feat: Report tag

package.json

@@ -30,6 +30,7 @@
     "@types/node": "^24.6.1",
     "@ungap/with-resolvers": "^0.1.0",
     "@upstash/ratelimit": "^2.0.5",
+    "@upstash/redis": "^1.33.0",
     "@vercel/kv": "^3.0.0",
     "axios": "^1.8.4",
     "canvas": "^3.2.0",

src/app/api/report-tag/route.ts

@@ -0,0 +1,95 @@
+import { NextResponse } from "next/server";
+import { connectToDatabase } from "@/lib/database/mongoose";
+import TagReport from "@/db/tagReport";
+import { Ratelimit } from "@upstash/ratelimit";
+import { redis } from "@/lib/utils/redis";
+
+const ALLOWED_EXAMS = ["CAT-1", "CAT-2", "FAT"];
+const ALLOWED_FIELDS = ["subject", "courseCode", "exam", "slot", "year"];
+
+const ratelimit = new Ratelimit({
+  redis,
+  limiter: Ratelimit.slidingWindow(3, "1 h"),//per id - 3 request - per hour
+  analytics: true,
+});
+
+function getClientIp(req: any): string {
+  return req.ip || "127.0.0.1";
+}
+
+export async function POST(req: Request & { ip?: string }) {
+  try {
+    await connectToDatabase();
+
+    const body = await req.json();
+    const { paperId } = body;
+
+    if (!paperId) {
+      return NextResponse.json(
+        { error: "paperId is required" },
+        { status: 400 }
+      );
+    }
+    const ip = getClientIp(req);
+    const key = `${ip}::${paperId}`;
+    const { success } = await ratelimit.limit(key);
+
+    if (!success) {
+      return NextResponse.json(
+        { error: "Rate limit exceeded for reporting." },
+        { status: 429 }
+      );
+    }
+    const MAX_REPORTS_PER_PAPER = 5; 
+    const count = await TagReport.countDocuments({ paperId });
+
+    if (count >= MAX_REPORTS_PER_PAPER) {
+      return NextResponse.json(
+        { error: "Received many reports; we are currently working on it." },
+        { status: 429 }
+      );
+    }
+    const reportedFields = (body.reportedFields ?? [])
+      .map((r: any) => ({
+        field: String(r.field).trim(),
+        value: r.value?.trim(),
+      }))
+      .filter((r: any) => r.field);
+
+    for (const rf of reportedFields) {
+      if (!ALLOWED_FIELDS.includes(rf.field)) {
+        return NextResponse.json(
+          { error: `Invalid field: ${rf.field}` },
+          { status: 400 }
+        );
+      }
+      if (rf.field === "exam" && rf.value) {
+        if (!ALLOWED_EXAMS.includes(rf.value)) {
+          return NextResponse.json(
+            { error: `Invalid exam value: ${rf.value}` },
+            { status: 400 }
+          );
+        }
+      }
+    }
+
+    const newReport = await TagReport.create({
+      paperId,
+      reportedFields,
+      comment: body.comment,
+      reporterEmail: body.reporterEmail,
+      reporterId: body.reporterId,
+    });
+
+    return NextResponse.json(
+      { message: "Report submitted.", report: newReport },
+      { status: 201 }
+    );
+  } catch (err) {
+    console.error(err);
+    return NextResponse.json(
+      { error: "Failed to submit tag report." },
+      { status: 500 }
+    );
+  }
+}

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

@@ -167,6 +167,11 @@ const PaperPage = async ({ params }: { params: { id: string } }) => {
             <PdfViewer
               url={paper.file_url}
               name={`${extractBracketContent(paper.subject)}-${paper.exam}-${paper.slot}-${paper.year}`}
+              paperId={params.id}
+              subject={paper.subject}
+              exam={paper.exam}
+              slot={paper.slot}
+              year={paper.year}
             ></PdfViewer>
           </center>
           <RelatedPapers />

src/components/ReportButton.tsx

@@ -0,0 +1,39 @@
+"use client";
+
+import { useState } from "react";
+import { FaFlag } from "react-icons/fa6";
+import { Button } from "./ui/button";
+import ReportTagModal from "./ReportTagModal";
+
+export default function ReportButton({ 
+  paperId, subject, exam, slot, year 
+}: {
+  paperId: string;
+  subject?: string;
+  exam?: string;
+  slot?: string;
+  year?: string;
+}) {
+  const [open, setOpen] = useState(false);
+
+  return (
+    <>
+      <Button
+        onClick={() => setOpen(true)}
+        className="h-10 w-10 rounded p-0 text-white transition hover:bg-red-600 bg-red-500"
+      >
+        <FaFlag className="text-sm" />
+      </Button>
+
+      <ReportTagModal
+        paperId={paperId}
+        subject={subject}
+        exam={exam}
+        slot={slot}
+        year={year}
+        open={open}
+        setOpen={setOpen}
+      />
+    </>
+  );
+}