/*
 * 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.api.querybuilder.schema;

import com.datastax.oss.driver.api.core.CqlIdentifier;
import com.datastax.oss.driver.api.core.type.DataType;
import com.datastax.oss.driver.api.core.type.DataTypes;
import com.datastax.oss.driver.api.querybuilder.SchemaBuilder;
import edu.umd.cs.findbugs.annotations.NonNull;

public interface CreateFunctionStart {

  /**
   * Adds IF NOT EXISTS to the create function specification. This indicates that the function
   * should not be created if it already exists.
   */
  @NonNull
  CreateFunctionStart ifNotExists();

  /**
   * Adds OR REPLACE to the create function specification. This indicates that the function should
   * replace an existing function with the same name if it exists.
   */
  @NonNull
  CreateFunctionStart orReplace();

  /**
   * Adds a parameter definition in the CREATE FUNCTION statement.
   *
   * <p>Parameter keys are added in the order of their declaration.
   *
   * <p>To create the data type, use the constants and static methods in {@link DataTypes}, or
   * {@link SchemaBuilder#udt(CqlIdentifier, boolean)}.
   */
  @NonNull
  CreateFunctionStart withParameter(@NonNull CqlIdentifier paramName, @NonNull DataType paramType);

  /**
   * Shortcut for {@link #withParameter(CqlIdentifier, DataType)
   * withParameter(CqlIdentifier.asCql(paramName), dataType)}.
   */
  @NonNull
  default CreateFunctionStart withParameter(
      @NonNull String paramName, @NonNull DataType paramType) {
    return withParameter(CqlIdentifier.fromCql(paramName), paramType);
  }

  /**
   * Adds RETURNS NULL ON NULL to the create function specification. This indicates that the body of
   * the function should be skipped when null input is provided.
   */
  @NonNull
  CreateFunctionWithNullOption returnsNullOnNull();

  /**
   * Adds CALLED ON NULL to the create function specification. This indicates that the body of the
   * function not be skipped when null input is provided.
   */
  @NonNull
  CreateFunctionWithNullOption calledOnNull();
}
