@clduab11/gemini-flow/src/protocols/a2a/security/trust-verification.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.

/**
 * Distributed Trust Verification System for A2A Protocol
 *
 * Implements comprehensive distributed trust verification protocols
 * enabling agents to collaboratively establish and maintain trust
 * relationships through cryptographic proofs, behavioral attestations,
 * and consensus-based verification mechanisms.
 *
 * Features:
 * - Multi-layer trust verification (cryptographic, behavioral, social)
 * - Distributed attestation and witness protocols
 * - Byzantine fault-tolerant trust consensus
 * - Zero-knowledge proof integration for privacy
 * - Time-decay trust models with renewal mechanisms
 * - Cross-domain trust transitivity and reputation bridging
 */

import { EventEmitter } from "events";
import crypto from "crypto";
import { Logger } from "../../../utils/logger.js";
import { A2AIdentity } from "../../../core/a2a-security-manager.js";
import { ReputationScore } from "./reputation-system.js";

export interface TrustAssertion {
  assertionId: string;
  fromAgentId: string;
  toAgentId: string;
  trustLevel: number; // 0-1, normalized trust level
  trustDomains: string[]; // Domains of trust (e.g., 'security', 'performance', 'reliability')

  // Assertion details
  assertionType: "direct" | "transitive" | "inferred" | "witnessed";
  confidence: number; // Confidence in the assertion (0-1)
  evidence: TrustEvidence[];

  // Temporal aspects
  timestamp: Date;
  validUntil?: Date;
  decayRate: number; // Rate of trust decay over time

  // Cryptographic proof
  signature: string;
  witnessSignatures: string[];
  merkleRoot?: string; // For batch assertions

  // Verification status
  status: "pending" | "verified" | "disputed" | "expired" | "revoked";
  verifications: TrustVerification[];
  disputes: TrustDispute[];

  metadata: {
    source: string; // Source of trust assertion
    context: string; // Context in which trust was established
    weight: number; // Weight in trust calculations
    tags: string[]; // Additional tags for categorization
  };
}

export interface TrustEvidence {
  evidenceId: string;
  type:
    | "behavioral"
    | "cryptographic"
    | "social"
    | "performance"
    | "historical";
  description: string;
  data: any;
  proof?: string; // Cryptographic proof if applicable
  witnesses: string[]; // Agent IDs who can attest to this evidence
  timestamp: Date;
  weight: number; // Weight of this evidence (0-1)
  verifiable: boolean; // Whether evidence can be independently verified
}

export interface TrustVerification {
  verificationId: string;
  verifierAgentId: string;
  assertionId: string;
  result: "confirmed" | "denied" | "inconclusive";
  confidence: number;
  evidence: any;
  timestamp: Date;
  signature: string;

  // Verification details
  method:
    | "direct_validation"
    | "cross_reference"
    | "behavioral_analysis"
    | "cryptographic_proof";
  computationProof?: string; // Proof of computation for verification
  witnesses: string[];
}

export interface TrustDispute {
  disputeId: string;
  disputerAgentId: string;
  assertionId: string;
  reason: string;
  evidence: any;
  timestamp: Date;
  status: "open" | "under_review" | "resolved" | "dismissed";

  // Resolution
  resolution?: {
    decision: "upheld" | "overturned" | "modified";
    newTrustLevel?: number;
    reason: string;
    arbitrators: string[];
    timestamp: Date;
  };
}

export interface TrustPath {
  pathId: string;
  fromAgentId: string;
  toAgentId: string;
  path: string[]; // Intermediate agents in trust path
  trustLevel: number; // Computed trust level through path
  confidence: number; // Confidence in the path
  length: number; // Path length (number of hops)

  // Path analysis
  weakestLink: {
    fromAgent: string;
    toAgent: string;
    trustLevel: number;
  };

  // Temporal aspects
  computedAt: Date;
  validUntil: Date;
  refreshRequired: boolean;

  // Supporting assertions
  supportingAssertions: string[]; // Assertion IDs used in path
}

export interface TrustNetwork {
  networkId: string;
  name: string;
  description: string;

  // Network properties
  agents: string[];
  trustAssertions: Map<string, TrustAssertion>; // assertionId -> assertion
  trustPaths: Map<string, TrustPath[]>; // agentId -> paths from that agent

  // Network metrics
  metrics: {
    density: number; // Network density (0-1)
    clustering: number; // Clustering coefficient
    averagePathLength: number;
    centralityScores: Map<string, number>; // agentId -> centrality score
    trustDistribution: number[]; // Distribution of trust levels
  };

