/**
 * ╔═══════════════════════════════════════════════════════════════════════════════════════╗
 * ║                           KNOWLEDGE COMPILER                                          ║
 * ║═══════════════════════════════════════════════════════════════════════════════════════║
 * ║                                                                                       ║
 * ║   Aggregerer viden fra hele systemet til en unified "System State Summary"            ║
 * ║                                                                                       ║
 * ║   DATAKILDER:                                                                         ║
 * ║   ┌──────────────┐  ┌──────────────┐  ┌──────────────┐  ┌──────────────┐             ║
 * ║   │   HyperLog   │  │    Neo4j     │  │   Metrics    │  │  SelfHealing │             ║
 * ║   │   (Events)   │  │   (Graph)    │  │  (Counters)  │  │   (Status)   │             ║
 * ║   └──────┬───────┘  └──────┬───────┘  └──────┬───────┘  └──────┬───────┘             ║
 * ║          │                 │                 │                 │                      ║
 * ║          └────────────────┴────────────────┴────────────────┘                        ║
 * ║                                    │                                                  ║
 * ║                                    ▼                                                  ║
 * ║                      ┌─────────────────────────┐                                     ║
 * ║                      │   KNOWLEDGE COMPILER    │                                     ║
 * ║                      │   • compile()           │                                     ║
 * ║                      │   • getSystemSummary()  │                                     ║
 * ║                      │   • getInsights()       │                                     ║
 * ║                      └───────────┬─────────────┘                                     ║
 * ║                                  │                                                    ║
 * ║                                  ▼                                                    ║
 * ║                      ┌─────────────────────────┐                                     ║
 * ║                      │   CognitiveNode Widget  │                                     ║
 * ║                      │   (Visual Dashboard)    │                                     ║
 * ║                      └─────────────────────────┘                                     ║
 * ║                                                                                       ║
 * ╚═══════════════════════════════════════════════════════════════════════════════════════╝
 */

import { hyperLog, HyperLog } from '../HyperLog.js';
import { selfHealing, SelfHealingAdapter } from '../SelfHealingAdapter.js';
import { neo4jAdapter } from '../../adapters/Neo4jAdapter.js';

// ═══════════════════════════════════════════════════════════════════════════
// TYPES
// ═══════════════════════════════════════════════════════════════════════════

export interface HealthStatus {
  overall: 'HEALTHY' | 'DEGRADED' | 'CRITICAL';
  score: number;
  services: {
    name: string;
    status: 'healthy' | 'unhealthy' | 'unknown';
    lastCheck: string;
  }[];
  healingStats: {
    attempts: number;
    successes: number;
    failures: number;
    successRate: number;
  };
}

export interface ActivitySummary {
  last24h: {
    events: number;
    errors: number;
    healingAttempts: number;
    graphChanges: number;
  };
  topEventTypes: { type: string; count: number }[];
  activeAgents: string[];
}

export interface GraphStats {
  totalNodes: number;
  totalRelationships: number;
  nodesByLabel: Record<string, number>;
  recentChanges: {
    added: number;
    modified: number;
    deleted: number;
  };
}

export interface Insight {
  id: string;
  type: 'anomaly' | 'pattern' | 'trend';
  severity: 'info' | 'warning' | 'critical';
  title: string;
  description: string;
  data?: any;
  timestamp: string;
}

export interface Recommendation {
  id: string;
  priority: 'low' | 'medium' | 'high';
  action: string;
  reason: string;
  impact: string;
}

export interface RecentEvent {
  id: string;
  type: string;
  timestamp: string;
  summary: string;
  data?: Record<string, any>;
}

export interface SystemStateSummary {
  timestamp: string;
  health: HealthStatus;
  activity: ActivitySummary;
  insights: Insight[];
  recommendations: Recommendation[];
  recentEvents: RecentEvent[];
  graphStats: GraphStats;
}

