@clduab11/gemini-flow/src/protocols/a2a/security/reputation-system.ts

Revolutionary AI agent swarm coordination platform with Google Services integration, multimedia processing, and production-ready monitoring. Features 8 Google AI services, quantum computing capabilities, and enterprise-grade security.

/**
 * Reputation System for A2A Protocol
 *
 * Implements dynamic reputation scoring and trust metrics for agents
 * in the distributed system, providing continuous assessment of agent
 * trustworthiness based on behavior, performance, and peer feedback.
 *
 * Features:
 * - Dynamic reputation scoring with multi-factor analysis
 * - Peer-to-peer trust evaluation and feedback
 * - Historical reputation tracking and trend analysis
 * - Stake-weighted reputation for economic incentives
 * - Reputation-based access control and privileges
 * - Reputation recovery mechanisms for rehabilitated agents
 */

import { EventEmitter } from "events";
import crypto from "crypto";
import { Logger } from "../../../utils/logger.js";
import { A2AIdentity, A2AMessage } from "../../../core/a2a-security-manager.js";
import { BehaviorProfile } from "./malicious-detection.js";

export interface ReputationScore {
  agentId: string;
  overallScore: number; // 0-1000, overall reputation score
  trustLevel: "untrusted" | "low" | "medium" | "high" | "excellent";

  // Component scores (0-100 each)
  behaviorScore: number; // Based on behavior analysis
  performanceScore: number; // Based on task completion and quality
  consensusScore: number; // Based on consensus participation
  peerScore: number; // Based on peer evaluations
  stabilityScore: number; // Based on consistency over time

  // Detailed metrics
  metrics: {
    successfulOperations: number;
    failedOperations: number;
    consensusParticipation: number;
    messageReliability: number;
    responseTime: number;
    resourceEfficiency: number;
    securityCompliance: number;
    innovationScore: number;
  };

  // Historical data
  history: {
    scores: { timestamp: Date; score: number }[];
    events: ReputationEvent[];
    trends: ReputationTrend[];
  };

  // Peer feedback
  peerFeedback: {
    positiveCount: number;
    negativeCount: number;
    neutralCount: number;
    recentFeedback: PeerFeedback[];
  };

  // Stake and economic factors
  stake: {
    amount: number; // Economic stake in the system
    lockPeriod: number; // Lock period for stake
    slashingHistory: SlashingEvent[];
  };

  // Reputation metadata
  metadata: {
    lastUpdated: Date;
    updateCount: number;
    version: string;
    flags: string[]; // Special flags (e.g., 'recovering', 'probation')
  };
}

export interface PeerFeedback {
  fromAgentId: string;
  toAgentId: string;
  rating: number; // 1-5 rating
  category:
    | "behavior"
    | "performance"
    | "reliability"
    | "security"
    | "cooperation";
  comment?: string;
  evidence?: any;
  timestamp: Date;
  signature: string; // Cryptographic signature
  weight: number; // Weight based on rater's reputation
}

export interface ReputationEvent {
  eventId: string;
  agentId: string;
  type: "positive" | "negative" | "neutral";
  category: string;
  impact: number; // -100 to +100
  description: string;
  evidence: any;
  timestamp: Date;
  reportedBy?: string;
  verified: boolean;
}

export interface ReputationTrend {
  period: "daily" | "weekly" | "monthly";
  startDate: Date;
  endDate: Date;
  averageScore: number;
  trend: "increasing" | "decreasing" | "stable";
  volatility: number;
  confidence: number;
}

export interface SlashingEvent {
  eventId: string;
  agentId: string;
  reason: string;
  amountSlashed: number;
  timestamp: Date;
  evidence: any;
  appealStatus?: "pending" | "approved" | "rejected";
}

export interface ReputationChallenge {
  challengeId: string;
  agentId: string;
  type:
    | "behavior_verification"
    | "skill_demonstration"
    | "consensus_participation"
    | "peer_collaboration";
  description: string;
  requirements: any;
  reward: number;
  penalty: number;
  timeLimit: number;
  createdAt: Date;
  status: "pending" | "in_progress" | "completed" | "failed" | "expired";
}

export interface ReputationConfig {
  // Scoring weights (must sum to 1.0)
  weights: {
    behavior: number;
    performance: number;
    consensus: number;
    peer: number;
    stability: number;
  };

  // Score decay and aging
  decayFactors: {
    dailyDecay: number; // Daily score decay rate
    inactivityPenalty: number; // Penalty for inactivity
    recoveryBonus: number; // Bonus for recovery efforts
  };

