/*
    *    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.delete.render;
  
  import java.util.Objects;
  import java.util.Optional;
  import java.util.stream.Collectors;
  
  import org.jspecify.annotations.Nullable;
  import org.mybatis.dynamic.sql.common.OrderByModel;
  import org.mybatis.dynamic.sql.common.OrderByRenderer;
  import org.mybatis.dynamic.sql.delete.DeleteModel;
  import org.mybatis.dynamic.sql.render.ExplicitTableAliasCalculator;
  import org.mybatis.dynamic.sql.render.RenderedParameterInfo;
  import org.mybatis.dynamic.sql.render.RenderingContext;
  import org.mybatis.dynamic.sql.render.RenderingStrategy;
  import org.mybatis.dynamic.sql.render.TableAliasCalculator;
  import org.mybatis.dynamic.sql.util.FragmentAndParameters;
  import org.mybatis.dynamic.sql.util.FragmentCollector;
  import org.mybatis.dynamic.sql.where.EmbeddedWhereModel;
  
  public class DeleteRenderer {
      private final DeleteModel deleteModel;
      private final RenderingContext renderingContext;
  
      private DeleteRenderer(Builder builder) {
          deleteModel = Objects.requireNonNull(builder.deleteModel);
          TableAliasCalculator tableAliasCalculator = builder.deleteModel.tableAlias()
                  .map(a -> ExplicitTableAliasCalculator.of(deleteModel.table(), a))
                  .orElseGet(TableAliasCalculator::empty);
          renderingContext = RenderingContext
                  .withRenderingStrategy(Objects.requireNonNull(builder.renderingStrategy))
                  .withTableAliasCalculator(tableAliasCalculator)
                  .withStatementConfiguration(deleteModel.statementConfiguration())
                  .build();
      }
  
      public DeleteStatementProvider render() {
          FragmentCollector fragmentCollector = new FragmentCollector();
  
          fragmentCollector.add(calculateDeleteStatementStart());
          calculateWhereClause().ifPresent(fragmentCollector::add);
          calculateOrderByClause().ifPresent(fragmentCollector::add);
          calculateLimitClause().ifPresent(fragmentCollector::add);
  
          return toDeleteStatementProvider(fragmentCollector);
      }
  
      private DeleteStatementProvider toDeleteStatementProvider(FragmentCollector fragmentCollector) {
          return DefaultDeleteStatementProvider
                  .withDeleteStatement(fragmentCollector.collectFragments(Collectors.joining(" "))) //$NON-NLS-1$
                  .withParameters(fragmentCollector.parameters())
                  .build();
      }
  
      private FragmentAndParameters calculateDeleteStatementStart() {
          String aliasedTableName = renderingContext.aliasedTableName(deleteModel.table());
          return FragmentAndParameters.fromFragment("delete from " + aliasedTableName); //$NON-NLS-1$
      }
  
      private Optional<FragmentAndParameters> calculateWhereClause() {
          return deleteModel.whereModel().flatMap(this::renderWhereClause);
      }
  
      private Optional<FragmentAndParameters> renderWhereClause(EmbeddedWhereModel whereModel) {
          return whereModel.render(renderingContext);
      }
  
      private Optional<FragmentAndParameters> calculateLimitClause() {
          return deleteModel.limit().map(this::renderLimitClause);
      }
  
      private FragmentAndParameters renderLimitClause(Long limit) {
          RenderedParameterInfo parameterInfo = renderingContext.calculateLimitParameterInfo();
  
          return FragmentAndParameters.withFragment("limit " + parameterInfo.renderedPlaceHolder()) //$NON-NLS-1$
                  .withParameter(parameterInfo.parameterMapKey(), limit)
                  .build();
      }
  
      private Optional<FragmentAndParameters> calculateOrderByClause() {
          return deleteModel.orderByModel().map(this::renderOrderByClause);
      }
  
      private FragmentAndParameters renderOrderByClause(OrderByModel orderByModel) {
          return new OrderByRenderer(renderingContext).render(orderByModel);
     }
 
     public static Builder withDeleteModel(DeleteModel deleteModel) {
         return new Builder().withDeleteModel(deleteModel);
     }
 
     public static class Builder {
         private @Nullable DeleteModel deleteModel;
         private @Nullable RenderingStrategy renderingStrategy;
 
         public Builder withDeleteModel(DeleteModel deleteModel) {
             this.deleteModel = deleteModel;
             return this;
         }
 
         public Builder withRenderingStrategy(RenderingStrategy renderingStrategy) {
             this.renderingStrategy = renderingStrategy;
             return this;
         }
 
         public DeleteRenderer build() {
             return new DeleteRenderer(this);
         }
     }
 }