// ═══════════════════════════════════════════════════════════════════════════
// KNOWLEDGE COMPILER CLASS
// ═══════════════════════════════════════════════════════════════════════════

export class KnowledgeCompiler {
  private static instance: KnowledgeCompiler;
  private lastCompilation: SystemStateSummary | null = null;
  private autoCompilationInterval: ReturnType<typeof setInterval> | null = null;

  private constructor() { }

  public static getInstance(): KnowledgeCompiler {
    if (!KnowledgeCompiler.instance) {
      KnowledgeCompiler.instance = new KnowledgeCompiler();
    }
    return KnowledgeCompiler.instance;
  }

  /**
   * Start auto-compilation at the specified interval
   */
  public startAutoCompilation(intervalMs: number = 60000): void {
    if (this.autoCompilationInterval) {
      console.log('[KnowledgeCompiler] Auto-compilation already running');
      return;
    }

    console.log(`[KnowledgeCompiler] Starting auto-compilation every ${intervalMs / 1000}s`);

    // Run initial compilation after 5 seconds
    setTimeout(() => this.compile().catch(err =>
      console.warn('[KnowledgeCompiler] Initial compilation failed:', err)
    ), 5000);

    // Set up periodic compilation
    this.autoCompilationInterval = setInterval(async () => {
      try {
        await this.compile();
      } catch (error) {
        console.warn('[KnowledgeCompiler] Periodic compilation failed:', error);
      }
    }, intervalMs);
  }

  /**
   * Stop auto-compilation
   */
  public stopAutoCompilation(): void {
    if (this.autoCompilationInterval) {
      clearInterval(this.autoCompilationInterval);
      this.autoCompilationInterval = null;
      console.log('[KnowledgeCompiler] Auto-compilation stopped');
    }
  }

  /**
   * MAIN COMPILATION METHOD
   */
  async compile(): Promise<SystemStateSummary> {
    console.log('[KnowledgeCompiler] Starting compilation...');
    const startTime = Date.now();

    try {
      // Gather data from all sources in parallel
      const [health, activity, graphStats, recentEvents] = await Promise.all([
        this.compileHealthStatus(),
        this.compileActivitySummary(),
        this.compileGraphStats(),
        this.compileRecentEvents(),
      ]);

      // Generate insights based on compiled data
      const insights = this.generateInsights(health, activity, graphStats);

      // Generate recommendations
      const recommendations = this.generateRecommendations(health, activity, insights);

      const summary: SystemStateSummary = {
        timestamp: new Date().toISOString(),
        health,
        activity,
        insights,
        recommendations,
        recentEvents,
        graphStats,
      };

      this.lastCompilation = summary;

      const duration = Date.now() - startTime;
      console.log(`[KnowledgeCompiler] Compilation complete in ${duration}ms`);

      return summary;
    } catch (error) {
      console.error('[KnowledgeCompiler] Compilation failed:', error);
      throw error;
    }
  }

  /**
   * Get the last compiled summary (cached)
   */
  getLastCompilation(): SystemStateSummary | null {
    return this.lastCompilation;
  }

  /**
   * Get system summary (compile if needed)
   */
  async getSystemSummary(forceRefresh: boolean = false): Promise<SystemStateSummary> {
    if (forceRefresh || !this.lastCompilation) {
      return await this.compile();
    }
    return this.lastCompilation;
  }

  /**
   * Quick health check without full compilation
   */
  async quickHealth(): Promise<{ status: string; score: number; timestamp: string }> {
    const health = await this.compileHealthStatus();
    return {
      status: health.overall,
      score: health.score,
      timestamp: new Date().toISOString(),
    };
  }

  // ═══════════════════════════════════════════════════════════════════════════
  // DATA SOURCE COMPILATION METHODS
  // ═══════════════════════════════════════════════════════════════════════════

  /**
   * Compile health status from SelfHealing + services
   */
  private async compileHealthStatus(): Promise<HealthStatus> {
    const systemStatus = selfHealing.getSystemStatus();
    const hyperLogData = hyperLog.exportForAnalysis();

