Add Express backend server with API routes

server.js

@@ -0,0 +1,202 @@
+const express = require('express');
+const multer = require('multer');
+const path = require('path');
+const fs = require('fs');
+const { v4: uuidv4 } = require('uuid');
+const cors = require('cors');
+
+const app = express();
+const PORT = process.env.PORT || 3000;
+
+// Middleware
+app.use(cors());
+app.use(express.json());
+app.use(express.static('public'));
+app.use('/uploads', express.static(path.join(__dirname, 'public', 'uploads')));
+
+// In-memory data store
+let posts = [];
+let votes = {};
+let comments = [];
+
+// Multer config for file uploads
+const storage = multer.diskStorage({
+  destination: (req, file, cb) => {
+    const uploadDir = path.join(__dirname, 'public', 'uploads');
+    if (!fs.existsSync(uploadDir)) fs.mkdirSync(uploadDir, { recursive: true });
+    cb(null, uploadDir);
+  },
+  filename: (req, file, cb) => {
+    const id = uuidv4().slice(0, 8);
+    const ext = path.extname(file.originalname);
+    cb(null, `${id}${ext}`);
+  }
+});
+
+const ALLOWED_TYPES = ['image/jpeg', 'image/png', 'image/gif', 'image/webp'];
+
+const upload = multer({
+  storage,
+  limits: { fileSize: 20 * 1024 * 1024 },
+  fileFilter: (req, file, cb) => {
+    if (ALLOWED_TYPES.includes(file.mimetype)) {
+      cb(null, true);
+    } else {
+      cb(new Error('Unsupported file type. Only JPEG, PNG, GIF, and WebP are allowed.'), false);
+    }
+  }
+});
+
+// Load seed data
+function loadSeedData() {
+  const seedPath = path.join(__dirname, 'seed', 'data.js');
+  if (fs.existsSync(seedPath)) {
+    const seed = require(seedPath);
+    posts = seed.posts.map(p => ({ ...p, id: p.id, createdAt: new Date().toISOString() }));
+    comments = seed.comments || [];
+  }
+}
+
+// --- API Routes ---
+
+// GET /api/posts - List all posts with optional sort
+app.get('/api/posts', (req, res) => {
+  const { sort = 'new' } = req.query;
+  let sorted = [...posts];
+
+  switch (sort) {
+    case 'viral':
+      sorted.sort((a, b) => (b.upvotes || 0) - (a.upvotes || 0));
+      break;
+    case 'top':
+      const today = new Date();
+      today.setHours(0, 0, 0, 0);
+      const todayPosts = posts.filter(p => new Date(p.createdAt) >= today);
+      sorted = todayPosts.sort((a, b) => (b.upvotes || 0) - (a.upvotes || 0));
+      break;
+    case 'user':
+      sorted.sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt));
+      break;
+    default:
+      sorted.sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt));
+  }
+
+  sorted = sorted.map(p => ({
+    ...p,
+    commentCount: comments.filter(c => c.postId === p.id).length
+  }));
+
+  res.json(sorted);
+});
+
+// GET /api/posts/:id - Single post
+app.get('/api/posts/:id', (req, res) => {
+  const post = posts.find(p => p.id === req.params.id);
+  if (!post) return res.status(404).json({ error: 'Post not found' });
+  const commentCount = comments.filter(c => c.postId === post.id).length;
+  res.json({ ...post, commentCount });
+});
+
+// POST /api/posts - Create new post
+app.post('/api/posts', upload.single('image'), (req, res) => {
+  if (!req.file) {
+    return res.status(400).json({ error: 'No image file provided' });
+  }
+
+  const post = {
+    id: uuidv4().slice(0, 8),
+    title: req.body.title || 'Untitled',
+    url: `/uploads/${req.file.filename}`,
+    upvotes: 1,
+    views: 0,
+    tags: req.body.tags ? req.body.tags.split(',').map(t => t.trim()).filter(Boolean) : [],
+    createdAt: new Date().toISOString(),
+    author: req.body.author || 'Anonymous'
+  };
+
+  posts.unshift(post);
+  res.status(201).json(post);
+});
+
+// POST /api/posts/:id/vote - Vote on a post
+app.post('/api/posts/:id/vote', (req, res) => {
+  const post = posts.find(p => p.id === req.params.id);
+  if (!post) return res.status(404).json({ error: 'Post not found' });
+
+  const { direction } = req.body;
+  const userId = req.body.userId || 'anonymous';
+
+  if (direction === 'up') {
+    post.upvotes = (post.upvotes || 0) + 1;
+  } else if (direction === 'down') {
+    post.upvotes = Math.max(0, (post.upvotes || 0) - 1);
+  }
+
+  post.views = (post.views || 0) + 1;
+
+  res.json({ upvotes: post.upvotes, views: post.views });
+});
+
+// GET /api/comments/:postId - Get comments for a post
+app.get('/api/comments/:postId', (req, res) => {
+  const postComments = comments.filter(c => c.postId === req.params.postId);
+  res.json(postComments);
+});
+
+// POST /api/comments - Create a comment
+app.post('/api/comments', (req, res) => {
+  const { postId, text, author, parentId } = req.body;
+
+  if (!postId || !text) {
+    return res.status(400).json({ error: 'postId and text are required' });
+  }
+
+  const comment = {
+    id: uuidv4().slice(0, 8),
+    postId,
+    text,
+    author: author || 'Anonymous',
+    parentId: parentId || null,
+    timestamp: new Date().toISOString()
+  };
+
+  comments.push(comment);
+  res.status(201).json(comment);
+});
+
+// POST /api/upload - File upload endpoint
+app.post('/api/upload', upload.single('image'), (req, res) => {
+  if (!req.file) {
+    return res.status(400).json({ error: 'No file uploaded' });
+  }
+
+  const post = {
+    id: uuidv4().slice(0, 8),
+    title: req.body.title || 'Untitled',
+    url: `/uploads/${req.file.filename}`,
+    upvotes: 1,
+    views: 0,
+    tags: req.body.tags ? req.body.tags.split(',').map(t => t.trim()).filter(Boolean) : [],
+    createdAt: new Date().toISOString(),
+    author: req.body.author || 'You'
+  };
+
+  posts.unshift(post);
+  res.status(201).json(post);
+});
+
+// Health check
+app.get('/api/health', (req, res) => {
+  res.json({ status: 'ok', posts: posts.length, comments: comments.length, uptime: process.uptime() });
+});
+
+// Initialize and start
+loadSeedData();
+console.log(`🚀 Imgur Clone running on port ${PORT}`);
+console.log(`📦 ${posts.length} seed posts loaded`);
+
+// Listen on both IPv4 and IPv6 for health check compatibility
+const server = app.listen(PORT, () => {
+  console.log(`✅ Server listening on http://0.0.0.0:${PORT}`);
+  console.log(`✅ Server listening on http://[::]:${PORT}`);
+});