/**
 * Privacy APIs - v5.2.0
 * 
 * Advanced privacy features for Solana
 */

import type { LunaHeliusClient } from '../../LunaHeliusClient';
import type { RpcResponse, StealthAddress, PrivacyScore, GraphPrivacyAnalysis, ShieldedTransactionPattern } from '../../types';

// Stealth Address API
export class StealthAddressApi {
  constructor(private readonly _client: LunaHeliusClient) {}

  /** Generate a stealth address for receiving funds privately */
  async generateStealthAddress(recipientViewKey: string): Promise<RpcResponse<StealthAddress>> {
    // Stealth address generation using ECDH
    const ephemeralKeypair = this.generateEphemeralKeypair();
    const sharedSecret = this.deriveSharedSecret(ephemeralKeypair.privateKey, recipientViewKey);
    const stealthAddress = this.deriveStealthAddress(sharedSecret);
    const viewTag = this.computeViewTag(sharedSecret);

    return {
      result: {
        ephemeralPubkey: ephemeralKeypair.publicKey,
        stealthAddress,
        viewTag,
      },
      error: null,
    };
  }

  /** Scan for incoming stealth payments */
  async scanForPayments(_params: {
    viewKey: string;
    startSlot?: number;
    endSlot?: number;
  }): Promise<RpcResponse<any[]>> {
    // Would scan blockchain for payments to stealth addresses
    return { result: [], error: null };
  }

  private generateEphemeralKeypair(): { publicKey: string; privateKey: string } {
    // Placeholder - would use crypto library
    return { publicKey: 'ephemeral_pub', privateKey: 'ephemeral_priv' };
  }

  private deriveSharedSecret(_privateKey: string, _publicKey: string): string {
    return 'shared_secret';
  }

  private deriveStealthAddress(_sharedSecret: string): string {
    return 'stealth_address';
  }

  private computeViewTag(sharedSecret: string): string {
    return sharedSecret.substring(0, 4);
  }
}

// Privacy Pool API
export class PrivacyPoolApi {
  constructor(private readonly _client: LunaHeliusClient) {}

  /** Get available privacy pools */
  async getAvailablePools(): Promise<RpcResponse<any[]>> {
    return {
      result: [
        { denomination: 0.1, poolSize: 1000, anonymitySet: 500 },
        { denomination: 1, poolSize: 5000, anonymitySet: 2500 },
        { denomination: 10, poolSize: 2000, anonymitySet: 1000 },
        { denomination: 100, poolSize: 500, anonymitySet: 250 },
      ],
      error: null,
    };
  }

  /** Calculate optimal deposit strategy */
  async calculateOptimalDeposit(amount: number): Promise<RpcResponse<any>> {
    // Break amount into optimal denominations
    const denominations = [100, 10, 1, 0.1];
    const breakdown: Array<{ denomination: number; count: number }> = [];
    let remaining = amount;

    for (const denom of denominations) {
      if (remaining >= denom) {
        const count = Math.floor(remaining / denom);
        breakdown.push({ denomination: denom, count });
        remaining -= count * denom;
      }
    }

    return {
      result: {
        breakdown,
        estimatedPrivacyGain: 85,
        recommendedDelay: '2-24 hours',
      },
      error: null,
    };
  }
}

// Transaction Graph Privacy API
export class TransactionGraphPrivacyApi {
  constructor(private readonly client: LunaHeliusClient) {}

  /** Analyze transaction graph for privacy leaks */
  async analyzeGraphPrivacy(address: string): Promise<RpcResponse<GraphPrivacyAnalysis>> {
    // Would analyze transaction patterns
    const signatures = await this.client.rpcCall('getSignaturesForAddress', [address, { limit: 100 }]);
    
    // Simplified analysis
    const txCount = signatures.result?.length ?? 0;
    const clusteringRisk = Math.min(txCount / 10, 100);

    return {
      result: {
        address,
        clusteringRisk,
        linkedAddresses: [],
        commonInputs: 0,
        changeAddressPatterns: 0,
        privacyLevel: clusteringRisk > 70 ? 'LOW' : clusteringRisk > 40 ? 'MEDIUM' : 'HIGH',
      },
      error: null,
    };
  }

  /** Find connected addresses through graph analysis */
  async findConnectedAddresses(_address: string, _depth: number = 2): Promise<RpcResponse<string[]>> {
    // Would traverse transaction graph
    return { result: [], error: null };
  }
}

// Shielded Pattern API
export class ShieldedPatternApi {
  constructor(private readonly client: LunaHeliusClient) {}

  /** Detect shielded transaction patterns */
  async detectShieldedPatterns(signature: string): Promise<RpcResponse<ShieldedTransactionPattern>> {
    const tx = await this.client.rpcCall('getTransaction', [
      signature,
      { encoding: 'jsonParsed', maxSupportedTransactionVersion: 0 },
    ]);

    if (tx.error || !tx.result) {
      return { result: null, error: tx.error };
    }

    // Analyze for shielding patterns
    const instructions = tx.result?.transaction?.message?.instructions ?? [];
    const usesZkCompression = instructions.some((ix: any) => 
      ix.programId?.includes('compr') || ix.programId?.includes('light')
    );

    return {
      result: {
        isShielded: usesZkCompression,
        shieldingMethod: usesZkCompression ? 'ZK_COMPRESSION' : 'NONE',
        confidenceLevel: usesZkCompression ? 0.9 : 0.1,
        estimatedPrivacyGain: usesZkCompression ? 80 : 0,
      },
      error: null,
    };
  }
}

// Privacy Score Engine API  
export class PrivacyScoreEngineApi {
  constructor(private readonly client: LunaHeliusClient) {}

  /** Calculate comprehensive privacy score for an address */
  async calculatePrivacyScore(address: string): Promise<RpcResponse<PrivacyScore>> {
    // Get transaction history
    const signatures = await this.client.rpcCall('getSignaturesForAddress', [address, { limit: 100 }]);
    const txCount = signatures.result?.length ?? 0;

    // Analyze patterns
    const addressReuseScore = Math.max(0, 100 - txCount * 2);
    const mixingScore = 20; // Would check for mixer usage
    const timingScore = 50; // Would analyze timing patterns
    const amountPrivacyScore = 40; // Would check for round amounts

    const overallScore = Math.round(
      (addressReuseScore + mixingScore + timingScore + amountPrivacyScore) / 4
    );

    const recommendations: string[] = [];
    if (addressReuseScore < 50) recommendations.push('Use unique addresses for each transaction');
    if (mixingScore < 50) recommendations.push('Consider using privacy pools');
    if (timingScore < 50) recommendations.push('Randomize transaction timing');
    if (amountPrivacyScore < 50) recommendations.push('Use standard denominations');

    return {
      result: {
        address,
        overallScore,
        addressReuseScore,
        mixingScore,
        timingScore,
        amountPrivacyScore,
        recommendations,
      },
      error: null,
    };
  }

  /** Get privacy recommendations */
  async getPrivacyRecommendations(address: string): Promise<RpcResponse<string[]>> {
    const score = await this.calculatePrivacyScore(address);
    return {
      result: score.result?.recommendations ?? [],
      error: score.error,
    };
  }
}