java/com/google/android/libraries/mobiledatadownload/populator/ManifestConfigHelper.java

/*
 * Copyright 2022 Google LLC
 *
 * 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.android.libraries.mobiledatadownload.populator;

import android.util.Log;
import com.google.android.libraries.mobiledatadownload.AddFileGroupRequest;
import com.google.android.libraries.mobiledatadownload.MobileDataDownload;
import com.google.android.libraries.mobiledatadownload.tracing.PropagatedFluentFuture;
import com.google.android.libraries.mobiledatadownload.tracing.PropagatedFutures;
import com.google.common.base.Optional;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.mobiledatadownload.DownloadConfigProto.DataFile;
import com.google.mobiledatadownload.DownloadConfigProto.DataFileGroup;
import com.google.mobiledatadownload.DownloadConfigProto.DeltaFile;
import com.google.mobiledatadownload.DownloadConfigProto.ManifestConfig;
import java.util.ArrayList;
import java.util.List;

/** Shared functions for ManifestConfig. */
public final class ManifestConfigHelper {
  public static final String URL_TEMPLATE_CHECKSUM_PLACEHOLDER = "{checksum}";

  private static final String TAG = "ManifestConfigHelper";

  private final MobileDataDownload mobileDataDownload;
  private final Optional<ManifestConfigOverrider> overriderOptional;

  /** Creates a new helper for converting manifest configs into data file groups. */
  ManifestConfigHelper(
      MobileDataDownload mobileDataDownload, Optional<ManifestConfigOverrider> overriderOptional) {
    this.mobileDataDownload = mobileDataDownload;
    this.overriderOptional = overriderOptional;
  }

  /**
   * Reads file groups from {@link ManifestConfig} and adds to MDD after applying the {@link
   * ManifestConfigOverrider} if it's present. This static method is shared with {@link
   * ManifestFileGroupPopulator}.
   *
   * @param mobileDataDownload The MDD instance.
   * @param manifestConfig The proto that contains configs for file groups and modifiers.
   * @param overriderOptional An optional overrider that takes manifest config and returns a list of
   *     file groups to be added to MDD.
   */
  static ListenableFuture<Void> refreshFromManifestConfig(
      MobileDataDownload mobileDataDownload,
      ManifestConfig manifestConfig,
      Optional<ManifestConfigOverrider> overriderOptional) {
    ManifestConfigHelper helper = new ManifestConfigHelper(mobileDataDownload, overriderOptional);
    return PropagatedFluentFuture.from(helper.applyOverrider(manifestConfig))
        .transformAsync(helper::addAllFileGroups, MoreExecutors.directExecutor());
  }

  /** Adds the specified list of file groups to MDD. */
  ListenableFuture<Void> addAllFileGroups(List<DataFileGroup> fileGroups) {
    List<ListenableFuture<Boolean>> addFileGroupFutures = new ArrayList<>();

    for (DataFileGroup dataFileGroup : fileGroups) {
      if (dataFileGroup == null || dataFileGroup.getGroupName().isEmpty()) {
        continue;
      }

      ListenableFuture<Boolean> addFileGroupFuture =
          mobileDataDownload.addFileGroup(
              AddFileGroupRequest.newBuilder().setDataFileGroup(dataFileGroup).build());

      PropagatedFutures.addCallback(
          addFileGroupFuture,
          new FutureCallback<Boolean>() {
            @Override
            public void onSuccess(Boolean result) {
              String groupName = dataFileGroup.getGroupName();
              if (result.booleanValue()) {
                Log.d(TAG, "Added file groups " + groupName);
              } else {
                Log.d(TAG, "Failed to add file group " + groupName);
              }
            }

            @Override
            public void onFailure(Throwable t) {
              Log.e(TAG, "Failed to add file group", t);
            }
          },
          MoreExecutors.directExecutor());
      addFileGroupFutures.add(addFileGroupFuture);
    }
    return PropagatedFutures.whenAllComplete(addFileGroupFutures)
        .call(() -> null, MoreExecutors.directExecutor());
  }

