#!/usr/bin/env node

/**
 * Test script for Random Primary Node Selection
 * Demonstrates how the random selection works
 */

const http = require('http');

const BASE_URL = 'http://localhost:3001';

function makeRequest(path, method = 'POST', body = null) {
  return new Promise((resolve, reject) => {
    const options = {
      hostname: 'localhost',
      port: 3001,
      path: path,
      method: method,
      headers: {
        'Content-Type': 'application/json'
      }
    };

    const req = http.request(options, (res) => {
      let data = '';
      
      res.on('data', (chunk) => {
        data += chunk;
      });
      
      res.on('end', () => {
        try {
          const jsonData = JSON.parse(data);
          resolve({ status: res.statusCode, data: jsonData });
        } catch (error) {
          resolve({ status: res.statusCode, data: data });
        }
      });
    });

    req.on('error', (error) => {
      reject(error);
    });

    if (body) {
      req.write(JSON.stringify(body));
    }

    req.end();
  });
}

async function testRandomSelection() {
  console.log('🎲 Testing Random Primary Node Selection');
  console.log('======================================');
  console.log('');
  
  try {
    // First, check current discovery status
    console.log('1. Checking current discovery status...');
    const discoveryResponse = await makeRequest('/api/discovery/nodes', 'GET');
    
    if (discoveryResponse.status !== 200) {
      console.log('❌ Failed to get discovery status');
      return;
    }
    
    const discovery = discoveryResponse.data;
    console.log(`   Current Primary: ${discovery.primaryNode || 'None'}`);
    console.log(`   Total Nodes: ${discovery.totalNodes}`);
    console.log(`   Client Initialized: ${discovery.clientInitialized}`);
    
    if (discovery.nodes.length === 0) {
      console.log('\n💡 No nodes discovered yet. Send some discovery messages first:');
      console.log('   npm run test-discovery broadcast');
      return;
    }
    
    console.log('\n2. Testing random primary node selection...');
    
    // Store current primary for comparison
    const currentPrimary = discovery.primaryNode;
    const availableNodes = discovery.nodes.map(n => n.ip);
    
    console.log(`   Available nodes: ${availableNodes.join(', ')}`);
    console.log(`   Current primary: ${currentPrimary}`);
    
    // Perform random selection
    const randomResponse = await makeRequest('/api/discovery/random-primary', 'POST', {
      timestamp: new Date().toISOString()
    });
    
    if (randomResponse.status === 200) {
      const result = randomResponse.data;
      console.log('\n✅ Random selection successful!');
      console.log(`   New Primary: ${result.primaryNode}`);
      console.log(`   Previous Primary: ${currentPrimary}`);
      console.log(`   Message: ${result.message}`);
      console.log(`   Total Nodes: ${result.totalNodes}`);
      console.log(`   Client Initialized: ${result.clientInitialized}`);
      
      // Verify the change
      if (result.primaryNode !== currentPrimary) {
        console.log('\n🎯 Primary node successfully changed!');
      } else {
        console.log('\n⚠️  Primary node remained the same (only one node available)');
      }
      
    } else {
      console.log('\n❌ Random selection failed:');
      console.log(`   Status: ${randomResponse.status}`);
      console.log(`   Error: ${randomResponse.data.error || 'Unknown error'}`);
    }
    
    // Show updated status
    console.log('\n3. Checking updated discovery status...');
    const updatedResponse = await makeRequest('/api/discovery/nodes', 'GET');
    if (updatedResponse.status === 200) {
      const updated = updatedResponse.data;
      console.log(`   Current Primary: ${updated.primaryNode}`);
      console.log(`   Client Base URL: ${updated.clientBaseUrl}`);
    }
    
    console.log('\n💡 To test in the frontend:');
    console.log('   1. Open http://localhost:3001 in your browser');
    console.log('   2. Look at the cluster header for primary node info');
    console.log('   3. Click the 🎲 button to randomly select a new primary node');
    console.log('   4. Watch the display change in real-time');
    
  } catch (error) {
    console.error('\n❌ Test failed:', error.message);
    console.log('\n💡 Make sure the backend is running: npm start');
  }
}

// Run the test
testRandomSelection().catch(console.error);