feat: implement dynamic P2P polling app with real-time synchronization

- Add complete P2P polling application with React + TypeScript frontend
- Implement Node.js backend with Yjs WebSocket and WebRTC signaling
- Support dynamic poll creation, answer management, and voting
- Add CRDT-based state synchronization using Yjs for conflict-free merging
- Implement user tracking and vote prevention (one vote per user per option)
- Create modern UI with Tailwind CSS and visual feedback
- Add comprehensive documentation and setup instructions

Features:
- Users can create polls with custom questions
- Anyone can add answer options to any poll
- Real-time voting with instant cross-client synchronization
- Smart vote tracking with visual feedback for voted options
- User attribution showing who created polls and options
- Connection status indicators for WebSocket and P2P connections

Technical:
- Hybrid P2P architecture (WebSocket + WebRTC)
- CRDT-based state management with Yjs

README.md

@@ -1 +1,279 @@
-# P2P Poll App
+# P2P Poll App
+
+A peer-to-peer polling application built with React, TypeScript, Tailwind CSS, Node.js, Yjs, and WebSocket for real-time collaborative voting.
+
+**Users can create polls, add answers, and vote in real-time with automatic P2P synchronization across all connected clients.**
+
+## Architecture
+
+**Hybrid P2P Approach:**
+- Backend serves as both a Yjs WebSocket provider (for state synchronization) and signaling server (for WebRTC peer discovery)
+- Clients sync poll data via Yjs CRDT for conflict-free merging
+- Direct P2P connections via WebRTC for real-time updates when possible
+- Server fallback ensures reliability when P2P fails
+
+## Tech Stack
+
+**Backend:**
+- Node.js + TypeScript
+- Express.js
+- WebSocket (ws)
+- y-websocket (Yjs WebSocket provider)
+- CORS support
+
+**Frontend:**
+- React 18 + TypeScript
+- Vite (build tool)
+- Tailwind CSS
+- Yjs (CRDT library)
+- y-websocket (server sync)
+- y-webrtc (P2P sync)
+- lucide-react (icons)
+
+## Project Structure
+
+```
+quicgroup/
+├── server/                 # Backend Node.js server
+│   ├── src/
+│   │   ├── index.ts       # Main server entry
+│   │   ├── yjs-server.ts  # Yjs WebSocket provider
+│   │   ├── signaling-server.ts  # WebRTC signaling
+│   │   ├── types/         # TypeScript types
+│   │   └── utils/         # Utilities
+│   ├── package.json
+│   └── tsconfig.json
+│
+└── frontend/              # React frontend
+    ├── src/
+    │   ├── components/    # React components
+    │   ├── hooks/         # Custom React hooks
+    │   ├── lib/           # Yjs setup and utilities
+    │   ├── types/         # TypeScript types
+    │   └── styles/        # CSS styles
+    ├── package.json
+    └── vite.config.ts
+```
+
+## Setup Instructions
+
+### Prerequisites
+- Node.js 18+ and npm
+
+### Backend Setup
+
+1. Navigate to server directory:
+```bash
+cd server
+```
+
+2. Install dependencies:
+```bash
+npm install
+```
+
+3. Copy environment file:
+```bash
+cp .env.example .env
+```
+
+4. Start the development server:
+```bash
+npm run dev
+```
+
+The server will run on `http://localhost:3000` with:
+- Yjs WebSocket: `ws://localhost:3000/yjs`
+- Signaling WebSocket: `ws://localhost:3000/signal`
+
+### Frontend Setup
+
+1. Navigate to frontend directory:
+```bash
+cd frontend
+```
+
+2. Install dependencies:
+```bash
+npm install
+```
+
+3. Copy environment file (optional):
+```bash
+cp .env.example .env
+```
+
+4. Start the development server:
+```bash
+npm run dev
+```
+
+The frontend will run on `http://localhost:5173`
+
+## Running the Application
+
+1. **Start Backend** (Terminal 1):
+```bash
+cd server
+npm run dev
+```
+
+2. **Start Frontend** (Terminal 2):
+```bash
+cd frontend
+npm run dev
+```
+
+3. **Open Browser:**
+   - Navigate to `http://localhost:5173`
+   - Open multiple tabs/windows to test P2P synchronization
+
+## Features
+
+### Dynamic Poll Creation
+- **Create Polls** - Any user can create new polls with custom questions
+- **Add Answers** - Anyone can add answer options to any poll
+- **Real-time Voting** - Vote on options with instant updates across all clients
+- **Smart Vote Tracking** - One vote per user per option (prevents duplicate voting)
+- **Visual Feedback** - Green border and " Voted" indicator on voted options
+- **User Attribution** - See who created each poll and option
+- **Live Vote Counts** - See vote percentages and counts update in real-time
+- **P2P Synchronization** - Uses Yjs CRDT for conflict-free state merging
+- **Connection Status** - Visual indicator showing WebSocket and peer connections
+- **Hybrid Architecture** - Combines WebSocket server sync with WebRTC P2P
+- **Beautiful UI** - Modern gradient design with Tailwind CSS
+
+## How to Use
+
+### Create a Poll
+1. Enter your question in the "Create a New Poll" form at the top
+2. Click "Create Poll"
+3. Your poll appears instantly for all connected users
+
+### Add Answer Options
+1. Find the poll you want to add an answer to
+2. Type your answer in the "Add a new option..." field
+3. Click "Add"
+4. Your answer appears instantly for all users
+
+### Vote on Options
+1. Click the vote button (thumbs up icon) on any option
+2. You can only vote once per option
+3. Voted options show a green border and " Voted" indicator
+4. Vote counts update in real-time across all clients
+
+### Multi-User Testing
+1. Open multiple browser tabs/windows
+2. Create polls from different tabs
+3. Add answers from different tabs
+4. Vote from different tabs
+5. Watch real-time synchronization in action!
+
+## How It Works
+
+### CRDT Synchronization
+The app uses Yjs (a CRDT library) to ensure all clients converge to the same state without conflicts:
+- Each client maintains a local Yjs document
+- Changes are automatically synced via WebSocket to the server
+- WebRTC provides direct P2P connections between clients
+- Yjs handles merge conflicts automatically
+- One vote per user per option is enforced via `votedBy` tracking
+
+## Data Model
+```typescript
+{
+  polls: Array<{
+    id: string,
+    question: string,
+    createdBy: string,
+    timestamp: number,
+    options: Array<{
+      id: string,
+      text: string,
+      votes: number,
+      votedBy: string[],  // Tracks which users have voted
+      createdBy: string,
+      timestamp: number
+    }>
+  }>
+}
+```
+
+## Testing P2P Functionality
+
+1. Open the app in multiple browser tabs/windows
+2. **Create polls** from different tabs - they appear everywhere instantly
+3. **Add answer options** from different tabs to the same poll
+4. **Vote** from different tabs - watch vote counts update in real-time
+5. Try voting twice on the same option - it won't let you!
+6. Check the connection status indicator for peer count
+7. Verify visual feedback (green border) on options you've voted on
+
+## Development
+
+### Backend Scripts
+- `npm run dev` - Start development server with hot reload
+- `npm run build` - Build for production
+- `npm start` - Run production build
+
+### Frontend Scripts
+- `npm run dev` - Start Vite dev server
+- `npm run build` - Build for production
+- `npm run preview` - Preview production build
+
+## Environment Variables
+
+### Backend (.env)
+```
+PORT=3000
+YJS_WS_PORT=1234
+NODE_ENV=development
+CORS_ORIGIN=http://localhost:5173
+```
+
+### Frontend (.env)
+```
+VITE_WS_URL=ws://localhost:3000
+```
+
+## Components
+
+### Frontend Components
+- **PollView** - Main view showing all polls and create poll form
+- **CreatePoll** - Form to create new polls
+- **PollCard** - Individual poll display with metadata
+- **OptionList** - List of answer options with vote tracking
+- **AddOption** - Form to add new answer options
+- **VoteButton** - Vote button with disabled state for voted options
+- **ConnectionStatus** - Shows WebSocket and P2P connection status
+
+### Key Functions
+- `createPoll(question)` - Create a new poll
+- `addOption(pollId, text)` - Add an option to a specific poll
+- `vote(pollId, optionId)` - Vote on an option (one vote per user)
+- `hasVoted(option)` - Check if current user has voted on an option
+
+## User Tracking
+
+Each user gets a unique ID stored in localStorage:
+- Format: `user-xxxxxxxxx`
+- Used to track poll/option creators
+- Used to prevent duplicate voting
+- Persists across browser sessions
+
+## Future Enhancements
+
+- [ ] Edit/delete polls and options
+- [ ] User nicknames instead of IDs
+- [ ] Poll expiration/closing
+- [ ] Vote history and analytics
+- [ ] Export poll results
+- [ ] Persistent storage (database)
+- [ ] Dark mode toggle
+- [ ] Mobile responsive improvements
+- [ ] Poll categories/tags
+- [ ] Search/filter polls
+
+## License
+
+MIT

