DoMigrations.java

/*
 * Copyright 2016 Victor Albertos
 *
 * 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 io.rx_cache2.internal.migration;

import io.reactivex.Observable;
import io.reactivex.ObservableSource;
import io.reactivex.functions.Function;
import io.rx_cache2.MigrationCache;
import io.rx_cache2.internal.Persistence;
import java.util.List;
import javax.inject.Inject;

public final class DoMigrations {
  private final io.rx_cache2.internal.migration.GetCacheVersion getCacheVersion;
  private final io.rx_cache2.internal.migration.GetPendingMigrations getPendingMigrations;
  private final io.rx_cache2.internal.migration.DeleteRecordMatchingClassName
      deleteRecordMatchingClassName;
  private final io.rx_cache2.internal.migration.UpgradeCacheVersion upgradeCacheVersion;
  private final GetClassesToEvictFromMigrations getClassesToEvictFromMigrations;
  private final List<MigrationCache> migrations;

  @Inject public DoMigrations(Persistence persistence, List<MigrationCache> migrations,
      String encryptKey) {
    this.getClassesToEvictFromMigrations = new GetClassesToEvictFromMigrations();
    this.getCacheVersion = new io.rx_cache2.internal.migration.GetCacheVersion(persistence);
    this.getPendingMigrations = new io.rx_cache2.internal.migration.GetPendingMigrations();
    this.migrations = migrations;
    this.upgradeCacheVersion = new io.rx_cache2.internal.migration.UpgradeCacheVersion(persistence);
    this.deleteRecordMatchingClassName = new io.rx_cache2.internal.migration.DeleteRecordMatchingClassName(persistence, encryptKey);
  }

  public Observable<Integer> react() {
    return getCacheVersion.react()
        .flatMap(new Function<Integer, ObservableSource<List<MigrationCache>>>() {
          @Override public ObservableSource<List<MigrationCache>> apply(Integer currentCacheVersion)
              throws Exception {
            return getPendingMigrations.with(currentCacheVersion, migrations).react();
          }
        })
        .flatMap(new Function<List<MigrationCache>, ObservableSource<List<Class>>>() {
          @Override public ObservableSource<List<Class>> apply(List<MigrationCache> migrationCaches)
              throws Exception {
            return getClassesToEvictFromMigrations.with(migrationCaches).react();
          }
        }).flatMap(new Function<List<Class>, ObservableSource<Integer>>() {
          @Override public ObservableSource<Integer> apply(List<Class> classes) throws Exception {
            return deleteRecordMatchingClassName.with(classes).react();
          }
        })
        .flatMap(new Function<Integer, ObservableSource<Integer>>() {
          @Override public ObservableSource<Integer> apply(Integer ignore) throws Exception {
            return upgradeCacheVersion.with(migrations).react();
          }
        });
  }
}