import * as plugins from '../plugins.js';
import { DcRouter } from '../classes.dcrouter.js';

export class MetricsManager {
  private logger: plugins.smartlog.Smartlog;
  private smartMetrics: plugins.smartmetrics.SmartMetrics;
  private dcRouter: DcRouter;
  private resetInterval?: NodeJS.Timeout;
  
  // Constants
  private readonly MAX_TOP_DOMAINS = 1000; // Limit topDomains Map size
  
  // Track email-specific metrics
  private emailMetrics = {
    sentToday: 0,
    receivedToday: 0,
    failedToday: 0,
    bouncedToday: 0,
    queueSize: 0,
    lastResetDate: new Date().toDateString(),
    deliveryTimes: [] as number[], // Track delivery times in ms
    recipients: new Map<string, number>(), // Track email count by recipient
    recentActivity: [] as Array<{ timestamp: number; type: string; details: string }>,
  };
  
  // Track DNS-specific metrics
  private dnsMetrics = {
    totalQueries: 0,
    cacheHits: 0,
    cacheMisses: 0,
    queryTypes: {} as Record<string, number>,
    topDomains: new Map<string, number>(),
    lastResetDate: new Date().toDateString(),
    queryTimestamps: [] as number[], // Track query timestamps for rate calculation
    responseTimes: [] as number[], // Track response times in ms
  };
  
  // Track security-specific metrics
  private securityMetrics = {
    blockedIPs: 0,
    authFailures: 0,
    spamDetected: 0,
    malwareDetected: 0,
    phishingDetected: 0,
    lastResetDate: new Date().toDateString(),
    incidents: [] as Array<{ timestamp: number; type: string; severity: string; details: string }>,
  };
  
  constructor(dcRouter: DcRouter) {
    this.dcRouter = dcRouter;
    // Create a new Smartlog instance for metrics
    this.logger = new plugins.smartlog.Smartlog({
      logContext: {
        environment: 'production',
        runtime: 'node',
        zone: 'dcrouter-metrics',
      }
    });
    this.smartMetrics = new plugins.smartmetrics.SmartMetrics(this.logger, 'dcrouter');
  }
  
  public async start(): Promise<void> {
    // Start SmartMetrics collection
    this.smartMetrics.start();
    
    // Reset daily counters at midnight
    this.resetInterval = setInterval(() => {
      const currentDate = new Date().toDateString();
      
      if (currentDate !== this.emailMetrics.lastResetDate) {
        this.emailMetrics.sentToday = 0;
        this.emailMetrics.receivedToday = 0;
        this.emailMetrics.failedToday = 0;
        this.emailMetrics.bouncedToday = 0;
        this.emailMetrics.deliveryTimes = [];
        this.emailMetrics.recipients.clear();
        this.emailMetrics.recentActivity = [];
        this.emailMetrics.lastResetDate = currentDate;
      }
      
      if (currentDate !== this.dnsMetrics.lastResetDate) {
        this.dnsMetrics.totalQueries = 0;
        this.dnsMetrics.cacheHits = 0;
        this.dnsMetrics.cacheMisses = 0;
        this.dnsMetrics.queryTypes = {};
        this.dnsMetrics.topDomains.clear();
        this.dnsMetrics.queryTimestamps = [];
        this.dnsMetrics.responseTimes = [];
        this.dnsMetrics.lastResetDate = currentDate;
      }
      
      if (currentDate !== this.securityMetrics.lastResetDate) {
        this.securityMetrics.blockedIPs = 0;
        this.securityMetrics.authFailures = 0;
        this.securityMetrics.spamDetected = 0;
        this.securityMetrics.malwareDetected = 0;
        this.securityMetrics.phishingDetected = 0;
        this.securityMetrics.incidents = [];
        this.securityMetrics.lastResetDate = currentDate;
      }
    }, 60000); // Check every minute
    
    this.logger.log('info', 'MetricsManager started');
  }
  
  public async stop(): Promise<void> {
    // Clear the reset interval
    if (this.resetInterval) {
      clearInterval(this.resetInterval);
      this.resetInterval = undefined;
    }
    
    this.smartMetrics.stop();
    this.logger.log('info', 'MetricsManager stopped');
  }
  
