Disaster Recovery

// Disaster recovery plan structure
const disasterRecoveryPlan = {
  // Plan metadata
  metadata: {
    name: 'Disaster Recovery Plan',
    version: '1.0',
    lastUpdated: '2025-05-15',
    approvedBy: 'CTO',
    reviewCycle: 'Annual'
  },
  
  // Risk assessment
  riskAssessment: {
    threats: [
      { type: 'natural', name: 'Earthquake', probability: 'low', impact: 'high' },
      { type: 'natural', name: 'Flood', probability: 'medium', impact: 'high' },
      { type: 'technical', name: 'Data Center Outage', probability: 'medium', impact: 'high' },
      { type: 'technical', name: 'Database Corruption', probability: 'low', impact: 'critical' },
      { type: 'security', name: 'Ransomware Attack', probability: 'medium', impact: 'critical' },
      { type: 'security', name: 'DDoS Attack', probability: 'high', impact: 'medium' }
    ],
    
    criticalSystems: [
      { name: 'User Authentication', rto: 1, rpo: 0.25 }, // RTO in hours, RPO in hours
      { name: 'Payment Processing', rto: 2, rpo: 0 },
      { name: 'Core Database', rto: 4, rpo: 0.5 },
      { name: 'API Services', rto: 4, rpo: 1 },
      { name: 'Content Delivery', rto: 8, rpo: 24 }
    ]
  },
  
  // Recovery strategies
  recoveryStrategies: {
    dataBackup: {
      strategy: 'Multi-tier backup',
      description: 'Combination of full, incremental, and differential backups',
      schedule: {
        full: 'Weekly, Sunday 01:00 UTC',
        incremental: 'Daily, 01:00 UTC',
        differential: 'Wednesday, 01:00 UTC'
      },
      retention: {
        full: '12 months',
        incremental: '30 days',
        differential: '60 days'
      },
      locations: [
        { type: 'primary', provider: 'AWS S3', region: 'us-east-1' },
        { type: 'secondary', provider: 'Azure Blob', region: 'westeurope' },
        { type: 'offline', provider: 'Tape Backup', location: 'Secure Facility' }
      ]
    },
    
    systemRecovery: {
      strategy: 'Multi-region active-passive',
      description: 'Primary region active with standby secondary region',
      regions: [
        { role: 'primary', provider: 'AWS', region: 'us-east-1' },
        { role: 'secondary', provider: 'AWS', region: 'us-west-2' }
      ],
      failoverType: 'Automated with manual confirmation',
      failbackType: 'Manual after validation'
    }
  },
  
  // Response procedures
  responseProcedures: {
    roles: [
      { name: 'Incident Commander', responsibilities: ['Overall coordination', 'Decision making'] },
      { name: 'Technical Lead', responsibilities: ['Technical assessment', 'Recovery execution'] },
      { name: 'Communications Lead', responsibilities: ['Stakeholder updates', 'Customer communication'] }
    ],
    
    procedures: [
      {
        name: 'Initial Assessment',
        steps: [
          'Identify affected systems and services',
          'Determine incident severity and impact',
          'Notify appropriate response team members',
          'Establish communication channels'
        ]
      },
      {
        name: 'Containment',
        steps: [
          'Isolate affected systems',
          'Prevent further damage or data loss',
          'Secure unaffected systems and data',
          'Document current state for investigation'
        ]
      },
      {
        name: 'Recovery Execution',
        steps: [
          'Activate appropriate recovery strategy',
          'Restore systems from backups if needed',
          'Verify data integrity',
          'Test recovered systems'
        ]
      },
      {
        name: 'Service Restoration',
        steps: [
          'Gradually restore services based on priority',
          'Monitor system performance and stability',
          'Verify all functionality is restored',
          'Return to normal operations'
        ]
      }
    ]
  }
};

// Backup system configuration
const backupSystem = {
  // Backup types
  types: {
    full: {
      description: 'Complete backup of all data',
      frequency: 'weekly',
      retention: '12 months'
    },
    incremental: {
      description: 'Backup of changes since last backup',
      frequency: 'daily',
      retention: '30 days'
    },
    differential: {
      description: 'Backup of changes since last full backup',
      frequency: 'semi-weekly',
      retention: '60 days'
    }
  },
  
