// Copyright 2016 The Bazel Authors. All rights reserved.
//
// 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.google.devtools.build.lib.runtime;

import static com.google.devtools.build.lib.analysis.TargetCompleteEvent.newFileFromArtifact;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.actions.CompletionContext;
import com.google.devtools.build.lib.actions.CompletionContext.ArtifactReceiver;
import com.google.devtools.build.lib.actions.EventReportingArtifacts;
import com.google.devtools.build.lib.buildeventstream.ArtifactGroupNamer;
import com.google.devtools.build.lib.buildeventstream.BuildEvent;
import com.google.devtools.build.lib.buildeventstream.BuildEvent.LocalFile.LocalFileType;
import com.google.devtools.build.lib.buildeventstream.BuildEventContext;
import com.google.devtools.build.lib.buildeventstream.BuildEventId;
import com.google.devtools.build.lib.buildeventstream.BuildEventStreamProtos;
import com.google.devtools.build.lib.buildeventstream.GenericBuildEvent;
import com.google.devtools.build.lib.buildeventstream.PathConverter;
import com.google.devtools.build.lib.collect.nestedset.NestedSetView;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import java.util.Collection;

/**
 * A {@link BuildEvent} introducing a set of artifacts to be referred to later by its name. Those
 * events are generated by the {@link BuildEventStreamer} upon seeing an {@link
 * EventReportingArtifacts}, if necessary.
 */
class NamedArtifactGroup implements BuildEvent {
  private final String name;
  private final CompletionContext completionContext;
  private final NestedSetView<Artifact> view;

  NamedArtifactGroup(
      String name, CompletionContext completionContext, NestedSetView<Artifact> view) {
    this.name = name;
    this.completionContext = completionContext;
    this.view = view;
  }

  @Override
  public BuildEventId getEventId() {
    return BuildEventId.fromArtifactGroupName(name);
  }

  @Override
  public Collection<BuildEventId> getChildrenEvents() {
    return ImmutableSet.of();
  }

  @Override
  public Collection<LocalFile> referencedLocalFiles() {
    // This has to be consistent with the code below.
    ImmutableList.Builder<LocalFile> artifacts = ImmutableList.builder();
    completionContext.visitArtifacts(
        view.directs(),
        new ArtifactReceiver() {
          @Override
          public void accept(Artifact artifact) {
            artifacts.add(
                new LocalFile(
                    completionContext.pathResolver().toPath(artifact), LocalFileType.OUTPUT));
          }

          @Override
          public void acceptFilesetMapping(
              Artifact fileset, PathFragment relName, Path targetFile) {
            artifacts.add(
                new LocalFile(
                    completionContext.pathResolver().convertPath(targetFile),
                    LocalFileType.OUTPUT));
          }
        });
    return artifacts.build();
  }

  @Override
  public BuildEventStreamProtos.BuildEvent asStreamProto(BuildEventContext converters) {
    PathConverter pathConverter = converters.pathConverter();
    ArtifactGroupNamer namer = converters.artifactGroupNamer();

    BuildEventStreamProtos.NamedSetOfFiles.Builder builder =
        BuildEventStreamProtos.NamedSetOfFiles.newBuilder();
    completionContext.visitArtifacts(
        view.directs(),
        new ArtifactReceiver() {
          @Override
          public void accept(Artifact artifact) {
            String uri = pathConverter.apply(completionContext.pathResolver().toPath(artifact));
            if (uri != null) {
              builder.addFiles(newFileFromArtifact(artifact).setUri(uri));
            }
          }

          @Override
          public void acceptFilesetMapping(
              Artifact fileset, PathFragment relName, Path targetFile) {
            String uri =
                converters
                    .pathConverter()
                    .apply(completionContext.pathResolver().convertPath(targetFile));
            if (uri != null) {
              builder.addFiles(newFileFromArtifact(null, fileset, relName).setUri(uri).build());
            }
          }
        });
    for (NestedSetView<Artifact> child : view.transitives()) {
      builder.addFileSets(namer.apply(child.identifier()));
    }
    return GenericBuildEvent.protoChaining(this).setNamedSetOfFiles(builder.build()).build();
  }
}