/*
    *    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.update.render;
  
  import java.util.Objects;
  import java.util.Optional;
  
  import org.jspecify.annotations.Nullable;
  import org.mybatis.dynamic.sql.render.RenderedParameterInfo;
  import org.mybatis.dynamic.sql.render.RenderingContext;
  import org.mybatis.dynamic.sql.select.render.SubQueryRenderer;
  import org.mybatis.dynamic.sql.util.AbstractColumnMapping;
  import org.mybatis.dynamic.sql.util.ColumnToColumnMapping;
  import org.mybatis.dynamic.sql.util.ConstantMapping;
  import org.mybatis.dynamic.sql.util.FragmentAndParameters;
  import org.mybatis.dynamic.sql.util.NullMapping;
  import org.mybatis.dynamic.sql.util.SelectMapping;
  import org.mybatis.dynamic.sql.util.StringConstantMapping;
  import org.mybatis.dynamic.sql.util.StringUtilities;
  import org.mybatis.dynamic.sql.util.UpdateMappingVisitor;
  import org.mybatis.dynamic.sql.util.ValueMapping;
  import org.mybatis.dynamic.sql.util.ValueOrNullMapping;
  import org.mybatis.dynamic.sql.util.ValueWhenPresentMapping;
  
  public class SetPhraseVisitor extends UpdateMappingVisitor<Optional<FragmentAndParameters>> {
  
      private final RenderingContext renderingContext;
  
      public SetPhraseVisitor(RenderingContext renderingContext) {
          this.renderingContext = Objects.requireNonNull(renderingContext);
      }
  
      @Override
      public Optional<FragmentAndParameters> visit(NullMapping mapping) {
          return buildNullFragment(mapping);
      }
  
      @Override
      public Optional<FragmentAndParameters> visit(ConstantMapping mapping) {
          String fragment = renderingContext.aliasedColumnName(mapping.column())
                  + " = " + mapping.constant(); //$NON-NLS-1$
          return FragmentAndParameters.withFragment(fragment)
                  .buildOptional();
      }
  
      @Override
      public Optional<FragmentAndParameters> visit(StringConstantMapping mapping) {
          String fragment = renderingContext.aliasedColumnName(mapping.column())
                  + " = " //$NON-NLS-1$
                  + StringUtilities.formatConstantForSQL(mapping.constant());
  
          return FragmentAndParameters.withFragment(fragment)
                  .buildOptional();
      }
  
      @Override
      public <T> Optional<FragmentAndParameters> visit(ValueMapping<T> mapping) {
          return buildValueFragment(mapping, mapping.value());
      }
  
      @Override
      public <T> Optional<FragmentAndParameters> visit(ValueOrNullMapping<T> mapping) {
          return mapping.value()
                  .map(v -> buildValueFragment(mapping, v))
                  .orElseGet(() -> buildNullFragment(mapping));
      }
  
      @Override
      public <T> Optional<FragmentAndParameters> visit(ValueWhenPresentMapping<T> mapping) {
          return mapping.value().flatMap(v -> buildValueFragment(mapping, v));
      }
  
      @Override
      public Optional<FragmentAndParameters> visit(SelectMapping mapping) {
          String prefix = renderingContext.aliasedColumnName(mapping.column()) + " = ("; //$NON-NLS-1$
  
          FragmentAndParameters fragmentAndParameters = SubQueryRenderer.withSelectModel(mapping.selectModel())
                  .withRenderingContext(renderingContext)
                  .withPrefix(prefix)
                  .withSuffix(")") //$NON-NLS-1$
                  .build()
                  .render();
  
          return Optional.of(fragmentAndParameters);
      }
  
     @Override
     public Optional<FragmentAndParameters> visit(ColumnToColumnMapping mapping) {
         FragmentAndParameters fragmentAndParameters = mapping.rightColumn().render(renderingContext)
                 .mapFragment(f -> renderingContext.aliasedColumnName(mapping.column()) + " = " + f); //$NON-NLS-1$
         return Optional.of(fragmentAndParameters);
     }
 
     private <T> Optional<FragmentAndParameters> buildValueFragment(AbstractColumnMapping mapping, @Nullable T value) {
         RenderedParameterInfo parameterInfo = renderingContext.calculateParameterInfo(mapping.column());
         String setPhrase = renderingContext.aliasedColumnName(mapping.column())
                 + " = "  //$NON-NLS-1$
                 + parameterInfo.renderedPlaceHolder();
 
         return FragmentAndParameters.withFragment(setPhrase)
                 .withParameter(parameterInfo.parameterMapKey(), value)
                 .buildOptional();
     }
 
     private Optional<FragmentAndParameters> buildNullFragment(AbstractColumnMapping mapping) {
         return FragmentAndParameters
                 .withFragment(renderingContext.aliasedColumnName(mapping.column()) + " = null") //$NON-NLS-1$
                 .buildOptional();
     }
 }