Add index.js

index.js

@@ -0,0 +1,191 @@
+const express = require('express');
+const bodyParser = require('body-parser');
+const bcrypt = require('bcryptjs');
+const jwt = require('jsonwebtoken');
+const { ActivityPubRouter, createActor } = require('activitypub-express');
+const uuid = require('uuid');
+const fetch = require('node-fetch');
+
+const app = express();
+const port = 3000;
+
+const SECRET_KEY = 'your_secret_key'; // Replace with a secure key in a real app
+
+// In-memory "database" for users and posts
+const users = {};
+const posts = {};
+const followers = {};
+
+// Middleware to parse JSON
+app.use(bodyParser.json());
+
+// Helper function to create an actor URL
+const actorURL = (username) => `http://localhost:${port}/users/${username}`;
+
+// Helper function to generate JWT token
+const generateToken = (user) => {
+    return jwt.sign({ id: user.username }, SECRET_KEY, { expiresIn: '1h' });
+};
+
+// Middleware to protect routes
+const authenticate = (req, res, next) => {
+    const token = req.headers['authorization']?.split(' ')[1];
+    if (!token) {
+        return res.status(401).json({ error: 'Unauthorized' });
+    }
+
+    jwt.verify(token, SECRET_KEY, (err, decoded) => {
+        if (err) {
+            return res.status(403).json({ error: 'Invalid or expired token' });
+        }
+        req.user = decoded;
+        next();
+    });
+};
+
+// Route to create a new user (actor with password)
+app.post('/users', async (req, res) => {
+    const { username, displayName, password } = req.body;
+
+    if (users[username]) {
+        return res.status(400).json({ error: 'User already exists' });
+    }
+
+    // Hash the password before saving
+    const hashedPassword = await bcrypt.hash(password, 10);
+
+    const actor = createActor({
+        id: actorURL(username),
+        username,
+        displayName,
+        inbox: `http://localhost:${port}/users/${username}/inbox`,
+        outbox: `http://localhost:${port}/users/${username}/outbox`,
+        followers: `http://localhost:${port}/users/${username}/followers`,
+        following: `http://localhost:${port}/users/${username}/following`,
+    });
+
+    users[username] = { ...actor, password: hashedPassword };
+    res.status(201).json(actor);
+});
+
+// Route to log in a user and get a token
+app.post('/login', async (req, res) => {
+    const { username, password } = req.body;
+
+    const user = users[username];
+    if (!user) {
+        return res.status(404).json({ error: 'User not found' });
+    }
+
+    // Compare hashed password
+    const isPasswordValid = await bcrypt.compare(password, user.password);
+    if (!isPasswordValid) {
+        return res.status(401).json({ error: 'Invalid password' });
+    }
+
+    // Generate and return JWT token
+    const token = generateToken(user);
+    res.json({ token });
+});
+
+// Route to create a post (status update) with authentication
+app.post('/users/:username/posts', authenticate, (req, res) => {
+    const { username } = req.params;
+    const { content } = req.body;
+
+    if (req.user.id !== username) {
+        return res.status(403).json({ error: 'You can only post as yourself' });
+    }
+
+    if (!users[username]) {
+        return res.status(404).json({ error: 'User not found' });
+    }
+
+    const post = {
+        id: `http://localhost:${port}/posts/${uuid.v4()}`,
+        type: 'Note',
+        content,
+        author: users[username],
+        published: new Date().toISOString(),
+    };
+
+    posts[post.id] = post;
+    res.status(201).json(post);
+});
+
+// Route to get a user’s posts
+app.get('/users/:username/posts', authenticate, (req, res) => {
+    const { username } = req.params;
+
+    if (req.user.id !== username) {
+        return res.status(403).json({ error: 'You can only view your own posts' });
+    }
+
+    if (!users[username]) {
+        return res.status(404).json({ error: 'User not found' });
+    }
+
+    const userPosts = Object.values(posts).filter(post => post.author.username === username);
+    res.json(userPosts);
+});
+
+// ActivityPub setup
+const activityPubRouter = new ActivityPubRouter();
+
+// Handle incoming Follow activity
+activityPubRouter.post('/users/:username/inbox', authenticate, async (req, res) => {
+    const { username } = req.params;
+    const activity = req.body;
+
+    if (!users[username]) {
+        return res.status(404).json({ error: 'User not found' });
+    }
+
+    if (activity.type === 'Follow') {
+        const actor = activity.actor;
+
+        // Add follower to the user’s list of followers
+        if (!followers[username]) {
+            followers[username] = [];
+        }
+        followers[username].push(actor.id);
+
+        res.status(200).json({ status: 'Followed successfully' });
+
+        // Optionally, notify the actor that the follow was accepted
+        await sendFollowResponse(actor, username);
+    } else {
+        res.status(400).json({ error: 'Unsupported activity type' });
+    }
+});
+
+// Federated actor info endpoint
+activityPubRouter.get('/users/:username', (req, res) => {
+    const { username } = req.params;
+
+    if (!users[username]) {
+        return res.status(404).json({ error: 'User not found' });
+    }
+
+    res.json(users[username]);
+});
+
+// Outbox endpoint to send posts
+activityPubRouter.get('/users/:username/outbox', (req, res) => {
+    const { username } = req.params;
+
+    if (!users[username]) {
+        return res.status(404).json({ error: 'User not found' });
+    }
+
+    // Fetch posts from this user’s outbox
+    const userPosts = Object.values(posts).filter(post => post.author.username === username);
+    res.json(userPosts);
+});
+
+app.use(activityPubRouter.router);
+
+// Start the server
+app.listen(port, () => {
+    console.log(`Federated social network with authentication running at http://localhost:${port}`);
+});