    // Calculate healing stats from HyperLog
    const healingAttempts = hyperLogData.summary['HEALING_ATTEMPT'] || 0;
    const healingSuccesses = hyperLogData.summary['HEALING_SUCCESS'] || 0;
    const healingFailures =
      hyperLogData.summary['HEALING_CRASH'] || hyperLogData.summary['HEALING_FAILED'] || 0;

    const successRate =
      healingAttempts > 0 ? Math.round((healingSuccesses / healingAttempts) * 100) : 100;

    // Calculate overall score
    let score = 100;
    if (systemStatus.overallHealth === 'DEGRADED') score = 70;
    if (systemStatus.overallHealth === 'CRITICAL') score = 30;
    score = Math.max(0, score - healingFailures * 5);

    return {
      overall: systemStatus.overallHealth as 'HEALTHY' | 'DEGRADED' | 'CRITICAL',
      score: Math.max(0, Math.min(100, score)),
      services: systemStatus.services.map(s => ({
        name: s.name,
        status: s.status as 'healthy' | 'unhealthy' | 'unknown',
        lastCheck: new Date().toISOString(),
      })),
      healingStats: {
        attempts: healingAttempts,
        successes: healingSuccesses,
        failures: healingFailures,
        successRate,
      },
    };
  }

  /**
   * Compile activity summary from HyperLog
   */
  private async compileActivitySummary(): Promise<ActivitySummary> {
    const hyperLogData = hyperLog.exportForAnalysis();
    const recentEvents = hyperLog.getRecentEvents(1000);

    // Filter to last 24h
    const oneDayAgo = Date.now() - 24 * 60 * 60 * 1000;
    const last24hEvents = recentEvents.filter(e => e.timestamp > oneDayAgo);

    // Count errors
    const errors = last24hEvents.filter(
      e =>
        e.eventType.includes('ERROR') ||
        e.eventType.includes('FAIL') ||
        e.eventType.includes('CRASH')
    ).length;

    // Count healing attempts
    const healingAttempts = last24hEvents.filter(e => e.eventType.startsWith('HEALING_')).length;

    // Top event types
    const eventCounts: Record<string, number> = {};
    for (const event of last24hEvents) {
      eventCounts[event.eventType] = (eventCounts[event.eventType] || 0) + 1;
    }
    const topEventTypes = Object.entries(eventCounts)
      .sort((a, b) => b[1] - a[1])
      .slice(0, 10)
      .map(([type, count]) => ({ type, count }));

    return {
      last24h: {
        events: last24hEvents.length,
        errors,
        healingAttempts,
        graphChanges: 0, // Will be populated from Neo4j
      },
      topEventTypes,
      activeAgents: ['claude', 'gemini', 'system'], // TODO: Track from messages
    };
  }

  /**
   * Compile graph statistics from Neo4j
   */
  private async compileGraphStats(): Promise<GraphStats> {
    try {
      const countResult = await neo4jAdapter.executeQuery(`
        MATCH (n)
        WITH count(n) as nodes
        OPTIONAL MATCH ()-[r]->()
        RETURN nodes, count(r) as relationships
      `);

      const labelResult = await neo4jAdapter.executeQuery(`
        MATCH (n)
        WITH labels(n) as nodeLabels
        UNWIND nodeLabels as label
        RETURN label, count(*) as count
        ORDER BY count DESC
      `);

      const nodesByLabel: Record<string, number> = {};
      for (const row of labelResult) {
        const countVal = row.count;
        const count =
          typeof countVal === 'object' && countVal !== null && 'low' in countVal
            ? countVal.low
            : typeof countVal === 'object' && countVal !== null && 'toNumber' in countVal
              ? countVal.toNumber()
              : Number(countVal || 0);

        nodesByLabel[row.label] = count;
      }

      const rawNodes = countResult[0]?.nodes;
      const rawRels = countResult[0]?.relationships;

