/*
 * Copyright 2018 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.
 */
package tech.pegasys.pantheon.ethereum.vm.operations;

import tech.pegasys.pantheon.ethereum.core.Gas;
import tech.pegasys.pantheon.ethereum.vm.AbstractOperation;
import tech.pegasys.pantheon.ethereum.vm.Code;
import tech.pegasys.pantheon.ethereum.vm.GasCalculator;
import tech.pegasys.pantheon.ethereum.vm.MessageFrame;
import tech.pegasys.pantheon.util.uint.UInt256;

public class CodeCopyOperation extends AbstractOperation {

  public CodeCopyOperation(final GasCalculator gasCalculator) {
    super(0x39, "CODECOPY", 3, 0, false, 1, gasCalculator);
  }

  @Override
  public Gas cost(final MessageFrame frame) {
    final UInt256 offset = frame.getStackItem(0).asUInt256();
    final UInt256 length = frame.getStackItem(2).asUInt256();

    return gasCalculator().dataCopyOperationGasCost(frame, offset, length);
  }

  @Override
  public void execute(final MessageFrame frame) {
    final Code code = frame.getCode();

    final UInt256 memOffset = frame.popStackItem().asUInt256();
    final UInt256 sourceOffset = frame.popStackItem().asUInt256();
    final UInt256 numBytes = frame.popStackItem().asUInt256();

    frame.writeMemory(memOffset, sourceOffset, numBytes, code.getBytes());
  }
}
