@supernick135/face-scanner-client/examples/student-client.js

Node.js client library for ZKTeco face scanning devices integration with comprehensive API support

/**
 * Face Scanner Student Client Example
 * 
 * This example demonstrates how to use the Face Scanner WebSocket client
 * for a student to receive their own scan notifications with API key authentication.
 */

require('dotenv').config();
const WebSocketClient = require('../lib/client/WebSocketClient');

async function studentExample() {
  console.log('🎓 Starting Face Scanner Student Client Example');

  // Use configuration from .env file
  const config = {
    wsUrl: process.env.WS_URL || 'ws://localhost:8080/ws',
    apiKey: process.env.STUDENT_TOKEN,
    schoolId: process.env.SCHOOL_ID || 'sch001',
    studentId: process.env.STUDENT_ID || 'std12345',
    reconnect: process.env.RECONNECT === 'true',
    heartbeatInterval: parseInt(process.env.HEARTBEAT_INTERVAL || '30000')
  };

  // Check if token is configured
  if (!config.apiKey || config.apiKey === 'your-student-token-here') {
    console.error('❌ Please configure STUDENT_TOKEN in .env file');
    process.exit(1);
  }

  // Create student client using API key authentication
  const studentClient = WebSocketClient.createStudentClient(config);

  // Set up event listeners
  studentClient.on('connected', () => {
    console.log('✅ Student connected to Face Scanner server');
  });

  studentClient.on('authenticated', () => {
    console.log('🔐 Student authenticated successfully');
    console.log('📡 Student will automatically receive scan notifications for their ID');
  });

  studentClient.on('authError', (error) => {
    console.error('❌ Authentication failed:', error.message);
  });

  studentClient.on('disconnected', ({ code, reason }) => {
    console.log(`🔌 Student disconnected: ${code} - ${reason}`);
  });

  studentClient.on('reconnecting', (attempt) => {
    console.log(`🔄 Attempting to reconnect... (${attempt})`);
  });

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

  // Listen for face scan events related to this student
  studentClient.on('faceDetected', (data) => {
    console.log('👤 Face detected for you:', {
      deviceId: data.deviceId,
      confidence: data.confidence,
      timestamp: new Date(data.timestamp).toLocaleString()
    });
  });

  studentClient.on('scanComplete', (data) => {
    console.log('✅ Scan completed for you:', {
      deviceId: data.deviceId,
      success: data.success || 'completed',
      timestamp: new Date(data.timestamp).toLocaleString()
    });
    
    // Show success message
    if (data.success) {
      console.log('🎉 Your attendance has been recorded successfully!');
    }
  });

  studentClient.on('noFace', (data) => {
    console.log('👻 No face detected during your scan attempt:', {
      deviceId: data.deviceId,
      reason: data.reason,
      timestamp: new Date(data.timestamp).toLocaleString()
    });
  });

  studentClient.on('faceError', (data) => {
    console.log('⚠️ Error during your face scan:', {
      deviceId: data.deviceId,
      error: data.error,
      timestamp: new Date(data.timestamp).toLocaleString()
    });
  });

  // Listen for system alerts
  studentClient.on('systemAlert', (data) => {
    console.log('📢 System alert:', data);
  });

  // Handle pong responses
  studentClient.on('pong', (data) => {
    console.log('🏓 Received pong from server, connection is healthy');
  });

  try {
    // Connect to server
    await studentClient.connect();

    // Send periodic pings to keep connection alive
    const pingInterval = setInterval(() => {
      if (studentClient.isConnected) {
        studentClient.sendPingMessage();
        console.log('🏓 Sent ping to server');
      }
    }, 45000); // Every 45 seconds

    // Keep running and listening for events
    console.log('👂 Student client is now listening for scan events...');
    console.log('⏱️  Client will run for 2 minutes for demonstration...');
    
    setTimeout(() => {
      console.log('🛑 Shutting down student client');
      clearInterval(pingInterval);
      studentClient.disconnect();
      process.exit(0);
    }, 120000); // Run for 2 minutes

  } catch (error) {
    console.error('❌ Failed to start student client:', error);
    process.exit(1);
  }
}

// Handle process termination
process.on('SIGINT', () => {
  console.log('\n🛑 Received SIGINT, shutting down gracefully...');
  process.exit(0);
});

// Run the example
studentExample().catch(console.error);