      const totalNodes =
        typeof rawNodes === 'object' && rawNodes !== null && 'low' in rawNodes
          ? rawNodes.low
          : typeof rawNodes === 'object' && rawNodes !== null && 'toNumber' in rawNodes
            ? rawNodes.toNumber()
            : Number(rawNodes || 0);

      const totalRelationships =
        typeof rawRels === 'object' && rawRels !== null && 'low' in rawRels
          ? rawRels.low
          : typeof rawRels === 'object' && rawRels !== null && 'toNumber' in rawRels
            ? rawRels.toNumber()
            : Number(rawRels || 0);

      return {
        totalNodes,
        totalRelationships,
        nodesByLabel,
        recentChanges: {
          added: 0,
          modified: 0,
          deleted: 0,
        },
      };
    } catch (error) {
      console.warn('[KnowledgeCompiler] Failed to get graph stats:', error);
      return {
        totalNodes: 0,
        totalRelationships: 0,
        nodesByLabel: {},
        recentChanges: { added: 0, modified: 0, deleted: 0 },
      };
    }
  }

  /**
   * Compile recent events for display
   */
  private async compileRecentEvents(): Promise<RecentEvent[]> {
    const events = hyperLog.getRecentEvents(20);

    return events
      .map(e => ({
        id: e.id,
        type: e.eventType,
        timestamp: new Date(e.timestamp).toISOString(),
        summary: this.summarizeEvent(e.eventType, e.data),
        data: e.data,
      }))
      .reverse(); // Most recent first
  }

  /**
   * Generate human-readable event summary
   */
  private summarizeEvent(eventType: string, data: Record<string, any>): string {
    switch (eventType) {
      case 'HEALING_SUCCESS':
        return `System healed: ${data.strategy || 'unknown strategy'}`;
      case 'HEALING_CRASH':
      case 'HEALING_FAILED':
        return `Healing failed: ${data.originalError || 'unknown error'}`;
      case 'HEALING_ATTEMPT':
        return `Attempting to heal: ${data.strategy || 'unknown'}`;
      case 'ERROR_UNHANDLED':
        return `Unhandled error: ${data.message || data.code || 'unknown'}`;
      default:
        return `${eventType}: ${JSON.stringify(data).slice(0, 50)}...`;
    }
  }

  // ═══════════════════════════════════════════════════════════════════════════
  // INSIGHT & RECOMMENDATION GENERATION
  // ═══════════════════════════════════════════════════════════════════════════

  /**
   * Generate insights from compiled data
   * ENHANCED: Now includes predictive alerts and proactive pattern detection
   */
  private generateInsights(
    health: HealthStatus,
    activity: ActivitySummary,
    graphStats: GraphStats
  ): Insight[] {
    const insights: Insight[] = [];

    // ═══════════════════════════════════════════════════════════════════
    // PREDICTIVE INSIGHTS (from SelfHealing predictive alerts)
    // ═══════════════════════════════════════════════════════════════════
    const predictiveAlerts = selfHealing.getPredictiveAlerts();
    for (const alert of predictiveAlerts) {
      insights.push({
        id: `insight_predictive_${alert.errorCode}_${Date.now()}`,
        type: 'anomaly',
        severity: alert.severity === 'critical' ? 'critical' : 'warning',
        title: `🔮 Predicted Failure: ${alert.errorCode}`,
        description: `${(alert.probability * 100).toFixed(0)}% probability of ${alert.errorCode} failure ${alert.expectedIn}. ${alert.recommendation}`,
        data: {
          errorCode: alert.errorCode,
          probability: alert.probability,
          expectedIn: alert.expectedIn,
        },
        timestamp: new Date().toISOString(),
      });
    }