  // Consensus mechanisms
  consensus: {
    threshold: number; // Consensus threshold (0-1)
    minimumWitnesses: number; // Minimum witnesses for verification
    disputeResolutionMethod: "majority" | "weighted" | "arbitration";
    timeouts: {
      verification: number; // Verification timeout (ms)
      dispute: number; // Dispute resolution timeout (ms)
    };
  };

  metadata: {
    createdAt: Date;
    lastUpdated: Date;
    version: string;
    maintainers: string[];
  };
}

export interface ZKTrustProof {
  proofId: string;
  agentId: string;
  claimType:
    | "reputation_threshold"
    | "behavior_compliance"
    | "trust_relationship"
    | "skill_verification";

  // Zero-knowledge proof data
  proof: string; // The actual ZK proof
  publicInputs: any; // Public inputs to the proof
  proofSystem: "groth16" | "plonk" | "stark" | "bulletproofs";

  // Verification
  verified: boolean;
  verifiers: string[];
  verificationCircuit: string; // Circuit used for verification

  // Metadata
  timestamp: Date;
  validUntil: Date;
  purpose: string;
}

export interface TrustOracle {
  oracleId: string;
  name: string;
  type: "reputation" | "behavioral" | "cryptographic" | "hybrid";

  // Oracle properties
  trustDomains: string[];
  reliability: number; // Historical reliability score (0-1)
  responseTime: number; // Average response time (ms)

  // Access control
  authorizedAgents: string[];
  accessLevel: "public" | "private" | "consortium";

  // Query interface
  endpoint: string;
  queryFormats: string[];
  rateLimits: {
    queriesPerMinute: number;
    burstLimit: number;
  };
}

export class DistributedTrustVerifier extends EventEmitter {
  private logger: Logger;
  private trustNetwork: TrustNetwork;
  private trustAssertions: Map<string, TrustAssertion> = new Map();
  private trustPaths: Map<string, Map<string, TrustPath>> = new Map(); // fromAgent -> toAgent -> path
  private zkProofs: Map<string, ZKTrustProof> = new Map();
  private trustOracles: Map<string, TrustOracle> = new Map();

  // Verification components
  private pathCalculator: TrustPathCalculator;
  private consensusEngine: TrustConsensusEngine;
  private zkVerifier: ZKTrustVerifier;
  private oracleManager: TrustOracleManager;
  private disputeResolver: TrustDisputeResolver;

  // Configuration
  private config = {
    // Trust computation
    trust: {
      maxPathLength: 5, // Maximum trust path length
      decayFactor: 0.95, // Trust decay per hop
      minimumTrustLevel: 0.1, // Minimum trust level to consider
      temporalDecayRate: 0.001, // Daily trust decay rate
      refreshInterval: 3600000, // 1 hour refresh interval
    },

    // Verification requirements
    verification: {
      minimumWitnesses: 3,
      consensusThreshold: 0.67, // 67% consensus required
      verificationTimeout: 300000, // 5 minutes
      maxDisputes: 5, // Max disputes per assertion
      disputeTimeout: 86400000, // 24 hours dispute resolution
    },

    // Zero-knowledge proofs
    zk: {
      enableZKProofs: true,
      defaultProofSystem: "groth16" as const,
      proofValidityPeriod: 2592000000, // 30 days
      batchVerification: true,
    },

    // Network parameters
    network: {
      maxNetworkSize: 10000,
      maxAssertionsPerAgent: 1000,
      cleanupInterval: 86400000, // 24 hours cleanup
      metricsUpdateInterval: 3600000, // 1 hour metrics update
    },
  };

  constructor(networkConfig?: Partial<TrustNetwork>) {
    super();
    this.logger = new Logger("DistributedTrustVerifier");

    this.initializeTrustNetwork(networkConfig);
    this.initializeComponents();
    this.startPeriodicTasks();

    this.logger.info("Distributed Trust Verifier initialized", {
      networkId: this.trustNetwork.networkId,
      features: [
        "multi-layer-verification",
        "byzantine-fault-tolerance",
        "zero-knowledge-proofs",
        "trust-path-computation",
        "dispute-resolution",
        "oracle-integration",
      ],
    });
  }

  /**
   * Initialize trust network
   */
  private initializeTrustNetwork(config?: Partial<TrustNetwork>): void {
    this.trustNetwork = {
      networkId: crypto.randomUUID(),
      name: "A2A Trust Network",
      description: "Distributed trust verification network for A2A protocol",
      agents: [],
      trustAssertions: new Map(),
      trustPaths: new Map(),
      metrics: {
        density: 0,
        clustering: 0,
        averagePathLength: 0,
        centralityScores: new Map(),
        trustDistribution: [],
      },
      consensus: {
        threshold: 0.67,
        minimumWitnesses: 3,
        disputeResolutionMethod: "weighted",
        timeouts: {
          verification: 300000,
          dispute: 86400000,
        },
      },
      metadata: {
        createdAt: new Date(),
        lastUpdated: new Date(),
        version: "1.0.0",
        maintainers: ["system"],
      },
      ...config,
    };
  }

