import * as borsh from 'borsh';
import * as web3 from "@solana/web3.js";
import * as BufferLayout from "@solana/buffer-layout";
const BN = require("bn.js");
import {Buffer} from "buffer";
/**
 * The public key of the account we are saying hello to
 */
 let greetedPubkey: web3.PublicKey;
 /**
 * The state of a greeting account managed by the hello world program
 */
class GreetingAccount {
    counter = 0;
    constructor(fields: {counter: number} | undefined = undefined) {
      if (fields) {
        this.counter = fields.counter;
      }
    }
  }

const GreetingSchema = new Map([
    [GreetingAccount, {kind: 'struct', fields: [['counter', 'u32']]}],
  ]);

  const GREETING_SIZE = borsh.serialize(
    GreetingSchema,
    new GreetingAccount(),
  ).length;

const connection = new web3.Connection(web3.clusterApiUrl("devnet"));

async function main(){
    //pays for the transaction (message)
     const key: Uint8Array = Uint8Array.from([PRIVATE KEY DEL QUE PAGA]);
     /*const data_to_send: Buffer = Buffer.from(
            Uint8Array.of(0, ...new BN(10).toArray("le", 8)
            ));

             const data_b = borsh.serialize(
              GreetingSchema,
              new GreetingAccount(),
              
            )*/

    const layout = BufferLayout.struct([BufferLayout.u32("counter")])
    let data: Buffer = Buffer.alloc(layout.span);
    layout.encode({counter:4}, data);

    const signer: web3.Keypair = web3.Keypair.fromSecretKey(key);
    let programId: web3.PublicKey = new web3.PublicKey("PROGRAM ID");
    
    const GREETING_SEED = 'hello 42';
    /*
    greetedPubkey = await web3.PublicKey.createWithSeed(
      signer.publicKey,
      GREETING_SEED,
      programId,
    );
    console.log(greetedPubkey.toBase58(), 'has been grenerated');
    //*/
    
    greetedPubkey = new web3.PublicKey("PUBLIC KEY ASOCIADA AL PROGRAM ID punto anterior");

    let fees = 0;
    const lamports = await connection.getMinimumBalanceForRentExemption(
        GREETING_SIZE,
    );
//This creteAccount with Seed  only first time    
  /*  const transaction = new web3.Transaction()
    .add(
     web3.SystemProgram.createAccountWithSeed({
       fromPubkey: signer.publicKey,
       basePubkey: signer.publicKey,
       seed: GREETING_SEED,
       newAccountPubkey: greetedPubkey,
       lamports,
       space: GREETING_SIZE,
       programId,
     }),
   );
    transaction.add(
        new web3.TransactionInstruction({
            keys: [
            {pubkey: greetedPubkey, isSigner: false, isWritable: true}],
            programId,
            data: data
        })
    );*/

 const transaction2 = new web3.Transaction().add(
   new web3.TransactionInstruction({
  keys: [
    {pubkey: greetedPubkey, isSigner: false, isWritable: true}],
    programId,
    data: data
})
 );

    await web3.sendAndConfirmTransaction(connection, transaction2, [signer])
        .then((sig)=> {
            console.log("sig: {}", sig);
        });
    reportGreetings();
    }

    async function reportGreetings(): Promise<void> {
        const accountInfo = await connection.getAccountInfo(greetedPubkey);
        if (accountInfo === null) {
          throw 'Error: cannot find the greeted account';
        }
        const greeting = borsh.deserialize(
          GreetingSchema,
          GreetingAccount,
          accountInfo.data,
        );
        console.log(greetedPubkey.toBase58(),
            'has been greeted',
            Number(greeting.counter),
            'time(s)',
        );
    }

    main();