/*
    * 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 de.softwareforge.testing.postgres.embedded;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  import java.io.IOException;
  import java.util.Set;
  import java.util.function.Consumer;
  import javax.sql.DataSource;
  
  import com.google.common.collect.ImmutableList;
  import edu.umd.cs.findbugs.annotations.NonNull;
  import org.flywaydb.core.Flyway;
  import org.flywaydb.core.api.FlywayException;
  import org.flywaydb.core.api.configuration.FluentConfiguration;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * An {@link EmbeddedPostgresPreparer<DataSource>} that uses the <a href="https://flywaydb.org/">Flyway version control for your database</a> framework to
   * migrate a data source to a known state.
   */
  public final class FlywayPreparer implements EmbeddedPostgresPreparer<DataSource> {
  
      private static final Logger LOG = LoggerFactory.getLogger(FlywayPreparer.class);
  
      private final ImmutableList.Builder<Consumer<FluentConfiguration>> customizers = ImmutableList.builder();
  
      /**
       * Creates a new instance using one or more classpath locations.
       *
       * @param locations One or more locations on the classpath.
       * @return A {@link FlywayPreparer} instance.
       */
      @NonNull
      public static FlywayPreparer forClasspathLocation(String... locations) {
          FlywayPreparermbedded/FlywayPreparer.html#FlywayPreparer">FlywayPreparer preparer = new FlywayPreparer();
          preparer.addCustomizer(c -> c.locations(locations));
          return preparer;
      }
  
      /**
       * Create a new, uninitialized preparer instance. Use {@link #addCustomizer(Consumer)} to modify the configuration for the {@link FluentConfiguration}
       * object.
       */
      public FlywayPreparer() {
      }
  
      /**
       * Add a customizer instance. Each customizer is called once with the {@link FluentConfiguration} instance before setting the datasource and calling {@link
       * FluentConfiguration#load()} and {@link Flyway#migrate()}.
       *
       * @param customizer A {@link Consumer<FluentConfiguration>} instance. Must not be null.
       * @return This object.
       */
      @NonNull
      public FlywayPreparer addCustomizer(@NonNull Consumer<FluentConfiguration> customizer) {
          checkNotNull(customizer, "customizer is null");
          customizers.add(customizer);
  
          return this;
      }
  
      /**
       * Add customizer instances. Each customizer is called once with the {@link FluentConfiguration} instance before setting the datasource and calling {@link
       * FluentConfiguration#load()} and {@link Flyway#migrate()}.
       *
       * @param customizers A set of {@link Consumer<FluentConfiguration>} instances. Must not be null.
       * @return This object.
       */
      @NonNull
      public FlywayPreparer addCustomizers(@NonNull Set<Consumer<FluentConfiguration>> customizers) {
          checkNotNull(customizers, "customizers is null");
          customizers.addAll(customizers);
  
          return this;
      }
  
      /**
       * @deprecated Use {@link #addCustomizer(Consumer)}.
       */
      @Deprecated
      @NonNull
      public FlywayPreparer customize(@NonNull Consumer<FluentConfiguration> customizer) {
          return addCustomizer(customizer);
      }
  
     @Override
     public void prepare(@NonNull DataSource dataSource) throws IOException {
         checkNotNull(dataSource, "dataSource is null");
 
         try {
             final FluentConfiguration config = Flyway.configure();
 
             customizers.build().forEach(c -> c.accept(config));
 
             config.dataSource(dataSource);
             Flyway flyway = config.load();
             flyway.migrate();
 
         } catch (FlywayException e) {
             throw new IOException(e);
         }
     }
 }