/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.maven.search.api.request;
  
  import java.time.Instant;
  import java.util.Map;
  import java.util.Objects;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Field, that is used as key in record.
   */
  public abstract class Field {
      private final String fieldName;
  
      private Field(String fieldName) {
          this.fieldName = requireNonNull(fieldName);
      }
  
      /**
       * Returns the field name.
       */
      public String getFieldName() {
          return fieldName;
      }
  
      /**
       * Returns the value of the field from given record instance, or {@code null} if field not present in record.
       * See subclasses for proper return types.
       */
      public abstract Object getFieldValue(Map<Field, Object> record);
  
      @Override
      public boolean equals(Object o) {
          if (this == o) {
              return true;
          }
          if (o == null || getClass() != o.getClass()) {
              return false;
          }
          Field fieldName1 = (Field) o;
          return Objects.equals(getFieldName(), fieldName1.getFieldName());
      }
  
      @Override
      public int hashCode() {
          return Objects.hash(getFieldName());
      }
  
      @Override
      public String toString() {
          return fieldName;
      }
  
      public static class StringField extends Field {
          public StringField(String fieldName) {
              super(fieldName);
          }
  
          @Override
          public String getFieldValue(Map<Field, Object> record) {
              return (String) record.get(this);
          }
      }
  
      public static class NumberField extends Field {
          public NumberField(String fieldName) {
              super(fieldName);
          }
  
          @Override
          public Number getFieldValue(Map<Field, Object> record) {
              return (Number) record.get(this);
          }
      }
  
      public static class BooleanField extends Field {
          public BooleanField(String fieldName) {
              super(fieldName);
          }
  
          @Override
         public Boolean getFieldValue(Map<Field, Object> record) {
             return (Boolean) record.get(this);
         }
     }
 
     /**
      * @since 7.0.4
      */
     public static class InstantField extends Field {
         public InstantField(String fieldName) {
             super(fieldName);
         }
 
         public Instant getFieldValue(Map<Field, Object> record) {
             return (Instant) record.get(this);
         }
     }
 }