/**
 * Performance Metrics Collector
 * Real-time system and swarm performance monitoring
 */

class PerformanceMetricsCollector {
  constructor(swarm) {
    this.swarm = swarm;
    this.metrics = [];
    this.collectionInterval = null;
    this.maxSamples = 100;
  }

  startCollection(intervalMs = 60000) {
    this.collectionInterval = setInterval(() => {
      this.collect();
    }, intervalMs);
    this.swarm.log('success', 'Performance metrics collection started');
  }

  stopCollection() {
    if (this.collectionInterval) {
      clearInterval(this.collectionInterval);
      this.collectionInterval = null;
    }
  }

  collect() {
    const sample = {
      timestamp: Date.now(),
      memory: process.memoryUsage(),
      cpu: process.cpuUsage(),
      uptime: process.uptime(),
      agents: this.swarm.getPerformanceReport?.()?.agents || {}
    };
    this.metrics.push(sample);
    if (this.metrics.length > this.maxSamples) {
      this.metrics.shift();
    }
  }

  getReport() {
    if (this.metrics.length === 0) return { status: 'no_data' };

    const latest = this.metrics[this.metrics.length - 1];
    const previous = this.metrics.length > 1 ? this.metrics[this.metrics.length - 2] : latest;

    const memDiff = latest.memory.heapUsed - previous.memory.heapUsed;
    const trend = memDiff > 1000000 ? 'increasing' : memDiff < -1000000 ? 'decreasing' : 'stable';

    return {
      current: {
        heapUsed: `${(latest.memory.heapUsed / 1024 / 1024).toFixed(1)}MB`,
        heapTotal: `${(latest.memory.heapTotal / 1024 / 1024).toFixed(1)}MB`,
        rss: `${(latest.memory.rss / 1024 / 1024).toFixed(1)}MB`,
        uptime: `${Math.floor(latest.uptime)}s`,
        cpuUser: `${(latest.cpu.user / 1000000).toFixed(1)}s`,
        cpuSystem: `${(latest.cpu.system / 1000000).toFixed(1)}s`
      },
      trend,
      samples: this.metrics.length,
      recommendations: this.generateRecommendations(latest)
    };
  }

  generateRecommendations(sample) {
    const recs = [];
    const heapMB = sample.memory.heapUsed / 1024 / 1024;
    if (heapMB > 400) recs.push('⚠️ High memory usage — consider restarting');
    if (sample.uptime > 86400) recs.push('🔄 Long uptime — scheduled restart recommended');
    if (recs.length === 0) recs.push('✅ System performance within normal range');
    return recs;
  }
}

module.exports = PerformanceMetricsCollector;