  // Backup targets
  targets: {
    database: {
      type: 'PostgreSQL',
      method: 'pg_dump',
      options: {
        format: 'custom',
        compress: 9,
        jobs: 4
      }
    },
    fileStorage: {
      type: 'Object Storage',
      method: 'sync',
      options: {
        deleteExtraneous: false,
        preservePermissions: true
      }
    },
    configurations: {
      type: 'Configuration Files',
      method: 'archive',
      options: {
        format: 'tar.gz',
        includeSecrets: false
      }
    }
  },
  
  // Backup execution
  async executeBackup(type, targets) {
    console.log(`Starting ${type} backup for targets: ${targets.join(', ')}`);
    
    const backupId = this.generateBackupId(type);
    const timestamp = new Date().toISOString();
    
    const results = {
      backupId,
      type,
      timestamp,
      targets: {}
    };
    
    for (const target of targets) {
      try {
        const targetConfig = this.targets[target];
        
        if (!targetConfig) {
          throw new Error(`Unknown backup target: ${target}`);
        }
        
        console.log(`Backing up ${target} using ${targetConfig.method}`);
        
        const result = await this.backupTarget(target, targetConfig, type);
        
        results.targets[target] = {
          status: 'success',
          size: result.size,
          duration: result.duration,
          location: result.location
        };
      } catch (error) {
        console.error(`Backup failed for ${target}: ${error.message}`);
        
        results.targets[target] = {
          status: 'failed',
          error: error.message
        };
      }
    }
    
    await this.storeBackupMetadata(results);
    
    return results;
  },
  
  // Backup verification
  async verifyBackup(backupId) {
    console.log(`Verifying backup: ${backupId}`);
    
    const metadata = await this.getBackupMetadata(backupId);
    const results = {
      backupId,
      timestamp: new Date().toISOString(),
      targets: {}
    };
    
    for (const [target, info] of Object.entries(metadata.targets)) {
      if (info.status !== 'success') {
        results.targets[target] = {
          status: 'skipped',
          reason: 'Original backup failed'
        };
        continue;
      }
      
      try {
        console.log(`Verifying ${target} backup`);
        
        const result = await this.verifyBackupTarget(target, info.location);
        
        results.targets[target] = {
          status: 'success',
          integrityCheck: result.integrityCheck,
          restorability: result.restorability
        };
      } catch (error) {
        console.error(`Verification failed for ${target}: ${error.message}`);
        
        results.targets[target] = {
          status: 'failed',
          error: error.message
        };
      }
    }
    
    await this.storeVerificationResults(results);
    
    return results;
  }
};

// Failover system configuration
const failoverSystem = {
  // Monitoring configuration
  monitoring: {
    endpoints: [
      { name: 'API Gateway', url: 'https://api.example.com/health', threshold: 3 },
      { name: 'Auth Service', url: 'https://auth.example.com/health', threshold: 3 },
      { name: 'Database', url: 'https://db.example.com/health', threshold: 2 }
    ],
    interval: 30, // seconds
    regions: ['us-east-1', 'us-west-2']
  },
  
  // Failover configuration
  failover: {
    mode: 'active-passive',
    healthThreshold: 0.7, // 70% of endpoints must be healthy
    cooldown: 300, // seconds between failover attempts
    regions: {
      primary: {
        name: 'us-east-1',
        priority: 1,
        services: [
          { name: 'API Gateway', endpoint: 'api-primary.example.com' },
          { name: 'Auth Service', endpoint: 'auth-primary.example.com' },
          { name: 'Database', endpoint: 'db-primary.example.com' }
        ]
      },
      secondary: {
        name: 'us-west-2',
        priority: 2,
        services: [
          { name: 'API Gateway', endpoint: 'api-secondary.example.com' },
          { name: 'Auth Service', endpoint: 'auth-secondary.example.com' },
          { name: 'Database', endpoint: 'db-secondary.example.com' }
        ]
      }
    },
    dns: {
      provider: 'Route53',
      ttl: 60,
      records: [
        { name: 'api.example.com', type: 'CNAME' },
        { name: 'auth.example.com', type: 'CNAME' },
        { name: 'db.example.com', type: 'CNAME' }
      ]
    }
  },
  
