From c97f95b80d39d058b970d41ecc31d58b22058564 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:10:36 +0530
Subject: [PATCH 01/56] fix: use ObjectId for teacherId reference

---
 models/Announcement.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Announcement.ts b/models/Announcement.ts
index cf5260c..433e93b 100644
--- a/models/Announcement.ts
+++ b/models/Announcement.ts
@@ -14,7 +14,7 @@ export interface IAnnouncement {
 
 const AnnouncementSchema = new Schema<IAnnouncement>(
   {
-    teacherId: { type: String, required: true, index: true },
+    teacherId: { type: Schema.Types.ObjectId, ref: 'Teacher', required: true, index: true },
     title: { type: String, required: true },
     content: { type: String, required: true },
     audience: { type: String, default: 'All' },

From a34e2a4dc8706b3ee43ba0478124937f079d992d Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:17:46 +0530
Subject: [PATCH 02/56] fix: restrict audience with enum values

---
 models/Announcement.ts | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/models/Announcement.ts b/models/Announcement.ts
index 433e93b..c6f6350 100644
--- a/models/Announcement.ts
+++ b/models/Announcement.ts
@@ -14,15 +14,24 @@ export interface IAnnouncement {
 
 const AnnouncementSchema = new Schema<IAnnouncement>(
   {
-    teacherId: { type: Schema.Types.ObjectId, ref: 'Teacher', required: true, index: true },
-    title: { type: String, required: true },
-    content: { type: String, required: true },
-    audience: { type: String, default: 'All' },
-    category: { type: String, enum: ['academic', 'events', 'admin', 'general'], default: 'general' },
+    teacherId: {
+      type: Schema.Types.ObjectId,
+      ref: "Teacher",
+      required: true,
+      index: true,
+    },
+    title: { type: String, required: true, trim: true, minlength: 3 },
+    content: { type: String, required: true, trim: true, minlength: 5 },
+    audience: { type: String, enum: ["All", "CS-A", "CS-B"], default: "All" },
+    category: {
+      type: String,
+      enum: ["academic", "events", "admin", "general"],
+      default: "general",
+    },
     pinned: { type: Boolean, default: false },
   },
-  { timestamps: true }
-)
+  { timestamps: true },
+);
 
 export const Announcement =
   models.Announcement ?? model<IAnnouncement>('Announcement', AnnouncementSchema)

From dd9f0903ab3239ca3d659daaff38f44dcfebfaf6 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:24:25 +0530
Subject: [PATCH 03/56] feat: add compound indexes for teacherId and pinned
 queries to improve performance

---
 models/Announcement.ts | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/models/Announcement.ts b/models/Announcement.ts
index c6f6350..94a0368 100644
--- a/models/Announcement.ts
+++ b/models/Announcement.ts
@@ -1,22 +1,21 @@
-import mongoose, { Schema, model, models } from 'mongoose'
+import mongoose, { Schema, model, models } from "mongoose";
 
 export interface IAnnouncement {
-  _id: mongoose.Types.ObjectId
-  teacherId: string
-  title: string
-  content: string
-  audience: string
-  category: 'academic' | 'events' | 'admin' | 'general'
-  pinned: boolean
-  createdAt: Date
-  updatedAt: Date
+  _id: mongoose.Types.ObjectId;
+  teacherId: string;
+  title: string;
+  content: string;
+  audience: string;
+  category: "academic" | "events" | "admin" | "general";
+  pinned: boolean;
+  createdAt: Date;
+  updatedAt: Date;
 }
 
 const AnnouncementSchema = new Schema<IAnnouncement>(
   {
     teacherId: {
-      type: Schema.Types.ObjectId,
-      ref: "Teacher",
+      type: String,
       required: true,
       index: true,
     },
@@ -33,5 +32,10 @@ const AnnouncementSchema = new Schema<IAnnouncement>(
   { timestamps: true },
 );
 
+AnnouncementSchema.index({ teacherId: 1, pinned: 1 });
+
+AnnouncementSchema.index({ teacherId: 1, createdAt: -1 });
+
 export const Announcement =
-  models.Announcement ?? model<IAnnouncement>('Announcement', AnnouncementSchema)
+  models.Announcement ??
+  model<IAnnouncement>("Announcement", AnnouncementSchema);
\ No newline at end of file

From d419ed86028f76d0f0f6f417088a9d3ad9b50b46 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:26:48 +0530
Subject: [PATCH 04/56] fix: replace teacherId string with ObjectId reference

---
 models/Assignment.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Assignment.ts b/models/Assignment.ts
index 874f1fc..8c25627 100644
--- a/models/Assignment.ts
+++ b/models/Assignment.ts
@@ -17,7 +17,7 @@ export interface IAssignment {
 
 const AssignmentSchema = new Schema<IAssignment>(
   {
-    teacherId: { type: String, required: true, index: true },
+    teacherId: { type: Schema.Types.ObjectId, ref: 'Teacher', required: true, index: true },
     title: { type: String, required: true },
     description: { type: String, default: '' },
     subject: { type: String, required: true },

From 93125d9b0601a6c7ba387789496da47d25350a42 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:29:21 +0530
Subject: [PATCH 05/56] fix: add validation for title, description, subject,
 and class fields

---
 models/Assignment.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/models/Assignment.ts b/models/Assignment.ts
index 8c25627..eba5f31 100644
--- a/models/Assignment.ts
+++ b/models/Assignment.ts
@@ -18,10 +18,10 @@ export interface IAssignment {
 const AssignmentSchema = new Schema<IAssignment>(
   {
     teacherId: { type: Schema.Types.ObjectId, ref: 'Teacher', required: true, index: true },
-    title: { type: String, required: true },
-    description: { type: String, default: '' },
-    subject: { type: String, required: true },
-    class: { type: String, required: true },
+    title: {type: String, required: true, trim: true, minlength: 3},
+    description: { type: String, default: '', maxlength: 1000 },
+    subject: {enum: ['Mathematics', 'Data Structures', 'Operating Systems', 'DBMS', 'Computer Networks']},
+    class: { enum: ['CS-A', 'CS-B'] },
     deadline: { type: Date, required: true },
     status: { type: String, enum: ['active', 'closed'], default: 'active' },
     kanbanStatus: { type: String, enum: ['todo', 'in_progress', 'submitted'], default: 'todo' },

From 07e9f161d1865e1c7b825bc2a4171f9f00d3a070 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:30:32 +0530
Subject: [PATCH 06/56] fix: enforce deadline to be in the future

---
 models/Assignment.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/models/Assignment.ts b/models/Assignment.ts
index eba5f31..0856064 100644
--- a/models/Assignment.ts
+++ b/models/Assignment.ts
@@ -22,7 +22,10 @@ const AssignmentSchema = new Schema<IAssignment>(
     description: { type: String, default: '', maxlength: 1000 },
     subject: {enum: ['Mathematics', 'Data Structures', 'Operating Systems', 'DBMS', 'Computer Networks']},
     class: { enum: ['CS-A', 'CS-B'] },
-    deadline: { type: Date, required: true },
+    deadline: { validate: {
+      validator: (value: Date) => value > new Date(),
+      message: 'Deadline must be in the future'
+    } },
     status: { type: String, enum: ['active', 'closed'], default: 'active' },
     kanbanStatus: { type: String, enum: ['todo', 'in_progress', 'submitted'], default: 'todo' },
     maxMarks: { type: Number, default: 100 },