  // Thresholds
  thresholds: {
    quarantineThreshold: number; // Below this, agent may be quarantined
    privilegeThreshold: number; // Above this, agent gets special privileges
    slashingThreshold: number; // Below this, economic slashing may occur
  };

  // Peer feedback
  peerFeedback: {
    minRaterScore: number; // Minimum rater score to give feedback
    maxFeedbackAge: number; // Max age of feedback to consider
    weightByRaterScore: boolean; // Weight feedback by rater's score
  };

  // Economic parameters
  economic: {
    minStakeAmount: number;
    maxSlashingPercentage: number;
    stakeLockPeriod: number;
    reputationStakingEnabled: boolean;
  };
}

export class ReputationSystem extends EventEmitter {
  private logger: Logger;
  private reputationScores: Map<string, ReputationScore> = new Map();
  private peerFeedbacks: Map<string, PeerFeedback[]> = new Map(); // agentId -> feedbacks
  private reputationEvents: Map<string, ReputationEvent[]> = new Map(); // agentId -> events
  private activeChallenges: Map<string, ReputationChallenge> = new Map();
  private config: ReputationConfig;

  // Reputation calculation components
  private behaviorAnalyzer: BehaviorReputationAnalyzer;
  private performanceTracker: PerformanceTracker;
  private consensusEvaluator: ConsensusEvaluator;
  private peerEvaluator: PeerEvaluator;
  private stabilityAnalyzer: StabilityAnalyzer;

  // Economic components
  private stakeManager: StakeManager;
  private slashingController: SlashingController;

  constructor(config: Partial<ReputationConfig> = {}) {
    super();
    this.logger = new Logger("ReputationSystem");

    this.initializeConfig(config);
    this.initializeComponents();
    this.startReputationUpdates();

    this.logger.info("Reputation System initialized", {
      features: [
        "dynamic-scoring",
        "peer-feedback",
        "stake-weighting",
        "reputation-challenges",
        "trend-analysis",
        "slashing-protection",
      ],
      config: this.config,
    });
  }

  /**
   * Initialize configuration with defaults
   */
  private initializeConfig(config: Partial<ReputationConfig>): void {
    this.config = {
      weights: {
        behavior: 0.3,
        performance: 0.25,
        consensus: 0.2,
        peer: 0.15,
        stability: 0.1,
        ...config.weights,
      },
      decayFactors: {
        dailyDecay: 0.995, // 0.5% daily decay
        inactivityPenalty: 0.02, // 2% penalty for inactivity
        recoveryBonus: 0.01, // 1% bonus for recovery activities
        ...config.decayFactors,
      },
      thresholds: {
        quarantineThreshold: 300, // Below 300 may be quarantined
        privilegeThreshold: 750, // Above 750 gets special privileges
        slashingThreshold: 200, // Below 200 may face slashing
        ...config.thresholds,
      },
      peerFeedback: {
        minRaterScore: 400, // Minimum 400 score to rate others
        maxFeedbackAge: 7776000000, // 90 days
        weightByRaterScore: true,
        ...config.peerFeedback,
      },
      economic: {
        minStakeAmount: 1000,
        maxSlashingPercentage: 0.1, // 10% max slashing
        stakeLockPeriod: 2592000000, // 30 days
        reputationStakingEnabled: true,
        ...config.economic,
      },
    };
  }

  /**
   * Initialize reputation system components
   */
  private initializeComponents(): void {
    this.behaviorAnalyzer = new BehaviorReputationAnalyzer(this.config);
    this.performanceTracker = new PerformanceTracker(this.config);
    this.consensusEvaluator = new ConsensusEvaluator(this.config);
    this.peerEvaluator = new PeerEvaluator(this.config);
    this.stabilityAnalyzer = new StabilityAnalyzer(this.config);

    if (this.config.economic.reputationStakingEnabled) {
      this.stakeManager = new StakeManager(this.config);
      this.slashingController = new SlashingController(this.config);
    }
  }

  /**
   * Start periodic reputation updates
   */
  private startReputationUpdates(): void {
    // Update reputation scores every 5 minutes
    setInterval(async () => {
      await this.updateAllReputationScores();
    }, 300000);

    // Apply daily decay every 24 hours
    setInterval(async () => {
      await this.applyDailyDecay();
    }, 86400000);