frontend/.env.example

@@ -0,0 +1 @@
+VITE_WS_URL=ws://localhost:3000

frontend/.gitignore

@@ -0,0 +1,6 @@
+node_modules
+dist
+dist-ssr
+*.local
+.env
+.DS_Store

frontend/index.html

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+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/vite.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>P2P Poll App</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>

frontend/package.json

@@ -0,0 +1,35 @@
+{
+  "name": "p2p-poll-frontend",
+  "private": true,
+  "version": "1.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc && vite build",
+    "preview": "vite preview",
+    "lint": "eslint . --ext ts,tsx --report-unused-disable-directives --max-warnings 0"
+  },
+  "dependencies": {
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "yjs": "^13.6.8",
+    "y-websocket": "^1.5.0",
+    "y-webrtc": "^10.2.5",
+    "lucide-react": "^0.294.0"
+  },
+  "devDependencies": {
+    "@types/react": "^18.2.37",
+    "@types/react-dom": "^18.2.15",
+    "@typescript-eslint/eslint-plugin": "^6.10.0",
+    "@typescript-eslint/parser": "^6.10.0",
+    "@vitejs/plugin-react": "^4.2.0",
+    "autoprefixer": "^10.4.16",
+    "eslint": "^8.53.0",
+    "eslint-plugin-react-hooks": "^4.6.0",
+    "eslint-plugin-react-refresh": "^0.4.4",
+    "postcss": "^8.4.31",
+    "tailwindcss": "^3.3.5",
+    "typescript": "^5.2.2",
+    "vite": "^5.0.0"
+  }
+}