From 89e8c8ddb08a5354db3885109b8fe165243616e7 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:31:52 +0530
Subject: [PATCH 07/56] fix: add constraints to maxMarks field

---
 models/Assignment.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Assignment.ts b/models/Assignment.ts
index 0856064..6be2a55 100644
--- a/models/Assignment.ts
+++ b/models/Assignment.ts
@@ -28,7 +28,7 @@ const AssignmentSchema = new Schema<IAssignment>(
     } },
     status: { type: String, enum: ['active', 'closed'], default: 'active' },
     kanbanStatus: { type: String, enum: ['todo', 'in_progress', 'submitted'], default: 'todo' },
-    maxMarks: { type: Number, default: 100 },
+    maxMarks: { type: Number, default: 100, min: 1, max: 1000 },
   },
   { timestamps: true }
 )

From 2f5d289365e221a1330d4e57a0e4600a0ef9dfd4 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:33:41 +0530
Subject: [PATCH 08/56] feat: add indexes for performance optimization

---
 models/Assignment.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/models/Assignment.ts b/models/Assignment.ts
index 6be2a55..f70689d 100644
--- a/models/Assignment.ts
+++ b/models/Assignment.ts
@@ -32,5 +32,7 @@ const AssignmentSchema = new Schema<IAssignment>(
   },
   { timestamps: true }
 )
-
+AssignmentSchema.index({ teacherId: 1, class: 1 });
+AssignmentSchema.index({ status: 1 });
+AssignmentSchema.index({ deadline: 1 });
 export const Assignment = models.Assignment ?? model<IAssignment>('Assignment', AssignmentSchema)

From ed4412849b6c6804b6106b792f63dd1c8fb2792a Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:34:44 +0530
Subject: [PATCH 09/56] fix: change attendance date type from string to Date

---
 models/Attendance.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Attendance.ts b/models/Attendance.ts
index 3f05fb1..defc556 100644
--- a/models/Attendance.ts
+++ b/models/Attendance.ts
@@ -18,7 +18,7 @@ const AttendanceSchema = new Schema<IAttendance>(
     studentId: { type: Schema.Types.ObjectId, ref: 'Student', required: true },
     studentName: { type: String, required: true },
     class: { type: String, required: true },
-    date: { type: String, required: true },
+    date: { type: Date, required: true },
     status: { type: String, enum: ['present', 'absent', 'late'], required: true },
   },
   { timestamps: true }

From d4fe8e17a38796e690977b6b19086c83afac9adc Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:35:52 +0530
Subject: [PATCH 10/56] fix: strengthen unique index with teacherId

---
 models/Attendance.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Attendance.ts b/models/Attendance.ts
index defc556..33fee9c 100644
--- a/models/Attendance.ts
+++ b/models/Attendance.ts
@@ -24,6 +24,6 @@ const AttendanceSchema = new Schema<IAttendance>(
   { timestamps: true }
 )
 
-AttendanceSchema.index({ studentId: 1, date: 1 }, { unique: true })
+AttendanceSchema.index( { teacherId: 1, studentId: 1, date: 1 }, { unique: true })
 
 export const Attendance = models.Attendance ?? model<IAttendance>('Attendance', AttendanceSchema)

From 9e9c61441ce8153be1a724316f16b0b107ed294e Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:36:39 +0530
Subject: [PATCH 11/56] fix: replace teacherId with ObjectId reference

---
 models/Attendance.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Attendance.ts b/models/Attendance.ts
index 33fee9c..a88cb67 100644
--- a/models/Attendance.ts
+++ b/models/Attendance.ts
@@ -14,7 +14,7 @@ export interface IAttendance {
 
 const AttendanceSchema = new Schema<IAttendance>(
   {
-    teacherId: { type: String, required: true, index: true },
+    teacherId: { type: Schema.Types.ObjectId, ref: 'Teacher', required: true, index: true },
     studentId: { type: Schema.Types.ObjectId, ref: 'Student', required: true },
     studentName: { type: String, required: true },
     class: { type: String, required: true },

From bababd37f502307515447def910577b32401b45a Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:39:03 +0530
Subject: [PATCH 12/56] fix: remove redundant studentName and class fields

---
 models/Attendance.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/models/Attendance.ts b/models/Attendance.ts
index a88cb67..20a09f4 100644
--- a/models/Attendance.ts
+++ b/models/Attendance.ts
@@ -16,8 +16,8 @@ const AttendanceSchema = new Schema<IAttendance>(
   {
     teacherId: { type: Schema.Types.ObjectId, ref: 'Teacher', required: true, index: true },
     studentId: { type: Schema.Types.ObjectId, ref: 'Student', required: true },
-    studentName: { type: String, required: true },
-    class: { type: String, required: true },
+    // revome the studentName because If student name changes → data becomes inconsistent
+    // remove because  Data inconsistency
     date: { type: Date, required: true },
     status: { type: String, enum: ['present', 'absent', 'late'], required: true },
   },

From dd0b2ec393a12de2f8aa70286cfef303523ddb0a Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:42:10 +0530
Subject: [PATCH 13/56] fix: improve attendance schema consistency and data
 integrity

---
 models/Attendance.ts | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/models/Attendance.ts b/models/Attendance.ts
index 20a09f4..177468a 100644
--- a/models/Attendance.ts
+++ b/models/Attendance.ts
@@ -24,6 +24,16 @@ const AttendanceSchema = new Schema<IAttendance>(
   { timestamps: true }
 )
 
-AttendanceSchema.index( { teacherId: 1, studentId: 1, date: 1 }, { unique: true })
+// existing uniqueness constraint
+AttendanceSchema.index({ studentId: 1, date: 1 }, { unique: true })
+
+// NEW: optimize teacher dashboard queries
+AttendanceSchema.index({ teacherId: 1, date: 1 })
+
+// NEW: optimize class-wise filtering
+AttendanceSchema.index({ teacherId: 1, class: 1 })
+
+// NEW: optimize status filtering (present/absent/late)
+AttendanceSchema.index({ teacherId: 1, status: 1 })
 
 export const Attendance = models.Attendance ?? model<IAttendance>('Attendance', AttendanceSchema)

From 91865869fe098ef0fd58faa8ce99b9a1c112f658 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:43:34 +0530
Subject: [PATCH 14/56] fix: replace teacherId with ObjectId reference

---
 models/Grade.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Grade.ts b/models/Grade.ts
index 311b757..fbbbdb4 100644
--- a/models/Grade.ts
+++ b/models/Grade.ts
@@ -16,7 +16,7 @@ export interface IGrade {
 
 const GradeSchema = new Schema<IGrade>(
   {
-    teacherId: { type: String, required: true, index: true },
+    teacherId: { type: Schema.Types.ObjectId, ref: "Teacher", required: true, index: true },
     studentId: { type: Schema.Types.ObjectId, ref: "Student", required: true },
     studentName: { type: String, required: true },
     subject: { type: String, required: true },

From eb1dace8e4e25ed5282ee9c206ee3c933f2b6e66 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:45:03 +0530
Subject: [PATCH 15/56]  fix: remove redundant studentName

---
 models/Grade.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Grade.ts b/models/Grade.ts
index fbbbdb4..ff704e0 100644
--- a/models/Grade.ts
+++ b/models/Grade.ts
@@ -18,7 +18,7 @@ const GradeSchema = new Schema<IGrade>(
   {
     teacherId: { type: Schema.Types.ObjectId, ref: "Teacher", required: true, index: true },
     studentId: { type: Schema.Types.ObjectId, ref: "Student", required: true },
-    studentName: { type: String, required: true },
+    // removes the studentName because can cause- data inconsistency
     subject: { type: String, required: true },
     marks: {
       type: Number,