    // Update trends weekly
    setInterval(async () => {
      await this.updateReputationTrends();
    }, 604800000);
  }

  /**
   * Initialize agent reputation
   */
  async initializeAgentReputation(
    agentId: string,
    identity: A2AIdentity,
    initialStake?: number,
  ): Promise<ReputationScore> {
    if (this.reputationScores.has(agentId)) {
      return this.reputationScores.get(agentId)!;
    }

    const reputationScore: ReputationScore = {
      agentId,
      overallScore: 500, // Start with neutral score
      trustLevel: "medium",

      behaviorScore: 75,
      performanceScore: 70,
      consensusScore: 70,
      peerScore: 60,
      stabilityScore: 80,

      metrics: {
        successfulOperations: 0,
        failedOperations: 0,
        consensusParticipation: 0,
        messageReliability: 1.0,
        responseTime: 1000,
        resourceEfficiency: 0.8,
        securityCompliance: 1.0,
        innovationScore: 0.5,
      },

      history: {
        scores: [{ timestamp: new Date(), score: 500 }],
        events: [],
        trends: [],
      },

      peerFeedback: {
        positiveCount: 0,
        negativeCount: 0,
        neutralCount: 0,
        recentFeedback: [],
      },

      stake: {
        amount: initialStake || 0,
        lockPeriod: 0,
        slashingHistory: [],
      },

      metadata: {
        lastUpdated: new Date(),
        updateCount: 0,
        version: "1.0.0",
        flags: identity.trustLevel === "untrusted" ? ["new_agent"] : [],
      },
    };

    // Adjust initial score based on trust level
    reputationScore.overallScore = this.adjustInitialScore(
      reputationScore.overallScore,
      identity.trustLevel,
    );
    reputationScore.trustLevel = this.calculateTrustLevel(
      reputationScore.overallScore,
    );

    this.reputationScores.set(agentId, reputationScore);
    this.peerFeedbacks.set(agentId, []);
    this.reputationEvents.set(agentId, []);

    // Initialize stake if provided
    if (initialStake && this.stakeManager) {
      await this.stakeManager.addStake(agentId, initialStake);
    }

    this.logger.info("Agent reputation initialized", {
      agentId,
      initialScore: reputationScore.overallScore,
      trustLevel: reputationScore.trustLevel,
      stake: initialStake || 0,
    });

    this.emit("reputation_initialized", {
      agentId,
      reputation: reputationScore,
    });
    return reputationScore;
  }

  /**
   * Record reputation event
   */
  async recordReputationEvent(
    event: Omit<ReputationEvent, "eventId" | "timestamp" | "verified">,
  ): Promise<void> {
    const reputationEvent: ReputationEvent = {
      eventId: crypto.randomUUID(),
      timestamp: new Date(),
      verified: false,
      ...event,
    };

    // Get or create events list for agent
    const events = this.reputationEvents.get(event.agentId) || [];
    events.push(reputationEvent);
    this.reputationEvents.set(event.agentId, events);

    // Immediately update reputation score
    await this.updateAgentReputationScore(event.agentId);

    this.logger.info("Reputation event recorded", {
      agentId: event.agentId,
      type: event.type,
      category: event.category,
      impact: event.impact,
    });

    this.emit("reputation_event", reputationEvent);
  }

  /**
   * Submit peer feedback
   */
  async submitPeerFeedback(
    fromAgentId: string,
    toAgentId: string,
    rating: number,
    category:
      | "behavior"
      | "performance"
      | "reliability"
      | "security"
      | "cooperation",
    comment?: string,
    evidence?: any,
  ): Promise<boolean> {
    // Validate rater's reputation
    const raterScore = this.reputationScores.get(fromAgentId);
    if (
      !raterScore ||
      raterScore.overallScore < this.config.peerFeedback.minRaterScore
    ) {
      this.logger.warn(
        "Peer feedback rejected - insufficient rater reputation",
        {
          fromAgent: fromAgentId,
          raterScore: raterScore?.overallScore || 0,
          required: this.config.peerFeedback.minRaterScore,
        },
      );
      return false;
    }

    // Create feedback entry
    const feedback: PeerFeedback = {
      fromAgentId,
      toAgentId,
      rating: Math.max(1, Math.min(5, rating)), // Clamp to 1-5
      category,
      comment,
      evidence,
      timestamp: new Date(),
      signature: await this.signFeedback(
        fromAgentId,
        toAgentId,
        rating,
        category,
      ),
      weight: this.config.peerFeedback.weightByRaterScore
        ? Math.min(1.0, raterScore.overallScore / 1000)
        : 1.0,
    };

