From c8984f9515b155d4ae1aa3672980ffc76bdbda84 Mon Sep 17 00:00:00 2001
From: nikit <nchizhikov@myseneca.ca>
Date: Mon, 6 Jul 2026 20:01:07 -0400
Subject: [PATCH] perf(expenses,study): add skip/limit pagination to list
 endpoints

Both routes hard-capped results at 200 with no way to page past that,
so users with more than 200 expenses or study sessions could never
see older entries. Accept optional limit (clamped 1-200, default 200
to preserve prior behavior) and skip query params, and return total
count alongside the page so callers can tell if more data exists.

Fixes #13
---
 src/app/api/expenses/route.ts       | 9 +++++++--
 src/app/api/study/sessions/route.ts | 9 +++++++--
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/app/api/expenses/route.ts b/src/app/api/expenses/route.ts
index a032679..31f00f5 100644
--- a/src/app/api/expenses/route.ts
+++ b/src/app/api/expenses/route.ts
@@ -17,6 +17,8 @@ export async function GET(req: NextRequest) {
   const { searchParams } = new URL(req.url);
   const from = searchParams.get("from");
   const to = searchParams.get("to");
+  const limit = Math.min(Math.max(Number(searchParams.get("limit")) || 200, 1), 200);
+  const skip = Math.max(Number(searchParams.get("skip")) || 0, 0);
 
   const filter: Record<string, unknown> = { userId };
   if (from || to) {
@@ -37,9 +39,12 @@ export async function GET(req: NextRequest) {
     }
   }
 
-  const expenses = await Expense.find(filter).sort({ date: -1 }).limit(200).lean();
+  const [expenses, total] = await Promise.all([
+    Expense.find(filter).sort({ date: -1 }).skip(skip).limit(limit).lean(),
+    Expense.countDocuments(filter),
+  ]);
 
-  return NextResponse.json({ expenses });
+  return NextResponse.json({ expenses, total, skip, limit });
 }
 
 export async function POST(req: NextRequest) {
diff --git a/src/app/api/study/sessions/route.ts b/src/app/api/study/sessions/route.ts
index 709ff8a..3ddd671 100644
--- a/src/app/api/study/sessions/route.ts
+++ b/src/app/api/study/sessions/route.ts
@@ -18,6 +18,8 @@ export async function GET(req: NextRequest) {
   const subject = searchParams.get("subject");
   const from = searchParams.get("from");
   const to = searchParams.get("to");
+  const limit = Math.min(Math.max(Number(searchParams.get("limit")) || 200, 1), 200);
+  const skip = Math.max(Number(searchParams.get("skip")) || 0, 0);
 
   const filter: Record<string, unknown> = { userId };
   if (subject) filter.subject = String(subject);
@@ -27,9 +29,12 @@ export async function GET(req: NextRequest) {
     if (to) (filter.date as Record<string, Date>).$lte = new Date(to);
   }
 
-  const sessions = await StudySession.find(filter).sort({ date: -1 }).limit(200).lean();
+  const [sessions, total] = await Promise.all([
+    StudySession.find(filter).sort({ date: -1 }).skip(skip).limit(limit).lean(),
+    StudySession.countDocuments(filter),
+  ]);
 
-  return NextResponse.json({ sessions });
+  return NextResponse.json({ sessions, total, skip, limit });
 }
 
 export async function POST(req: NextRequest) {