From d12bc5e0a59d23e9f8cf32f710cf13ce0282870b Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:46:56 +0530
Subject: [PATCH 16/56] fix: add enum validation for subject and term fields

---
 models/Grade.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/models/Grade.ts b/models/Grade.ts
index ff704e0..6bb974f 100644
--- a/models/Grade.ts
+++ b/models/Grade.ts
@@ -19,7 +19,7 @@ const GradeSchema = new Schema<IGrade>(
     teacherId: { type: Schema.Types.ObjectId, ref: "Teacher", required: true, index: true },
     studentId: { type: Schema.Types.ObjectId, ref: "Student", required: true },
     // removes the studentName because can cause- data inconsistency
-    subject: { type: String, required: true },
+    subject: {enum: ['Mathematics', 'Data Structures', 'Operating Systems', 'DBMS', 'Computer Networks']},
     marks: {
       type: Number,
       required: true,
@@ -27,7 +27,7 @@ const GradeSchema = new Schema<IGrade>(
     },
     maxMarks: { type: Number, default: 100, min: 1 },
     grade: { type: String, default: "" },
-    term: { type: String, default: "Term 1" },
+    term: { enum: ["Term 1", "Term 2"] },
   },
   { timestamps: true },
 );

From 2c48ed08ec67c006045ce42a789455ef3ada7fbc Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:50:46 +0530
Subject: [PATCH 17/56] fix: define subject field type with enum validation

---
 models/Grade.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/models/Grade.ts b/models/Grade.ts
index 6bb974f..fecdf28 100644
--- a/models/Grade.ts
+++ b/models/Grade.ts
@@ -19,7 +19,9 @@ const GradeSchema = new Schema<IGrade>(
     teacherId: { type: Schema.Types.ObjectId, ref: "Teacher", required: true, index: true },
     studentId: { type: Schema.Types.ObjectId, ref: "Student", required: true },
     // removes the studentName because can cause- data inconsistency
-    subject: {enum: ['Mathematics', 'Data Structures', 'Operating Systems', 'DBMS', 'Computer Networks']},
+    subject: { type: String,
+      enum: ['Mathematics', 'Data Structures', 'Operating Systems', 'DBMS', 'Computer Networks'],
+      required: true,},
     marks: {
       type: Number,
       required: true,

From fcf5426553e178c74f596c180eae10122e5f21f0 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:51:18 +0530
Subject: [PATCH 18/56] fix: add type and default value for term field

---
 models/Grade.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/models/Grade.ts b/models/Grade.ts
index fecdf28..e679297 100644
--- a/models/Grade.ts
+++ b/models/Grade.ts
@@ -29,7 +29,9 @@ const GradeSchema = new Schema<IGrade>(
     },
     maxMarks: { type: Number, default: 100, min: 1 },
     grade: { type: String, default: "" },
-    term: { enum: ["Term 1", "Term 2"] },
+    term: {   type: String,
+      enum: ["Term 1", "Term 2"],
+      default: "Term 1", },
   },
   { timestamps: true },
 );

From 6e0aaba4447f2dbc5959a4809f9e92131ce7d25f Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:52:09 +0530
Subject: [PATCH 19/56] fix: restore studentName field to prevent data
 inconsistency issues

---
 models/Grade.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Grade.ts b/models/Grade.ts
index e679297..cb1cc5a 100644
--- a/models/Grade.ts
+++ b/models/Grade.ts
@@ -18,7 +18,7 @@ const GradeSchema = new Schema<IGrade>(
   {
     teacherId: { type: Schema.Types.ObjectId, ref: "Teacher", required: true, index: true },
     studentId: { type: Schema.Types.ObjectId, ref: "Student", required: true },
-    // removes the studentName because can cause- data inconsistency
+    studentName: { type: String, required: true },
     subject: { type: String,
       enum: ['Mathematics', 'Data Structures', 'Operating Systems', 'DBMS', 'Computer Networks'],
       required: true,},

From fef2da76358f70d0a51d262e33ad156d85f1fcaa Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:54:50 +0530
Subject: [PATCH 20/56] fix: add trimming to required student fields to ensure
 data consistency

---
 models/Student.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/models/Student.ts b/models/Student.ts
index 85ed899..35af2ea 100644
--- a/models/Student.ts
+++ b/models/Student.ts
@@ -18,9 +18,9 @@ export interface IStudent {
 const StudentSchema = new Schema<IStudent>(
   {
     teacherId: { type: String, required: true, index: true },
-    name: { type: String, required: true },
-    rollNo: { type: String, required: true },
-    class: { type: String, required: true },
+    name: { type: String, required: true, trim: true },
+    rollNo: { type: String, required: true, trim: true },
+    class: { type: String, required: true, trime: true },
     email: { type: String, default: '' },
     phone: { type: String, default: '' },
     address: { type: String, default: '' },

From 4d4e8dab32e2f4d408c91cb933f05e36e742abcd Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:55:18 +0530
Subject: [PATCH 21/56] fix: add email format validation to student schema

---
 models/Student.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/models/Student.ts b/models/Student.ts
index 35af2ea..5fb2cb9 100644
--- a/models/Student.ts
+++ b/models/Student.ts
@@ -21,7 +21,10 @@ const StudentSchema = new Schema<IStudent>(
     name: { type: String, required: true, trim: true },
     rollNo: { type: String, required: true, trim: true },
     class: { type: String, required: true, trime: true },
-    email: { type: String, default: '' },
+    email: {  type: String,
+      default: '',
+      trim: true,
+      match: [/^\S+@\S+\.\S+$/, 'Invalid email format'], },
     phone: { type: String, default: '' },
     address: { type: String, default: '' },
     parentName: { type: String, default: '' },

From ecb9abe1a5464e4d7b093e93a6ac316d465e1bdd Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:56:13 +0530
Subject: [PATCH 22/56] fix: normalize optional student fields by adding
 trimming

---
 models/Student.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/models/Student.ts b/models/Student.ts
index 5fb2cb9..e5171ca 100644
--- a/models/Student.ts
+++ b/models/Student.ts
@@ -25,10 +25,10 @@ const StudentSchema = new Schema<IStudent>(
       default: '',
       trim: true,
       match: [/^\S+@\S+\.\S+$/, 'Invalid email format'], },
-    phone: { type: String, default: '' },
-    address: { type: String, default: '' },
-    parentName: { type: String, default: '' },
-    parentPhone: { type: String, default: '' },
+    phone: { type: String, default: '', trim: true },
+    address: { type: String, default: '', trim: true },
+    parentName: { type: String, default: '', trim: true },
+    parentPhone: { type: String, default: '', trim: true },
   },
   { timestamps: true }
 )

From be7c74f3c449c057bb0e288a97c352fd6747548d Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:56:54 +0530
Subject: [PATCH 23/56] fix: normalize rollNo to uppercase to enforce
 uniqueness consistency

---
 models/Student.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Student.ts b/models/Student.ts
index e5171ca..f3253e9 100644
--- a/models/Student.ts
+++ b/models/Student.ts
@@ -19,7 +19,7 @@ const StudentSchema = new Schema<IStudent>(
   {
     teacherId: { type: String, required: true, index: true },
     name: { type: String, required: true, trim: true },
-    rollNo: { type: String, required: true, trim: true },
+    rollNo: { type: String, required: true, trim: true,  uppercase: true, },
     class: { type: String, required: true, trime: true },
     email: {  type: String,
       default: '',

