program.js

const { 
  Connection, 
  PublicKey,
  SystemProgram,
  Transaction,
  TransactionInstruction,
  Keypair,
  LAMPORTS_PER_SOL
} = require('@solana/web3.js');
const anchor = require('@coral-xyz/anchor');

class MultisigProgram {
  constructor(connection, programId) {
    this.connection = connection;
    this.programId = new PublicKey(programId);
    this.feePercentage = 1; // 1% default fee
  }

  async initialize(adminKey) {
    const multisigAccount = Keypair.generate();
    const createAccountIx = SystemProgram.createAccount({
      fromPubkey: adminKey.publicKey,
      newAccountPubkey: multisigAccount.publicKey,
      lamports: await this.connection.getMinimumBalanceForRentExemption(1000),
      space: 1000,
      programId: this.programId
    });

    const tx = new Transaction().add(createAccountIx);
    return { transaction: tx, multisigAccount };
  }

  async setFeePercentage(newFeePercentage, adminKey) {
    if (newFeePercentage < 0 || newFeePercentage > 100) {
      throw new Error('Invalid fee percentage');
    }

    const data = Buffer.from([1, newFeePercentage]); // 1 = set fee instruction
    const instruction = new TransactionInstruction({
      keys: [
        { pubkey: adminKey.publicKey, isSigner: true, isWritable: true }
      ],
      programId: this.programId,
      data: data,
    });

    const tx = new Transaction().add(instruction);
    this.feePercentage = newFeePercentage;
    return tx;
  }

  calculateFee(amount) {
    return Math.floor((amount * this.feePercentage) / 100);
  }

  async proposeTransaction(fromPubkey, toPubkey, amount) {
    const fee = this.calculateFee(amount);
    const totalAmount = amount + fee;

    const transaction = new Transaction().add(
      SystemProgram.transfer({
        fromPubkey: new PublicKey(fromPubkey),
        toPubkey: new PublicKey(toPubkey),
        lamports: totalAmount,
      })
    );

    return { transaction, fee };
  }

  async approveTransaction(transaction, signerKey) {
    transaction.partialSign(signerKey);
    return transaction;
  }

  async executeTransaction(transaction) {
    const signature = await this.connection.sendTransaction(transaction);
    await this.connection.confirmTransaction(signature);
    return signature;
  }
}

module.exports = MultisigProgram;