// Copyright 2017 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.android;

import static java.util.stream.Collectors.toSet;

import com.android.builder.core.VariantConfiguration;
import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.devtools.build.android.ResourceShrinkerAction.Options;
import com.google.devtools.build.android.aapt2.Aapt2ConfigOptions;
import com.google.devtools.build.android.aapt2.CompiledResources;
import com.google.devtools.build.android.aapt2.ResourceCompiler;
import com.google.devtools.build.android.aapt2.ResourceLinker;
import com.google.devtools.build.android.aapt2.StaticLibrary;
import com.google.devtools.common.options.OptionsParser;
import com.google.devtools.common.options.ShellQuotedParamsFilePreProcessor;
import java.io.Closeable;
import java.io.File;
import java.nio.file.FileSystems;
import java.nio.file.Path;
import java.util.concurrent.ExecutionException;
import java.util.function.Function;

/**
 * An action to perform resource shrinking using the Gradle resource shrinker.
 *
 * <pre>
 * Example Usage:
 *   java/com/google/build/android/ResourceShrinkerAction
 *       --aapt2 path to sdk/aapt2
 *       --annotationJar path to sdk/annotationJar
 *       --androidJar path to sdk/androidJar
 *       --shrunkJar path to proguard dead code removal jar
 *       --resources path to processed resources zip
 *       --rTxt path to processed resources R.txt
 *       --primaryManifest path to processed resources AndroidManifest.xml
 *       --dependencyManifest path to dependency library manifest (repeated flag)
 *       --shrunkResourceApk path to write shrunk ap_
 *       --shrunkResources path to write shrunk resources zip
 * </pre>
 */
public class Aapt2ResourceShrinkingAction {

  public static void main(String[] args) throws Exception {
    final Profiler profiler = LoggingProfiler.createAndStart("shrink").startTask("flags");
    // Parse arguments.
    OptionsParser optionsParser =
        OptionsParser.newOptionsParser(Options.class, Aapt2ConfigOptions.class);
    optionsParser.enableParamsFileSupport(
        new ShellQuotedParamsFilePreProcessor(FileSystems.getDefault()));
    optionsParser.parseAndExitUponError(args);
    Aapt2ConfigOptions aapt2ConfigOptions = optionsParser.getOptions(Aapt2ConfigOptions.class);
    Options options = optionsParser.getOptions(Options.class);
    options.dependencyManifests =
        Converters.concatLists(options.dependencyManifests, options.deprecatedDependencyManifests);
    profiler.recordEndOf("flags").startTask("setup");

    final ListeningExecutorService executorService = ExecutorServiceCloser.createDefaultService();
    try (ScopedTemporaryDirectory scopedTmp =
            new ScopedTemporaryDirectory("android_resources_tmp");
        Closeable closer = ExecutorServiceCloser.createWith(executorService)) {

      Path workingResourcesDirectory = scopedTmp.subDirectoryOf("resources");
      final ResourceCompiler resourceCompiler =
          ResourceCompiler.create(
              executorService,
              workingResourcesDirectory,
              aapt2ConfigOptions.aapt2,
              aapt2ConfigOptions.buildToolsVersion);
      profiler.recordEndOf("setup").startTask("compile");

      final ResourcesZip resourcesZip =
          ResourcesZip.createFrom(
              options.resourcesZip, scopedTmp.subDirectoryOf("merged-resources"));
      final CompiledResources compiled =
          resourcesZip
              .shrink(
                  options
                      .dependencyManifests
                      .stream()
                      .map(Path::toFile)
                      .map(manifestToPackageUsing(executorService))
                      .map(futureToString())
                      .collect(toSet()),
                  options.rTxt,
                  options.shrunkJar,
                  options.primaryManifest,
                  options.proguardMapping,
                  options.log,
                  scopedTmp.subDirectoryOf("shrunk-resources"))
              .writeArchiveTo(options.shrunkResources, false)
              .compile(resourceCompiler, workingResourcesDirectory);
      profiler.recordEndOf("compile");

      ResourceLinker.create(aapt2ConfigOptions.aapt2, scopedTmp.subDirectoryOf("linking"))
          .profileUsing(profiler)
          .dependencies(ImmutableList.of(StaticLibrary.from(aapt2ConfigOptions.androidJar)))
          .link(compiled)
          .copyPackageTo(options.shrunkApk)
          .copyRTxtTo(options.rTxtOutput);
      profiler.recordEndOf("shrink");
    }
  }

  static Function<File, ListenableFuture<String>> manifestToPackageUsing(
      ListeningExecutorService executor) {
    return f -> executor.submit(() -> VariantConfiguration.getManifestPackage(f));
  }

  static Function<ListenableFuture<String>, String> futureToString() {
    return f -> {
      try {
        return f.get();
      } catch (InterruptedException | ExecutionException e) {
        throw new RuntimeException(e);
      }
    };
  }
}