From 56ad31bf6c4e202eb7197d57e656f99cd5047930 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:58:02 +0530
Subject: [PATCH 24/56] fix: add index for teacherId and class to optimize
 student queries

---
 models/Student.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Student.ts b/models/Student.ts
index f3253e9..e089081 100644
--- a/models/Student.ts
+++ b/models/Student.ts
@@ -33,6 +33,6 @@ const StudentSchema = new Schema<IStudent>(
   { timestamps: true }
 )
 
-StudentSchema.index({ teacherId: 1, rollNo: 1 }, { unique: true })
+StudentSchema.index({ teacherId: 1, class: 1 }, { unique: true });
 
 export const Student = models.Student ?? model<IStudent>('Student', StudentSchema)

From b5aa1a07d2ee62d0003f42e9f53e364aadecd88d Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 21:59:31 +0530
Subject: [PATCH 25/56] fix: enforce minimum length validation on required
 student fields

---
 models/Student.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/models/Student.ts b/models/Student.ts
index e089081..4c5f19e 100644
--- a/models/Student.ts
+++ b/models/Student.ts
@@ -17,10 +17,10 @@ export interface IStudent {
 
 const StudentSchema = new Schema<IStudent>(
   {
-    teacherId: { type: String, required: true, index: true },
-    name: { type: String, required: true, trim: true },
-    rollNo: { type: String, required: true, trim: true,  uppercase: true, },
-    class: { type: String, required: true, trime: true },
+    teacherId: { type: String, required: true, index: true, minlength: 1 },
+    name: { type: String, required: true, trim: true, minlength: 1 },
+    rollNo: { type: String, required: true, trim: true,  uppercase: true,minlength: 1 },
+    class: { type: String, required: true, trime: true,minlength: 1 },
     email: {  type: String,
       default: '',
       trim: true,

From f259b72bebdc639b8fb306df60fc36de44f9f793 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:00:55 +0530
Subject: [PATCH 26/56] fix: add trimming to teacher fields for data
 consistency

---
 models/Teacher.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/models/Teacher.ts b/models/Teacher.ts
index 837bbc8..3e21aa2 100644
--- a/models/Teacher.ts
+++ b/models/Teacher.ts
@@ -23,9 +23,9 @@ export interface ITeacher {
 const TeacherSchema = new Schema<ITeacher>(
   {
     clerkId: { type: String, required: true, unique: true },
-    name: { type: String, required: true },
-    email: { type: String, required: true },
-    department: { type: String, default: "" },
+    name: { type: String, required: true, trim: true },
+    email: { type: String, required: true, trim: true },
+    department: { type: String, default: "", trim: true },
     subjects: { type: [String], default: [] },
     phone: { type: String, default: "" },
     bio: { type: String, default: "" },

From 22dab3eb2d03c288b6713a11ba23846f43dc6fce Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:01:20 +0530
Subject: [PATCH 27/56] fix: add email format validation to teacher schema

---
 models/Teacher.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/models/Teacher.ts b/models/Teacher.ts
index 3e21aa2..a2351a2 100644
--- a/models/Teacher.ts
+++ b/models/Teacher.ts
@@ -24,7 +24,10 @@ const TeacherSchema = new Schema<ITeacher>(
   {
     clerkId: { type: String, required: true, unique: true },
     name: { type: String, required: true, trim: true },
-    email: { type: String, required: true, trim: true },
+    email: {  type: String,
+      required: true,
+      trim: true,
+      match: [/^\S+@\S+\.\S+$/, 'Invalid email format'], },
     department: { type: String, default: "", trim: true },
     subjects: { type: [String], default: [] },
     phone: { type: String, default: "" },

From 2f6f66de3f60b2bb535b5b277edd3699a99b6960 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:01:56 +0530
Subject: [PATCH 28/56] fix: validate subjects array to prevent empty or
 invalid values

---
 models/Teacher.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/models/Teacher.ts b/models/Teacher.ts
index a2351a2..fa5cfda 100644
--- a/models/Teacher.ts
+++ b/models/Teacher.ts
@@ -29,7 +29,12 @@ const TeacherSchema = new Schema<ITeacher>(
       trim: true,
       match: [/^\S+@\S+\.\S+$/, 'Invalid email format'], },
     department: { type: String, default: "", trim: true },
-    subjects: { type: [String], default: [] },
+    subjects: {  type: [String],
+      default: [],
+      validate: {
+        validator: (arr: string[]) => arr.every(s => typeof s === 'string' && s.trim().length > 0),
+        message: 'Subjects must be non-empty strings',
+      }, },
     phone: { type: String, default: "" },
     bio: { type: String, default: "" },
     academicHistory: {

From a9b06a0bba5f86099c9c803d556ad75b6bd4cc69 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:02:39 +0530
Subject: [PATCH 29/56] fix: add trimming to academicHistory fields

---
 models/Teacher.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/models/Teacher.ts b/models/Teacher.ts
index fa5cfda..7c39478 100644
--- a/models/Teacher.ts
+++ b/models/Teacher.ts
@@ -40,9 +40,9 @@ const TeacherSchema = new Schema<ITeacher>(
     academicHistory: {
       type: [
         {
-          year: { type: String, required: true },
-          title: { type: String, required: true },
-          description: { type: String },
+          year: { type: String, required: true, trim: true },
+          title: { type: String, required: true, trim: true },
+          description: { type: String, trim: true },
         },
       ],
       default: [],

From ac536766765a3caa34d7342880165ee30cd7aae1 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:03:35 +0530
Subject: [PATCH 30/56] fix: normalize optional teacher fields by adding
 trimming

---
 models/Teacher.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/models/Teacher.ts b/models/Teacher.ts
index 7c39478..c82d106 100644
--- a/models/Teacher.ts
+++ b/models/Teacher.ts
@@ -35,8 +35,8 @@ const TeacherSchema = new Schema<ITeacher>(
         validator: (arr: string[]) => arr.every(s => typeof s === 'string' && s.trim().length > 0),
         message: 'Subjects must be non-empty strings',
       }, },
-    phone: { type: String, default: "" },
-    bio: { type: String, default: "" },
+    phone: { type: String, default: "", trim: true },
+    bio: { type: String, default: "", trim: true },
     academicHistory: {
       type: [
         {

From 39fab09feff55ed2922e8754f2280f3119d0be88 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:04:07 +0530
Subject: [PATCH 31/56] fix: add indexes for department and subjects to improve
 query performance

---
 models/Teacher.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/models/Teacher.ts b/models/Teacher.ts
index c82d106..d7c64ef 100644
--- a/models/Teacher.ts
+++ b/models/Teacher.ts
@@ -51,4 +51,7 @@ const TeacherSchema = new Schema<ITeacher>(
   { timestamps: true },
 );
 
+TeacherSchema.index({ department: 1 });
+TeacherSchema.index({ subjects: 1 });
+
 export const Teacher = models.Teacher ?? model<ITeacher>('Teacher', TeacherSchema)

From 3601932f87ec1a713b09f153fdfb27e682f21385 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:08:10 +0530
Subject: [PATCH 32/56] fix: add missing await for findOneAndUpdate in grades
 POST endpoint

