Namespace System

// Transfer 10 tKOIN to 1DQzuCcTKacbs9GGScRTU1Hc8BsyARTPqe
const koinContractId = Base58.decode("1NvZvWNqDX7t93inmLBvbv6kxhpEZYRFWK");
const tranferEntryPoint = 0x62efa292;
const from = contractId; // this contract
const to = Base58.decode("1DQzuCcTKacbs9GGScRTU1Hc8BsyARTPqe");
const amount = 10 * 10 ** 8; // needs to be multiplied by 10^8 because Koin is 8 decimals

const koinTransferArgs = new koin.transfer_arguments();
koinTransferArgs.from = from;
koinTransferArgs.to = to;
koinTransferArgs.value = amount;

const resBuf = System.callContract(koinContractId, tranferEntryPoint, Protobuf.encode(koinTransferArgs, koin.transfer_arguments.encode));
System.require(resBuf, `expected resBuf not "null", got "null"`);

if (resBuf) {
  const transferRes = Protobuf.decode<koin.transfer_result>(resBuf, koin.transfer_result.decode, RETURN_BYTES[0]);
  System.require(transferRes.value, `expected transfer not "true", got "false"`);

  const impacted: Uint8Array[] = [];
  impacted.push(from);
  impacted.push(to);

  const transferEvent = new token.transfer_event();
  transferEvent.from = from;
  transferEvent.to = to;
  transferEvent.value = amount;

  System.event('koin.transfer', Protobuf.encode(transferEvent, token.transfer_event.encode), impacted);

  System.log(`transfered ${amount / 10 ** 8} tKoin from ${Base58.encode(from)} to ${Base58.encode(to)}`);
}

System.checkAuthority(authority.authorization_type.transaction_application, Base58.decode('1DQzuCcTKacbs9GGScRTU1Hc8BsyARTPqe));

const from = Base58.decode("1DQzuCcTKacbs9GGScRTU1Hc8BsyARTPqe");
const to = Base58.decode("1DQzuCcTKacbs9GGScRTU1Hc8BsyARTPqe");
const impacted: Uint8Array[] = [];
impacted.push(from);
impacted.push(to);

const transferEvent = new token.transfer_event();
transferEvent.from = from;
transferEvent.to = to;
transferEvent.value = amount;

System.event('koin.transfer', Protobuf.encode(transferEvent, token.transfer_event.encode), impacted);

System.exitContract(0);

const rdbuf = System.getContractArguments();
const contractArgs = Protobuf.decode<foobar.foobar_arguments>(rdbuf, foobar.foobar_arguments.decode, RETURN_BYTES[0]);
System.log('contractArgs: ' + contractArgs.value.toString());

 const b = System.getBlock();
 System.log("signer: " + Base58.encode((b.header!.signer!)));

const blField = System.getBlockField('header.signer');
System.require(blField, `expected blField not "null", got "null"`);

if (blField) {
  System.log("signer: " + Base58.encode(blField.bytes_value!));
}

const callerData = System.getCaller();
System.log('callerData.caller_privilege: ' + callerData.caller_privilege.toString());
if (callerData.caller) {
  System.log('callerData.caller (b58): ' + Base58.encode(callerData.caller!));
}

const address = System.getContractAddress('koin');
System.log('address (b58): ' + Base58.encode(address));

const contractId = System.getContractId();
System.log('contractId (b58): ' + Base58.encode(contractId));

const name = System.getContractName(Base58.decode('1DQzuCcTKacbs9GGScRTU1Hc8BsyARTPqe'));
System.log('contract name: ' + name);

if (System.applyTransaction(trx) != error.error_code.success)
  System.log(getErrorMessage())

 const headInfo = System.getHeadInfo();
 System.log('headInfo.head_block_time: ' + headInfo.head_block_time.toString());
 System.log('headInfo.head_topology.height: ' + headInfo.head_topology!.height.toString());
 System.log('headInfo.last_irreversible_block.: ' + headInfo.last_irreversible_block.toString());

const lastIrreversibleBlock = System.getLastIrreversibleBlock();
System.log('lastIrreversibleBlock: ' + lastIrreversibleBlock.toString());

 const op = System.getOperation();

 const tx = System.getTransaction();
 System.log("payer: " + Base58.encode((tx.header!.payer!)));

 const txField = System.getTransactionField('header.payer');
 if (txField) {
   System.log("payer: " + Base58.encode(txField.bytes_value!));
 }

const digest = System.hash(Crypto.multicodec.sha2_256, StringBytes.stringToBytes('hello world!));

System.log('Hello World!');

const message = 'hello-world';
const signatureData = Base64.decode('IHhJwlD7P-o6x7L38den1MnumUhnYmNhTZhIUQQhezvEMf7rx89NbIIioNCIQSk1PQYdQ9mOI4-rDYiwO2pLvM4=');
const digest = System.hash(Crypto.multicodec.sha2_256, StringBytes.stringToBytes(message));
const recoveredKey = System.recoverPublicKey(signatureData, digest!);
const addr = Crypto.addressFromPublicKey(recoveredKey!);
System.log('recoveredKey (b58): ' + Base58.encode(addr));

revert the transaction if the account is not authorized

System.requireAuthority(authority.authorization_type.transaction_application, Base58.decode('1DQzuCcTKacbs9GGScRTU1Hc8BsyARTPqe));

let verify = System.verifySignature(recoveredKey!, signatureData, digest!);
System.require(verify == true, `expected "true", got "${verify}"`);