  // Get server metrics from SmartMetrics and SmartProxy
  public async getServerStats() {
    const smartMetricsData = await this.smartMetrics.getMetrics();
    const proxyMetrics = this.dcRouter.smartProxy ? this.dcRouter.smartProxy.getMetrics() : null;
    const proxyStats = this.dcRouter.smartProxy ? this.dcRouter.smartProxy.getStatistics() : null;
    
    return {
      uptime: process.uptime(),
      startTime: Date.now() - (process.uptime() * 1000),
      memoryUsage: {
        heapUsed: process.memoryUsage().heapUsed,
        heapTotal: process.memoryUsage().heapTotal,
        external: process.memoryUsage().external,
        rss: process.memoryUsage().rss,
        // Add SmartMetrics memory data
        maxMemoryMB: this.smartMetrics.maxMemoryMB,
        actualUsageBytes: smartMetricsData.memoryUsageBytes,
        actualUsagePercentage: smartMetricsData.memoryPercentage,
      },
      cpuUsage: {
        user: parseFloat(smartMetricsData.cpuUsageText || '0'),
        system: 0, // SmartMetrics doesn't separate user/system
      },
      activeConnections: proxyStats ? proxyStats.activeConnections : 0,
      totalConnections: proxyMetrics ? proxyMetrics.totals.connections() : 0,
      requestsPerSecond: proxyMetrics ? proxyMetrics.requests.perSecond() : 0,
      throughput: proxyMetrics ? {
        bytesIn: proxyMetrics.totals.bytesIn(),
        bytesOut: proxyMetrics.totals.bytesOut()
      } : { bytesIn: 0, bytesOut: 0 },
    };
  }
  
  // Get email metrics
  public async getEmailStats() {
    // Calculate average delivery time
    const avgDeliveryTime = this.emailMetrics.deliveryTimes.length > 0
      ? this.emailMetrics.deliveryTimes.reduce((a, b) => a + b, 0) / this.emailMetrics.deliveryTimes.length
      : 0;
    
    // Get top recipients
    const topRecipients = Array.from(this.emailMetrics.recipients.entries())
      .sort((a, b) => b[1] - a[1])
      .slice(0, 10)
      .map(([email, count]) => ({ email, count }));
    
    // Get recent activity (last 50 entries)
    const recentActivity = this.emailMetrics.recentActivity.slice(-50);
    
    return {
      sentToday: this.emailMetrics.sentToday,
      receivedToday: this.emailMetrics.receivedToday,
      failedToday: this.emailMetrics.failedToday,
      bounceRate: this.emailMetrics.bouncedToday > 0 
        ? (this.emailMetrics.bouncedToday / this.emailMetrics.sentToday) * 100 
        : 0,
      deliveryRate: this.emailMetrics.sentToday > 0 
        ? ((this.emailMetrics.sentToday - this.emailMetrics.failedToday) / this.emailMetrics.sentToday) * 100 
        : 100,
      queueSize: this.emailMetrics.queueSize,
      averageDeliveryTime: Math.round(avgDeliveryTime),
      topRecipients,
      recentActivity,
    };
  }
  
  // Get DNS metrics
  public async getDnsStats() {
    const cacheHitRate = this.dnsMetrics.totalQueries > 0 
      ? (this.dnsMetrics.cacheHits / this.dnsMetrics.totalQueries) * 100 
      : 0;
    
    const topDomains = Array.from(this.dnsMetrics.topDomains.entries())
      .sort((a, b) => b[1] - a[1])
      .slice(0, 10)
      .map(([domain, count]) => ({ domain, count }));
    
    // Calculate queries per second from recent timestamps
    const now = Date.now();
    const oneMinuteAgo = now - 60000;
    const recentQueries = this.dnsMetrics.queryTimestamps.filter(ts => ts >= oneMinuteAgo);
    const queriesPerSecond = recentQueries.length / 60;
    
    // Calculate average response time
    const avgResponseTime = this.dnsMetrics.responseTimes.length > 0
      ? this.dnsMetrics.responseTimes.reduce((a, b) => a + b, 0) / this.dnsMetrics.responseTimes.length
      : 0;
    
    return {
      queriesPerSecond: Math.round(queriesPerSecond * 10) / 10,
      totalQueries: this.dnsMetrics.totalQueries,
      cacheHits: this.dnsMetrics.cacheHits,
      cacheMisses: this.dnsMetrics.cacheMisses,
      cacheHitRate: cacheHitRate,
      topDomains: topDomains,
      queryTypes: this.dnsMetrics.queryTypes,
      averageResponseTime: Math.round(avgResponseTime),
      activeDomains: this.dnsMetrics.topDomains.size,
    };
  }
  