---
 app/api/grades/route.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index b9da63d..d37502d 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -73,7 +73,7 @@ export async function POST(req: NextRequest) {
     const max = data.maxMarks!
     const term = data.term ?? 'Term 1'
     
-    const grade = Grade.findOneAndUpdate(
+    const grade = await Grade.findOneAndUpdate(
       { teacherId: userId, studentId: data.studentId, subject: data.subject, term },
       { $set: { ...data, term, teacherId: userId, grade: calcGrade(data.marks, max) } },
       { upsert: true, new: true }

From e415ec138649b9724f5b0c9331ad4f275b40fc29 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:08:55 +0530
Subject: [PATCH 33/56] fix: provide default value for maxMarks to prevent
 runtime errors

---
 app/api/grades/route.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index d37502d..61b8c9f 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -70,7 +70,7 @@ export async function POST(req: NextRequest) {
     if (!parsed.success) return NextResponse.json({ error: parsed.error.flatten() }, { status: 400 })
 
     const data = parsed.data
-    const max = data.maxMarks!
+    const max = data.maxMarks ?? 100;
     const term = data.term ?? 'Term 1'
     
     const grade = await Grade.findOneAndUpdate(

From 7706a23a3218aab491375336384c930b3c2f192b Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:09:31 +0530
Subject: [PATCH 34/56] fix: correct grade calculation boundary for A+ grade

---
 app/api/grades/route.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index 61b8c9f..6d62e61 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -21,7 +21,7 @@ const GradeSchema = z.object({
 
 function calcGrade(marks: number, max: number): string {
   const pct = (marks / max) * 100
-  if (pct > 90) return 'A+'
+  if (pct >= 90) return 'A+'
   if (pct >= 80) return 'A'
   if (pct >= 70) return 'B+'
   if (pct >= 60) return 'B'

From 0eef839778bda9bf2ba03ab75947c434e3b04f6d Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:10:37 +0530
Subject: [PATCH 35/56] fix: validate studentId as a valid MongoDB ObjectId

---
 app/api/grades/route.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index 6d62e61..edab58a 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -5,7 +5,7 @@ import { Grade } from '@/models/Grade'
 import { z } from 'zod'
 
 const GradeSchema = z.object({
-  studentId: z.string().min(1),
+  studentId: z.string().regex(/^[0-9a-fA-F]{24}$/, 'Invalid studentId'),
   studentName: z.string().min(1),
   subject: z.string().min(1),
   marks: z.number().min(0),

From 9511c9a5e9de6b2189d7bf678248e0ad1d716776 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:12:29 +0530
Subject: [PATCH 36/56] fix: convert studentId to ObjectId in GET query for
 correct filtering

---
 app/api/grades/route.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index edab58a..601ae96 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -3,6 +3,7 @@ import { NextRequest, NextResponse } from 'next/server'
 import { connectDB } from '@/lib/mongodb'
 import { Grade } from '@/models/Grade'
 import { z } from 'zod'
+import mongoose from "mongoose";
 
 const GradeSchema = z.object({
   studentId: z.string().regex(/^[0-9a-fA-F]{24}$/, 'Invalid studentId'),
@@ -41,7 +42,9 @@ export async function GET(req: NextRequest) {
     const subject = searchParams.get('subject')
 
     const query: Record<string, unknown> = { teacherId: userId }
-    if (studentId) query.studentId = studentId
+    if (studentId && mongoose.Types.ObjectId.isValid(studentId)) {
+      query.studentId = new mongoose.Types.ObjectId(studentId);
+    }
     if (subject) query.subject = subject
 
     const grades = await Grade.find(query).sort({ createdAt: -1 }).lean()

From dab7aea230376a946481779d771dfa65b832f56e Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:14:38 +0530
Subject: [PATCH 37/56] fix: prevent exposure of internal error stack in API
 response

---
 app/api/grades/route.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index 601ae96..3b6232d 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -51,7 +51,7 @@ export async function GET(req: NextRequest) {
     return NextResponse.json(grades)
   } catch (error) {
     console.error('GET /api/grades error:', error instanceof Error ? error.message : error)
-    return NextResponse.json({ error: error instanceof Error ? error.stack : 'Internal server error' }, { status: 500 })
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
   }
 }
 
@@ -86,6 +86,6 @@ export async function POST(req: NextRequest) {
     if (error instanceof Error) {
       console.error('POST /api/grades error:', error.message)
     }
-    return NextResponse.json({ error: error instanceof Error ? error.stack : 'Internal server error' }, { status: 500 })
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
   }
 }

From cf32081132820cf0377de366ed03a43613ff26fd Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:15:49 +0530
Subject: [PATCH 38/56] fix: normalize input fields by trimming strings before
 database operation

---
 app/api/grades/route.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index 3b6232d..ab7b49c 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -72,7 +72,11 @@ export async function POST(req: NextRequest) {
     const parsed = GradeSchema.safeParse(body)
     if (!parsed.success) return NextResponse.json({ error: parsed.error.flatten() }, { status: 400 })
 
-    const data = parsed.data
+    const data = {
+      ...parsed.data,
+      studentName: parsed.data.studentName.trim(),
+      subject: parsed.data.subject.trim(),
+    };
     const max = data.maxMarks ?? 100;
     const term = data.term ?? 'Term 1'
     

From d0a8b6726a66dfa92f7e95798f6e62c9c26f67f3 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:22:47 +0530
Subject: [PATCH 39/56] fix: handle null currentUser to prevent creating
 invalid teacher records

---
 app/api/profile/route.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/app/api/profile/route.ts b/app/api/profile/route.ts
index a3d98bf..cd5654e 100644
--- a/app/api/profile/route.ts
+++ b/app/api/profile/route.ts
@@ -20,6 +20,9 @@ export async function GET(req: NextRequest) {
 
     if (!teacher) {
       const clerkUser = await currentUser()
+      if (!clerkUser) {
+        return NextResponse.json({ error: "User not found" }, { status: 404 });
+      }
       const created = await Teacher.create({
         clerkId: userId,
         name: clerkUser?.fullName ?? '',

From cf3581b4adc476869ee236761198e2d6d9df6a21 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:24:51 +0530
Subject: [PATCH 40/56] fix: strengthen input validation by trimming string
 fields

---
 app/api/profile/route.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/api/profile/route.ts b/app/api/profile/route.ts
index cd5654e..b9b09fc 100644
--- a/app/api/profile/route.ts
+++ b/app/api/profile/route.ts
@@ -63,7 +63,7 @@ export async function PUT(req: NextRequest) {
     if (department !== undefined && typeof department !== 'string') {
       return NextResponse.json({ error: 'department must be a string' }, { status: 400 })
     }
-    if (!Array.isArray(subjects) || !subjects.every((s) => typeof s === 'string')) {
+    if (!Array.isArray(subjects) || !subjects.every((s) => typeof s === 'string' && s.trim())) {
       return NextResponse.json({ error: 'subjects must be an array of strings' }, { status: 400 })
     }
     if (phone !== undefined && typeof phone !== 'string') {

From 20e910ef43e143d933b835343a60a66c5a9bbcf9 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:26:03 +0530
Subject: [PATCH 41/56] fix: validate subjects array to prevent empty or
 invalid values