    // Add to feedback list
    const feedbacks = this.peerFeedbacks.get(toAgentId) || [];
    feedbacks.push(feedback);
    this.peerFeedbacks.set(toAgentId, feedbacks);

    // Update target agent's reputation
    await this.updateAgentReputationScore(toAgentId);

    this.logger.info("Peer feedback submitted", {
      fromAgent: fromAgentId,
      toAgent: toAgentId,
      rating,
      category,
      weight: feedback.weight,
    });

    this.emit("peer_feedback", feedback);
    return true;
  }

  /**
   * Update agent reputation based on behavior profile
   */
  async updateReputationFromBehavior(
    agentId: string,
    behaviorProfile: BehaviorProfile,
    consensusMetrics?: any,
  ): Promise<void> {
    const reputation = this.reputationScores.get(agentId);
    if (!reputation) return;

    // Update behavior score
    reputation.behaviorScore =
      await this.behaviorAnalyzer.calculateBehaviorScore(behaviorProfile);

    // Update consensus score if metrics provided
    if (consensusMetrics) {
      reputation.consensusScore =
        await this.consensusEvaluator.calculateConsensusScore(consensusMetrics);
    }

    // Update stability score based on historical patterns
    reputation.stabilityScore =
      await this.stabilityAnalyzer.calculateStabilityScore(reputation.history);

    // Recalculate overall score
    await this.recalculateOverallScore(agentId);

    this.logger.debug("Reputation updated from behavior", {
      agentId,
      behaviorScore: reputation.behaviorScore,
      consensusScore: reputation.consensusScore,
      stabilityScore: reputation.stabilityScore,
      overallScore: reputation.overallScore,
    });
  }

  /**
   * Process reputation challenge
   */
  async createReputationChallenge(
    agentId: string,
    type:
      | "behavior_verification"
      | "skill_demonstration"
      | "consensus_participation"
      | "peer_collaboration",
    description: string,
    requirements: any,
    reward: number = 50,
    penalty: number = 25,
    timeLimit: number = 3600000, // 1 hour
  ): Promise<ReputationChallenge> {
    const challenge: ReputationChallenge = {
      challengeId: crypto.randomUUID(),
      agentId,
      type,
      description,
      requirements,
      reward,
      penalty,
      timeLimit,
      createdAt: new Date(),
      status: "pending",
    };

    this.activeChallenges.set(challenge.challengeId, challenge);

    // Auto-expire challenge after time limit
    setTimeout(async () => {
      const currentChallenge = this.activeChallenges.get(challenge.challengeId);
      if (currentChallenge && currentChallenge.status === "pending") {
        currentChallenge.status = "expired";
        await this.recordReputationEvent({
          agentId,
          type: "negative",
          category: "challenge_expired",
          impact: -penalty,
          description: `Challenge ${challenge.challengeId} expired without response`,
          evidence: { challengeId: challenge.challengeId },
        });
      }
    }, timeLimit);

    this.logger.info("Reputation challenge created", {
      challengeId: challenge.challengeId,
      agentId,
      type,
      reward,
      penalty,
    });

    this.emit("reputation_challenge_created", challenge);
    return challenge;
  }

  /**
   * Submit challenge response
   */
  async submitChallengeResponse(
    challengeId: string,
    agentId: string,
    response: any,
  ): Promise<{ success: boolean; reward?: number; penalty?: number }> {
    const challenge = this.activeChallenges.get(challengeId);

    if (!challenge || challenge.agentId !== agentId) {
      return { success: false };
    }

    if (challenge.status !== "pending") {
      return { success: false };
    }

    challenge.status = "in_progress";

    // Validate challenge response
    const validation = await this.validateChallengeResponse(
      challenge,
      response,
    );

    if (validation.success) {
      challenge.status = "completed";

      await this.recordReputationEvent({
        agentId,
        type: "positive",
        category: "challenge_completed",
        impact: challenge.reward,
        description: `Successfully completed ${challenge.type} challenge`,
        evidence: { challengeId, response, validation },
      });

      this.logger.info("Challenge completed successfully", {
        challengeId,
        agentId,
        reward: challenge.reward,
      });

      return { success: true, reward: challenge.reward };
    } else {
      challenge.status = "failed";