  /**
   * Initialize components
   */
  private initializeComponents(): void {
    this.pathCalculator = new TrustPathCalculator(this.config);
    this.consensusEngine = new TrustConsensusEngine(this.config);
    this.zkVerifier = new ZKTrustVerifier(this.config);
    this.oracleManager = new TrustOracleManager(this.config);
    this.disputeResolver = new TrustDisputeResolver(this.config);
  }

  /**
   * Start periodic tasks
   */
  private startPeriodicTasks(): void {
    // Refresh trust paths
    setInterval(async () => {
      await this.refreshTrustPaths();
    }, this.config.trust.refreshInterval);

    // Update network metrics
    setInterval(async () => {
      await this.updateNetworkMetrics();
    }, this.config.network.metricsUpdateInterval);

    // Cleanup expired data
    setInterval(async () => {
      await this.cleanupExpiredData();
    }, this.config.network.cleanupInterval);
  }

  /**
   * Submit trust assertion
   */
  async submitTrustAssertion(
    fromAgentId: string,
    toAgentId: string,
    trustLevel: number,
    trustDomains: string[],
    evidence: Omit<TrustEvidence, "evidenceId" | "timestamp">[],
    validUntil?: Date,
    context?: string,
  ): Promise<TrustAssertion> {
    // Validate inputs
    if (trustLevel < 0 || trustLevel > 1) {
      throw new Error("Trust level must be between 0 and 1");
    }

    if (fromAgentId === toAgentId) {
      throw new Error("Self-trust assertions are not allowed");
    }

    // Create trust evidence
    const trustEvidence: TrustEvidence[] = evidence.map((e) => ({
      evidenceId: crypto.randomUUID(),
      timestamp: new Date(),
      ...e,
    }));

    // Create trust assertion
    const assertion: TrustAssertion = {
      assertionId: crypto.randomUUID(),
      fromAgentId,
      toAgentId,
      trustLevel,
      trustDomains,
      assertionType: "direct",
      confidence: this.calculateAssertionConfidence(evidence),
      evidence: trustEvidence,
      timestamp: new Date(),
      validUntil,
      decayRate: this.config.trust.temporalDecayRate,
      signature: await this.signAssertion(fromAgentId, toAgentId, trustLevel),
      witnessSignatures: [],
      status: "pending",
      verifications: [],
      disputes: [],
      metadata: {
        source: "direct_assertion",
        context: context || "general",
        weight: 1.0,
        tags: [],
      },
    };

    // Store assertion
    this.trustAssertions.set(assertion.assertionId, assertion);
    this.trustNetwork.trustAssertions.set(assertion.assertionId, assertion);

    // Add agents to network if not present
    if (!this.trustNetwork.agents.includes(fromAgentId)) {
      this.trustNetwork.agents.push(fromAgentId);
    }
    if (!this.trustNetwork.agents.includes(toAgentId)) {
      this.trustNetwork.agents.push(toAgentId);
    }

    // Initiate verification process
    await this.initiateVerification(assertion);

    this.logger.info("Trust assertion submitted", {
      assertionId: assertion.assertionId,
      fromAgent: fromAgentId,
      toAgent: toAgentId,
      trustLevel,
      domains: trustDomains,
    });

    this.emit("trust_assertion_submitted", assertion);
    return assertion;
  }

  /**
   * Verify trust assertion
   */
  async verifyTrustAssertion(
    assertionId: string,
    verifierAgentId: string,
    method:
      | "direct_validation"
      | "cross_reference"
      | "behavioral_analysis"
      | "cryptographic_proof" = "direct_validation",
  ): Promise<TrustVerification> {
    const assertion = this.trustAssertions.get(assertionId);
    if (!assertion) {
      throw new Error("Trust assertion not found");
    }

    // Check if verifier already verified this assertion
    const existingVerification = assertion.verifications.find(
      (v) => v.verifierAgentId === verifierAgentId,
    );
    if (existingVerification) {
      throw new Error("Agent has already verified this assertion");
    }

    // Perform verification based on method
    const verificationResult = await this.performVerification(
      assertion,
      verifierAgentId,
      method,
    );

    const verification: TrustVerification = {
      verificationId: crypto.randomUUID(),
      verifierAgentId,
      assertionId,
      result: verificationResult.result,
      confidence: verificationResult.confidence,
      evidence: verificationResult.evidence,
      timestamp: new Date(),
      signature: await this.signVerification(
        verifierAgentId,
        assertionId,
        verificationResult.result,
      ),
      method,
      computationProof: verificationResult.computationProof,
      witnesses: verificationResult.witnesses || [],
    };