  // Health check
  async checkHealth() {
    const results = {
      timestamp: new Date().toISOString(),
      regions: {}
    };
    
    for (const region of this.monitoring.regions) {
      results.regions[region] = {
        endpoints: {},
        overall: 'unknown'
      };
      
      let healthyCount = 0;
      
      for (const endpoint of this.monitoring.endpoints) {
        try {
          const health = await this.checkEndpoint(endpoint, region);
          
          results.regions[region].endpoints[endpoint.name] = health;
          
          if (health.status === 'healthy') {
            healthyCount++;
          }
        } catch (error) {
          console.error(`Health check failed for ${endpoint.name} in ${region}: ${error.message}`);
          
          results.regions[region].endpoints[endpoint.name] = {
            status: 'error',
            error: error.message
          };
        }
      }
      
      const healthRatio = healthyCount / this.monitoring.endpoints.length;
      results.regions[region].overall = healthRatio >= this.failover.healthThreshold ? 'healthy' : 'unhealthy';
      results.regions[region].healthRatio = healthRatio;
    }
    
    await this.storeHealthResults(results);
    await this.evaluateFailover(results);
    
    return results;
  },
  
  // Failover execution
  async executeFailover(fromRegion, toRegion) {
    console.log(`Executing failover from ${fromRegion} to ${toRegion}`);
    
    const failoverId = this.generateFailoverId();
    const timestamp = new Date().toISOString();
    
    const results = {
      failoverId,
      timestamp,
      fromRegion,
      toRegion,
      services: {}
    };
    
    // Update DNS records
    for (const record of this.failover.dns.records) {
      try {
        const targetEndpoint = this.failover.regions[toRegion].services.find(
          s => s.name === record.name.split('.')[0]
        )?.endpoint;
        
        if (!targetEndpoint) {
          throw new Error(`No matching service found for ${record.name}`);
        }
        
        console.log(`Updating DNS record ${record.name} to point to ${targetEndpoint}`);
        
        await this.updateDnsRecord(record.name, record.type, targetEndpoint);
        
        results.services[record.name] = {
          status: 'success',
          newEndpoint: targetEndpoint
        };
      } catch (error) {
        console.error(`Failed to update DNS for ${record.name}: ${error.message}`);
        
        results.services[record.name] = {
          status: 'failed',
          error: error.message
        };
      }
    }
    
    // Update failover state
    await this.updateFailoverState({
      activeRegion: toRegion,
      lastFailover: timestamp,
      inCooldown: true
    });
    
    // Set cooldown timer
    setTimeout(() => {
      this.updateFailoverState({ inCooldown: false });
    }, this.failover.cooldown * 1000);
    
    await this.storeFailoverResults(results);
    
    return results;
  }
};

// Disaster recovery testing framework
const drTestingFramework = {
  // Test types
  testTypes: {
    tabletop: {
      name: 'Tabletop Exercise',
      description: 'Discussion-based test of DR procedures',
      participants: ['IT Team', 'Business Stakeholders'],
      duration: '2-4 hours',
      frequency: 'Quarterly',
      disruption: 'None'
    },
    walkthrough: {
      name: 'Walkthrough Test',
      description: 'Step-by-step verification of DR procedures',
      participants: ['IT Team'],
      duration: '4-8 hours',
      frequency: 'Bi-annually',
      disruption: 'Minimal'
    },
    simulation: {
      name: 'Simulation Test',
      description: 'Simulated disaster with actual recovery procedures',
      participants: ['IT Team', 'Business Stakeholders'],
      duration: '8-12 hours',
      frequency: 'Annually',
      disruption: 'Moderate'
    },
    fullScale: {
      name: 'Full-Scale Test',
      description: 'Complete test of all DR capabilities',
      participants: ['All Staff'],
      duration: '1-2 days',
      frequency: 'Annually',
      disruption: 'Significant'
    }
  },
  