  // Get security metrics
  public async getSecurityStats() {
    // Get recent incidents (last 20)
    const recentIncidents = this.securityMetrics.incidents.slice(-20);
    
    return {
      blockedIPs: this.securityMetrics.blockedIPs,
      authFailures: this.securityMetrics.authFailures,
      spamDetected: this.securityMetrics.spamDetected,
      malwareDetected: this.securityMetrics.malwareDetected,
      phishingDetected: this.securityMetrics.phishingDetected,
      totalThreatsBlocked: this.securityMetrics.spamDetected + 
        this.securityMetrics.malwareDetected + 
        this.securityMetrics.phishingDetected,
      recentIncidents,
    };
  }
  
  // Get connection info from SmartProxy
  public async getConnectionInfo() {
    const proxyMetrics = this.dcRouter.smartProxy ? this.dcRouter.smartProxy.getMetrics() : null;
    
    if (!proxyMetrics) {
      return [];
    }
    
    const connectionsByRoute = proxyMetrics.connections.byRoute();
    const connectionInfo = [];
    
    for (const [routeName, count] of connectionsByRoute) {
      connectionInfo.push({
        type: 'https',
        count,
        source: routeName,
        lastActivity: new Date(),
      });
    }
    
    return connectionInfo;
  }
  
  // Email event tracking methods
  public trackEmailSent(recipient?: string, deliveryTimeMs?: number): void {
    this.emailMetrics.sentToday++;
    
    if (recipient) {
      const count = this.emailMetrics.recipients.get(recipient) || 0;
      this.emailMetrics.recipients.set(recipient, count + 1);
    }
    
    if (deliveryTimeMs) {
      this.emailMetrics.deliveryTimes.push(deliveryTimeMs);
      // Keep only last 1000 delivery times
      if (this.emailMetrics.deliveryTimes.length > 1000) {
        this.emailMetrics.deliveryTimes.shift();
      }
    }
    
    this.emailMetrics.recentActivity.push({
      timestamp: Date.now(),
      type: 'sent',
      details: recipient || 'unknown',
    });
    
    // Keep only last 1000 activities
    if (this.emailMetrics.recentActivity.length > 1000) {
      this.emailMetrics.recentActivity.shift();
    }
  }
  
  public trackEmailReceived(sender?: string): void {
    this.emailMetrics.receivedToday++;
    
    this.emailMetrics.recentActivity.push({
      timestamp: Date.now(),
      type: 'received',
      details: sender || 'unknown',
    });
    
    // Keep only last 1000 activities
    if (this.emailMetrics.recentActivity.length > 1000) {
      this.emailMetrics.recentActivity.shift();
    }
  }
  
  public trackEmailFailed(recipient?: string, reason?: string): void {
    this.emailMetrics.failedToday++;
    
    this.emailMetrics.recentActivity.push({
      timestamp: Date.now(),
      type: 'failed',
      details: `${recipient || 'unknown'}: ${reason || 'unknown error'}`,
    });
    
    // Keep only last 1000 activities
    if (this.emailMetrics.recentActivity.length > 1000) {
      this.emailMetrics.recentActivity.shift();
    }
  }
  
  public trackEmailBounced(recipient?: string): void {
    this.emailMetrics.bouncedToday++;
    
    this.emailMetrics.recentActivity.push({
      timestamp: Date.now(),
      type: 'bounced',
      details: recipient || 'unknown',
    });
    
    // Keep only last 1000 activities
    if (this.emailMetrics.recentActivity.length > 1000) {
      this.emailMetrics.recentActivity.shift();
    }
  }
  
  public updateQueueSize(size: number): void {
    this.emailMetrics.queueSize = size;
  }
  
  // DNS event tracking methods
  public trackDnsQuery(queryType: string, domain: string, cacheHit: boolean, responseTimeMs?: number): void {
    this.dnsMetrics.totalQueries++;
    
    if (cacheHit) {
      this.dnsMetrics.cacheHits++;
    } else {
      this.dnsMetrics.cacheMisses++;
    }
    
    // Track query timestamp
    this.dnsMetrics.queryTimestamps.push(Date.now());
    
    // Keep only timestamps from last 5 minutes
    const fiveMinutesAgo = Date.now() - 300000;
    this.dnsMetrics.queryTimestamps = this.dnsMetrics.queryTimestamps.filter(ts => ts >= fiveMinutesAgo);
    
    // Track response time if provided
    if (responseTimeMs) {
      this.dnsMetrics.responseTimes.push(responseTimeMs);
      // Keep only last 1000 response times
      if (this.dnsMetrics.responseTimes.length > 1000) {
        this.dnsMetrics.responseTimes.shift();
      }
    }
    
    // Track query types
    this.dnsMetrics.queryTypes[queryType] = (this.dnsMetrics.queryTypes[queryType] || 0) + 1;
    