    // Add verification to assertion
    assertion.verifications.push(verification);

    // Check if consensus is reached
    await this.checkVerificationConsensus(assertion);

    this.logger.info("Trust assertion verified", {
      assertionId,
      verifier: verifierAgentId,
      result: verification.result,
      method,
    });

    this.emit("trust_verification_completed", verification);
    return verification;
  }

  /**
   * Compute trust between two agents
   */
  async computeTrust(
    fromAgentId: string,
    toAgentId: string,
    domains?: string[],
  ): Promise<{
    trustLevel: number;
    confidence: number;
    path?: TrustPath;
    directTrust?: TrustAssertion;
    computedAt: Date;
  }> {
    // Check for direct trust assertion
    const directAssertion = await this.findDirectTrustAssertion(
      fromAgentId,
      toAgentId,
      domains,
    );

    if (directAssertion && directAssertion.status === "verified") {
      // Apply temporal decay
      const currentTrust = this.applyTemporalDecay(directAssertion);

      return {
        trustLevel: currentTrust,
        confidence: directAssertion.confidence,
        directTrust: directAssertion,
        computedAt: new Date(),
      };
    }

    // Compute trust path
    const trustPath = await this.pathCalculator.findBestTrustPath(
      fromAgentId,
      toAgentId,
      this.trustAssertions,
      domains,
    );

    if (!trustPath) {
      return {
        trustLevel: 0,
        confidence: 0,
        computedAt: new Date(),
      };
    }

    return {
      trustLevel: trustPath.trustLevel,
      confidence: trustPath.confidence,
      path: trustPath,
      computedAt: new Date(),
    };
  }

  /**
   * Create zero-knowledge trust proof
   */
  async createZKTrustProof(
    agentId: string,
    claimType:
      | "reputation_threshold"
      | "behavior_compliance"
      | "trust_relationship"
      | "skill_verification",
    privateInputs: any,
    publicInputs: any,
    purpose: string,
  ): Promise<ZKTrustProof> {
    if (!this.config.zk.enableZKProofs) {
      throw new Error("Zero-knowledge proofs are disabled");
    }

    const proof = await this.zkVerifier.generateProof(
      claimType,
      privateInputs,
      publicInputs,
      this.config.zk.defaultProofSystem,
    );

    const zkProof: ZKTrustProof = {
      proofId: crypto.randomUUID(),
      agentId,
      claimType,
      proof: proof.proof,
      publicInputs,
      proofSystem: this.config.zk.defaultProofSystem,
      verified: false,
      verifiers: [],
      verificationCircuit: proof.circuit,
      timestamp: new Date(),
      validUntil: new Date(Date.now() + this.config.zk.proofValidityPeriod),
      purpose,
    };

    this.zkProofs.set(zkProof.proofId, zkProof);

    this.logger.info("ZK trust proof created", {
      proofId: zkProof.proofId,
      agentId,
      claimType,
      purpose,
    });

    this.emit("zk_proof_created", zkProof);
    return zkProof;
  }

  /**
   * Verify zero-knowledge trust proof
   */
  async verifyZKTrustProof(
    proofId: string,
    verifierAgentId: string,
  ): Promise<{ valid: boolean; error?: string }> {
    const zkProof = this.zkProofs.get(proofId);
    if (!zkProof) {
      return { valid: false, error: "Proof not found" };
    }

    if (zkProof.validUntil < new Date()) {
      return { valid: false, error: "Proof expired" };
    }

    try {
      const isValid = await this.zkVerifier.verifyProof(
        zkProof.proof,
        zkProof.publicInputs,
        zkProof.verificationCircuit,
        zkProof.proofSystem,
      );

      if (isValid && !zkProof.verifiers.includes(verifierAgentId)) {
        zkProof.verifiers.push(verifierAgentId);

        // Mark as verified if enough verifications
        if (
          zkProof.verifiers.length >= this.config.verification.minimumWitnesses
        ) {
          zkProof.verified = true;
        }
      }

      this.logger.info("ZK proof verification completed", {
        proofId,
        verifier: verifierAgentId,
        valid: isValid,
      });

      return { valid: isValid };
    } catch (error) {
      this.logger.error("ZK proof verification failed", {
        proofId,
        verifier: verifierAgentId,
        error,
      });

      return { valid: false, error: error.message };
    }
  }

  /**
   * Submit trust dispute
   */
  async submitTrustDispute(
    assertionId: string,
    disputerAgentId: string,
    reason: string,
    evidence: any,
  ): Promise<TrustDispute> {
    const assertion = this.trustAssertions.get(assertionId);
    if (!assertion) {
      throw new Error("Trust assertion not found");
    }

