Skillnora — AI-powered eLearning Platform

A full-stack eLearning platform built with Next.js 15, Express.js, Supabase, and Razorpay.

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Tech Stack

Layer	Technology
Frontend	Next.js 15 (App Router), TypeScript, Tailwind CSS
Backend	Express.js (Node), ES Modules
Database	Supabase (PostgreSQL) + Supabase Auth
Payments	Razorpay
Storage	Supabase Storage (videos, thumbnails, avatars)
AI	Groq API (LLaMA models) — summaries, AI chat
Auth	Supabase Auth (email magic link, Google, GitHub OAuth) + optional TOTP 2FA

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Project Structure

Skillnora/
├── frontend/         # Next.js 15 app
│   └── src/app/
│       ├── (dashboard)/  # Protected routes (student, instructor, admin)
│       │   ├── admin/        # Admin overview, courses, payments, students…
│       │   ├── instructor/   # Instructor studio dashboard
│       │   ├── courses/      # Course detail & lecture player
│       │   ├── notes/        # Student notes
│       │   └── settings/     # User settings & 2FA enrollment
│       └── auth/         # Login / signup page
├── backend/          # Express API server
│   ├── src/features/ # Feature-based modules (courses, enrollments, admin…)
│   ├── migrations/   # SQL schema (001_initial_schema.sql)
│   └── server.js
└── package.json      # Root: runs both frontend + backend concurrently

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Quick Start

1. Install dependencies

npm install          # root (installs concurrently)
cd frontend && npm install
cd ../backend && npm install

2. Configure environment

cp .env.example .env

Fill in the following in backend/.env:

Variable	Description
DATABASE_URL	Supabase Postgres connection string (pooler)
SUPABASE_URL	Your Supabase project URL
SUPABASE_SERVICE_ROLE_KEY	Supabase service role key (server-only)
SUPABASE_ANON_KEY	Supabase anon/public key
RAZORPAY_KEY_ID	Razorpay Key ID
RAZORPAY_KEY_SECRET	Razorpay Key Secret
GROQ_API_KEY	Groq API key for AI features
PORT	Backend port (default: 5000)

And in frontend/.env.local:

Variable	Description
NEXT_PUBLIC_SUPABASE_URL	Supabase project URL
NEXT_PUBLIC_SUPABASE_ANON_KEY	Supabase anon key
NEXT_PUBLIC_API_URL	Backend URL (e.g. http://localhost:5000)
NEXT_PUBLIC_RAZORPAY_KEY_ID	Razorpay publishable key

3. Set up the Database

Open the Supabase SQL editor and run:

backend/migrations/001_initial_schema.sql

This creates all tables, triggers, and RLS policies in one shot.

4. Run development servers

# From project root — runs both frontend and backend:
npm run dev:all

# Or separately:
npm run dev:api    # Express backend on :5000
npm run dev        # Next.js frontend on :3000

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Database Schema Overview

See backend/migrations/001_initial_schema.sql for the full schema.

Core Tables

Table	Purpose
users	User profiles (student / instructor / admin roles)
courses	Course catalog with pricing, metadata, and ratings
lectures	Individual video lectures within a course
enrollments	Tracks which user enrolled in which course
orders	Razorpay payment records
refunds	Refund ledger (issued when courses are deleted)
reviews	Star ratings and review text per course
certificates	Issued completion certificates with a unique code
notes	Student notes linked to a specific lecture
lecture_comments	Q&A discussion threads on lectures
wishlist_items	Courses saved to a user's wishlist
cart_items	Courses in a user's cart
notifications	In-app notification feed
support_tickets	User-submitted support requests

orders.status values

Status	Meaning
created	Order initiated via Razorpay
paid	Payment confirmed (Razorpay webhook)
success	Alias used in some Razorpay flows
captured	Payment captured by Razorpay
failed	Payment failed
refunded	Payment reversed / refunded

Revenue Calculation: SUM(amount WHERE status IN ('paid','success','captured')) - SUM(amount WHERE status = 'refunded') — both admin and instructor dashboards use this identical formula from the orders table for consistency.

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Key Features

• 🎓 Multi-role platform — Student, Instructor, and Admin dashboards
• 📹 Video lectures — Supabase Storage with signed URL generation (6-hour expiry)
• 💳 Razorpay payments — Order creation, webhook verification, refund on course deletion
• 🔐 Two-Factor Authentication (2FA) — TOTP via Google Authenticator (opt-in per user)
• 📊 Analytics dashboards — Revenue charts, student enrollment trends, course health
• 💬 Q&A discussions — Threaded comments with emoji reactions and image uploads on lectures
• 📝 Notes — Per-lecture notes with direct "Go to Video" deep-link navigation
• 📝 Test Series Engine — Full-featured exam simulator with live timers, anti-cheat mechanisms (tab focus tracking, disable copy/paste), section switching, and a dynamic question palette.
  • Mobile-First Design: Test taking experience is highly optimized for mobile devices with swipeable/hideable palettes, proper 100dvh viewport constraints, auto-stacking layouts for options and controls, and zero horizontal clipping.
  • Auto-Submit: Smart timers that lock the test and seamlessly auto-save/submit answers the exact second the clock expires, redirecting users directly to their analysis.
• 🏆 Certificates — Auto-issued on course completion with a unique verification code
• 🔔 Notifications — Real-time in-app feed for replies, new comments, and support tickets
• 🤖 AI features — Groq-powered lecture summaries and an AI chat assistant
• 🎫 Support tickets — Users can submit tickets; admin is notified via the notification feed

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Supabase Setup Notes

1. Create a Supabase project and copy SUPABASE_URL and SUPABASE_ANON_KEY.
2. Add SUPABASE_SERVICE_ROLE_KEY to your backend env (never expose client-side).
3. In Authentication → URL Configuration, add your app URL to allowed redirect URLs.
4. Enable Google and/or GitHub OAuth providers if needed.
5. Run 001_initial_schema.sql in the SQL editor to create all tables and RLS policies.
6. Create a Storage bucket named course-thumbnails (for videos and images).

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Revenue & Statistics Consistency

Both the Admin Dashboard (/admin) and Instructor Dashboard (/instructor) calculate revenue identically:

SUM(amount) FILTER (WHERE status IN ('paid', 'success', 'captured'))
- SUM(amount) FILTER (WHERE status = 'refunded')

Student counts only count users with role = 'student' — instructors enrolling in their own free courses for testing are excluded.