frontend/postcss.config.js

@@ -0,0 +1,6 @@
+export default {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+}

frontend/src/App.tsx

@@ -0,0 +1,8 @@
+import { PollView } from './components/PollView';
+import './styles/index.css';
+
+function App() {
+  return <PollView />;
+}
+
+export default App;

frontend/src/components/AddOption.tsx

@@ -0,0 +1,38 @@
+import { useState } from 'react';
+import { Plus } from 'lucide-react';
+
+interface AddOptionProps {
+  onAdd: (text: string) => void;
+}
+
+export function AddOption({ onAdd }: AddOptionProps) {
+  const [text, setText] = useState('');
+
+  const handleSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    if (text.trim()) {
+      onAdd(text);
+      setText('');
+    }
+  };
+
+  return (
+    <form onSubmit={handleSubmit} className="flex gap-2">
+      <input
+        type="text"
+        value={text}
+        onChange={(e) => setText(e.target.value)}
+        placeholder="Add a new option..."
+        className="flex-1 px-4 py-3 rounded-lg bg-white/10 border border-white/20 text-white placeholder-white/50 focus:outline-none focus:ring-2 focus:ring-white/30"
+      />
+      <button
+        type="submit"
+        disabled={!text.trim()}
+        className="px-6 py-3 bg-white text-purple-600 rounded-lg font-semibold hover:bg-white/90 disabled:opacity-50 disabled:cursor-not-allowed transition-all duration-200 flex items-center gap-2"
+      >
+        <Plus className="w-5 h-5" />
+        Add
+      </button>
+    </form>
+  );
+}

frontend/src/components/ConnectionStatus.tsx

@@ -0,0 +1,34 @@
+import { Wifi, WifiOff, Users } from 'lucide-react';
+
+interface ConnectionStatusProps {
+  isConnected: boolean;
+  wsProvider: any;
+  webrtcProvider: any;
+}
+
+export function ConnectionStatus({ isConnected, wsProvider, webrtcProvider }: ConnectionStatusProps) {
+  const peerCount = webrtcProvider?.room?.peers?.size || 0;
+
+  return (
+    <div className="flex items-center gap-4 text-white/90 text-sm">
+      <div className="flex items-center gap-2">
+        {isConnected ? (
+          <>
+            <Wifi className="w-4 h-4 text-green-400" />
+            <span>Connected</span>
+          </>
+        ) : (
+          <>
+            <WifiOff className="w-4 h-4 text-red-400" />
+            <span>Disconnected</span>
+          </>
+        )}
+      </div>
+      
+      <div className="flex items-center gap-2">
+        <Users className="w-4 h-4" />
+        <span>{peerCount} peer{peerCount !== 1 ? 's' : ''}</span>
+      </div>
+    </div>
+  );
+}

frontend/src/components/CreatePoll.tsx

@@ -0,0 +1,43 @@
+import { useState } from 'react';
+import { Plus } from 'lucide-react';
+
+interface CreatePollProps {
+  onCreate: (question: string) => void;
+}
+
+export function CreatePoll({ onCreate }: CreatePollProps) {
+  const [question, setQuestion] = useState('');
+
+  const handleSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    if (question.trim()) {
+      onCreate(question);
+      setQuestion('');
+    }
+  };
+
+  return (
+    <form onSubmit={handleSubmit} className="mb-8">
+      <div className="bg-white/10 backdrop-blur-lg rounded-2xl shadow-2xl p-6 border border-white/20">
+        <h2 className="text-xl font-bold text-white mb-4">Create a New Poll</h2>
+        <div className="flex gap-2">
+          <input
+            type="text"
+            value={question}
+            onChange={(e) => setQuestion(e.target.value)}
+            placeholder="Enter your question..."
+            className="flex-1 px-4 py-3 rounded-lg bg-white/10 border border-white/20 text-white placeholder-white/50 focus:outline-none focus:ring-2 focus:ring-white/30"
+          />
+          <button
+            type="submit"
+            disabled={!question.trim()}
+            className="px-6 py-3 bg-white text-purple-600 rounded-lg font-semibold hover:bg-white/90 disabled:opacity-50 disabled:cursor-not-allowed transition-all duration-200 flex items-center gap-2"
+          >
+            <Plus className="w-5 h-5" />
+            Create Poll
+          </button>
+        </div>
+      </div>
+    </form>
+  );
+}