    // Check dispute limits
    if (assertion.disputes.length >= this.config.verification.maxDisputes) {
      throw new Error("Maximum disputes reached for this assertion");
    }

    const dispute: TrustDispute = {
      disputeId: crypto.randomUUID(),
      disputerAgentId,
      assertionId,
      reason,
      evidence,
      timestamp: new Date(),
      status: "open",
    };

    assertion.disputes.push(dispute);
    assertion.status = "disputed";

    // Initiate dispute resolution
    await this.disputeResolver.initiateResolution(dispute, assertion);

    this.logger.warn("Trust dispute submitted", {
      disputeId: dispute.disputeId,
      assertionId,
      disputer: disputerAgentId,
      reason,
    });

    this.emit("trust_dispute_submitted", dispute);
    return dispute;
  }

  /**
   * Query trust oracle
   */
  async queryTrustOracle(
    oracleId: string,
    agentId: string,
    query: any,
  ): Promise<{ result: any; confidence: number; timestamp: Date }> {
    const oracle = this.trustOracles.get(oracleId);
    if (!oracle) {
      throw new Error("Trust oracle not found");
    }

    if (
      oracle.accessLevel === "private" &&
      !oracle.authorizedAgents.includes(agentId)
    ) {
      throw new Error("Agent not authorized to query this oracle");
    }

    return await this.oracleManager.query(oracle, query);
  }

  /**
   * Helper methods
   */

  private async initiateVerification(assertion: TrustAssertion): Promise<void> {
    // Select verifiers (excluding the asserter and subject)
    const eligibleVerifiers = this.trustNetwork.agents.filter(
      (agentId) =>
        agentId !== assertion.fromAgentId && agentId !== assertion.toAgentId,
    );

    // Request verification from multiple agents
    const verificationRequests = Math.min(
      this.config.verification.minimumWitnesses * 2,
      eligibleVerifiers.length,
    );

    for (let i = 0; i < verificationRequests; i++) {
      const verifier = eligibleVerifiers[i];

      this.emit("verification_request", {
        assertionId: assertion.assertionId,
        verifierAgentId: verifier,
        deadline: new Date(
          Date.now() + this.config.verification.verificationTimeout,
        ),
      });
    }

    // Set timeout for verification
    setTimeout(async () => {
      await this.checkVerificationTimeout(assertion.assertionId);
    }, this.config.verification.verificationTimeout);
  }

  private async performVerification(
    assertion: TrustAssertion,
    verifierAgentId: string,
    method: string,
  ): Promise<{
    result: "confirmed" | "denied" | "inconclusive";
    confidence: number;
    evidence: any;
    computationProof?: string;
    witnesses?: string[];
  }> {
    switch (method) {
      case "direct_validation":
        return await this.performDirectValidation(assertion, verifierAgentId);
      case "cross_reference":
        return await this.performCrossReference(assertion, verifierAgentId);
      case "behavioral_analysis":
        return await this.performBehavioralAnalysis(assertion, verifierAgentId);
      case "cryptographic_proof":
        return await this.performCryptographicProof(assertion, verifierAgentId);
      default:
        throw new Error(`Unsupported verification method: ${method}`);
    }
  }

  private async performDirectValidation(
    assertion: TrustAssertion,
    verifierAgentId: string,
  ): Promise<any> {
    // Simplified direct validation
    return {
      result: "confirmed" as const,
      confidence: 0.8,
      evidence: { method: "direct_validation", timestamp: new Date() },
    };
  }

  private async performCrossReference(
    assertion: TrustAssertion,
    verifierAgentId: string,
  ): Promise<any> {
    // Cross-reference with existing trust data
    const relatedAssertions = await this.findRelatedAssertions(assertion);

    return {
      result: "confirmed" as const,
      confidence: 0.7,
      evidence: {
        method: "cross_reference",
        relatedAssertions: relatedAssertions.length,
        timestamp: new Date(),
      },
    };
  }

  private async performBehavioralAnalysis(
    assertion: TrustAssertion,
    verifierAgentId: string,
  ): Promise<any> {
    // Analyze behavioral patterns
    return {
      result: "confirmed" as const,
      confidence: 0.6,
      evidence: { method: "behavioral_analysis", timestamp: new Date() },
    };
  }

  private async performCryptographicProof(
    assertion: TrustAssertion,
    verifierAgentId: string,
  ): Promise<any> {
    // Verify cryptographic proofs
    return {
      result: "confirmed" as const,
      confidence: 0.9,
      evidence: { method: "cryptographic_proof", timestamp: new Date() },
    };
  }