  // Test scenarios
  scenarios: {
    dataCorruption: {
      name: 'Database Corruption',
      description: 'Simulated corruption of primary database',
      scope: ['Database', 'Application Services'],
      objectives: [
        'Validate database backup integrity',
        'Test restoration procedures',
        'Verify application functionality with restored data'
      ]
    },
    infrastructureFailure: {
      name: 'Infrastructure Failure',
      description: 'Simulated failure of primary infrastructure',
      scope: ['Compute', 'Network', 'Storage'],
      objectives: [
        'Test infrastructure failover mechanisms',
        'Validate DNS and routing updates',
        'Verify system performance in secondary region'
      ]
    },
    ransomwareAttack: {
      name: 'Ransomware Attack',
      description: 'Simulated ransomware infection',
      scope: ['All Systems'],
      objectives: [
        'Test isolation procedures',
        'Validate clean system restoration',
        'Verify data recovery from offline backups'
      ]
    }
  },
  
  // Test execution
  async executeTest(testType, scenario, options = {}) {
    console.log(`Executing ${testType} test for scenario: ${scenario}`);
    
    const testConfig = this.testTypes[testType];
    const scenarioConfig = this.scenarios[scenario];
    
    if (!testConfig) {
      throw new Error(`Unknown test type: ${testType}`);
    }
    
    if (!scenarioConfig) {
      throw new Error(`Unknown scenario: ${scenario}`);
    }
    
    const testId = this.generateTestId();
    const timestamp = new Date().toISOString();
    
    // Create test plan
    const testPlan = {
      id: testId,
      type: testConfig.name,
      scenario: scenarioConfig.name,
      timestamp,
      participants: options.participants || testConfig.participants,
      objectives: scenarioConfig.objectives,
      scope: scenarioConfig.scope,
      steps: await this.generateTestSteps(testType, scenario)
    };
    
    // Execute test
    const results = {
      testId,
      startTime: timestamp,
      endTime: null,
      status: 'in_progress',
      steps: {}
    };
    
    try {
      for (const [index, step] of testPlan.steps.entries()) {
        console.log(`Executing step ${index + 1}: ${step.description}`);
        
        const stepResult = await this.executeTestStep(step, options);
        
        results.steps[index] = stepResult;
        
        if (stepResult.status === 'failed' && !options.continueOnFailure) {
          throw new Error(`Test failed at step ${index + 1}: ${stepResult.error}`);
        }
      }
      
      results.status = 'completed';
    } catch (error) {
      console.error(`Test execution failed: ${error.message}`);
      
      results.status = 'failed';
      results.error = error.message;
    }
    
    results.endTime = new Date().toISOString();
    
    // Generate report
    const report = await this.generateTestReport(testPlan, results);
    
    await this.storeTestResults(results, report);
    
    return {
      results,
      report
    };
  },
  
  // Test reporting
  async generateTestReport(testPlan, results) {
    console.log('Generating test report');
    
    const successfulSteps = Object.values(results.steps).filter(s => s.status === 'success').length;
    const totalSteps = testPlan.steps.length;
    const successRate = (successfulSteps / totalSteps) * 100;
    
    const report = {
      testId: results.testId,
      title: `${testPlan.type} - ${testPlan.scenario}`,
      executionDate: results.startTime,
      duration: this.calculateDuration(results.startTime, results.endTime),
      summary: {
        status: results.status,
        successRate: `${successRate.toFixed(1)}%`,
        successfulSteps,
        totalSteps
      },
      objectives: {
        defined: testPlan.objectives,
        achieved: this.evaluateObjectives(testPlan.objectives, results)
      },
      findings: await this.identifyFindings(results),
      recommendations: await this.generateRecommendations(results)
    };
    
    return report;
  }
};