frontend/src/components/OptionList.tsx

@@ -0,0 +1,60 @@
+import { PollOption } from '../types/poll.types';
+import { VoteButton } from './VoteButton';
+
+interface OptionListProps {
+  options: PollOption[];
+  onVote: (optionId: string) => void;
+  hasVoted?: (option: PollOption) => boolean;
+}
+
+export function OptionList({ options, onVote, hasVoted }: OptionListProps) {
+  const totalVotes = options.reduce((sum, opt) => sum + opt.votes, 0);
+
+  const sortedOptions = [...options].sort((a, b) => b.votes - a.votes);
+
+  return (
+    <div className="space-y-3">
+      {sortedOptions.length === 0 ? (
+        <div className="text-center py-8 text-white/60">
+          No options yet. Add one to get started!
+        </div>
+      ) : (
+        sortedOptions.map((option) => {
+          const percentage = totalVotes > 0 ? (option.votes / totalVotes) * 100 : 0;
+          const userHasVoted = hasVoted ? hasVoted(option) : false;
+          
+          return (
+            <div
+              key={option.id}
+              className={`bg-white/10 backdrop-blur-sm rounded-lg p-4 border transition-all duration-200 ${
+                userHasVoted 
+                  ? 'border-green-400/50 bg-green-400/10' 
+                  : 'border-white/20 hover:border-white/30'
+              }`}
+            >
+              <div className="flex items-center justify-between mb-2">
+                <span className="text-white font-medium text-lg">
+                  {option.text}
+                  {userHasVoted && <span className="ml-2 text-green-400 text-sm">✓ Voted</span>}
+                </span>
+                <VoteButton optionId={option.id} votes={option.votes} onVote={onVote} disabled={userHasVoted} />
+              </div>
+              
+              <div className="w-full bg-white/10 rounded-full h-2 overflow-hidden">
+                <div
+                  className="bg-gradient-to-r from-green-400 to-blue-500 h-full transition-all duration-500 ease-out"
+                  style={{ width: `${percentage}%` }}
+                />
+              </div>
+              
+              <div className="mt-2 flex justify-between text-xs text-white/60">
+                <span>by {option.createdBy}</span>
+                <span>{percentage.toFixed(1)}%</span>
+              </div>
+            </div>
+          );
+        })
+      )}
+    </div>
+  );
+}

frontend/src/components/PollCard.tsx

@@ -0,0 +1,50 @@
+import { Poll } from '../types/poll.types';
+import { AddOption } from './AddOption';
+import { OptionList } from './OptionList';
+import { User, Clock } from 'lucide-react';
+
+interface PollCardProps {
+  poll: Poll;
+  onAddOption: (pollId: string, text: string) => void;
+  onVote: (pollId: string, optionId: string) => void;
+  hasVoted: (option: any) => boolean;
+}
+
+export function PollCard({ poll, onAddOption, onVote, hasVoted }: PollCardProps) {
+  const handleAddOption = (text: string) => {
+    onAddOption(poll.id, text);
+  };
+
+  const handleVote = (optionId: string) => {
+    onVote(poll.id, optionId);
+  };
+
+  const formatTime = (timestamp: number) => {
+    const date = new Date(timestamp);
+    return date.toLocaleString();
+  };
+
+  return (
+    <div className="bg-white/10 backdrop-blur-lg rounded-2xl shadow-2xl p-8 border border-white/20 mb-6">
+      <div className="mb-6">
+        <h2 className="text-3xl font-bold text-white mb-3">{poll.question}</h2>
+        <div className="flex items-center gap-4 text-white/60 text-sm">
+          <div className="flex items-center gap-1">
+            <User className="w-4 h-4" />
+            <span>{poll.createdBy}</span>
+          </div>
+          <div className="flex items-center gap-1">
+            <Clock className="w-4 h-4" />
+            <span>{formatTime(poll.timestamp)}</span>
+          </div>
+        </div>
+      </div>
+
+      <div className="mb-6">
+        <AddOption onAdd={handleAddOption} />
+      </div>
+
+      <OptionList options={poll.options} onVote={handleVote} hasVoted={hasVoted} />
+    </div>
+  );
+}

frontend/src/components/PollView.tsx

@@ -0,0 +1,57 @@
+import { RefreshCw } from 'lucide-react';
+import { usePoll } from '../hooks/usePoll';
+import { CreatePoll } from './CreatePoll';
+import { PollCard } from './PollCard';
+import { ConnectionStatus } from './ConnectionStatus';
+
+export function PollView() {
+  const { polls, createPoll, addOption, vote, hasVoted, isConnected, wsProvider, webrtcProvider } = usePoll();
+
+  return (
+    <div className="min-h-screen p-4 py-8">
+      <div className="max-w-4xl mx-auto">
+        <div className="mb-8 flex items-center justify-between">
+          <div>
+            <h1 className="text-4xl font-bold text-white mb-2">P2P Polling App</h1>
+            <p className="text-white/70">Create polls, add answers, and vote in real-time</p>
+          </div>
+          <ConnectionStatus 
+            isConnected={isConnected} 
+            wsProvider={wsProvider}
+            webrtcProvider={webrtcProvider}
+          />
+        </div>
+
+        <CreatePoll onCreate={createPoll} />
+
+        {polls.length === 0 ? (
+          <div className="bg-white/10 backdrop-blur-lg rounded-2xl shadow-2xl p-12 border border-white/20 text-center">
+            <p className="text-white/60 text-lg mb-2">No polls yet!</p>
+            <p className="text-white/40">Create the first poll to get started.</p>
+          </div>
+        ) : (
+          <div className="space-y-6">
+            {polls.map((poll) => (
+              <PollCard
+                key={poll.id}
+                poll={poll}
+                onAddOption={addOption}
+                onVote={vote}
+                hasVoted={hasVoted}
+              />
+            ))}
+          </div>
+        )}
+
+        <div className="mt-8 text-center text-white/50 text-sm">
+          <p>QUIC P2P Experiment !</p>
+          <p className="flex items-center justify-center gap-2 mt-1">
+            <RefreshCw className="w-4 h-4" />
+            Real-time P2P synchronization with Yjs
+          </p>
+          <p className="mt-1">Open multiple tabs to see live updates!</p>
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/components/VoteButton.tsx