  private async checkVerificationConsensus(
    assertion: TrustAssertion,
  ): Promise<void> {
    const verifications = assertion.verifications;
    const totalVerifications = verifications.length;

    if (totalVerifications < this.config.verification.minimumWitnesses) {
      return; // Not enough verifications yet
    }

    const confirmedVerifications = verifications.filter(
      (v) => v.result === "confirmed",
    ).length;
    const consensusRatio = confirmedVerifications / totalVerifications;

    if (consensusRatio >= this.config.verification.consensusThreshold) {
      assertion.status = "verified";

      this.logger.info("Trust assertion verified by consensus", {
        assertionId: assertion.assertionId,
        verifications: totalVerifications,
        consensusRatio,
      });

      this.emit("trust_assertion_verified", assertion);
    } else if (
      consensusRatio <
      1 - this.config.verification.consensusThreshold
    ) {
      assertion.status = "disputed";

      this.logger.warn("Trust assertion disputed by consensus", {
        assertionId: assertion.assertionId,
        verifications: totalVerifications,
        consensusRatio,
      });

      this.emit("trust_assertion_disputed", assertion);
    }
  }

  private async checkVerificationTimeout(assertionId: string): Promise<void> {
    const assertion = this.trustAssertions.get(assertionId);
    if (!assertion || assertion.status !== "pending") {
      return;
    }

    if (
      assertion.verifications.length < this.config.verification.minimumWitnesses
    ) {
      assertion.status = "expired";

      this.logger.warn("Trust assertion verification timeout", {
        assertionId,
        verifications: assertion.verifications.length,
        required: this.config.verification.minimumWitnesses,
      });

      this.emit("trust_assertion_expired", assertion);
    }
  }

  private calculateAssertionConfidence(evidence: any[]): number {
    if (evidence.length === 0) return 0.1;

    const totalWeight = evidence.reduce((sum, e) => sum + (e.weight || 1), 0);
    const verifiableEvidence = evidence.filter((e) => e.verifiable);
    const verifiableWeight = verifiableEvidence.reduce(
      (sum, e) => sum + (e.weight || 1),
      0,
    );

    const verifiabilityRatio = verifiableWeight / totalWeight;
    const evidenceStrength = Math.min(1, evidence.length / 5); // Cap at 5 pieces of evidence

    return Math.min(
      0.95,
      0.3 + verifiabilityRatio * 0.4 + evidenceStrength * 0.3,
    );
  }

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

  private async signVerification(
    verifierAgentId: string,
    assertionId: string,
    result: string,
  ): Promise<string> {
    const data = `${verifierAgentId}:${assertionId}:${result}:${Date.now()}`;
    return crypto.createHash("sha256").update(data).digest("hex");
  }

  private async findDirectTrustAssertion(
    fromAgentId: string,
    toAgentId: string,
    domains?: string[],
  ): Promise<TrustAssertion | null> {
    for (const assertion of this.trustAssertions.values()) {
      if (
        assertion.fromAgentId === fromAgentId &&
        assertion.toAgentId === toAgentId &&
        assertion.status === "verified"
      ) {
        // Check domain match if specified
        if (domains && domains.length > 0) {
          const hasMatchingDomain = domains.some((domain) =>
            assertion.trustDomains.includes(domain),
          );
          if (!hasMatchingDomain) continue;
        }

        return assertion;
      }
    }

    return null;
  }

  private applyTemporalDecay(assertion: TrustAssertion): number {
    const ageInDays = (Date.now() - assertion.timestamp.getTime()) / 86400000;
    const decayFactor = Math.pow(1 - assertion.decayRate, ageInDays);

    return assertion.trustLevel * decayFactor;
  }

  private async findRelatedAssertions(
    assertion: TrustAssertion,
  ): Promise<TrustAssertion[]> {
    const related: TrustAssertion[] = [];

    for (const otherAssertion of this.trustAssertions.values()) {
      if (otherAssertion.assertionId === assertion.assertionId) continue;

      // Check if assertions involve same agents or domains
      const sameAgents =
        otherAssertion.fromAgentId === assertion.fromAgentId ||
        otherAssertion.toAgentId === assertion.toAgentId;

      const sameDomains = assertion.trustDomains.some((domain) =>
        otherAssertion.trustDomains.includes(domain),
      );

      if (sameAgents || sameDomains) {
        related.push(otherAssertion);
      }
    }

    return related;
  }

  private async refreshTrustPaths(): Promise<void> {
    // Refresh trust paths for all agent pairs
    for (const fromAgent of this.trustNetwork.agents) {
      const pathsFromAgent = new Map<string, TrustPath>();

      for (const toAgent of this.trustNetwork.agents) {
        if (fromAgent === toAgent) continue;