// Incident response integration
const incidentResponseIntegration = {
  // Incident severity levels
  severityLevels: {
    critical: {
      name: 'Critical',
      description: 'Severe impact on critical business functions',
      responseTime: 15, // minutes
      drActivation: 'automatic',
      notificationChannels: ['email', 'sms', 'phone', 'slack']
    },
    high: {
      name: 'High',
      description: 'Significant impact on important business functions',
      responseTime: 30, // minutes
      drActivation: 'manual_approval',
      notificationChannels: ['email', 'sms', 'slack']
    },
    medium: {
      name: 'Medium',
      description: 'Limited impact on business functions',
      responseTime: 60, // minutes
      drActivation: 'assessment_required',
      notificationChannels: ['email', 'slack']
    },
    low: {
      name: 'Low',
      description: 'Minimal impact on business functions',
      responseTime: 240, // minutes
      drActivation: 'none',
      notificationChannels: ['email']
    }
  },
  
  // Incident types that may trigger DR
  incidentTypes: {
    infrastructure_failure: {
      name: 'Infrastructure Failure',
      drProcedures: ['system_recovery', 'failover'],
      assessmentCriteria: [
        'Duration exceeds 30 minutes',
        'Affects multiple availability zones',
        'No ETA for resolution'
      ]
    },
    data_corruption: {
      name: 'Data Corruption',
      drProcedures: ['data_recovery', 'point_in_time_restore'],
      assessmentCriteria: [
        'Affects critical data',
        'Corruption is widespread',
        'Cannot be fixed with simple queries'
      ]
    },
    security_breach: {
      name: 'Security Breach',
      drProcedures: ['containment', 'clean_recovery'],
      assessmentCriteria: [
        'Evidence of data exfiltration',
        'System compromise',
        'Malware infection'
      ]
    },
    natural_disaster: {
      name: 'Natural Disaster',
      drProcedures: ['regional_failover', 'alternate_site_activation'],
      assessmentCriteria: [
        'Physical damage to data center',
        'Extended power or connectivity loss',
        'Staff unable to access facilities'
      ]
    }
  },
  
  // Incident handling
  async handleIncident(incident) {
    console.log(`Handling incident: ${incident.id} - ${incident.type}`);
    
    // Determine severity
    const severity = incident.severity || await this.assessSeverity(incident);
    const severityConfig = this.severityLevels[severity];
    
    if (!severityConfig) {
      throw new Error(`Unknown severity level: ${severity}`);
    }
    
    // Determine if DR should be activated
    let activateDR = false;
    
    if (severityConfig.drActivation === 'automatic') {
      activateDR = true;
    } else if (severityConfig.drActivation === 'manual_approval') {
      activateDR = await this.requestDRApproval(incident);
    } else if (severityConfig.drActivation === 'assessment_required') {
      activateDR = await this.assessDRNeed(incident);
    }
    
    // Execute DR procedures if needed
    if (activateDR) {
      const incidentTypeConfig = this.incidentTypes[incident.type];
      
      if (!incidentTypeConfig) {
        console.warn(`No DR procedures defined for incident type: ${incident.type}`);
        return;
      }
      
      console.log(`Activating DR procedures for incident ${incident.id}`);
      
      for (const procedure of incidentTypeConfig.drProcedures) {
        await this.executeDRProcedure(procedure, incident);
      }
    }
    
    // Update incident with DR information
    await this.updateIncidentWithDRInfo(incident, {
      drActivated: activateDR,
      procedures: activateDR ? this.incidentTypes[incident.type].drProcedures : [],
      timestamp: new Date().toISOString()
    });
  },
  
  // Execute DR procedure
  async executeDRProcedure(procedure, incident) {
    console.log(`Executing DR procedure: ${procedure}`);
    
    switch (procedure) {
      case 'system_recovery':
        await this.recoverSystems(incident);
        break;
      case 'failover':
        await this.executeFaailover(incident);
        break;
      case 'data_recovery':
        await this.recoverData(incident);
        break;
      case 'point_in_time_restore':
        await this.restoreToPointInTime(incident);
        break;
      case 'containment':
        await this.containSecurity(incident);
        break;
      case 'clean_recovery':
        await this.recoverCleanSystems(incident);
        break;
      case 'regional_failover':
        await this.failoverToAlternateRegion(incident);
        break;
      case 'alternate_site_activation':
        await this.activateAlternateSite(incident);
        break;
      default:
        throw new Error(`Unknown DR procedure: ${procedure}`);
    }
  }
};