    // Track top domains with size limit
    const currentCount = this.dnsMetrics.topDomains.get(domain) || 0;
    this.dnsMetrics.topDomains.set(domain, currentCount + 1);
    
    // If we've exceeded the limit, remove the least accessed domains
    if (this.dnsMetrics.topDomains.size > this.MAX_TOP_DOMAINS) {
      // Convert to array, sort by count, and keep only top domains
      const sortedDomains = Array.from(this.dnsMetrics.topDomains.entries())
        .sort((a, b) => b[1] - a[1])
        .slice(0, Math.floor(this.MAX_TOP_DOMAINS * 0.8)); // Keep 80% to avoid frequent cleanup
      
      // Clear and repopulate with top domains
      this.dnsMetrics.topDomains.clear();
      sortedDomains.forEach(([domain, count]) => {
        this.dnsMetrics.topDomains.set(domain, count);
      });
    }
  }
  
  // Security event tracking methods
  public trackBlockedIP(ip?: string, reason?: string): void {
    this.securityMetrics.blockedIPs++;
    
    this.securityMetrics.incidents.push({
      timestamp: Date.now(),
      type: 'ip_blocked',
      severity: 'medium',
      details: `IP ${ip || 'unknown'} blocked: ${reason || 'security policy'}`,
    });
    
    // Keep only last 1000 incidents
    if (this.securityMetrics.incidents.length > 1000) {
      this.securityMetrics.incidents.shift();
    }
  }
  
  public trackAuthFailure(username?: string, ip?: string): void {
    this.securityMetrics.authFailures++;
    
    this.securityMetrics.incidents.push({
      timestamp: Date.now(),
      type: 'auth_failure',
      severity: 'low',
      details: `Authentication failed for ${username || 'unknown'} from ${ip || 'unknown'}`,
    });
    
    // Keep only last 1000 incidents
    if (this.securityMetrics.incidents.length > 1000) {
      this.securityMetrics.incidents.shift();
    }
  }
  
  public trackSpamDetected(sender?: string): void {
    this.securityMetrics.spamDetected++;
    
    this.securityMetrics.incidents.push({
      timestamp: Date.now(),
      type: 'spam_detected',
      severity: 'low',
      details: `Spam detected from ${sender || 'unknown'}`,
    });
    
    // Keep only last 1000 incidents
    if (this.securityMetrics.incidents.length > 1000) {
      this.securityMetrics.incidents.shift();
    }
  }
  
  public trackMalwareDetected(source?: string): void {
    this.securityMetrics.malwareDetected++;
    
    this.securityMetrics.incidents.push({
      timestamp: Date.now(),
      type: 'malware_detected',
      severity: 'high',
      details: `Malware detected from ${source || 'unknown'}`,
    });
    
    // Keep only last 1000 incidents
    if (this.securityMetrics.incidents.length > 1000) {
      this.securityMetrics.incidents.shift();
    }
  }
  
  public trackPhishingDetected(source?: string): void {
    this.securityMetrics.phishingDetected++;
    
    this.securityMetrics.incidents.push({
      timestamp: Date.now(),
      type: 'phishing_detected',
      severity: 'high',
      details: `Phishing attempt from ${source || 'unknown'}`,
    });
    
    // Keep only last 1000 incidents
    if (this.securityMetrics.incidents.length > 1000) {
      this.securityMetrics.incidents.shift();
    }
  }
  
  // Get network metrics from SmartProxy
  public async getNetworkStats() {
    const proxyMetrics = this.dcRouter.smartProxy ? this.dcRouter.smartProxy.getMetrics() : null;
    
    if (!proxyMetrics) {
      return {
        connectionsByIP: new Map<string, number>(),
        throughputRate: { bytesInPerSecond: 0, bytesOutPerSecond: 0 },
        topIPs: [],
        totalDataTransferred: { bytesIn: 0, bytesOut: 0 },
      };
    }
    
    // Get metrics using the new API
    const connectionsByIP = proxyMetrics.connections.byIP();
    const instantThroughput = proxyMetrics.throughput.instant();
    
    // Get throughput rate
    const throughputRate = {
      bytesInPerSecond: instantThroughput.in,
      bytesOutPerSecond: instantThroughput.out
    };
    
    // Get top IPs
    const topIPs = proxyMetrics.connections.topIPs(10);
    
    // Get total data transferred
    const totalDataTransferred = {
      bytesIn: proxyMetrics.totals.bytesIn(),
      bytesOut: proxyMetrics.totals.bytesOut()
    };
    
    return {
      connectionsByIP,
      throughputRate,
      topIPs,
      totalDataTransferred,
    };
  }
}