content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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
   *
   *     http://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 com.datastax.oss.driver.internal.mapper.processor.entity;
  
  import com.datastax.oss.driver.api.mapper.MapperException;
  import com.datastax.oss.driver.api.mapper.annotations.Update;
  import com.datastax.oss.driver.api.querybuilder.QueryBuilder;
  import com.datastax.oss.driver.api.querybuilder.update.UpdateStart;
  import com.datastax.oss.driver.internal.mapper.processor.MethodGenerator;
  import com.datastax.oss.driver.internal.querybuilder.update.DefaultUpdate;
  import com.squareup.javapoet.MethodSpec;
  import java.util.Optional;
  import javax.lang.model.element.Modifier;
  
  public class EntityHelperUpdateStartMethodGenerator implements MethodGenerator {
  
    private final EntityDefinition entityDefinition;
  
    EntityHelperUpdateStartMethodGenerator(EntityDefinition entityDefinition) {
      this.entityDefinition = entityDefinition;
    }
  
    @Override
    public Optional<MethodSpec> generate() {
      MethodSpec.Builder updateBuilder =
          MethodSpec.methodBuilder("updateStart")
              .addAnnotation(Override.class)
              .addModifiers(Modifier.PUBLIC)
              .returns(DefaultUpdate.class);
  
      if (!entityDefinition.getRegularColumns().iterator().hasNext()) {
        updateBuilder.addStatement(
            "throw new $T($S)",
            MapperException.class,
            String.format(
                "Entity %s does not have any non PK columns. %s is not possible",
                entityDefinition.getClassName().simpleName(), Update.class.getSimpleName()));
      } else {
        updateBuilder
            .addStatement("throwIfKeyspaceMissing()")
            .addStatement(
                "$1T update = (keyspaceId == null)\n"
                    + "? $2T.update(tableId)\n"
                    + ": $2T.update(keyspaceId, tableId)",
                UpdateStart.class,
                QueryBuilder.class)
            .addCode("$[return (($1T)update", DefaultUpdate.class);
  
        for (PropertyDefinition property : entityDefinition.getRegularColumns()) {
          // we cannot use getAllColumns because update cannot SET for PKs
          updateBuilder.addCode(
              "\n.setColumn($1L, $2T.bindMarker($1L))", property.getCqlName(), QueryBuilder.class);
        }
        updateBuilder.addCode(")");
        updateBuilder.addCode("$];\n");
      }
      return Optional.of(updateBuilder.build());
    }
  }
  