/*
    *    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.caseexpression;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Objects;
  import java.util.Optional;
  import java.util.stream.Stream;
  
  import org.jspecify.annotations.Nullable;
  import org.mybatis.dynamic.sql.BasicColumn;
  import org.mybatis.dynamic.sql.BindableColumn;
  import org.mybatis.dynamic.sql.SortSpecification;
  import org.mybatis.dynamic.sql.render.RenderingContext;
  import org.mybatis.dynamic.sql.select.render.SimpleCaseRenderer;
  import org.mybatis.dynamic.sql.util.FragmentAndParameters;
  import org.mybatis.dynamic.sql.util.Validator;
  
  public class SimpleCaseModel<T> implements BasicColumn, SortSpecification {
      private final BindableColumn<T> column;
      private final List<SimpleCaseWhenCondition<T>> whenConditions;
      private final @Nullable BasicColumn elseValue;
      private final @Nullable String alias;
      private final String descendingPhrase;
  
      private SimpleCaseModel(Builder<T> builder) {
          column = Objects.requireNonNull(builder.column);
          whenConditions = builder.whenConditions;
          elseValue = builder.elseValue;
          alias = builder.alias;
          descendingPhrase = builder.descendingPhrase;
          Validator.assertNotEmpty(whenConditions, "ERROR.40"); //$NON-NLS-1$
      }
  
      public BindableColumn<T> column() {
          return column;
      }
  
      public Stream<SimpleCaseWhenCondition<T>> whenConditions() {
          return whenConditions.stream();
      }
  
      public Optional<BasicColumn> elseValue() {
          return Optional.ofNullable(elseValue);
      }
  
      @Override
      public Optional<String> alias() {
          return Optional.ofNullable(alias);
      }
  
      @Override
      public SimpleCaseModel<T> as(String alias) {
          return new Builder<T>()
                  .withColumn(column)
                  .withWhenConditions(whenConditions)
                  .withElseValue(elseValue)
                  .withAlias(alias)
                  .withDescendingPhrase(descendingPhrase)
                  .build();
      }
  
      @Override
      public SimpleCaseModel<T> descending() {
          return new Builder<T>()
                  .withColumn(column)
                  .withWhenConditions(whenConditions)
                  .withElseValue(elseValue)
                  .withAlias(alias)
                  .withDescendingPhrase(" DESC") //$NON-NLS-1$
                  .build();
      }
  
      @Override
      public FragmentAndParameters renderForOrderBy(RenderingContext renderingContext) {
          return render(renderingContext).mapFragment(f -> f + descendingPhrase);
      }
  
      @Override
      public FragmentAndParameters render(RenderingContext renderingContext) {
          return new SimpleCaseRenderer<>(this, renderingContext).render();
      }
  
      public static class Builder<T> {
          private @Nullable BindableColumn<T> column;
         private final List<SimpleCaseWhenCondition<T>> whenConditions = new ArrayList<>();
         private @Nullable BasicColumn elseValue;
         private @Nullable String alias;
         private String descendingPhrase = ""; //$NON-NLS-1$
 
         public Builder<T> withColumn(BindableColumn<T> column) {
             this.column = column;
             return this;
         }
 
         public Builder<T> withWhenConditions(List<SimpleCaseWhenCondition<T>> whenConditions) {
             this.whenConditions.addAll(whenConditions);
             return this;
         }
 
         public Builder<T> withElseValue(@Nullable BasicColumn elseValue) {
             this.elseValue = elseValue;
             return this;
         }
 
         public Builder<T> withAlias(@Nullable String alias) {
             this.alias = alias;
             return this;
         }
 
         public Builder<T> withDescendingPhrase(String descendingPhrase) {
             this.descendingPhrase = descendingPhrase;
             return this;
         }
 
         public SimpleCaseModel<T> build() {
             return new SimpleCaseModel<>(this);
         }
     }
 }