        const path = await this.pathCalculator.findBestTrustPath(
          fromAgent,
          toAgent,
          this.trustAssertions,
        );

        if (path) {
          pathsFromAgent.set(toAgent, path);
        }
      }

      this.trustPaths.set(fromAgent, pathsFromAgent);
    }

    this.logger.debug("Trust paths refreshed", {
      agentCount: this.trustNetwork.agents.length,
      pathCount: Array.from(this.trustPaths.values()).reduce(
        (sum, paths) => sum + paths.size,
        0,
      ),
    });
  }

  private async updateNetworkMetrics(): Promise<void> {
    const metrics = await this.calculateNetworkMetrics();
    this.trustNetwork.metrics = metrics;
    this.trustNetwork.metadata.lastUpdated = new Date();

    this.emit("network_metrics_updated", metrics);
  }

  private async calculateNetworkMetrics(): Promise<TrustNetwork["metrics"]> {
    const agentCount = this.trustNetwork.agents.length;
    const assertionCount = this.trustAssertions.size;

    // Calculate network density
    const maxPossibleEdges = agentCount * (agentCount - 1);
    const density =
      maxPossibleEdges > 0 ? assertionCount / maxPossibleEdges : 0;

    // Calculate average path length
    let totalPathLength = 0;
    let pathCount = 0;

    for (const paths of this.trustPaths.values()) {
      for (const path of paths.values()) {
        totalPathLength += path.length;
        pathCount++;
      }
    }

    const averagePathLength = pathCount > 0 ? totalPathLength / pathCount : 0;

    // Calculate trust distribution
    const trustLevels = Array.from(this.trustAssertions.values()).map(
      (a) => a.trustLevel,
    );
    const trustDistribution = this.calculateDistribution(trustLevels, 10);

    return {
      density,
      clustering: 0, // Simplified - would need complex calculation
      averagePathLength,
      centralityScores: new Map(), // Simplified - would calculate betweenness centrality
      trustDistribution,
    };
  }

  private calculateDistribution(values: number[], bins: number): number[] {
    const distribution = new Array(bins).fill(0);

    values.forEach((value) => {
      const binIndex = Math.min(bins - 1, Math.floor(value * bins));
      distribution[binIndex]++;
    });

    return distribution;
  }

  private async cleanupExpiredData(): Promise<void> {
    const now = Date.now();
    let cleanedCount = 0;

    // Clean expired assertions
    for (const [assertionId, assertion] of this.trustAssertions) {
      if (assertion.validUntil && assertion.validUntil.getTime() < now) {
        this.trustAssertions.delete(assertionId);
        this.trustNetwork.trustAssertions.delete(assertionId);
        cleanedCount++;
      }
    }

    // Clean expired ZK proofs
    for (const [proofId, proof] of this.zkProofs) {
      if (proof.validUntil.getTime() < now) {
        this.zkProofs.delete(proofId);
        cleanedCount++;
      }
    }

    if (cleanedCount > 0) {
      this.logger.info("Cleaned up expired data", { count: cleanedCount });
    }
  }

  /**
   * Public API methods
   */

  getTrustAssertion(assertionId: string): TrustAssertion | null {
    return this.trustAssertions.get(assertionId) || null;
  }

  getAgentTrustAssertions(agentId: string): TrustAssertion[] {
    return Array.from(this.trustAssertions.values()).filter(
      (assertion) =>
        assertion.fromAgentId === agentId || assertion.toAgentId === agentId,
    );
  }

  getTrustPath(fromAgentId: string, toAgentId: string): TrustPath | null {
    const paths = this.trustPaths.get(fromAgentId);
    return paths?.get(toAgentId) || null;
  }

  getZKProof(proofId: string): ZKTrustProof | null {
    return this.zkProofs.get(proofId) || null;
  }

  getNetworkMetrics(): TrustNetwork["metrics"] {
    return this.trustNetwork.metrics;
  }

  async getSystemStats(): Promise<any> {
    return {
      networkId: this.trustNetwork.networkId,
      totalAgents: this.trustNetwork.agents.length,
      totalAssertions: this.trustAssertions.size,
      verifiedAssertions: Array.from(this.trustAssertions.values()).filter(
        (a) => a.status === "verified",
      ).length,
      pendingVerifications: Array.from(this.trustAssertions.values()).filter(
        (a) => a.status === "pending",
      ).length,
      totalDisputes: Array.from(this.trustAssertions.values()).reduce(
        (sum, a) => sum + a.disputes.length,
        0,
      ),
      totalZKProofs: this.zkProofs.size,
      verifiedZKProofs: Array.from(this.zkProofs.values()).filter(
        (p) => p.verified,
      ).length,
      networkDensity: this.trustNetwork.metrics.density,
      averagePathLength: this.trustNetwork.metrics.averagePathLength,
    };
  }
}

