/*
    * 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 org.basepom.mojo.propertyhelper;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  import org.basepom.mojo.propertyhelper.beans.UuidDefinition;
  
  import java.io.IOException;
  import java.util.List;
  import java.util.Optional;
  import java.util.UUID;
  
  import com.google.common.collect.ImmutableList;
  import com.google.common.collect.ImmutableList.Builder;
  
  public class UuidField
          implements PropertyElement {
  
      private final UuidDefinition uuidDefinition;
      private final ValueProvider valueProvider;
  
      public UuidField(final UuidDefinition uuidDefinition, final ValueProvider valueProvider) {
          this.uuidDefinition = checkNotNull(uuidDefinition, "uuidDefinition is null");
          this.valueProvider = checkNotNull(valueProvider, "valueProvider is null");
      }
  
      public static List<UuidField> createUuids(final ValueCache valueCache, final UuidDefinition... uuidDefinitions)
              throws IOException {
          checkNotNull(valueCache, "valueCache is null");
  
          final Builder<UuidField> result = ImmutableList.builder();
  
          for (UuidDefinition uuidDefinition : uuidDefinitions) {
              uuidDefinition.check();
              final ValueProvider uuidValue = valueCache.getValueProvider(uuidDefinition);
              final UuidField uuidField = new UuidField(uuidDefinition, uuidValue);
              result.add(uuidField);
          }
  
          return result.build();
      }
  
      @Override
      public String getPropertyName() {
          return uuidDefinition.getId();
      }
  
      @Override
      public Optional<String> getPropertyValue() {
          // Only add the value from the provider if it is not null.
          UUID result = null;
          final Optional<String> propValue = valueProvider.getValue();
  
          if (propValue.isPresent()) {
              result = UUID.fromString(propValue.get());
          }
  
          if (result == null) {
              final Optional<UUID> definedValue = uuidDefinition.getValue();
              if (definedValue.isPresent()) {
                  result = definedValue.get();
              }
          }
  
          if (result == null) {
              result = UUID.randomUUID();
          }
  
          valueProvider.setValue(result.toString());
          return uuidDefinition.formatResult(result.toString());
      }
  
      @Override
      public boolean isExport() {
          return uuidDefinition.isExport();
      }
  
      @Override
      public String toString() {
          return getPropertyValue().orElse("");
      }
  }