      await this.recordReputationEvent({
        agentId,
        type: "negative",
        category: "challenge_failed",
        impact: -challenge.penalty,
        description: `Failed to complete ${challenge.type} challenge`,
        evidence: { challengeId, response, validation },
      });

      this.logger.warn("Challenge failed", {
        challengeId,
        agentId,
        penalty: challenge.penalty,
        reason: validation.reason,
      });

      return { success: false, penalty: challenge.penalty };
    }
  }

  /**
   * Apply reputation-based penalties (slashing)
   */
  async applySlashing(
    agentId: string,
    reason: string,
    percentage: number,
    evidence: any,
  ): Promise<boolean> {
    if (!this.slashingController) return false;

    const reputation = this.reputationScores.get(agentId);
    if (!reputation) return false;

    const slashingAmount = Math.min(
      reputation.stake.amount * percentage,
      reputation.stake.amount * this.config.economic.maxSlashingPercentage,
    );

    if (slashingAmount === 0) return false;

    const slashingEvent: SlashingEvent = {
      eventId: crypto.randomUUID(),
      agentId,
      reason,
      amountSlashed: slashingAmount,
      timestamp: new Date(),
      evidence,
    };

    // Execute slashing
    reputation.stake.amount -= slashingAmount;
    reputation.stake.slashingHistory.push(slashingEvent);

    // Record reputation event
    await this.recordReputationEvent({
      agentId,
      type: "negative",
      category: "slashing",
      impact: -100, // Maximum negative impact
      description: `Economic slashing applied: ${reason}`,
      evidence: slashingEvent,
    });

    this.logger.error("Agent slashed for malicious behavior", {
      agentId,
      reason,
      amountSlashed: slashingAmount,
      remainingStake: reputation.stake.amount,
    });

    this.emit("agent_slashed", slashingEvent);
    return true;
  }

  /**
   * Calculate trust level based on overall score
   */
  private calculateTrustLevel(
    score: number,
  ): "untrusted" | "low" | "medium" | "high" | "excellent" {
    if (score < 200) return "untrusted";
    if (score < 400) return "low";
    if (score < 600) return "medium";
    if (score < 800) return "high";
    return "excellent";
  }

  /**
   * Update all reputation scores
   */
  private async updateAllReputationScores(): Promise<void> {
    const agents = Array.from(this.reputationScores.keys());

    for (const agentId of agents) {
      await this.updateAgentReputationScore(agentId);
    }

    this.logger.debug("All reputation scores updated", {
      agentCount: agents.length,
    });
  }

  /**
   * Update individual agent reputation score
   */
  private async updateAgentReputationScore(agentId: string): Promise<void> {
    const reputation = this.reputationScores.get(agentId);
    if (!reputation) return;

    // Update peer score based on recent feedback
    reputation.peerScore = await this.peerEvaluator.calculatePeerScore(
      this.peerFeedbacks.get(agentId) || [],
    );

    // Update performance score based on recent events
    reputation.performanceScore =
      await this.performanceTracker.calculatePerformanceScore(
        this.reputationEvents.get(agentId) || [],
      );

    // Recalculate overall score
    await this.recalculateOverallScore(agentId);

    // Update metadata
    reputation.metadata.lastUpdated = new Date();
    reputation.metadata.updateCount++;

    // Add to history
    reputation.history.scores.push({
      timestamp: new Date(),
      score: reputation.overallScore,
    });

    // Limit history size
    if (reputation.history.scores.length > 1000) {
      reputation.history.scores = reputation.history.scores.slice(-500);
    }

    // Update trust level
    const newTrustLevel = this.calculateTrustLevel(reputation.overallScore);
    if (newTrustLevel !== reputation.trustLevel) {
      reputation.trustLevel = newTrustLevel;

      this.emit("trust_level_changed", {
        agentId,
        oldLevel: reputation.trustLevel,
        newLevel: newTrustLevel,
        score: reputation.overallScore,
      });
    }

    this.emit("reputation_updated", { agentId, reputation });
  }

  /**
   * Recalculate overall reputation score
   */
  private async recalculateOverallScore(agentId: string): Promise<void> {
    const reputation = this.reputationScores.get(agentId);
    if (!reputation) return;

    const weights = this.config.weights;

    const overallScore = Math.round(
      (reputation.behaviorScore * weights.behavior +
        reputation.performanceScore * weights.performance +
        reputation.consensusScore * weights.consensus +
        reputation.peerScore * weights.peer +
        reputation.stabilityScore * weights.stability) *
        10, // Scale to 0-1000
    );

