// Copyright 2015 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.rules.android;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableList;
import com.google.common.io.ByteStreams;
import com.google.devtools.build.lib.actions.Action;
import com.google.devtools.build.lib.actions.ActionExecutionContext;
import com.google.devtools.build.lib.actions.ActionOwner;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.analysis.RuleContext;
import com.google.devtools.build.lib.analysis.actions.AbstractFileWriteAction;
import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
import com.google.devtools.build.lib.rules.android.deployinfo.AndroidDeployInfoOuterClass;
import com.google.devtools.build.lib.rules.android.deployinfo.AndroidDeployInfoOuterClass.AndroidDeployInfo;
import com.google.devtools.build.lib.util.Fingerprint;
import com.google.protobuf.ByteString;
import com.google.protobuf.InvalidProtocolBufferException;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Writes AndroidDeployInfo proto message. This proto describes how
 * to deploy and launch an android_binary/android_test.
 */
@Immutable
public final class AndroidDeployInfoAction extends AbstractFileWriteAction {

  private static Iterable<Artifact> makeInputs(
      Artifact mergedManifest,
      Iterable<Artifact> additionalMergedManifests,
      Iterable<Artifact> apksToDeploy,
      Iterable<Artifact> dataDeps) {

    return ImmutableList.<Artifact>builder()
        .add(mergedManifest)
        .addAll(additionalMergedManifests)
        .addAll(apksToDeploy)
        .addAll(dataDeps)
        .build();
  }

  private static final String GUID = "eda283ba-9000-4b80-8dc4-7939101c44ba";
  private final ByteString byteString;

  AndroidDeployInfoAction(
      ActionOwner owner,
      Artifact outputFile,
      Artifact mergedManifest,
      Iterable<Artifact> additionalMergedManifests,
      Iterable<Artifact> apksToDeploy,
      Iterable<Artifact> dataDeps) {
    super(owner, makeInputs(mergedManifest, additionalMergedManifests, apksToDeploy, dataDeps),
        outputFile, false);
    AndroidDeployInfoOuterClass.AndroidDeployInfo.Builder builder =
        AndroidDeployInfoOuterClass.AndroidDeployInfo.newBuilder();
    builder.setMergedManifest(makeArtifactProto(mergedManifest));
    for (Artifact additionMergedManifest : additionalMergedManifests) {
      builder.addAdditionalMergedManifests(makeArtifactProto(additionMergedManifest));
    }
    for (Artifact apk : apksToDeploy) {
      builder.addApksToDeploy(makeArtifactProto(apk));
    }
    for (Artifact dataDep : dataDeps) {
      builder.addDataToDeploy(makeArtifactProto(dataDep));
    }
    this.byteString = builder.build().toByteString();
  }

  static void createDeployInfoAction(
      RuleContext ruleContext,
      Artifact deployInfo,
      Artifact mergedManifest,
      Iterable<Artifact> additionalMergedManifests,
      Iterable<Artifact> apksToDeploy,
      Iterable<Artifact> dataDeps) {
    Action action = new AndroidDeployInfoAction(ruleContext.getActionOwner(),
        deployInfo, mergedManifest, additionalMergedManifests, apksToDeploy, dataDeps);
    ruleContext.registerAction(action);
  }

  @Override
  public DeterministicWriter newDeterministicWriter(ActionExecutionContext ctx) throws IOException {

    return new DeterministicWriter() {
      @Override
      public void writeOutputFile(OutputStream out) throws IOException {
        try (InputStream in = byteString.newInput()) {
          ByteStreams.copy(in, out);
        }
        out.flush();
      }
    };
  }

  @VisibleForTesting
  public AndroidDeployInfo getDeployInfo() throws InvalidProtocolBufferException {
    return AndroidDeployInfo.parseFrom(byteString);
  }

  @Override
  protected String computeKey() {
    Fingerprint f = new Fingerprint()
        .addString(GUID);

    try (InputStream in = byteString.newInput()) {
      byte[] buffer = new byte[512];
      int amountRead;
      while ((amountRead = in.read(buffer)) != -1) {
        f.addBytes(buffer, 0, amountRead);
      }
    } catch (IOException e) {
      throw new RuntimeException(e);
    }

    return f.hexDigestAndReset();
  }

  private static AndroidDeployInfoOuterClass.Artifact makeArtifactProto(Artifact artifact) {
    return AndroidDeployInfoOuterClass.Artifact.newBuilder()
        .setExecRootPath(artifact.getExecPathString())
        .build();
  }
}