feat: implement EduScale online learning platform MVP

.gitignore

@@ -0,0 +1,11 @@
+node_modules/
+*.db
+*.db-journal
+*.db-shm
+*.db-wal
+dist/
+.env
+backend/uploads/videos/*
+backend/uploads/files/*
+!backend/uploads/videos/.gitkeep
+!backend/uploads/files/.gitkeep

README.md

@@ -1,2 +1,110 @@
-# Edus
--
+# EduScale — Online Learning Platform MVP
+
+A full-stack online learning platform built with Node.js + Express + SQLite (backend) and React + Vite (frontend).
+
+## Features
+
+- **Auth**: Register/Login with JWT, roles: `student`, `instructor`, `admin`
+- **Courses**: Create, publish, search/filter course catalog
+- **Video Streaming**: Upload & stream videos with Range request support, progress tracking
+- **Enrollments**: Enroll/unenroll in courses
+- **Assignments**: Create, submit, and grade assignments
+- **Discussions**: Course discussion threads with replies
+- **Announcements**: Instructor announcements per course
+- **Quizzes**: Create quizzes with auto-grading
+- **Certificates**: PDF certificates on 100% course completion
+- **Admin Dashboard**: User management, role changes, platform stats
+
+## Tech Stack
+
+| Layer     | Technology                         |
+|-----------|------------------------------------|
+| Backend   | Node.js, Express, SQLite (better-sqlite3) |
+| Auth      | bcryptjs, jsonwebtoken             |
+| File Upload | multer                           |
+| PDF       | pdfkit                             |
+| Frontend  | React 18, React Router v6, Vite    |
+| HTTP      | Axios                              |
+
+## Project Structure
+
+```
+Edus/
+├── backend/
+│   ├── routes/          # API route handlers
+│   ├── middleware/       # JWT auth middleware
+│   ├── uploads/          # Uploaded files (videos, files)
+│   ├── db.js             # SQLite initialization
+│   ├── schema.sql        # Database schema
+│   └── server.js         # Express entry point
+└── frontend/
+    └── src/
+        ├── pages/        # React pages
+        ├── components/   # Shared components
+        ├── context/      # Auth context
+        ├── api.js        # Axios instance
+        └── index.css     # Global styles
+```
+
+## Setup & Running
+
+### Prerequisites
+- Node.js v18+ (v20+ recommended)
+- npm
+
+### Backend
+
+```bash
+cd backend
+npm install
+npm start
+# Server runs on http://localhost:5000
+```
+
+### Frontend
+
+```bash
+cd frontend
+npm install
+npm run dev
+# App runs on http://localhost:3000
+```
+
+### Environment Variables
+
+Backend `.env` (already created):
+```
+JWT_SECRET=eduscale_super_secret_jwt_key_2024
+PORT=5000
+FRONTEND_URL=http://localhost:3000
+```
+
+## API Endpoints
+
+| Method | Path | Description |
+|--------|------|-------------|
+| POST | /api/register | Register user |
+| POST | /api/login | Login |
+| GET | /api/me | Current user |
+| GET | /api/courses | List published courses |
+| POST | /api/courses | Create course (instructor) |
+| GET | /api/courses/:id | Course detail |
+| POST | /api/enrollments | Enroll in course |
+| POST | /api/videos/upload | Upload video |
+| GET | /api/videos/:id | Stream video |
+| PUT | /api/videos/:id/progress | Update watch progress |
+| GET | /api/assignments/:courseId | List assignments |
+| POST | /api/assignments/:id/submit | Submit assignment |
+| GET | /api/discussions/:courseId | List discussions |
+| POST | /api/quizzes/:id/attempt | Submit quiz |
+| POST | /api/certificates/:courseId | Issue certificate |
+| GET | /api/certificates/:courseId/download | Download PDF |
+| GET | /api/admin/stats | Platform statistics (admin) |
+
+## Creating an Admin User
+
+Register normally, then update the role via SQLite or through an existing admin account:
+
+```bash
+sqlite3 backend/eduscale.db "UPDATE users SET role='admin' WHERE email='your@email.com';"
+```

backend/db.js

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+const Database = require('better-sqlite3');
+const path = require('path');
+const fs = require('fs');
+
+const DB_PATH = path.join(__dirname, 'eduscale.db');
+const SCHEMA_PATH = path.join(__dirname, 'schema.sql');
+
+const db = new Database(DB_PATH);
+
+db.pragma('journal_mode = WAL');
+db.pragma('foreign_keys = ON');
+
+const schema = fs.readFileSync(SCHEMA_PATH, 'utf8');
+db.exec(schema);
+
+module.exports = db;

backend/middleware/auth.js

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+const jwt = require('jsonwebtoken');
+const db = require('../db');
+
+function getJwtSecret() {
+  const secret = process.env.JWT_SECRET;
+  if (!secret) throw new Error('JWT_SECRET environment variable is required');
+  return secret;
+}
+
+function authenticate(req, res, next) {
+  const authHeader = req.headers.authorization;
+  if (!authHeader || !authHeader.startsWith('Bearer ')) {
+    return res.status(401).json({ error: 'No token provided' });
+  }
+  const token = authHeader.slice(7);
+  try {
+    const payload = jwt.verify(token, getJwtSecret());
+    const user = db.prepare('SELECT id, name, email, role FROM users WHERE id = ?').get(payload.id);
+    if (!user) return res.status(401).json({ error: 'User not found' });
+    req.user = user;
+    next();
+  } catch {
+    return res.status(401).json({ error: 'Invalid token' });
+  }
+}
+
+function optionalAuth(req, res, next) {
+  const authHeader = req.headers.authorization;
+  if (!authHeader || !authHeader.startsWith('Bearer ')) {
+    req.user = null;
+    return next();
+  }
+  const token = authHeader.slice(7);
+  try {
+    const payload = jwt.verify(token, getJwtSecret());
+    const user = db.prepare('SELECT id, name, email, role FROM users WHERE id = ?').get(payload.id);
+    req.user = user || null;
+  } catch {
+    req.user = null;
+  }
+  next();
+}
+
+function requireRole(...roles) {
+  return (req, res, next) => {
+    if (!req.user) return res.status(401).json({ error: 'Not authenticated' });
+    if (!roles.includes(req.user.role)) {
+      return res.status(403).json({ error: 'Insufficient permissions' });
+    }
+    next();
+  };
+}
+
+module.exports = { authenticate, optionalAuth, requireRole };