    // Apply stake weighting if enabled
    let finalScore = overallScore;
    if (
      this.config.economic.reputationStakingEnabled &&
      reputation.stake.amount > 0
    ) {
      const stakeMultiplier = Math.min(
        2.0,
        1 + reputation.stake.amount / 10000,
      );
      finalScore = Math.round(overallScore * stakeMultiplier);
    }

    reputation.overallScore = Math.max(0, Math.min(1000, finalScore));
  }

  /**
   * Apply daily reputation decay
   */
  private async applyDailyDecay(): Promise<void> {
    const decayFactor = this.config.decayFactors.dailyDecay;

    for (const [agentId, reputation] of this.reputationScores) {
      // Apply decay to component scores
      reputation.behaviorScore *= decayFactor;
      reputation.performanceScore *= decayFactor;
      reputation.consensusScore *= decayFactor;
      reputation.peerScore *= decayFactor;
      reputation.stabilityScore *= decayFactor;

      // Check for inactivity
      const daysSinceUpdate =
        (Date.now() - reputation.metadata.lastUpdated.getTime()) / 86400000;
      if (daysSinceUpdate > 1) {
        const inactivityPenalty =
          this.config.decayFactors.inactivityPenalty * daysSinceUpdate;
        reputation.overallScore = Math.max(
          0,
          reputation.overallScore - reputation.overallScore * inactivityPenalty,
        );
      }

      await this.recalculateOverallScore(agentId);
    }

    this.logger.info("Daily reputation decay applied", {
      agentCount: this.reputationScores.size,
      decayFactor,
    });
  }

  /**
   * Update reputation trends
   */
  private async updateReputationTrends(): Promise<void> {
    for (const [agentId, reputation] of this.reputationScores) {
      const trends = this.calculateReputationTrends(reputation.history.scores);
      reputation.history.trends = trends;
    }

    this.logger.info("Reputation trends updated");
  }

  /**
   * Helper methods
   */

  private adjustInitialScore(baseScore: number, trustLevel: string): number {
    const adjustments = {
      untrusted: -200,
      basic: -100,
      verified: 0,
      trusted: 100,
    };

    return Math.max(
      0,
      Math.min(
        1000,
        baseScore + (adjustments[trustLevel as keyof typeof adjustments] || 0),
      ),
    );
  }

  private async signFeedback(
    fromAgentId: string,
    toAgentId: string,
    rating: number,
    category: string,
  ): Promise<string> {
    const data = `${fromAgentId}:${toAgentId}:${rating}:${category}:${Date.now()}`;
    return crypto.createHash("sha256").update(data).digest("hex");
  }

  private async validateChallengeResponse(
    challenge: ReputationChallenge,
    response: any,
  ): Promise<{ success: boolean; reason?: string }> {
    // Implement challenge-specific validation logic
    switch (challenge.type) {
      case "behavior_verification":
        return this.validateBehaviorChallenge(challenge, response);
      case "skill_demonstration":
        return this.validateSkillChallenge(challenge, response);
      case "consensus_participation":
        return this.validateConsensusChallenge(challenge, response);
      case "peer_collaboration":
        return this.validateCollaborationChallenge(challenge, response);
      default:
        return { success: false, reason: "Unknown challenge type" };
    }
  }

  private async validateBehaviorChallenge(
    challenge: ReputationChallenge,
    response: any,
  ): Promise<{ success: boolean; reason?: string }> {
    // Validate behavior verification challenge
    return { success: true };
  }

  private async validateSkillChallenge(
    challenge: ReputationChallenge,
    response: any,
  ): Promise<{ success: boolean; reason?: string }> {
    // Validate skill demonstration challenge
    return { success: true };
  }

  private async validateConsensusChallenge(
    challenge: ReputationChallenge,
    response: any,
  ): Promise<{ success: boolean; reason?: string }> {
    // Validate consensus participation challenge
    return { success: true };
  }

  private async validateCollaborationChallenge(
    challenge: ReputationChallenge,
    response: any,
  ): Promise<{ success: boolean; reason?: string }> {
    // Validate peer collaboration challenge
    return { success: true };
  }

  private calculateReputationTrends(
    scores: { timestamp: Date; score: number }[],
  ): ReputationTrend[] {
    if (scores.length < 2) return [];

    const now = new Date();
    const trends: ReputationTrend[] = [];