---
 app/api/profile/route.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/app/api/profile/route.ts b/app/api/profile/route.ts
index b9b09fc..2c3f08c 100644
--- a/app/api/profile/route.ts
+++ b/app/api/profile/route.ts
@@ -63,7 +63,8 @@ export async function PUT(req: NextRequest) {
     if (department !== undefined && typeof department !== 'string') {
       return NextResponse.json({ error: 'department must be a string' }, { status: 400 })
     }
-    if (!Array.isArray(subjects) || !subjects.every((s) => typeof s === 'string' && s.trim())) {
+    if ( !Array.isArray(subjects) ||
+    !subjects.every(s => typeof s === 'string' && s.trim().length > 0)) {
       return NextResponse.json({ error: 'subjects must be an array of strings' }, { status: 400 })
     }
     if (phone !== undefined && typeof phone !== 'string') {

From fd57eab948c96fe896060262f0ecb4c8744bb550 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:26:41 +0530
Subject: [PATCH 42/56] fix: normalize input data before updating teacher
 profile

---
 app/api/profile/route.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/app/api/profile/route.ts b/app/api/profile/route.ts
index 2c3f08c..9bb88ed 100644
--- a/app/api/profile/route.ts
+++ b/app/api/profile/route.ts
@@ -92,7 +92,10 @@ export async function PUT(req: NextRequest) {
       }
     }
 
-    const updatePayload: Record<string, unknown> = { name, subjects }
+    const updatePayload: Record<string, unknown> = {
+      name: name.trim(),
+      subjects: subjects.map((s) => s.trim()),
+    };
     if (department !== undefined) updatePayload.department = department
     if (phone !== undefined) updatePayload.phone = phone
     if (bio !== undefined) updatePayload.bio = bio

From 78912f0903f6b653e23f9984574e8a6a74ff8747 Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:27:17 +0530
Subject: [PATCH 43/56] fix: enable schema validation in findOneAndUpdate
 operation

---
 app/api/profile/route.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/api/profile/route.ts b/app/api/profile/route.ts
index 9bb88ed..6e22809 100644
--- a/app/api/profile/route.ts
+++ b/app/api/profile/route.ts
@@ -104,8 +104,8 @@ export async function PUT(req: NextRequest) {
     const teacher = await Teacher.findOneAndUpdate(
       { clerkId: userId },
       { $set: updatePayload },
-      { new: true }
-    )
+      { new: true, runValidators: true },
+    );
     
     if (!teacher) {
       return NextResponse.json({ error: 'Teacher not found' }, { status: 404 })

From 4998e95ce1993bd79885575c3aca0644368ce6fd Mon Sep 17 00:00:00 2001
From: theniteshdev <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 22:30:23 +0530
Subject: [PATCH 44/56] fix: trim optional fields before updating teacher
 profile

---
 app/api/profile/route.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/app/api/profile/route.ts b/app/api/profile/route.ts
index 6e22809..d80be29 100644
--- a/app/api/profile/route.ts
+++ b/app/api/profile/route.ts
@@ -81,7 +81,7 @@ export async function PUT(req: NextRequest) {
           (entry: unknown) =>
             entry !== null &&
             typeof entry === 'object' &&
-            typeof (entry as Record<string, unknown>).year === 'string' &&
+            typeof (entry as Record<string, unknown>).year === 'string'  &&
             typeof (entry as Record<string, unknown>).title === 'string',
         )
       ) {
@@ -97,8 +97,8 @@ export async function PUT(req: NextRequest) {
       subjects: subjects.map((s) => s.trim()),
     };
     if (department !== undefined) updatePayload.department = department
-    if (phone !== undefined) updatePayload.phone = phone
-    if (bio !== undefined) updatePayload.bio = bio
+    if (phone !== undefined) updatePayload.phone = phone.trim()
+    if (bio !== undefined) updatePayload.bio = bio.trim()
     if (academicHistory !== undefined) updatePayload.academicHistory = academicHistory
 
     const teacher = await Teacher.findOneAndUpdate(

From c7ce708e32935ba36758a3e2901e54a244e80d60 Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 23:18:02 +0530
Subject: [PATCH 45/56] fix: resolve teacher ObjectId from clerkId for correct
 grade queries and writes

---
 app/api/grades/route.ts | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index ab7b49c..7f18cf9 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -4,6 +4,12 @@ import { connectDB } from '@/lib/mongodb'
 import { Grade } from '@/models/Grade'
 import { z } from 'zod'
 import mongoose from "mongoose";
+import { Teacher } from '@/models/Teacher'
+
+const teacher = await Teacher.findOne({ clerkId: userId }).select('_id').lean()
+if (!teacher) {
+  return NextResponse.json({ error: 'Teacher not found' }, { status: 404 })
+}
 
 const GradeSchema = z.object({
   studentId: z.string().regex(/^[0-9a-fA-F]{24}$/, 'Invalid studentId'),
@@ -41,7 +47,7 @@ export async function GET(req: NextRequest) {
     const studentId = searchParams.get('studentId')
     const subject = searchParams.get('subject')
 
-    const query: Record<string, unknown> = { teacherId: userId }
+    const query: Record<string, unknown> = { teacherId: teacher._id }
     if (studentId && mongoose.Types.ObjectId.isValid(studentId)) {
       query.studentId = new mongoose.Types.ObjectId(studentId);
     }
@@ -81,8 +87,8 @@ export async function POST(req: NextRequest) {
     const term = data.term ?? 'Term 1'
     
     const grade = await Grade.findOneAndUpdate(
-      { teacherId: userId, studentId: data.studentId, subject: data.subject, term },
-      { $set: { ...data, term, teacherId: userId, grade: calcGrade(data.marks, max) } },
+      { teacherId: teacher._id, studentId: new mongoose.Types.ObjectId(data.studentId), subject: data.subject, term },
+      { $set: { ...data, term, teacherId: teacher._id, grade: calcGrade(data.marks, max) } },
       { upsert: true, new: true }
     )
     return NextResponse.json(grade, { status: 201 })

From 5299665992c972c357e0cd999f20714c8954070e Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 23:24:18 +0530
Subject: [PATCH 46/56] fix: Enhance subjects validation in profile route

---
 app/api/profile/route.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/api/profile/route.ts b/app/api/profile/route.ts
index d80be29..c85b6af 100644
--- a/app/api/profile/route.ts
+++ b/app/api/profile/route.ts
@@ -63,8 +63,8 @@ export async function PUT(req: NextRequest) {
     if (department !== undefined && typeof department !== 'string') {
       return NextResponse.json({ error: 'department must be a string' }, { status: 400 })
     }
-    if ( !Array.isArray(subjects) ||
-    !subjects.every(s => typeof s === 'string' && s.trim().length > 0)) {
+
+    if ( !Array.isArray(subjects) || subjects.length === 0 || !subjects.every(s => typeof s === 'string' && s.trim().length > 0){
       return NextResponse.json({ error: 'subjects must be an array of strings' }, { status: 400 })
     }
     if (phone !== undefined && typeof phone !== 'string') {

From 7ffd9029aadbba566ba5377eb38831fa80fe4288 Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 23:32:21 +0530
Subject: [PATCH 47/56] fix: Change teacherId type to ObjectId in Announcement
 model and remove restrictive enum from audience to align with flexible UI and
 API validation

