/*
 * Copyright 2014-present Facebook, Inc.
 *
 * 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 com.facebook.buck.cxx;

import com.facebook.buck.shell.ShellStep;
import com.facebook.buck.step.ExecutionContext;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import java.nio.file.Path;

public class CxxLinkStep extends ShellStep {

  private final ImmutableMap<String, String> environment;
  private final ImmutableList<String> linker;
  private final Path argFilePath;

  /** Directory to use to store intermediate/temp files used for linking. */
  private final Path scratchDir;

  public CxxLinkStep(
      Path workingDirectory,
      ImmutableMap<String, String> environment,
      ImmutableList<String> linker,
      Path argFilePath,
      Path scratchDir) {
    super(workingDirectory);
    this.environment = environment;
    this.linker = linker;
    this.argFilePath = argFilePath;
    this.scratchDir = scratchDir;
  }

  @Override
  protected ImmutableList<String> getShellCommandInternal(ExecutionContext context) {
    return ImmutableList.<String>builder().addAll(linker).add("@" + argFilePath.toString()).build();
  }

  @Override
  public ImmutableMap<String, String> getEnvironmentVariables(ExecutionContext context) {
    return ImmutableMap.<String, String>builder()
        .putAll(environment)
        // Set `TMPDIR` to `scratchDir` so that the linker uses it for it's temp and intermediate
        // files.
        .put("TMPDIR", scratchDir.toString())
        .build();
  }

  @Override
  public String getShortName() {
    return "c++ link";
  }
}