@@ -0,0 +1,25 @@
+import { ThumbsUp } from 'lucide-react';
+
+interface VoteButtonProps {
+  optionId: string;
+  votes: number;
+  onVote: (optionId: string) => void;
+  disabled?: boolean;
+}
+
+export function VoteButton({ optionId, votes, onVote, disabled = false }: VoteButtonProps) {
+  return (
+    <button
+      onClick={() => !disabled && onVote(optionId)}
+      disabled={disabled}
+      className={`flex items-center gap-2 px-4 py-2 rounded-lg transition-all duration-200 text-white font-medium ${
+        disabled 
+          ? 'bg-white/10 cursor-not-allowed opacity-60' 
+          : 'bg-white/20 hover:bg-white/30'
+      }`}
+    >
+      <ThumbsUp className="w-4 h-4" />
+      <span>{votes}</span>
+    </button>
+  );
+}

frontend/src/hooks/usePoll.ts

@@ -0,0 +1,37 @@
+import { useCallback } from 'react';
+import { pollManager } from '../lib/poll-manager';
+import { useYjsSync } from './useYjsSync';
+
+export function usePoll() {
+  const { polls, isConnected, wsProvider, webrtcProvider } = useYjsSync();
+
+  const createPoll = useCallback((question: string) => {
+    return pollManager.createPoll(question);
+  }, []);
+
+  const addOption = useCallback((pollId: string, text: string) => {
+    pollManager.addOption(pollId, text);
+  }, []);
+
+  const vote = useCallback((pollId: string, optionId: string) => {
+    pollManager.vote(pollId, optionId);
+  }, []);
+
+  const hasVoted = useCallback((option: any) => {
+    return pollManager.hasVoted(option);
+  }, []);
+
+  const userId = pollManager.getUserId();
+
+  return {
+    polls,
+    createPoll,
+    addOption,
+    vote,
+    hasVoted,
+    userId,
+    isConnected,
+    wsProvider,
+    webrtcProvider
+  };
+}

frontend/src/hooks/useYjsSync.ts

@@ -0,0 +1,44 @@
+import { useEffect, useState } from 'react';
+import { Poll } from '../types/poll.types';
+import { 
+  initializeProviders, 
+  destroyProviders, 
+  yPolls,
+  wsProvider,
+  webrtcProvider 
+} from '../lib/yjs-setup';
+
+export function useYjsSync() {
+  const [polls, setPolls] = useState<Poll[]>([]);
+  const [isConnected, setIsConnected] = useState(false);
+
+  useEffect(() => {
+    const { wsProvider: ws } = initializeProviders();
+
+    const updatePolls = () => {
+      setPolls([...yPolls.toArray()]);
+    };
+
+    yPolls.observe(updatePolls);
+    updatePolls();
+
+    const handleStatus = (event: { status: string }) => {
+      setIsConnected(event.status === 'connected');
+    };
+
+    ws?.on('status', handleStatus);
+
+    return () => {
+      yPolls.unobserve(updatePolls);
+      ws?.off('status', handleStatus);
+      destroyProviders();
+    };
+  }, []);
+
+  return { 
+    polls, 
+    isConnected,
+    wsProvider,
+    webrtcProvider
+  };
+}

frontend/src/lib/poll-manager.ts

@@ -0,0 +1,43 @@
+import { PollOption } from '../types/poll.types';
+import { createPoll as yjsCreatePoll, addOption as yjsAddOption, voteForOption as yjsVoteForOption } from './yjs-setup';
+
+export class PollManager {
+  private userId: string;
+
+  constructor() {
+    this.userId = this.generateUserId();
+  }
+
+  private generateUserId(): string {
+    const stored = localStorage.getItem('p2p-poll-user-id');
+    if (stored) return stored;
+    
+    const newId = 'user-' + Math.random().toString(36).substr(2, 9);
+    localStorage.setItem('p2p-poll-user-id', newId);
+    return newId;
+  }
+
+  getUserId(): string {
+    return this.userId;
+  }
+
+  createPoll(question: string): string {
+    if (!question.trim()) return '';
+    return yjsCreatePoll(question.trim(), this.userId);
+  }
+
+  addOption(pollId: string, text: string): void {
+    if (!text.trim()) return;
+    yjsAddOption(pollId, text.trim(), this.userId);
+  }
+
+  vote(pollId: string, optionId: string): void {
+    yjsVoteForOption(pollId, optionId, this.userId);
+  }
+
+  hasVoted(option: PollOption): boolean {
+    return option.votedBy.includes(this.userId);
+  }
+}
+
+export const pollManager = new PollManager();