    // Calculate daily trend (last 24 hours)
    const dailyScores = scores.filter(
      (s) => now.getTime() - s.timestamp.getTime() < 86400000,
    );
    if (dailyScores.length > 1) {
      trends.push(this.calculateTrend("daily", dailyScores));
    }

    // Calculate weekly trend
    const weeklyScores = scores.filter(
      (s) => now.getTime() - s.timestamp.getTime() < 604800000,
    );
    if (weeklyScores.length > 1) {
      trends.push(this.calculateTrend("weekly", weeklyScores));
    }

    // Calculate monthly trend
    const monthlyScores = scores.filter(
      (s) => now.getTime() - s.timestamp.getTime() < 2592000000,
    );
    if (monthlyScores.length > 1) {
      trends.push(this.calculateTrend("monthly", monthlyScores));
    }

    return trends;
  }

  private calculateTrend(
    period: "daily" | "weekly" | "monthly",
    scores: { timestamp: Date; score: number }[],
  ): ReputationTrend {
    const sortedScores = scores.sort(
      (a, b) => a.timestamp.getTime() - b.timestamp.getTime(),
    );
    const firstScore = sortedScores[0];
    const lastScore = sortedScores[sortedScores.length - 1];

    const averageScore =
      sortedScores.reduce((sum, s) => sum + s.score, 0) / sortedScores.length;
    const scoreDiff = lastScore.score - firstScore.score;

    let trend: "increasing" | "decreasing" | "stable" = "stable";
    if (Math.abs(scoreDiff) > 10) {
      trend = scoreDiff > 0 ? "increasing" : "decreasing";
    }

    // Calculate volatility (standard deviation)
    const variance =
      sortedScores.reduce(
        (sum, s) => sum + Math.pow(s.score - averageScore, 2),
        0,
      ) / sortedScores.length;
    const volatility = Math.sqrt(variance);

    return {
      period,
      startDate: firstScore.timestamp,
      endDate: lastScore.timestamp,
      averageScore,
      trend,
      volatility,
      confidence: Math.min(1.0, sortedScores.length / 10), // Higher confidence with more data points
    };
  }

  /**
   * Public API methods
   */

  getReputationScore(agentId: string): ReputationScore | null {
    return this.reputationScores.get(agentId) || null;
  }

  getAllReputationScores(): ReputationScore[] {
    return Array.from(this.reputationScores.values());
  }

  getPeerFeedback(agentId: string): PeerFeedback[] {
    return this.peerFeedbacks.get(agentId) || [];
  }

  getReputationEvents(agentId: string): ReputationEvent[] {
    return this.reputationEvents.get(agentId) || [];
  }

  getActiveChallenges(agentId?: string): ReputationChallenge[] {
    const challenges = Array.from(this.activeChallenges.values());
    return agentId
      ? challenges.filter((c) => c.agentId === agentId)
      : challenges;
  }

  async getSystemStats(): Promise<any> {
    const scores = Array.from(this.reputationScores.values());
    const totalFeedback = Array.from(this.peerFeedbacks.values()).reduce(
      (sum, f) => sum + f.length,
      0,
    );
    const totalEvents = Array.from(this.reputationEvents.values()).reduce(
      (sum, e) => sum + e.length,
      0,
    );

    return {
      totalAgents: scores.length,
      averageScore:
        scores.reduce((sum, s) => sum + s.overallScore, 0) / scores.length || 0,
      trustLevelDistribution: this.calculateTrustLevelDistribution(scores),
      totalPeerFeedback: totalFeedback,
      totalReputationEvents: totalEvents,
      activeChallenges: this.activeChallenges.size,
      totalStaked: scores.reduce((sum, s) => sum + s.stake.amount, 0),
      slashingEvents: scores.reduce(
        (sum, s) => sum + s.stake.slashingHistory.length,
        0,
      ),
    };
  }

  private calculateTrustLevelDistribution(
    scores: ReputationScore[],
  ): Record<string, number> {
    const distribution = {
      untrusted: 0,
      low: 0,
      medium: 0,
      high: 0,
      excellent: 0,
    };

    scores.forEach((score) => {
      distribution[score.trustLevel]++;
    });

    return distribution;
  }
}

// Supporting analyzer classes

class BehaviorReputationAnalyzer {
  constructor(private config: ReputationConfig) {}

  async calculateBehaviorScore(profile: BehaviorProfile): Promise<number> {
    let score = 75; // Base score

