fix(subject): stop showing BMAT102L for subjects without a course code

src/app/paper/[id]/page.tsx

@@ -2,7 +2,7 @@ import { fetchPaperID } from "@/app/actions/get-papers-by-id";
 import RelatedPapers from "@/components/RelatedPaper";
 import Loader from "@/components/ui/loader";
 import { type ErrorResponse, type PaperResponse } from "@/interface";
-import { extractBracketContent } from "@/lib/utils/string";
+import { courseCodeOrName } from "@/lib/utils/string";
 import axios, { type AxiosResponse } from "axios";
 import { type Metadata } from "next";
 import { redirect } from "next/navigation";
@@ -177,7 +177,7 @@ const PaperPage = async ({ params }: { params: { id: string } }) => {
 
             <PDFViewer
               url={paper.file_url}
-              name={`${extractBracketContent(paper.subject)}-${paper.exam}-${paper.slot}-${paper.year}`}/>
+              name={`${courseCodeOrName(paper.subject)}-${paper.exam}-${paper.slot}-${paper.year}`}/>
 
             {/* <PdfViewer
               url={paper.file_url}

src/lib/utils/download.ts

@@ -1,5 +1,5 @@
 import { type IPaper } from "../../interface";
-import { extractBracketContent } from "./string";
+import { courseCodeOrName } from "./string";
 import axios from "axios";
 import toast from "react-hot-toast";
 
@@ -8,7 +8,7 @@ export const getSecureUrl = (url: string): string =>
 
 export const generateFileName = (paper: IPaper): string => {
   const extension = paper.file_url.split(".").pop();
-  return `${extractBracketContent(paper.subject)}-${paper.exam}-${paper.slot}-${paper.year}.${extension}`;
+  return `${courseCodeOrName(paper.subject)}-${paper.exam}-${paper.slot}-${paper.year}.${extension}`;
 };
 
 export const downloadFile = async (

src/lib/utils/string.ts

@@ -16,9 +16,13 @@ export function toSentenceCase(input: string): string {
 export function extractBracketContent(subject: string): string | null {
   const regex = /\[(.*?)\]/;
   const match = regex.exec(subject);
-  return match?.[1] ?? "BMAT102L";
+  return match?.[1] ?? null;
 }
 
 export function extractWithoutBracketContent(subject: string): string {
   return subject.replace(/\s*\[.*?\]\s*/g, "").trim();
+}
+
+export function courseCodeOrName(subject: string): string {
+  return extractBracketContent(subject) ?? extractWithoutBracketContent(subject);
 }