  /** Applies the overrider to the manifest config to generate a list of file groups for adding. */
  ListenableFuture<List<DataFileGroup>> applyOverrider(ManifestConfig manifestConfig) {
    if (overriderOptional.isPresent()) {
      return overriderOptional.get().override(maybeApplyFileUrlTemplate(manifestConfig));
    }
    List<DataFileGroup> results = new ArrayList<>();
    for (ManifestConfig.Entry entry : maybeApplyFileUrlTemplate(manifestConfig).getEntryList()) {
      results.add(entry.getDataFileGroup());
    }
    return Futures.immediateFuture(results);
  }

  /**
   * If file_url_template is populated and file url_to_download field is empty in the {@code
   * ManifestConfig} manifestConfig then construct the url_to_download field using the template.
   *
   * <p>NOTE: If file_url_template is empty then the files are expected to have the complete
   * download URL, validate and throw an {@link IllegalArgumentException} if url_to_download is not
   * populated.
   */
  public static ManifestConfig maybeApplyFileUrlTemplate(ManifestConfig manifestConfig) {
    if (!manifestConfig.hasUrlTemplate()
        || manifestConfig.getUrlTemplate().getFileUrlTemplate().isEmpty()) {
      return validateManifestConfigFileUrls(manifestConfig);
    }
    String fileDownloadUrlTemplate = manifestConfig.getUrlTemplate().getFileUrlTemplate();
    ManifestConfig.Builder updatedManifestConfigBuilder = manifestConfig.toBuilder().clearEntry();

    for (ManifestConfig.Entry entry : manifestConfig.getEntryList()) {
      DataFileGroup.Builder dataFileGroupBuilder = entry.getDataFileGroup().toBuilder().clearFile();
      for (DataFile dataFile : entry.getDataFileGroup().getFileList()) {
        DataFile.Builder dataFileBuilder = dataFile.toBuilder().clearDeltaFile();

        if (dataFile.getUrlToDownload().isEmpty()) {
          dataFileBuilder.setUrlToDownload(
              fileDownloadUrlTemplate.replace(
                  URL_TEMPLATE_CHECKSUM_PLACEHOLDER, dataFile.getChecksum()));
        }

        for (DeltaFile deltaFile : dataFile.getDeltaFileList()) {
          dataFileBuilder.addDeltaFile(
              deltaFile.getUrlToDownload().isEmpty()
                  ? deltaFile.toBuilder()
                      .setUrlToDownload(
                          fileDownloadUrlTemplate.replace(
                              URL_TEMPLATE_CHECKSUM_PLACEHOLDER, deltaFile.getChecksum()))
                      .build()
                  : deltaFile);
        }

        dataFileGroupBuilder.addFile(dataFileBuilder);
      }
      updatedManifestConfigBuilder.addEntry(
          entry.toBuilder().setDataFileGroup(dataFileGroupBuilder));
    }
    return updatedManifestConfigBuilder.build();
  }

  /**
   * Validates that all the files in {@code ManifestConfig} manifestConfig have the url_to_download
   * populated.
   */
  private static ManifestConfig validateManifestConfigFileUrls(ManifestConfig manifestConfig) {
    for (ManifestConfig.Entry entry : manifestConfig.getEntryList()) {
      for (DataFile dataFile : entry.getDataFileGroup().getFileList()) {
        if (dataFile.getUrlToDownload().isEmpty()) {
          throw new IllegalArgumentException(
              String.format("DataFile %s url_to_download is missing.", dataFile.getFileId()));
        }
        for (DeltaFile deltaFile : dataFile.getDeltaFileList()) {
          if (deltaFile.getUrlToDownload().isEmpty()) {
            throw new IllegalArgumentException(
                String.format(
                    "DeltaFile for file %s url_to_download is missing.", dataFile.getFileId()));
          }
        }
      }
    }
    return manifestConfig;
  }
}