/*
    * 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.fields;
  
  import org.basepom.mojo.propertyhelper.Field;
  import org.basepom.mojo.propertyhelper.FieldContext;
  import org.basepom.mojo.propertyhelper.ValueProvider;
  import org.basepom.mojo.propertyhelper.definitions.DateDefinition;
  
  import java.time.ZoneId;
  import java.time.ZonedDateTime;
  import java.time.temporal.ChronoUnit;
  import java.util.StringJoiner;
  
  import com.google.common.annotations.VisibleForTesting;
  
  
  public final class DateField extends Field<ZonedDateTime, DateDefinition> {
  
      private final ValueProvider valueProvider;
      private final ZoneId timezone;
  
      @VisibleForTesting
      public static DateField forTesting(DateDefinition dateDefinition, ValueProvider valueProvider) {
          return new DateField(dateDefinition, valueProvider, FieldContext.forTesting());
      }
  
      public DateField(final DateDefinition dateDefinition, final ValueProvider valueProvider, FieldContext fieldContext) {
          super(dateDefinition, fieldContext);
  
          this.valueProvider = valueProvider;
          this.timezone = dateDefinition.getTimezone();
      }
  
      @Override
      public String getFieldName() {
          return fieldDefinition.getId();
      }
  
      @Override
      public String getValue() {
          ZonedDateTime date = valueProvider.getValue()
              .map(value -> fieldDefinition.getParser().apply(value))
              .orElseGet(() -> fieldDefinition.getValue()
                  .map(fieldDefinition.getLongParser())
                  .orElseGet(this::now));
  
          String result = formatResult(date);
  
          if (fieldDefinition.getFormatter().isPresent()) {
              // format was set, store time in the chosen format
              valueProvider.setValue(result);
          } else {
              // not format was set. Store time as millis.
              valueProvider.setValue(Long.toString(date.toInstant().toEpochMilli()));
          }
  
          return result;
      }
  
      @Override
      public boolean isExposeAsProperty() {
          return fieldDefinition.isExport();
      }
  
      private ZonedDateTime now() {
          // code only saves in millisecond precision.
          return ZonedDateTime.now(timezone).truncatedTo(ChronoUnit.MILLIS);
      }
  
      @Override
      public String toString() {
          return new StringJoiner(", ", DateField.class.getSimpleName() + "[", "]")
              .add("valueProvider=" + valueProvider)
              .toString();
      }
  }