frontend/src/lib/yjs-setup.ts

@@ -0,0 +1,133 @@
+import * as Y from 'yjs';
+import { WebsocketProvider } from 'y-websocket';
+import { WebrtcProvider } from 'y-webrtc';
+import { Poll, PollOption } from '../types/poll.types';
+
+const WS_URL = import.meta.env.VITE_WS_URL || 'ws://localhost:3000';
+const ROOM_NAME = 'default-poll';
+
+export const ydoc = new Y.Doc();
+
+export const yPolls = ydoc.getArray<Poll>('polls');
+
+export let wsProvider: WebsocketProvider | null = null;
+export let webrtcProvider: WebrtcProvider | null = null;
+
+export function initializeProviders() {
+  wsProvider = new WebsocketProvider(
+    WS_URL + '/yjs',
+    ROOM_NAME,
+    ydoc,
+    { connect: true }
+  );
+
+  webrtcProvider = new WebrtcProvider(
+    ROOM_NAME,
+    ydoc,
+    { 
+      signaling: [WS_URL.replace('ws://', 'wss://').replace('http://', 'https://') + '/signal'],
+      password: null,
+      awareness: wsProvider.awareness,
+      maxConns: 20,
+      filterBcConns: true,
+      peerOpts: {}
+    }
+  );
+
+  wsProvider.on('status', (event: { status: string }) => {
+    console.log('WebSocket status:', event.status);
+  });
+
+  webrtcProvider.on('synced', (synced: boolean) => {
+    console.log('WebRTC synced:', synced);
+  });
+
+  return { wsProvider, webrtcProvider };
+}
+
+export function destroyProviders() {
+  wsProvider?.destroy();
+  webrtcProvider?.destroy();
+}
+
+export function createPoll(question: string, createdBy: string): string {
+  const pollId = Math.random().toString(36).substr(2, 9);
+  const poll: Poll = {
+    id: pollId,
+    question,
+    createdBy,
+    timestamp: Date.now(),
+    options: []
+  };
+  
+  yPolls.push([poll]);
+  return pollId;
+}
+
+export function addOption(pollId: string, text: string, createdBy: string): void {
+  const polls = yPolls.toArray();
+  const pollIndex = polls.findIndex(p => p.id === pollId);
+  
+  if (pollIndex !== -1) {
+    const poll = polls[pollIndex];
+    const option: PollOption = {
+      id: Math.random().toString(36).substr(2, 9),
+      text,
+      votes: 0,
+      votedBy: [],
+      createdBy,
+      timestamp: Date.now()
+    };
+    
+    const updatedPoll = {
+      ...poll,
+      options: [...poll.options, option]
+    };
+    
+    yPolls.delete(pollIndex, 1);
+    yPolls.insert(pollIndex, [updatedPoll]);
+  }
+}
+
+export function voteForOption(pollId: string, optionId: string, userId: string): void {
+  const polls = yPolls.toArray();
+  const pollIndex = polls.findIndex(p => p.id === pollId);
+  
+  if (pollIndex !== -1) {
+    const poll = polls[pollIndex];
+    const optionIndex = poll.options.findIndex(opt => opt.id === optionId);
+    
+    if (optionIndex !== -1) {
+      const option = poll.options[optionIndex];
+      
+      if (option.votedBy.includes(userId)) {
+        return;
+      }
+      
+      const updatedOption = {
+        ...option,
+        votes: option.votes + 1,
+        votedBy: [...option.votedBy, userId]
+      };
+      
+      const updatedOptions = [...poll.options];
+      updatedOptions[optionIndex] = updatedOption;
+      
+      const updatedPoll = {
+        ...poll,
+        options: updatedOptions
+      };
+      
+      yPolls.delete(pollIndex, 1);
+      yPolls.insert(pollIndex, [updatedPoll]);
+    }
+  }
+}
+
+export function getPolls(): Poll[] {
+  return yPolls.toArray();
+}
+
+export function getPoll(pollId: string): Poll | undefined {
+  return yPolls.toArray().find(p => p.id === pollId);
+}

frontend/src/main.tsx

@@ -0,0 +1,9 @@
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+import App from './App';
+
+ReactDOM.createRoot(document.getElementById('root')!).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>,
+);

frontend/src/styles/index.css

@@ -0,0 +1,17 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+body {
+  margin: 0;
+  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
+    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
+    sans-serif;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+#root {
+  min-height: 100vh;
+  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+}

frontend/src/types/poll.types.ts

@@ -0,0 +1,22 @@
+export interface PollOption {
+  id: string;
+  text: string;
+  votes: number;
+  votedBy: string[];
+  createdBy: string;
+  timestamp: number;
+}
+
+export interface Poll {
+  id: string;
+  question: string;
+  createdBy: string;
+  timestamp: number;
+  options: PollOption[];
+}
+
+export interface ConnectionStatus {
+  websocket: boolean;
+  webrtc: boolean;
+  peers: number;
+}

