/*
    *    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.select.function;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  import java.util.Objects;
  import java.util.function.Function;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  import org.mybatis.dynamic.sql.BasicColumn;
  import org.mybatis.dynamic.sql.BindableColumn;
  import org.mybatis.dynamic.sql.render.RenderingContext;
  import org.mybatis.dynamic.sql.util.FragmentAndParameters;
  import org.mybatis.dynamic.sql.util.FragmentCollector;
  
  public class OperatorFunction<T> extends AbstractUniTypeFunction<T, OperatorFunction<T>> {
  
      protected final BasicColumn secondColumn;
      protected final List<BasicColumn> subsequentColumns = new ArrayList<>();
      private final String operator;
  
      protected OperatorFunction(String operator, BasicColumn firstColumn, BasicColumn secondColumn,
              List<BasicColumn> subsequentColumns) {
          super(firstColumn);
          this.secondColumn = Objects.requireNonNull(secondColumn);
          this.subsequentColumns.addAll(subsequentColumns);
          this.operator = Objects.requireNonNull(operator);
      }
  
      @Override
      protected OperatorFunction<T> copy() {
          return new OperatorFunction<>(operator, column, secondColumn, subsequentColumns);
      }
  
      @Override
      public FragmentAndParameters render(RenderingContext renderingContext) {
          String paddedOperator = " " + operator + " "; //$NON-NLS-1$ //$NON-NLS-2$
  
          return Stream.of(Stream.of(column, secondColumn), subsequentColumns.stream())
                  .flatMap(Function.identity())
                  .map(column -> column.render(renderingContext))
                  .collect(FragmentCollector.collect())
                  .toFragmentAndParameters(Collectors.joining(paddedOperator, "(", ")")); //$NON-NLS-1$ //$NON-NLS-2$
      }
  
      public static <T> OperatorFunction<T> of(String operator, BindableColumn<T> firstColumn, BasicColumn secondColumn,
              BasicColumn... subsequentColumns) {
          return of(operator, firstColumn, secondColumn, Arrays.asList(subsequentColumns));
      }
  
      public static <T> OperatorFunction<T> of(String operator, BindableColumn<T> firstColumn, BasicColumn secondColumn,
              List<BasicColumn> subsequentColumns) {
          return new OperatorFunction<>(operator, firstColumn, secondColumn, subsequentColumns);
      }
  }