defarm-sdk/lib/core/BlockchainService.ts

DeFarm SDK - On-premise blockchain data processing and tokenization engine for agriculture supply chain

import type { Asset } from '../types';

interface BlockchainConfig {
  enabled: boolean;
  network: 'stellar' | 'ethereum' | 'polygon';
  endpoint?: string;
  credentials?: {
    publicKey?: string;
    privateKey?: string;
    apiKey?: string;
  };
}

interface BlockchainResult {
  transactionId: string;
  blockNumber: number;
  timestamp: Date;
}

export interface SignedTransaction {
  source: string;
  fee: string;
  operations: any[];
  sequence: string;
  timeBounds?: {
    minTime: number;
    maxTime: number;
  };
  signatures: Array<{
    hint: string;
    signature: string;
  }>;
}

// New interfaces for tokenization
export interface TokenizationBlockchainConfig {
  network: 'stellar' | 'ethereum' | 'polygon';
  rpcUrl: string;
  contractAddresses: {
    nft: string;
    ipcm: string;
    valuechains: string;
  };
}

export interface MintNFTParams {
  to: string;
  valuechainId: string;
  metadataUrl: string;
  asset: Asset;
}

export interface MintNFTResult {
  success: boolean;
  tokenId?: string;
  contractAddress?: string;
  transactionHash?: string;
  error?: string;
}

export interface NFTInfo {
  tokenId: string;
  contractAddress: string;
  owner: string;
  metadataUrl: string;
  valuechainId: string;
}

/**
 * Service for blockchain integration
 * Enhanced with tokenization capabilities using DeFarm backbone contracts
 */
export class BlockchainService {
  private config: BlockchainConfig;
  private tokenizationConfig?: TokenizationBlockchainConfig;
  private initialized = false;

  constructor(config: BlockchainConfig, tokenizationConfig?: TokenizationBlockchainConfig) {
    this.config = config;
    this.tokenizationConfig = tokenizationConfig;
  }

  async initialize(): Promise<void> {
    if (!this.config.enabled) {
      return;
    }

    // In real implementation, would initialize blockchain connection
    console.log(`Initializing blockchain service for ${this.config.network}`);
    
    // Verify credentials
    if (!this.config.credentials?.publicKey) {
      throw new Error('Blockchain public key required');
    }

    this.initialized = true;
  }

  async submitAsset(asset: Asset): Promise<BlockchainResult> {
    if (!this.initialized) {
      throw new Error('Blockchain service not initialized');
    }

    // Create hash of asset data
    const assetHash = this.createAssetHash(asset);

    // In real implementation, would submit to blockchain
    console.log(`Submitting asset ${asset.dfid} to ${this.config.network} blockchain`);

    // Simulate blockchain submission
    return {
      transactionId: `tx_${Date.now()}_${Math.random().toString(36).substring(7)}`,
      blockNumber: Math.floor(Math.random() * 1000000),
      timestamp: new Date()
    };
  }

  async verifyAsset(dfid: string, transactionId: string): Promise<boolean> {
    if (!this.initialized) {
      throw new Error('Blockchain service not initialized');
    }

    // In real implementation, would verify on blockchain
    console.log(`Verifying asset ${dfid} with transaction ${transactionId}`);

    // Simulate verification
    return true;
  }

  async disconnect(): Promise<void> {
    if (this.initialized) {
      console.log('Disconnecting blockchain service');
      this.initialized = false;
    }
  }

  private createAssetHash(asset: Asset): string {
    // In real implementation, would use proper hashing
    const data = {
      dfid: asset.dfid,
      name: asset.name,
      category: asset.category,
      ownership: asset.ownership.ownerId,
      created: asset.metadata.created
    };

    // Simple hash simulation
    return Buffer.from(JSON.stringify(data)).toString('base64');
  }

  /**
   * Mint NFT using DeFarm's smart contract (for tokenization)
   */
  async mintNFT(params: MintNFTParams): Promise<MintNFTResult> {
    if (!this.tokenizationConfig) {
      return {
        success: false,
        error: 'Tokenization not configured'
      };
    }

    try {
      // Call DeFarm's tokenization API (uses backbone smart contracts)
      const response = await fetch(`${this.getDeFarmAPIUrl()}/tokenization/mint`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${this.getDeFarmAPIKey()}`
        },
        body: JSON.stringify({
          to: params.to,
          valuechainId: params.valuechainId,
          metadataUrl: params.metadataUrl,
          contractId: this.tokenizationConfig.contractAddresses.nft,
          rpcUrl: this.tokenizationConfig.rpcUrl,
          assetData: {
            dfid: params.asset.dfid,
            category: params.asset.category,
            subcategory: params.asset.subcategory,
            name: params.asset.name
          }
        })
      });

      if (!response.ok) {
        const errorData = await response.json().catch(() => ({}));
        throw new Error(`Mint API failed: ${response.status} ${errorData.error || response.statusText}`);
      }

      const result = await response.json();

      return {
        success: result.success,
        tokenId: result.tokenId,
        contractAddress: this.tokenizationConfig.contractAddresses.nft,
        transactionHash: result.transactionHash,
        error: result.error
      };

