import { tap, expect } from '@git.zone/tstest/tapbundle';
import { SmartProxy, createHttpRoute } from '../ts/index.js';
import * as http from 'http';

tap.test('should not have memory leaks in long-running operations', async (tools) => {
  // Get initial memory usage
  const getMemoryUsage = () => {
    if (global.gc) {
      global.gc();
    }
    const usage = process.memoryUsage();
    return {
      heapUsed: Math.round(usage.heapUsed / 1024 / 1024), // MB
      external: Math.round(usage.external / 1024 / 1024), // MB
      rss: Math.round(usage.rss / 1024 / 1024) // MB
    };
  };

  // Create a target server
  const targetServer = http.createServer((req, res) => {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('OK');
  });
  await new Promise<void>((resolve) => targetServer.listen(3100, resolve));

  // Create the proxy - use non-privileged port
  const routes = [
    createHttpRoute(['test1.local', 'test2.local', 'test3.local'], { host: 'localhost', port: 3100 }),
  ];
  // Update route to use port 8080
  routes[0].match.ports = 8080;
  
  const proxy = new SmartProxy({
    ports: [8080], // Use non-privileged port
    routes: routes
  });
  await proxy.start();

  console.log('Starting memory leak test...');
  const initialMemory = getMemoryUsage();
  console.log('Initial memory:', initialMemory);

  // Function to make requests
  const makeRequest = (domain: string): Promise<void> => {
    return new Promise((resolve, reject) => {
      const req = http.request({
        hostname: 'localhost',
        port: 8080,
        path: '/',
        method: 'GET',
        headers: {
          'Host': domain
        }
      }, (res) => {
        res.on('data', () => {});
        res.on('end', resolve);
      });
      req.on('error', reject);
      req.end();
    });
  };

  // Test 1: Many requests to the same routes
  console.log('Test 1: Making 1000 requests to same routes...');
  for (let i = 0; i < 1000; i++) {
    await makeRequest(`test${(i % 3) + 1}.local`);
    if (i % 100 === 0) {
      console.log(`  Progress: ${i}/1000`);
    }
  }
  
  const afterSameRoutesMemory = getMemoryUsage();
  console.log('Memory after same routes:', afterSameRoutesMemory);

  // Test 2: Many requests to different routes (tests routeContextCache)
  console.log('Test 2: Making 1000 requests to different routes...');
  for (let i = 0; i < 1000; i++) {
    // Create unique domain to test cache growth
    await makeRequest(`test${i}.local`);
    if (i % 100 === 0) {
      console.log(`  Progress: ${i}/1000`);
    }
  }
  
  const afterDifferentRoutesMemory = getMemoryUsage();
  console.log('Memory after different routes:', afterDifferentRoutesMemory);

  // Test 3: Check metrics collector memory
  console.log('Test 3: Checking metrics collector...');
  const stats = proxy.getStats();
  console.log(`Active connections: ${stats.getActiveConnections()}`);
  console.log(`Total connections: ${stats.getTotalConnections()}`);
  console.log(`RPS: ${stats.getRequestsPerSecond()}`);
  
  // Test 4: Many rapid connections (tests requestTimestamps array)
  console.log('Test 4: Making 10000 rapid requests...');
  const rapidRequests = [];
  for (let i = 0; i < 10000; i++) {
    rapidRequests.push(makeRequest('test1.local'));
    if (i % 1000 === 0) {
      // Wait a bit to let some complete
      await Promise.all(rapidRequests);
      rapidRequests.length = 0;
      console.log(`  Progress: ${i}/10000`);
    }
  }
  await Promise.all(rapidRequests);
  
  const afterRapidMemory = getMemoryUsage();
  console.log('Memory after rapid requests:', afterRapidMemory);

  // Force garbage collection and check final memory
  await new Promise(resolve => setTimeout(resolve, 1000));
  const finalMemory = getMemoryUsage();
  console.log('Final memory:', finalMemory);

  // Memory leak checks
  const memoryGrowth = finalMemory.heapUsed - initialMemory.heapUsed;
  console.log(`Total memory growth: ${memoryGrowth} MB`);

  // Check for excessive memory growth
  // Allow some growth but not excessive (e.g., more than 50MB for this test)
  expect(memoryGrowth).toBeLessThan(50);
  
  // Check specific potential leaks
  // 1. Route context cache should not grow unbounded
  const routeHandler = proxy.routeConnectionHandler as any;
  if (routeHandler.routeContextCache) {
    console.log(`Route context cache size: ${routeHandler.routeContextCache.size}`);
    // Should not have 1000 entries from different routes test
    expect(routeHandler.routeContextCache.size).toBeLessThan(100);
  }

  // 2. Metrics collector should clean up old timestamps
  const metricsCollector = (proxy.getStats() as any);
  if (metricsCollector.requestTimestamps) {
    console.log(`Request timestamps array length: ${metricsCollector.requestTimestamps.length}`);
    // Should not exceed 10000 (the cleanup threshold)
    expect(metricsCollector.requestTimestamps.length).toBeLessThanOrEqual(10000);
  }

  // Cleanup
  await proxy.stop();
  await new Promise<void>((resolve) => targetServer.close(resolve));

  console.log('Memory leak test completed successfully');
});

// Run with: node --expose-gc test.memory-leak-check.node.ts
tap.start();