={() => ''}>{t`Reply`}</Button>
-          </footer>
+          {!isNested && (
+            <footer className={styles.footer}>
+              <Button clickHandler={() => ''}>{t`Reply`}</Button>
+            </footer>
+          )}
         </article>
         {comment.replies.length > 0 && (
           <ol className={styles.list}>
             {comment.replies.map((reply) => {
-              return <Comment key={reply.id} comment={reply} />;
+              return <Comment key={reply.id} comment={reply} isNested={true} />;
             })}
           </ol>
         )}
diff --git a/src/services/graphql/queries.ts b/src/services/graphql/queries.ts
index a40446e..1cbb616 100644
--- a/src/services/graphql/queries.ts
+++ b/src/services/graphql/queries.ts
@@ -168,7 +168,7 @@ export const getPostBySlug = async (slug: string): Promise<Article> => {
           }
         }
         commentCount
-        comments {
+        comments(where: { order: ASC, orderby: COMMENT_DATE }) {
           nodes {
             approved
             author {
diff --git a/src/ts/types/comments.ts b/src/ts/types/comments.ts
index d5c0052..75e7d23 100644
--- a/src/ts/types/comments.ts
+++ b/src/ts/types/comments.ts
@@ -20,6 +20,7 @@ export type Comment = {
   date: string;
   id: string;
   parentDatabaseId: number;
+  parentId: string | null;
   replies: Comment[];
 };
 
diff --git a/src/utils/helpers/format.ts b/src/utils/helpers/format.ts
index fc7f1c2..81bae9c 100644
--- a/src/utils/helpers/format.ts
+++ b/src/utils/helpers/format.ts
@@ -158,6 +158,34 @@ export const getFormattedComments = (rawComments: RawComment[]): Comment[] => {
 };
 
 /**
+ * Create a comments tree with replies.
+ * @param comments - A flatten comments list.
+ * @returns An array of comments with replies.
+ */
+export const buildCommentsTree = (comments: Comment[]) => {
+  type CommentsHashTable = {
+    [key: string]: Comment;
+  };
+
+  const hashTable: CommentsHashTable = Object.create(null);
+  const commentsTree: Comment[] = [];
+
+  comments.forEach(
+    (comment) => (hashTable[comment.id] = { ...comment, replies: [] })
+  );
+
+  comments.forEach((comment) => {
+    if (!comment.parentId) {
+      commentsTree.push(hashTable[comment.id]);
+    } else {
+      hashTable[comment.parentId].replies.push(hashTable[comment.id]);
+    }
+  });
+
+  return commentsTree;
+};
+
+/**
  * Format an article from RawArticle to Article type.
  * @param rawPost - An article coming from WP GraphQL.
  * @returns A formatted article.
@@ -183,11 +211,12 @@ export const getFormattedPost = (rawPost: RawArticle): Article => {
   };
 
   const formattedComments = getFormattedComments(comments.nodes);
+  const commentsTree = buildCommentsTree(formattedComments);
 
   const formattedPost: Article = {
     author: author.node,
     commentCount,
-    comments: formattedComments,
+    comments: commentsTree,
     content: contentParts.afterMore,
     databaseId,
     dates,