    // ═══════════════════════════════════════════════════════════════════
    // PATTERN DETECTION: Error clustering analysis
    // ═══════════════════════════════════════════════════════════════════
    const errorPatterns = this.detectErrorPatterns(activity);
    for (const pattern of errorPatterns) {
      insights.push({
        id: `insight_pattern_${pattern.code}_${Date.now()}`,
        type: 'pattern',
        severity: pattern.severity,
        title: `📊 Pattern: ${pattern.title}`,
        description: pattern.description,
        data: pattern.data,
        timestamp: new Date().toISOString(),
      });
    }

    // ═══════════════════════════════════════════════════════════════════
    // USAGE SPIKE DETECTION
    // ═══════════════════════════════════════════════════════════════════
    const usageSpikes = this.detectUsageSpikes(activity);
    for (const spike of usageSpikes) {
      insights.push({
        id: `insight_spike_${spike.eventType}_${Date.now()}`,
        type: 'trend',
        severity: spike.severity,
        title: `📈 Usage Spike: ${spike.eventType}`,
        description: spike.description,
        data: spike.data,
        timestamp: new Date().toISOString(),
      });
    }

    // Health-based insights
    if (health.healingStats.failures > 0) {
      insights.push({
        id: `insight_healing_${Date.now()}`,
        type: 'anomaly',
        severity: health.healingStats.failures > 3 ? 'critical' : 'warning',
        title: 'Self-Healing Failures Detected',
        description: `${health.healingStats.failures} healing attempts have failed. Success rate: ${health.healingStats.successRate}%`,
        timestamp: new Date().toISOString(),
      });
    }

    // Activity-based insights
    if (activity.last24h.errors > 10) {
      insights.push({
        id: `insight_errors_${Date.now()}`,
        type: 'anomaly',
        severity: 'warning',
        title: 'High Error Rate',
        description: `${activity.last24h.errors} errors detected in the last 24 hours`,
        data: { errorCount: activity.last24h.errors },
        timestamp: new Date().toISOString(),
      });
    }

    // Graph-based insights
    if (graphStats.totalNodes > 10000) {
      insights.push({
        id: `insight_graph_${Date.now()}`,
        type: 'trend',
        severity: 'info',
        title: 'Large Knowledge Graph',
        description: `Knowledge graph has grown to ${graphStats.totalNodes.toLocaleString()} nodes`,
        timestamp: new Date().toISOString(),
      });
    }

    // ═══════════════════════════════════════════════════════════════════
    // DEAD SERVICE DETECTION
    // ═══════════════════════════════════════════════════════════════════
    const deadServices = health.services.filter(s => s.status === 'unhealthy');
    if (deadServices.length > 0) {
      insights.push({
        id: `insight_dead_services_${Date.now()}`,
        type: 'anomaly',
        severity: 'critical',
        title: `☠️ Dead Services Detected`,
        description: `${deadServices.length} service(s) are unhealthy: ${deadServices.map(s => s.name).join(', ')}`,
        data: { services: deadServices.map(s => s.name) },
        timestamp: new Date().toISOString(),
      });
    }

    // Pattern detection from top events
    const healingEvents = activity.topEventTypes.filter(e => e.type.startsWith('HEALING_'));
    if (healingEvents.length > 0) {
      const totalHealingEvents = healingEvents.reduce((sum, e) => sum + e.count, 0);
      if (totalHealingEvents > 5) {
        insights.push({
          id: `insight_pattern_healing_${Date.now()}`,
          type: 'pattern',
          severity: 'info',
          title: 'Frequent Self-Healing Activity',
          description: `System has triggered ${totalHealingEvents} healing events recently`,
          data: { events: healingEvents },
          timestamp: new Date().toISOString(),
        });
      }
    }

    return insights;
  }

  /**
   * 📊 PATTERN DETECTION: Analyze error clustering
   */
  private detectErrorPatterns(activity: ActivitySummary): Array<{
    code: string;
    title: string;
    description: string;
    severity: 'info' | 'warning' | 'critical';
    data: any;
  }> {
    const patterns: Array<any> = [];

