/*
 * 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.ocaml;

import com.facebook.buck.model.BuildTarget;
import com.facebook.buck.rules.AbstractBuildRule;
import com.facebook.buck.rules.BinaryBuildRule;
import com.facebook.buck.rules.BuildContext;
import com.facebook.buck.rules.BuildRule;
import com.facebook.buck.rules.BuildRuleParams;
import com.facebook.buck.rules.BuildableContext;
import com.facebook.buck.rules.CommandTool;
import com.facebook.buck.rules.ForwardingBuildTargetSourcePath;
import com.facebook.buck.rules.HasRuntimeDeps;
import com.facebook.buck.rules.SourcePath;
import com.facebook.buck.rules.Tool;
import com.facebook.buck.rules.args.SourcePathArg;
import com.facebook.buck.step.Step;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import java.util.stream.Stream;

public class OcamlBinary extends AbstractBuildRule implements BinaryBuildRule, HasRuntimeDeps {

  private final BuildRule binary;

  public OcamlBinary(BuildRuleParams params, BuildRule binary) {
    super(params);
    this.binary = binary;
  }

  @Override
  public Tool getExecutableCommand() {
    return new CommandTool.Builder()
        .addArg(SourcePathArg.of(Preconditions.checkNotNull(binary.getSourcePathToOutput())))
        .build();
  }

  @Override
  public ImmutableList<Step> getBuildSteps(
      BuildContext context, BuildableContext buildableContext) {
    return ImmutableList.of();
  }

  @Override
  public SourcePath getSourcePathToOutput() {
    return new ForwardingBuildTargetSourcePath(
        getBuildTarget(), Preconditions.checkNotNull(binary.getSourcePathToOutput()));
  }

  // Since this rule doesn't actual generate the binary it references, and is just a wrapper for
  // the real binary rule, mark that rule as a runtime dep.
  @Override
  public Stream<BuildTarget> getRuntimeDeps() {
    return Stream.of(binary.getBuildTarget());
  }
}