frontend/tailwind.config.js

@@ -0,0 +1,11 @@
+/** @type {import('tailwindcss').Config} */
+export default {
+  content: [
+    "./index.html",
+    "./src/**/*.{js,ts,jsx,tsx}",
+  ],
+  theme: {
+    extend: {},
+  },
+  plugins: [],
+}

frontend/tsconfig.json

@@ -0,0 +1,21 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "useDefineForClassFields": true,
+    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "module": "ESNext",
+    "skipLibCheck": true,
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "noEmit": true,
+    "jsx": "react-jsx",
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true
+  },
+  "include": ["src"],
+  "references": [{ "path": "./tsconfig.node.json" }]
+}

frontend/tsconfig.node.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "composite": true,
+    "skipLibCheck": true,
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "allowSyntheticDefaultImports": true
+  },
+  "include": ["vite.config.ts"]
+}

frontend/vite.config.ts

@@ -0,0 +1,10 @@
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+
+export default defineConfig({
+  plugins: [react()],
+  server: {
+    port: 5173,
+    host: true
+  }
+})

server/.env.example

@@ -0,0 +1,4 @@
+PORT=3000
+YJS_WS_PORT=1234
+NODE_ENV=development
+CORS_ORIGIN=http://localhost:5173

server/.gitignore

@@ -0,0 +1,5 @@
+node_modules/
+dist/
+.env
+*.log
+.DS_Store

server/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "p2p-poll-server",
+  "version": "1.0.0",
+  "description": "Backend server for P2P polling app with Yjs and WebRTC signaling",
+  "main": "dist/index.js",
+  "scripts": {
+    "dev": "tsx watch src/index.ts",
+    "build": "tsc",
+    "start": "node dist/index.js"
+  },
+  "keywords": ["yjs", "websocket", "webrtc", "p2p"],
+  "author": "",
+  "license": "MIT",
+  "dependencies": {
+    "express": "^4.18.2",
+    "ws": "^8.14.2",
+    "y-websocket": "^1.5.0",
+    "yjs": "^13.6.8",
+    "cors": "^2.8.5",
+    "dotenv": "^16.3.1"
+  },
+  "devDependencies": {
+    "@types/express": "^4.17.20",
+    "@types/ws": "^8.5.8",
+    "@types/cors": "^2.8.15",
+    "@types/node": "^20.9.0",
+    "tsx": "^4.6.2",
+    "typescript": "^5.2.2"
+  }
+}

server/src/index.ts

@@ -0,0 +1,59 @@
+import express from 'express';
+import http from 'http';
+import cors from 'cors';
+import dotenv from 'dotenv';
+import { createYjsServer } from './yjs-server';
+import { createSignalingServer } from './signaling-server';
+import { logger } from './utils/logger';
+
+dotenv.config();
+
+const app = express();
+const PORT = process.env.PORT || 3000;
+
+app.use(cors({
+  origin: process.env.CORS_ORIGIN || 'http://localhost:5173',
+  credentials: true
+}));
+
+app.use(express.json());
+
+app.get('/health', (req, res) => {
+  res.json({ 
+    status: 'ok', 
+    timestamp: new Date().toISOString(),
+    services: {
+      yjs: 'running',
+      signaling: 'running'
+    }
+  });
+});
+
+app.get('/', (req, res) => {
+  res.json({ 
+    message: 'P2P Poll Server',
+    endpoints: {
+      health: '/health',
+      yjs: 'ws://localhost:' + PORT + '/yjs',
+      signaling: 'ws://localhost:' + PORT + '/signal'
+    }
+  });
+});
+
+const server = http.createServer(app);
+
+createYjsServer(server, PORT as number);
+createSignalingServer(server);
+
+server.listen(PORT, () => {
+  logger.info(`Server running on port ${PORT}`);
+  logger.info(`Yjs WebSocket: ws://localhost:${PORT}/yjs`);
+  logger.info(`Signaling WebSocket: ws://localhost:${PORT}/signal`);
+});
+
+process.on('SIGTERM', () => {
+  logger.info('SIGTERM signal received: closing HTTP server');
+  server.close(() => {
+    logger.info('HTTP server closed');
+  });
+});

