/*
 * Copyright 2015-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.android;

import com.facebook.buck.model.BuildTargets;
import com.facebook.buck.rules.AbstractBuildRule;
import com.facebook.buck.rules.AddToRuleKey;
import com.facebook.buck.rules.BuildContext;
import com.facebook.buck.rules.BuildRuleParams;
import com.facebook.buck.rules.BuildableContext;
import com.facebook.buck.rules.ExplicitBuildTargetSourcePath;
import com.facebook.buck.rules.SourcePath;
import com.facebook.buck.step.Step;
import com.facebook.buck.step.fs.CopyStep;
import com.facebook.buck.step.fs.MakeCleanDirectoryStep;
import com.google.common.collect.ImmutableCollection;
import com.google.common.collect.ImmutableList;
import java.nio.file.Path;

public class AssembleDirectories extends AbstractBuildRule {

  private final Path destinationDirectory;
  @AddToRuleKey private final ImmutableCollection<SourcePath> originalDirectories;

  public AssembleDirectories(
      BuildRuleParams buildRuleParams, ImmutableCollection<SourcePath> directories) {
    super(buildRuleParams);
    this.originalDirectories = directories;
    this.destinationDirectory =
        BuildTargets.getGenPath(
            getProjectFilesystem(), buildRuleParams.getBuildTarget(), "__assembled_%s__");
  }

  @Override
  public ImmutableList<Step> getBuildSteps(
      BuildContext context, BuildableContext buildableContext) {
    ImmutableList.Builder<Step> steps = ImmutableList.builder();
    steps.addAll(MakeCleanDirectoryStep.of(getProjectFilesystem(), destinationDirectory));
    for (SourcePath directory : originalDirectories) {
      Path resolvedPath = context.getSourcePathResolver().getAbsolutePath(directory);
      steps.add(
          CopyStep.forDirectory(
              getProjectFilesystem(),
              resolvedPath,
              destinationDirectory,
              CopyStep.DirectoryMode.CONTENTS_ONLY));
    }
    buildableContext.recordArtifact(destinationDirectory);
    return steps.build();
  }

  @Override
  public SourcePath getSourcePathToOutput() {
    return new ExplicitBuildTargetSourcePath(getBuildTarget(), destinationDirectory);
  }
}