    // Group error events
    const errorEvents = activity.topEventTypes.filter(
      e => e.type.includes('ERROR') || e.type.includes('FAIL')
    );

    // Detect repeated errors (same error > 5 times)
    for (const event of errorEvents) {
      if (event.count >= 5) {
        patterns.push({
          code: event.type,
          title: `Repeated ${event.type}`,
          description: `${event.type} has occurred ${event.count} times - investigate root cause`,
          severity: event.count >= 10 ? 'critical' : 'warning',
          data: { eventType: event.type, count: event.count },
        });
      }
    }

    // Detect error bursts (many errors in short time)
    const totalErrors = errorEvents.reduce((sum, e) => sum + e.count, 0);
    if (totalErrors > 20 && errorEvents.length > 3) {
      patterns.push({
        code: 'ERROR_BURST',
        title: 'Error Burst Detected',
        description: `${totalErrors} errors across ${errorEvents.length} different error types - possible cascading failure`,
        severity: 'critical',
        data: { totalErrors, errorTypes: errorEvents.length },
      });
    }

    return patterns;
  }

  /**
   * 📈 USAGE SPIKE DETECTION: Find abnormal activity
   */
  private detectUsageSpikes(activity: ActivitySummary): Array<{
    eventType: string;
    description: string;
    severity: 'info' | 'warning' | 'critical';
    data: any;
  }> {
    const spikes: Array<any> = [];

    // Calculate average event count
    const avgCount =
      activity.topEventTypes.reduce((sum, e) => sum + e.count, 0) /
      Math.max(activity.topEventTypes.length, 1);

    // Find events significantly above average (3x)
    for (const event of activity.topEventTypes) {
      if (event.count > avgCount * 3 && event.count >= 10) {
        spikes.push({
          eventType: event.type,
          description: `${event.type} activity is ${Math.round(event.count / avgCount)}x above average (${event.count} occurrences)`,
          severity: event.count > avgCount * 5 ? 'warning' : 'info',
          data: {
            count: event.count,
            average: Math.round(avgCount),
            multiplier: Math.round(event.count / avgCount),
          },
        });
      }
    }

    return spikes;
  }

  /**
   * Generate actionable recommendations
   */
  private generateRecommendations(
    health: HealthStatus,
    activity: ActivitySummary,
    insights: Insight[]
  ): Recommendation[] {
    const recommendations: Recommendation[] = [];

    // Based on health
    if (health.overall === 'DEGRADED') {
      recommendations.push({
        id: `rec_health_${Date.now()}`,
        priority: 'high',
        action: 'Investigate degraded services',
        reason: 'System health is degraded',
        impact: 'Prevent potential system failures',
      });
    }

    if (health.healingStats.successRate < 80) {
      recommendations.push({
        id: `rec_healing_${Date.now()}`,
        priority: 'medium',
        action: 'Review self-healing strategies',
        reason: `Healing success rate is ${health.healingStats.successRate}%`,
        impact: 'Improve system resilience',
      });
    }

    // Based on activity
    if (activity.last24h.errors > 20) {
      recommendations.push({
        id: `rec_errors_${Date.now()}`,
        priority: 'high',
        action: 'Review error logs and implement fixes',
        reason: `${activity.last24h.errors} errors in last 24h`,
        impact: 'Reduce system instability',
      });
    }

    // Based on insights
    const criticalInsights = insights.filter(i => i.severity === 'critical');
    if (criticalInsights.length > 0) {
      recommendations.push({
        id: `rec_critical_${Date.now()}`,
        priority: 'high',
        action: 'Address critical insights immediately',
        reason: `${criticalInsights.length} critical issues detected`,
        impact: 'Prevent system failures',
      });
    }

    return recommendations;
  }
}

// ═══════════════════════════════════════════════════════════════════════════
// SINGLETON EXPORT
// ═══════════════════════════════════════════════════════════════════════════

export const knowledgeCompiler = KnowledgeCompiler.getInstance();