    } catch (error) {
      return {
        success: false,
        error: error instanceof Error ? error.message : 'Unknown blockchain error'
      };
    }
  }

  /**
   * Map CID to blockchain using IPCM contract
   */
  async mapCIDToBlockchain(key: string, cid: string): Promise<{
    success: boolean;
    transactionHash?: string;
    error?: string;
  }> {
    if (!this.tokenizationConfig) {
      return {
        success: false,
        error: 'Tokenization not configured'
      };
    }

    try {
      // Call DeFarm's CID mapping API (uses backbone IPCM contract)
      const response = await fetch(`${this.getDeFarmAPIUrl()}/tokenization/map-cid`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${this.getDeFarmAPIKey()}`
        },
        body: JSON.stringify({
          key,
          cid,
          contractId: this.tokenizationConfig.contractAddresses.ipcm,
          rpcUrl: this.tokenizationConfig.rpcUrl
        })
      });

      if (!response.ok) {
        const errorData = await response.json().catch(() => ({}));
        throw new Error(`CID mapping API failed: ${response.status} ${errorData.error || response.statusText}`);
      }

      const result = await response.json();

      return {
        success: result.success,
        transactionHash: result.transactionHash,
        error: result.error
      };

    } catch (error) {
      return {
        success: false,
        error: error instanceof Error ? error.message : 'Unknown CID mapping error'
      };
    }
  }

  /**
   * Query NFTs owned by an address
   */
  async queryNFTByOwner(ownerAddress: string): Promise<NFTInfo[]> {
    if (!this.tokenizationConfig) {
      return [];
    }

    try {
      const response = await fetch(`${this.getDeFarmAPIUrl()}/tokenization/query-nfts?owner=${ownerAddress}`, {
        method: 'GET',
        headers: {
          'Authorization': `Bearer ${this.getDeFarmAPIKey()}`
        }
      });

      if (!response.ok) {
        throw new Error(`NFT query failed: ${response.status} ${response.statusText}`);
      }

      const result = await response.json();
      return result.nfts || [];

    } catch (error) {
      console.warn('Failed to query NFTs:', error);
      return [];
    }
  }

  /**
   * Get wallet balance
   */
  async getBalance(address: string): Promise<string> {
    if (!this.tokenizationConfig) {
      return '0';
    }

    try {
      const response = await fetch(`${this.getDeFarmAPIUrl()}/blockchain/balance?address=${address}&network=${this.tokenizationConfig.network}`, {
        method: 'GET',
        headers: {
          'Authorization': `Bearer ${this.getDeFarmAPIKey()}`
        }
      });

      if (!response.ok) {
        throw new Error(`Balance query failed: ${response.status} ${response.statusText}`);
      }

      const result = await response.json();
      return result.balance || '0';

    } catch (error) {
      console.warn('Failed to get balance:', error);
      return '0';
    }
  }

  /**
   * Get DeFarm API URL from environment
   */
  private getDeFarmAPIUrl(): string {
    return process.env.DEFARM_API_URL || 'https://api.defarm.com';
  }

  /**
   * Get DeFarm API key from environment
   */
  private getDeFarmAPIKey(): string {
    return process.env.DEFARM_API_KEY || 'defarm_sdk_default_key';
  }

  /**
   * Submit signed transaction to blockchain
   */
  async submitSignedTransaction(signedTx: SignedTransaction): Promise<{
    hash: string;
    success: boolean;
    error?: string;
  }> {
    if (!this.tokenizationConfig) {
      return {
        hash: '',
        success: false,
        error: 'Tokenization not configured'
      };
    }

    try {
      const response = await fetch(`${this.getDeFarmAPIUrl()}/blockchain/submit-transaction`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${this.getDeFarmAPIKey()}`
        },
        body: JSON.stringify({
          network: this.tokenizationConfig.network,
          signedTransaction: signedTx
        })
      });

      if (!response.ok) {
        const errorData = await response.json().catch(() => ({}));
        throw new Error(`Transaction submission failed: ${response.status} ${errorData.error || response.statusText}`);
      }

      const result = await response.json();

      return {
        hash: result.transactionHash || result.hash,
        success: result.success,
        error: result.error
      };

    } catch (error) {
      return {
        hash: '',
        success: false,
        error: error instanceof Error ? error.message : 'Unknown submission error'
      };
    }
  }

  /**
   * Get blockchain explorer URL for a transaction
   */
  getExplorerUrl(transactionId: string): string {
    const network = this.tokenizationConfig?.network || this.config.network;
    
    switch (network) {
      case 'stellar':
        return `https://stellar.expert/explorer/testnet/tx/${transactionId}`;
      case 'ethereum':
        return `https://etherscan.io/tx/${transactionId}`;
      case 'polygon':
        return `https://polygonscan.com/tx/${transactionId}`;
      default:
        return '';
    }
  }
}