server/src/signaling-server.ts

@@ -0,0 +1,126 @@
+import { WebSocketServer, WebSocket } from 'ws';
+import http from 'http';
+import { SignalingMessage } from './types/poll.types';
+import { logger } from './utils/logger';
+
+interface Client {
+  id: string;
+  ws: WebSocket;
+  roomId: string;
+}
+
+export function createSignalingServer(server: http.Server) {
+  const wss = new WebSocketServer({ 
+    server,
+    path: '/signal'
+  });
+
+  const clients = new Map<string, Client>();
+  const rooms = new Map<string, Set<string>>();
+
+  wss.on('connection', (ws: WebSocket) => {
+    let clientId: string | null = null;
+
+    ws.on('message', (data: Buffer) => {
+      try {
+        const message: SignalingMessage = JSON.parse(data.toString());
+
+        switch (message.type) {
+          case 'join':
+            clientId = message.from;
+            const roomId = message.roomId || 'default-room';
+            
+            clients.set(clientId, { id: clientId, ws, roomId });
+            
+            if (!rooms.has(roomId)) {
+              rooms.set(roomId, new Set());
+            }
+            rooms.get(roomId)!.add(clientId);
+
+            logger.info(`Client ${clientId} joined room ${roomId}`);
+
+            const roomClients = Array.from(rooms.get(roomId)!).filter(id => id !== clientId);
+            ws.send(JSON.stringify({
+              type: 'peers',
+              peers: roomClients
+            }));
+
+            roomClients.forEach(peerId => {
+              const peer = clients.get(peerId);
+              if (peer && peer.ws.readyState === WebSocket.OPEN) {
+                peer.ws.send(JSON.stringify({
+                  type: 'peer-joined',
+                  peerId: clientId
+                }));
+              }
+            });
+            break;
+
+          case 'offer':
+          case 'answer':
+          case 'ice-candidate':
+            if (message.to) {
+              const targetClient = clients.get(message.to);
+              if (targetClient && targetClient.ws.readyState === WebSocket.OPEN) {
+                targetClient.ws.send(JSON.stringify({
+                  type: message.type,
+                  from: message.from,
+                  data: message.data
+                }));
+              }
+            }
+            break;
+
+          case 'leave':
+            handleClientLeave(message.from);
+            break;
+        }
+      } catch (error) {
+        logger.error('Error processing signaling message:', error);
+      }
+    });
+
+    ws.on('close', () => {
+      if (clientId) {
+        handleClientLeave(clientId);
+      }
+    });
+
+    ws.on('error', (error) => {
+      logger.error('WebSocket error:', error);
+    });
+  });
+
+  function handleClientLeave(clientId: string) {
+    const client = clients.get(clientId);
+    if (client) {
+      const roomId = client.roomId;
+      const room = rooms.get(roomId);
+      
+      if (room) {
+        room.delete(clientId);
+        
+        room.forEach(peerId => {
+          const peer = clients.get(peerId);
+          if (peer && peer.ws.readyState === WebSocket.OPEN) {
+            peer.ws.send(JSON.stringify({
+              type: 'peer-left',
+              peerId: clientId
+            }));
+          }
+        });
+
+        if (room.size === 0) {
+          rooms.delete(roomId);
+        }
+      }
+      
+      clients.delete(clientId);
+      logger.info(`Client ${clientId} left room ${roomId}`);
+    }
+  }
+
+  logger.info('Signaling server running at path /signal');
+  
+  return wss;
+}

server/src/types/poll.types.ts

@@ -0,0 +1,24 @@
+export interface PollOption {
+  id: string;
+  text: string;
+  votes: number;
+  votedBy: string[];
+  createdBy: string;
+  timestamp: number;
+}
+
+export interface Poll {
+  id: string;
+  question: string;
+  createdBy: string;
+  timestamp: number;
+  options: PollOption[];
+}
+
+export interface SignalingMessage {
+  type: 'offer' | 'answer' | 'ice-candidate' | 'join' | 'leave';
+  from: string;
+  to?: string;
+  data?: any;
+  roomId?: string;
+}

server/src/utils/logger.ts

@@ -0,0 +1,16 @@
+export const logger = {
+  info: (message: string, ...args: any[]) => {
+    console.log(`[INFO] ${new Date().toISOString()} - ${message}`, ...args);
+  },
+  error: (message: string, ...args: any[]) => {
+    console.error(`[ERROR] ${new Date().toISOString()} - ${message}`, ...args);
+  },
+  warn: (message: string, ...args: any[]) => {
+    console.warn(`[WARN] ${new Date().toISOString()} - ${message}`, ...args);
+  },
+  debug: (message: string, ...args: any[]) => {
+    if (process.env.NODE_ENV === 'development') {
+      console.debug(`[DEBUG] ${new Date().toISOString()} - ${message}`, ...args);
+    }
+  }
+};

server/src/yjs-server.ts

@@ -0,0 +1,26 @@
+import { WebSocketServer } from 'ws';
+import { setupWSConnection } from 'y-websocket/bin/utils';
+import http from 'http';
+import { logger } from './utils/logger';
+
+export function createYjsServer(server: http.Server, port: number) {
+  const wss = new WebSocketServer({ 
+    server,
+    path: '/yjs'
+  });
+
+  wss.on('connection', (ws, req) => {
+    const docName = req.url?.split('?')[1]?.split('=')[1] || 'default-poll';
+    logger.info(`New Yjs connection for document: ${docName}`);
+    
+    setupWSConnection(ws, req, { docName });
+  });
+
+  wss.on('error', (error) => {
+    logger.error('Yjs WebSocket server error:', error);
+  });
+
+  logger.info(`Yjs WebSocket server running on port ${port} at path /yjs`);
+  
+  return wss;
+}

server/tsconfig.json

@@ -0,0 +1,20 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "module": "commonjs",
+    "lib": ["ES2020"],
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "moduleResolution": "node",
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}