/*
    *    Copyright 2016-2025 the original author or authors.
    *
    *    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
    *
    *       https://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.mybatis.dynamic.sql.where.condition;
  
  import java.util.NoSuchElementException;
  import java.util.function.Function;
  import java.util.function.Predicate;
  
  import org.jspecify.annotations.NonNull;
  import org.mybatis.dynamic.sql.AbstractSingleValueCondition;
  
  public class IsEqualTo<T> extends AbstractSingleValueCondition<T>
          implements AbstractSingleValueCondition.Filterable<T>, AbstractSingleValueCondition.Mappable<T> {
  
      private static final IsEqualTo<?> EMPTY = new IsEqualTo<Object>(-1) {
          @Override
          public Object value() {
              throw new NoSuchElementException("No value present"); //$NON-NLS-1$
          }
  
          @Override
          public boolean isEmpty() {
              return true;
          }
      };
  
      public static <T> IsEqualTo<T> empty() {
          @SuppressWarnings("unchecked")
          IsEqualTo<T> t = (IsEqualTo<T>) EMPTY;
          return t;
      }
  
      protected IsEqualTo(T value) {
          super(value);
      }
  
      @Override
      public String operator() {
          return "="; //$NON-NLS-1$
      }
  
      public static <T> IsEqualTo<T> of(T value) {
          return new IsEqualTo<>(value);
      }
  
      @Override
      public IsEqualTo<T> filter(Predicate<? super @NonNull T> predicate) {
          return filterSupport(predicate, IsEqualTo::empty, this);
      }
  
      @Override
      public <R> IsEqualTo<R> map(Function<? super @NonNull T, ? extends @NonNull R> mapper) {
          return mapSupport(mapper, IsEqualTo::new, IsEqualTo::empty);
      }
  }