/*
 * Copyright ConsenSys AG.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
package org.hyperledger.besu.ethereum.vm.operations;

import org.hyperledger.besu.ethereum.core.Account;
import org.hyperledger.besu.ethereum.core.Address;
import org.hyperledger.besu.ethereum.core.Gas;
import org.hyperledger.besu.ethereum.core.MutableAccount;
import org.hyperledger.besu.ethereum.core.Wei;
import org.hyperledger.besu.ethereum.vm.AbstractOperation;
import org.hyperledger.besu.ethereum.vm.EVM;
import org.hyperledger.besu.ethereum.vm.ExceptionalHaltReason;
import org.hyperledger.besu.ethereum.vm.GasCalculator;
import org.hyperledger.besu.ethereum.vm.MessageFrame;
import org.hyperledger.besu.ethereum.vm.Words;

import java.util.Optional;

public class SelfDestructOperation extends AbstractOperation {

  public SelfDestructOperation(final GasCalculator gasCalculator) {
    super(0xFF, "SELFDESTRUCT", 1, 0, false, 1, gasCalculator);
  }

  @Override
  public OperationResult execute(final MessageFrame frame, final EVM evm) {
    final Address recipientAddress = Words.toAddress(frame.popStackItem());

    // because of weird EIP150/158 reasons we care about a null account so we can't merge this.
    final Account recipientNullable = frame.getWorldState().get(recipientAddress);
    final Wei inheritance = frame.getWorldState().get(frame.getRecipientAddress()).getBalance();

    final boolean accountIsWarm =
        frame.warmUpAddress(recipientAddress) || gasCalculator().isPrecompile(recipientAddress);

    final Gas cost =
        gasCalculator()
            .selfDestructOperationGasCost(recipientNullable, inheritance)
            .plus(accountIsWarm ? Gas.ZERO : gasCalculator().getColdAccountAccessCost());
    final Optional<Gas> optionalCost = Optional.of(cost);

    if (frame.isStatic()) {
      return new OperationResult(
          optionalCost, Optional.of(ExceptionalHaltReason.ILLEGAL_STATE_CHANGE));
    } else if (frame.getRemainingGas().compareTo(cost) < 0) {
      return new OperationResult(optionalCost, Optional.of(ExceptionalHaltReason.INSUFFICIENT_GAS));
    }

    final Address address = frame.getRecipientAddress();
    final MutableAccount account = frame.getWorldState().getAccount(address).getMutable();

    frame.addSelfDestruct(address);

    final MutableAccount recipient =
        frame.getWorldState().getOrCreate(recipientAddress).getMutable();

    if (!account.getAddress().equals(recipient.getAddress())) {
      recipient.incrementBalance(account.getBalance());
    }

    // add refund in message frame
    frame.addRefund(recipient.getAddress(), account.getBalance());

    account.setBalance(Wei.ZERO);

    frame.setState(MessageFrame.State.CODE_SUCCESS);
    return new OperationResult(optionalCost, Optional.empty());
  }
}
