// Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

package com.android.tools.r8;

import com.android.tools.r8.DexIndexedConsumer.DirectoryConsumer;
import com.android.tools.r8.dex.ApplicationReader;
import com.android.tools.r8.dex.ApplicationWriter;
import com.android.tools.r8.graph.AppInfo;
import com.android.tools.r8.graph.DexApplication;
import com.android.tools.r8.graph.DexApplication.Builder;
import com.android.tools.r8.graph.DexProgramClass;
import com.android.tools.r8.naming.ClassNameMapper;
import com.android.tools.r8.naming.NamingLens;
import com.android.tools.r8.utils.FeatureClassMapping;
import com.android.tools.r8.utils.FeatureClassMapping.FeatureMappingException;
import com.android.tools.r8.utils.InternalOptions;
import com.android.tools.r8.utils.ThreadUtils;
import com.android.tools.r8.utils.Timing;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;

public class DexSplitterHelper {

  public static void run(
      D8Command command,
      FeatureClassMapping featureClassMapping,
      String output,
      String proguardMap)
      throws IOException, CompilationException, ExecutionException {
    InternalOptions options = command.getInternalOptions();
    options.enableDesugaring = false;
    options.enableMainDexListCheck = false;
    options.minimalMainDex = false;
    options.enableMinification = false;
    options.enableInlining = false;
    options.outline.enabled = false;

    ExecutorService executor = ThreadUtils.getExecutorService(ThreadUtils.NOT_SPECIFIED);
    try {
      try {
        Timing timing = new Timing("DexSplitter");
        DexApplication app =
            new ApplicationReader(command.getInputApp(), options, timing).read(null, executor);


        ClassNameMapper mapper = null;
        if (proguardMap != null) {
          mapper = ClassNameMapper.mapperFromFile(Paths.get(proguardMap));
        }
        Map<String, Builder> applications = getDistribution(app, featureClassMapping, mapper);
        for (Entry<String, Builder> entry : applications.entrySet()) {
          DexApplication featureApp = entry.getValue().build();
          // We use the same factory, reset sorting.
          featureApp.dexItemFactory.resetSortedIndices();
          assert !options.hasMethodsFilter();

          // Run d8 optimize to ensure jumbo strings are handled.
          AppInfo appInfo = new AppInfo(featureApp);
          featureApp = D8.optimize(featureApp, appInfo, options, timing, executor);
          // We create a specific consumer for each split.
          Path outputDir = Paths.get(output).resolve(entry.getKey());
          if (!Files.exists(outputDir)) {
            Files.createDirectory(outputDir);
          }
          DexIndexedConsumer consumer = new DirectoryConsumer(outputDir);

          try {
            new ApplicationWriter(
                    featureApp,
                    options,
                    D8.getMarker(options),
                    null,
                    NamingLens.getIdentityLens(),
                    null,
                    null,
                    consumer)
                .write(executor);
            options.printWarnings();
          } finally {
            consumer.finished(options.reporter);
          }
        }
      } catch (ExecutionException e) {
        R8.unwrapExecutionException(e);
        throw new AssertionError(e); // unwrapping method should have thrown
      } catch (FeatureMappingException e) {
        options.reporter.error(e.getMessage());
      } finally {
        options.signalFinishedToProgramConsumer();
      }
    } finally {
      executor.shutdown();
    }
  }

  private static Map<String, Builder> getDistribution(
      DexApplication app, FeatureClassMapping featureClassMapping, ClassNameMapper mapper)
      throws FeatureMappingException {
    Map<String, Builder> applications = new HashMap<>();
    for (DexProgramClass clazz : app.classes()) {
      String clazzName =
          mapper != null ? mapper.deobfuscateClassName(clazz.toString()) : clazz.toString();
      String feature = featureClassMapping.featureForClass(clazzName);
      Builder featureApplication = applications.get(feature);
      if (featureApplication == null) {
        featureApplication = DexApplication.builder(app.dexItemFactory, app.timing);
        applications.put(feature, featureApplication);
      }
      featureApplication.addProgramClass(clazz);
    }
    return applications;
  }
}