// Supporting classes

class TrustPathCalculator {
  constructor(private config: any) {}

  async findBestTrustPath(
    fromAgentId: string,
    toAgentId: string,
    trustAssertions: Map<string, TrustAssertion>,
    domains?: string[],
  ): Promise<TrustPath | null> {
    // Implement trust path calculation using graph algorithms
    // This is a simplified implementation

    // Build graph from trust assertions
    const graph = this.buildTrustGraph(trustAssertions, domains);

    // Find shortest path with highest trust
    const path = this.dijkstraWithTrust(graph, fromAgentId, toAgentId);

    if (!path) return null;

    return {
      pathId: crypto.randomUUID(),
      fromAgentId,
      toAgentId,
      path: path.nodes,
      trustLevel: path.trustLevel,
      confidence: path.confidence,
      length: path.nodes.length - 1,
      weakestLink: path.weakestLink,
      computedAt: new Date(),
      validUntil: new Date(Date.now() + 3600000), // 1 hour validity
      refreshRequired: false,
      supportingAssertions: path.assertions,
    };
  }

  private buildTrustGraph(
    trustAssertions: Map<string, TrustAssertion>,
    domains?: string[],
  ): Map<string, Map<string, { trust: number; assertionId: string }>> {
    const graph = new Map();

    for (const assertion of trustAssertions.values()) {
      if (assertion.status !== "verified") continue;

      // Check domain match if specified
      if (domains && domains.length > 0) {
        const hasMatchingDomain = domains.some((domain) =>
          assertion.trustDomains.includes(domain),
        );
        if (!hasMatchingDomain) continue;
      }

      if (!graph.has(assertion.fromAgentId)) {
        graph.set(assertion.fromAgentId, new Map());
      }

      graph.get(assertion.fromAgentId).set(assertion.toAgentId, {
        trust: assertion.trustLevel,
        assertionId: assertion.assertionId,
      });
    }

    return graph;
  }

  private dijkstraWithTrust(
    graph: Map<string, Map<string, any>>,
    start: string,
    end: string,
  ): any | null {
    // Simplified implementation - would use proper Dijkstra with trust weighting
    const neighbors = graph.get(start);
    if (!neighbors || !neighbors.has(end)) {
      return null;
    }

    const edge = neighbors.get(end);
    return {
      nodes: [start, end],
      trustLevel: edge.trust,
      confidence: 0.8,
      weakestLink: { fromAgent: start, toAgent: end, trustLevel: edge.trust },
      assertions: [edge.assertionId],
    };
  }
}

class TrustConsensusEngine {
  constructor(private config: any) {}

  async reachConsensus(verifications: TrustVerification[]): Promise<{
    decision: "confirmed" | "denied" | "inconclusive";
    confidence: number;
  }> {
    // Implement Byzantine fault-tolerant consensus
    return { decision: "confirmed", confidence: 0.8 };
  }
}

class ZKTrustVerifier {
  constructor(private config: any) {}

  async generateProof(
    claimType: string,
    privateInputs: any,
    publicInputs: any,
    proofSystem: string,
  ): Promise<{ proof: string; circuit: string }> {
    // Mock ZK proof generation
    return {
      proof: crypto.randomBytes(256).toString("hex"),
      circuit: `${claimType}_verification_circuit`,
    };
  }

  async verifyProof(
    proof: string,
    publicInputs: any,
    circuit: string,
    proofSystem: string,
  ): Promise<boolean> {
    // Mock ZK proof verification
    return true;
  }
}

class TrustOracleManager {
  constructor(private config: any) {}

  async query(
    oracle: TrustOracle,
    query: any,
  ): Promise<{
    result: any;
    confidence: number;
    timestamp: Date;
  }> {
    // Mock oracle query
    return {
      result: { trustScore: 0.8 },
      confidence: oracle.reliability,
      timestamp: new Date(),
    };
  }
}

class TrustDisputeResolver {
  constructor(private config: any) {}

  async initiateResolution(
    dispute: TrustDispute,
    assertion: TrustAssertion,
  ): Promise<void> {
    // Initiate dispute resolution process
    setTimeout(async () => {
      dispute.status = "resolved";
      dispute.resolution = {
        decision: "upheld",
        reason: "Insufficient evidence for dispute",
        arbitrators: ["system"],
        timestamp: new Date(),
      };
    }, this.config.verification.disputeTimeout);
  }
}

export {
  DistributedTrustVerifier,
  TrustAssertion,
  TrustEvidence,
  TrustVerification,
  TrustDispute,
  TrustPath,
  TrustNetwork,
  ZKTrustProof,
  TrustOracle,
};