/*
    *    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.Objects;
  import java.util.Optional;
  
  import org.jspecify.annotations.Nullable;
  import org.mybatis.dynamic.sql.BasicColumn;
  import org.mybatis.dynamic.sql.render.RenderingContext;
  import org.mybatis.dynamic.sql.util.FragmentAndParameters;
  
  public class Cast implements BasicColumn {
      private final BasicColumn column;
      private final String targetType;
      private final @Nullable String alias;
  
      private Cast(Builder builder) {
          column = Objects.requireNonNull(builder.column);
          targetType = Objects.requireNonNull(builder.targetType);
          alias = builder.alias;
      }
  
      @Override
      public Optional<String> alias() {
          return Optional.ofNullable(alias);
      }
  
      @Override
      public Cast as(String alias) {
          return new Builder().withColumn(column)
                  .withTargetType(targetType)
                  .withAlias(alias)
                  .build();
      }
  
      @Override
      public FragmentAndParameters render(RenderingContext renderingContext) {
          return column.render(renderingContext).mapFragment(this::applyCast);
      }
  
      private String applyCast(String in) {
          return "cast(" + in + " as " + targetType + ")"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
      }
  
      public static class Builder {
          private @Nullable BasicColumn column;
          private @Nullable String targetType;
          private @Nullable String alias;
  
          public Builder withColumn(BasicColumn column) {
              this.column = column;
              return this;
          }
  
          public Builder withTargetType(String targetType) {
              this.targetType = targetType;
              return this;
          }
  
          public Builder withAlias(String alias) {
              this.alias = alias;
              return this;
          }
  
          public Cast build() {
              return new Cast(this);
          }
      }
  }