---
 models/Announcement.ts | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/models/Announcement.ts b/models/Announcement.ts
index 94a0368..502988d 100644
--- a/models/Announcement.ts
+++ b/models/Announcement.ts
@@ -2,7 +2,7 @@ import mongoose, { Schema, model, models } from "mongoose";
 
 export interface IAnnouncement {
   _id: mongoose.Types.ObjectId;
-  teacherId: string;
+  teacherId: mongoose.Types.ObjectId;
   title: string;
   content: string;
   audience: string;
@@ -15,13 +15,14 @@ export interface IAnnouncement {
 const AnnouncementSchema = new Schema<IAnnouncement>(
   {
     teacherId: {
-      type: String,
+      type: Schema.Types.ObjectId,
+      ref: "Teacher",
       required: true,
       index: true,
     },
     title: { type: String, required: true, trim: true, minlength: 3 },
     content: { type: String, required: true, trim: true, minlength: 5 },
-    audience: { type: String, enum: ["All", "CS-A", "CS-B"], default: "All" },
+    audience: { type: String, default: "All", trim: true },
     category: {
       type: String,
       enum: ["academic", "events", "admin", "general"],
@@ -38,4 +39,4 @@ AnnouncementSchema.index({ teacherId: 1, createdAt: -1 });
 
 export const Announcement =
   models.Announcement ??
-  model<IAnnouncement>("Announcement", AnnouncementSchema);
\ No newline at end of file
+  model<IAnnouncement>("Announcement", AnnouncementSchema);

From d03cbf258f4f721ad5296051c34ff4f93045c087 Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 23:44:11 +0530
Subject: [PATCH 48/56] Refactor: teacherId type and update schema fields

fix: remove invalid runtime logic from Assignment model and correct indexes
---
 models/Assignment.ts | 40 ++++++++++++++++++++++++++++------------
 1 file changed, 28 insertions(+), 12 deletions(-)

diff --git a/models/Assignment.ts b/models/Assignment.ts
index f70689d..98bdf2e 100644
--- a/models/Assignment.ts
+++ b/models/Assignment.ts
@@ -2,7 +2,7 @@ import mongoose, { Schema, model, models } from 'mongoose'
 
 export interface IAssignment {
   _id: mongoose.Types.ObjectId
-  teacherId: string
+  teacherId: mongoose.Types.ObjectId
   title: string
   description: string
   subject: string
@@ -18,21 +18,37 @@ export interface IAssignment {
 const AssignmentSchema = new Schema<IAssignment>(
   {
     teacherId: { type: Schema.Types.ObjectId, ref: 'Teacher', required: true, index: true },
-    title: {type: String, required: true, trim: true, minlength: 3},
+    title: { type: String, required: true, trim: true, minlength: 3 },
     description: { type: String, default: '', maxlength: 1000 },
-    subject: {enum: ['Mathematics', 'Data Structures', 'Operating Systems', 'DBMS', 'Computer Networks']},
-    class: { enum: ['CS-A', 'CS-B'] },
-    deadline: { validate: {
-      validator: (value: Date) => value > new Date(),
-      message: 'Deadline must be in the future'
-    } },
+    subject: {
+      type: String,
+      enum: ['Mathematics', 'Data Structures', 'Operating Systems', 'DBMS', 'Computer Networks'],
+      required: true
+    },
+    class: {
+      type: String,
+      enum: ['CS-A', 'CS-B'],
+      required: true
+    },
+    deadline: {
+      type: Date,
+      required: true,
+      validate: {
+        validator: (value: Date) => value > new Date(),
+        message: 'Deadline must be in the future'
+      }
+    },
     status: { type: String, enum: ['active', 'closed'], default: 'active' },
     kanbanStatus: { type: String, enum: ['todo', 'in_progress', 'submitted'], default: 'todo' },
     maxMarks: { type: Number, default: 100, min: 1, max: 1000 },
   },
   { timestamps: true }
 )
-AssignmentSchema.index({ teacherId: 1, class: 1 });
-AssignmentSchema.index({ status: 1 });
-AssignmentSchema.index({ deadline: 1 });
-export const Assignment = models.Assignment ?? model<IAssignment>('Assignment', AssignmentSchema)
+
+// ✅ Correct indexes
+AssignmentSchema.index({ teacherId: 1, class: 1 })
+AssignmentSchema.index({ status: 1 })
+AssignmentSchema.index({ deadline: 1 })
+
+export const Assignment =
+  models.Assignment ?? model<IAssignment>('Assignment', AssignmentSchema)

From dc4009cd76ac292793613428af8d8cb3231ec637 Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 23:55:10 +0530
Subject: [PATCH 49/56] refactor: Attendance model to use ObjectId and remove
 fields

Changed teacherId to use ObjectId type and removed studentName and class properties.
---
 models/Attendance.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/models/Attendance.ts b/models/Attendance.ts
index 177468a..83077e7 100644
--- a/models/Attendance.ts
+++ b/models/Attendance.ts
@@ -2,10 +2,9 @@ import mongoose, { Schema, model, models } from 'mongoose'
 
 export interface IAttendance {
   _id: mongoose.Types.ObjectId
-  teacherId: string
+  teacherId: mongoose.Types.ObjectId
   studentId: mongoose.Types.ObjectId
-  studentName: string
-  class: string
+  // removed the class and studentName
   date: string
   status: 'present' | 'absent' | 'late'
   createdAt: Date

From cad1c1dd67bfd04d58045cb0af96325377130da9 Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sat, 18 Apr 2026 23:59:01 +0530
Subject: [PATCH 50/56] remove: studentName from IAttendance interface

Removed the studentName field to prevent data inconsistency.
---
 models/Attendance.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/models/Attendance.ts b/models/Attendance.ts
index 83077e7..b01b1bc 100644
--- a/models/Attendance.ts
+++ b/models/Attendance.ts
@@ -4,7 +4,8 @@ export interface IAttendance {
   _id: mongoose.Types.ObjectId
   teacherId: mongoose.Types.ObjectId
   studentId: mongoose.Types.ObjectId
-  // removed the class and studentName
+  // removed the studentName
+  class: string
   date: string
   status: 'present' | 'absent' | 'late'
   createdAt: Date
@@ -17,6 +18,7 @@ const AttendanceSchema = new Schema<IAttendance>(
     studentId: { type: Schema.Types.ObjectId, ref: 'Student', required: true },
     // revome the studentName because If student name changes → data becomes inconsistent
     // remove because  Data inconsistency
+     class: { type: String, required: true, trim: true },
     date: { type: Date, required: true },
     status: { type: String, enum: ['present', 'absent', 'late'], required: true },
   },

From cecc46fe64953311ee4f99327717f77f9264c5ea Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sun, 19 Apr 2026 00:01:05 +0530
Subject: [PATCH 51/56] Change teacherId type from string to ObjectId

---
 models/Grade.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/Grade.ts b/models/Grade.ts
index cb1cc5a..e32cd68 100644
--- a/models/Grade.ts
+++ b/models/Grade.ts
@@ -2,7 +2,7 @@ import mongoose, { Schema, model, models } from 'mongoose'
 
 export interface IGrade {
   _id: mongoose.Types.ObjectId
-  teacherId: string
+  teacherId: mongoose.Types.ObjectId
   studentId: mongoose.Types.ObjectId
   studentName: string
   subject: string

From 077de99c60a1b48cdd9a928bc38a524f34ee8bea Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sun, 19 Apr 2026 00:05:12 +0530
Subject: [PATCH 52/56] fix: email validation and update unique index

