#!/usr/bin/env node

/**
 * Mock SigSocket Server for Testing Browser Extension
 * 
 * This is a simple WebSocket server that simulates the SigSocket protocol
 * for testing the browser extension functionality.
 * 
 * Usage:
 *   node mock_sigsocket_server.js
 * 
 * The server will listen on ws://localhost:8080/ws
 */

const WebSocket = require('ws');
const http = require('http');

class MockSigSocketServer {
    constructor(port = 8080) {
        this.port = port;
        this.clients = new Map(); // clientId -> { ws, publicKey }
        this.requestCounter = 0;
        
        this.setupServer();
    }

    setupServer() {
        // Create HTTP server
        this.httpServer = http.createServer();
        
        // Create WebSocket server
        this.wss = new WebSocket.Server({ 
            server: this.httpServer,
            path: '/ws'
        });

        this.wss.on('connection', (ws, req) => {
            console.log('New WebSocket connection from:', req.socket.remoteAddress);
            this.handleConnection(ws);
        });

        this.httpServer.listen(this.port, () => {
            console.log(`Mock SigSocket Server listening on ws://localhost:${this.port}/ws`);
            console.log('Waiting for browser extension connections...');
        });
    }

    handleConnection(ws) {
        let clientId = null;
        let publicKey = null;

        ws.on('message', (data) => {
            try {
                const message = data.toString();
                console.log('Received message:', message);

                // Check if this is a client introduction (hex-encoded public key)
                if (!clientId && this.isHexString(message)) {
                    publicKey = message;
                    clientId = this.generateClientId();
                    
                    this.clients.set(clientId, { ws, publicKey });
                    
                    console.log(`Client registered: ${clientId} with public key: ${publicKey.substring(0, 16)}...`);
                    
                    // Send welcome message
                    ws.send(JSON.stringify({
                        type: 'welcome',
                        clientId: clientId,
                        message: 'Connected to Mock SigSocket Server'
                    }));
                    
                    // Schedule a test sign request after 3 seconds
                    setTimeout(() => {
                        this.sendTestSignRequest(clientId);
                    }, 3000);
                    
                    return;
                }

                // Try to parse as JSON (sign response)
                try {
                    const jsonMessage = JSON.parse(message);
                    this.handleSignResponse(clientId, jsonMessage);
                } catch (e) {
                    console.log('Received non-JSON message:', message);
                }

            } catch (error) {
                console.error('Error handling message:', error);
            }
        });

        ws.on('close', () => {
            if (clientId) {
                this.clients.delete(clientId);
                console.log(`Client disconnected: ${clientId}`);
            }
        });

        ws.on('error', (error) => {
            console.error('WebSocket error:', error);
        });
    }

    handleSignResponse(clientId, response) {
        console.log(`Received sign response from ${clientId}:`, response);
        
        if (response.id && response.signature) {
            console.log(`✅ Sign request ${response.id} completed successfully`);
            console.log(`   Signature: ${response.signature.substring(0, 32)}...`);
            
            // Send another test request after 10 seconds
            setTimeout(() => {
                this.sendTestSignRequest(clientId);
            }, 10000);
        } else {
            console.log('❌ Invalid sign response format');
        }
    }

    sendTestSignRequest(clientId) {
        const client = this.clients.get(clientId);
        if (!client) {
            console.log(`Client ${clientId} not found`);
            return;
        }

        this.requestCounter++;
        const requestId = `req_${this.requestCounter}_${Date.now()}`;
        const testMessage = `Test message ${this.requestCounter} - ${new Date().toISOString()}`;
        const messageBase64 = Buffer.from(testMessage).toString('base64');

        const signRequest = {
            id: requestId,
            message: messageBase64
        };

        console.log(`📝 Sending sign request to ${clientId}:`, requestId);
        console.log(`   Message: "${testMessage}"`);

        try {
            client.ws.send(JSON.stringify(signRequest));
        } catch (error) {
            console.error(`Failed to send sign request to ${clientId}:`, error);
        }
    }

    isHexString(str) {
        return /^[0-9a-fA-F]+$/.test(str) && str.length >= 32; // At least 16 bytes
    }

    generateClientId() {
        return `client_${Date.now()}_${Math.random().toString(36).substring(2, 8)}`;
    }

    // Send a test request to all connected clients
    broadcastTestRequest() {
        console.log('\n📢 Broadcasting test sign request to all clients...');
        for (const [clientId] of this.clients) {
            this.sendTestSignRequest(clientId);
        }
    }

    // Get server status
    getStatus() {
        return {
            port: this.port,
            connectedClients: this.clients.size,
            clients: Array.from(this.clients.keys())
        };
    }
}

// Create and start the server
const server = new MockSigSocketServer();

// Handle graceful shutdown
process.on('SIGINT', () => {
    console.log('\n🛑 Shutting down Mock SigSocket Server...');
    server.httpServer.close(() => {
        console.log('Server closed');
        process.exit(0);
    });
});

// Add some interactive commands
process.stdin.setEncoding('utf8');
console.log('\n📋 Available commands:');
console.log('  "test" - Send test sign request to all clients');
console.log('  "status" - Show server status');
console.log('  "quit" - Shutdown server');
console.log('  Type a command and press Enter\n');

process.stdin.on('readable', () => {
    const chunk = process.stdin.read();
    if (chunk !== null) {
        const command = chunk.trim().toLowerCase();
        
        switch (command) {
            case 'test':
                server.broadcastTestRequest();
                break;
                
            case 'status':
                const status = server.getStatus();
                console.log('\n📊 Server Status:');
                console.log(`   Port: ${status.port}`);
                console.log(`   Connected clients: ${status.connectedClients}`);
                if (status.clients.length > 0) {
                    console.log(`   Client IDs: ${status.clients.join(', ')}`);
                }
                console.log('');
                break;
                
            case 'quit':
            case 'exit':
                process.emit('SIGINT');
                break;
                
            case '':
                break;
                
            default:
                console.log(`Unknown command: ${command}`);
                break;
        }
    }
});

// Export for testing
module.exports = MockSigSocketServer;