Validate Merkel Root

const crypto = require('crypto');

function calculateMerkleRoot(transactions) {
  if (transactions.length === 0) {
    return null;
  }

  // Create a copy of the transactions array
  let hashes = [...transactions];

  // Construct the Merkle tree
  while (hashes.length > 1) {
    const levelHashes = [];

    // Pair adjacent hashes and compute their parent hash
    for (let i = 0; i < hashes.length; i += 2) {
      const left = hashes[i];
      const right = i + 1 < hashes.length ? hashes[i + 1] : left; // Duplicate last hash if odd number of hashes
      const parentHash = crypto.createHash('sha256').update(left + right).digest('hex');
      levelHashes.push(parentHash);
    }

    hashes = levelHashes;
  }

  return hashes[0];
}

function validateMerkleRoot(transactions, merkleRoot) {
  const calculatedRoot = calculateMerkleRoot(transactions);
  return calculatedRoot === merkleRoot;
}

// Example usage
const transactions = ['TransactionA', 'TransactionB', 'TransactionC', 'TransactionD'];
const merkleRoot = '1b07e75f11e1e54f5d71f1696bca801485d5e7d61a3e55bb62081f2cc0e465a1';

// Validate the Merkle root
const isValid = validateMerkleRoot(transactions, merkleRoot);
console.log(`Merkle root validation: ${isValid}`);