    // Analyze message patterns
    if (profile.protocolCompliance.signatureValidation > 0.9) score += 10;
    if (profile.protocolCompliance.nonceCompliance > 0.9) score += 5;
    if (profile.protocolCompliance.capabilityCompliance > 0.9) score += 5;

    // Penalize anomalies
    if (profile.anomalyIndicators.recentAnomalies > 5) score -= 15;
    if (profile.anomalyIndicators.totalAnomalies > 20) score -= 10;

    // Trust metrics influence
    score += (profile.trustMetrics.behaviorScore - 0.5) * 20;

    return Math.max(0, Math.min(100, score));
  }
}

class PerformanceTracker {
  constructor(private config: ReputationConfig) {}

  async calculatePerformanceScore(events: ReputationEvent[]): Promise<number> {
    if (events.length === 0) return 70; // Default score

    // Calculate recent performance (last 7 days)
    const recentEvents = events.filter(
      (e) => Date.now() - e.timestamp.getTime() < 604800000,
    );

    if (recentEvents.length === 0) return 70;

    const positiveEvents = recentEvents.filter((e) => e.type === "positive");
    const negativeEvents = recentEvents.filter((e) => e.type === "negative");

    const positiveImpact = positiveEvents.reduce((sum, e) => sum + e.impact, 0);
    const negativeImpact = negativeEvents.reduce(
      (sum, e) => sum + Math.abs(e.impact),
      0,
    );

    const netImpact = positiveImpact - negativeImpact;
    const baseScore = 70;

    return Math.max(0, Math.min(100, baseScore + netImpact));
  }
}

class ConsensusEvaluator {
  constructor(private config: ReputationConfig) {}

  async calculateConsensusScore(metrics: any): Promise<number> {
    let score = 70; // Base score

    if (metrics.participationRate > 0.8) score += 15;
    if (metrics.agreementRate > 0.7) score += 10;
    if (metrics.proposalQuality > 0.8) score += 10;
    if (metrics.responseLatency < 2000) score += 5;

    return Math.max(0, Math.min(100, score));
  }
}

class PeerEvaluator {
  constructor(private config: ReputationConfig) {}

  async calculatePeerScore(feedbacks: PeerFeedback[]): Promise<number> {
    if (feedbacks.length === 0) return 60; // Default score

    // Filter recent feedback
    const recentFeedbacks = feedbacks.filter(
      (f) =>
        Date.now() - f.timestamp.getTime() <
        this.config.peerFeedback.maxFeedbackAge,
    );

    if (recentFeedbacks.length === 0) return 60;

    // Calculate weighted average
    const weightedSum = recentFeedbacks.reduce(
      (sum, f) => sum + f.rating * f.weight,
      0,
    );
    const totalWeight = recentFeedbacks.reduce((sum, f) => sum + f.weight, 0);

    const avgRating = weightedSum / totalWeight;

    // Convert 1-5 rating to 0-100 score
    return (avgRating - 1) * 25;
  }
}

class StabilityAnalyzer {
  constructor(private config: ReputationConfig) {}

  async calculateStabilityScore(history: {
    scores: { timestamp: Date; score: number }[];
  }): Promise<number> {
    if (history.scores.length < 10) return 80; // Default for new agents

    // Calculate score variance over time
    const scores = history.scores.map((s) => s.score);
    const avgScore = scores.reduce((sum, s) => sum + s, 0) / scores.length;
    const variance =
      scores.reduce((sum, s) => sum + Math.pow(s - avgScore, 2), 0) /
      scores.length;
    const volatility = Math.sqrt(variance);

    // Lower volatility = higher stability score
    const stabilityScore = Math.max(0, 100 - volatility / 10);

    return Math.min(100, stabilityScore);
  }
}

class StakeManager {
  constructor(private config: ReputationConfig) {}

  async addStake(agentId: string, amount: number): Promise<boolean> {
    // Implementation for adding stake
    return true;
  }

  async removeStake(agentId: string, amount: number): Promise<boolean> {
    // Implementation for removing stake
    return true;
  }
}

class SlashingController {
  constructor(private config: ReputationConfig) {}

  async executeSlashing(
    agentId: string,
    amount: number,
    reason: string,
  ): Promise<boolean> {
    // Implementation for executing slashing
    return true;
  }
}

export {
  ReputationSystem,
  ReputationScore,
  PeerFeedback,
  ReputationEvent,
  ReputationTrend,
  ReputationChallenge,
  SlashingEvent,
  ReputationConfig,
};