---
 models/Student.ts | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/models/Student.ts b/models/Student.ts
index 4c5f19e..2453869 100644
--- a/models/Student.ts
+++ b/models/Student.ts
@@ -20,11 +20,13 @@ const StudentSchema = new Schema<IStudent>(
     teacherId: { type: String, required: true, index: true, minlength: 1 },
     name: { type: String, required: true, trim: true, minlength: 1 },
     rollNo: { type: String, required: true, trim: true,  uppercase: true,minlength: 1 },
-    class: { type: String, required: true, trime: true,minlength: 1 },
-    email: {  type: String,
-      default: '',
-      trim: true,
-      match: [/^\S+@\S+\.\S+$/, 'Invalid email format'], },
+    class: { type: String, required: true, trim: true,minlength: 1 },
+    email: {  type: String, trim: true,
+      validate:{
+        validator: (value?: string) => !value || /^\S+@\S+\.\S+$/.test(value),
+        message: 'Invalid email format',
+      }
+      },
     phone: { type: String, default: '', trim: true },
     address: { type: String, default: '', trim: true },
     parentName: { type: String, default: '', trim: true },
@@ -33,6 +35,6 @@ const StudentSchema = new Schema<IStudent>(
   { timestamps: true }
 )
 
-StudentSchema.index({ teacherId: 1, class: 1 }, { unique: true });
+StudentSchema.index({ teacherId: 1, rollNo: 1 }, { unique: true });
 
 export const Student = models.Student ?? model<IStudent>('Student', StudentSchema)

From 7a799a34f92842901d4ca33997cb08693e84bf47 Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sun, 19 Apr 2026 00:12:05 +0530
Subject: [PATCH 53/56] Refactor teacher lookup into a separate function

Refactored teacher retrieval logic into a separate function and updated its usage in the API route.
---
 app/api/grades/route.ts | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index 7f18cf9..7ad3bba 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -3,14 +3,13 @@ import { NextRequest, NextResponse } from 'next/server'
 import { connectDB } from '@/lib/mongodb'
 import { Grade } from '@/models/Grade'
 import { z } from 'zod'
-import mongoose from "mongoose";
+import mongoose from 'mongoose'
 import { Teacher } from '@/models/Teacher'
 
-const teacher = await Teacher.findOne({ clerkId: userId }).select('_id').lean()
-if (!teacher) {
-  return NextResponse.json({ error: 'Teacher not found' }, { status: 404 })
-}
-
+async function findTeacherByClerkId(userId: string){ 
+  return Teacher.findOne({ clerkId: userId }).select('_id').lean()
+};
+  
 const GradeSchema = z.object({
   studentId: z.string().regex(/^[0-9a-fA-F]{24}$/, 'Invalid studentId'),
   studentName: z.string().min(1),
@@ -42,7 +41,11 @@ export async function GET(req: NextRequest) {
   if (!userId) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
 
   try {
-    await connectDB()
+    await connectDB();
+    
+    const teacher = await findTeacherByClerkId(userId);
+    if (!teacher) return NextResponse.json({ error: 'Teacher not found' }, { status: 404 });
+    
     const { searchParams } = new URL(req.url)
     const studentId = searchParams.get('studentId')
     const subject = searchParams.get('subject')
@@ -67,6 +70,9 @@ export async function POST(req: NextRequest) {
 
   try {
     await connectDB()
+
+     const teacher = await findTeacherByClerkId(userId);
+     if (!teacher) return NextResponse.json({ error: 'Teacher not found' }, { status: 404 });
     
     let body
     try {

From 9038946f90bb29b46813cbd342b600ddbd15727f Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sun, 19 Apr 2026 00:15:22 +0530
Subject: [PATCH 54/56] Enhance studentId validation in grades route

Refactor studentId validation to improve error handling.
---
 app/api/grades/route.ts | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/app/api/grades/route.ts b/app/api/grades/route.ts
index 7ad3bba..124e205 100644
--- a/app/api/grades/route.ts
+++ b/app/api/grades/route.ts
@@ -50,10 +50,13 @@ export async function GET(req: NextRequest) {
     const studentId = searchParams.get('studentId')
     const subject = searchParams.get('subject')
 
-    const query: Record<string, unknown> = { teacherId: teacher._id }
-    if (studentId && mongoose.Types.ObjectId.isValid(studentId)) {
-      query.studentId = new mongoose.Types.ObjectId(studentId);
-    }
+    const query: Record<string, unknown> = { teacherId: teacher._id };
+
+  if (studentId) {
+     if (!mongoose.Types.ObjectId.isValid(studentId)) return NextResponse.json({ error: 'Invalid studentId' }, { status: 400 });
+     query.studentId = new mongoose.Types.ObjectId(studentId)
+  };
+    
     if (subject) query.subject = subject
 
     const grades = await Grade.find(query).sort({ createdAt: -1 }).lean()

From 7095a26dbc06d2360cc76ed932694bda090c0b14 Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sun, 19 Apr 2026 00:18:19 +0530
Subject: [PATCH 55/56] fix: validation for subjects array in route.ts

---
 app/api/profile/route.ts | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/app/api/profile/route.ts b/app/api/profile/route.ts
index c85b6af..bbd7c51 100644
--- a/app/api/profile/route.ts
+++ b/app/api/profile/route.ts
@@ -63,10 +63,15 @@ export async function PUT(req: NextRequest) {
     if (department !== undefined && typeof department !== 'string') {
       return NextResponse.json({ error: 'department must be a string' }, { status: 400 })
     }
-
-    if ( !Array.isArray(subjects) || subjects.length === 0 || !subjects.every(s => typeof s === 'string' && s.trim().length > 0){
+    
+   if (
+     !Array.isArray(subjects) ||
+     subjects.length === 0 ||
+     !subjects.every((s: unknown) => typeof s === 'string' && s.trim().length > 0)
+    ) {
       return NextResponse.json({ error: 'subjects must be an array of strings' }, { status: 400 })
     }
+    
     if (phone !== undefined && typeof phone !== 'string') {
       return NextResponse.json({ error: 'phone must be a string' }, { status: 400 })
     }

From 6978b98078f709a1ccc1c80f3cc35d4ff2491735 Mon Sep 17 00:00:00 2001
From: "nitesh.asm" <0911nitesh@gmail.com>
Date: Sun, 19 Apr 2026 00:31:19 +0530
Subject: [PATCH 56/56] Update route.ts

---
 app/api/assignments/route.ts | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/app/api/assignments/route.ts b/app/api/assignments/route.ts
index 19021d8..fed2776 100644
--- a/app/api/assignments/route.ts
+++ b/app/api/assignments/route.ts
@@ -4,13 +4,16 @@ import { connectDB } from '@/lib/mongodb'
 import { Assignment } from '@/models/Assignment'
 import { z } from 'zod'
 
+const SUBJECTS = ['Mathematics', 'Data Structures', 'Operating Systems', 'DBMS', 'Computer Networks'] as const;
+const CLASSES = ['CS-A', 'CS-B'] as const;
+
 const AssignmentSchema = z.object({
-  title: z.string().min(1),
-  description: z.string().optional(),
-  subject: z.string().min(1),
-  class: z.string().min(1),
-  deadline: z.string().min(1),
-  maxMarks: z.number().min(1).optional(),
+  title: z.string().trim().min(3),
+  description: z.string().max(1000).optional(),
+  subject: z.enum(SUBJECTS),
+  class: z.enum(CLASSES),
+  deadline: z.string().refine((value) => new Date(value) > new Date(), 'Deadline must be in the future'),
+  maxMarks: z.number().min(1).max(1000).optional(),
   status: z.enum(['active', 'closed']).optional(),
   kanbanStatus: z.enum(['todo', 'in_progress', 'submitted']).optional(),
 })