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.core.metadata.schema.parsing;
  
  import com.datastax.oss.driver.api.core.CqlIdentifier;
  import com.datastax.oss.driver.api.core.metadata.schema.FunctionMetadata;
  import com.datastax.oss.driver.api.core.metadata.schema.FunctionSignature;
  import com.datastax.oss.driver.api.core.type.DataType;
  import com.datastax.oss.driver.api.core.type.UserDefinedType;
  import com.datastax.oss.driver.internal.core.adminrequest.AdminRow;
  import com.datastax.oss.driver.internal.core.context.InternalDriverContext;
  import com.datastax.oss.driver.internal.core.metadata.schema.DefaultFunctionMetadata;
  import com.datastax.oss.driver.shaded.guava.common.collect.ImmutableList;
  import com.datastax.oss.driver.shaded.guava.common.collect.Lists;
  import java.util.List;
  import java.util.Map;
  import net.jcip.annotations.ThreadSafe;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  @ThreadSafe
  public class FunctionParser {
  
    private static final Logger LOG = LoggerFactory.getLogger(FunctionParser.class);
  
    private final DataTypeParser dataTypeParser;
    private final InternalDriverContext context;
    private final String logPrefix;
  
    public FunctionParser(DataTypeParser dataTypeParser, InternalDriverContext context) {
      this.dataTypeParser = dataTypeParser;
      this.context = context;
      this.logPrefix = context.getSessionName();
    }
  
    public FunctionMetadata parseFunction(
        AdminRow row,
        CqlIdentifier keyspaceId,
        Map<CqlIdentifier, UserDefinedType> userDefinedTypes) {
      // Cassandra < 3.0:
      // CREATE TABLE system.schema_functions (
      //     keyspace_name text,
      //     function_name text,
      //     signature frozen<list<text>>,
      //     argument_names list<text>,
      //     argument_types list<text>,
      //     body text,
      //     called_on_null_input boolean,
      //     language text,
      //     return_type text,
      //     PRIMARY KEY (keyspace_name, function_name, signature)
      // ) WITH CLUSTERING ORDER BY (function_name ASC, signature ASC)
      //
      // Cassandra >= 3.0:
      // CREATE TABLE system_schema.functions (
      //     keyspace_name text,
      //     function_name text,
      //     argument_names frozen<list<text>>,
      //     argument_types frozen<list<text>>,
      //     body text,
      //     called_on_null_input boolean,
      //     language text,
      //     return_type text,
      //     PRIMARY KEY (keyspace_name, function_name, argument_types)
      // ) WITH CLUSTERING ORDER BY (function_name ASC, argument_types ASC)
      String simpleName = row.getString("function_name");
      List<CqlIdentifier> argumentNames =
          ImmutableList.copyOf(
              Lists.transform(row.getListOfString("argument_names"), CqlIdentifier::fromInternal));
      List<String> argumentTypes = row.getListOfString("argument_types");
      if (argumentNames.size() != argumentTypes.size()) {
        LOG.warn(
            "[{}] Error parsing system row for function {}.{}, "
                + "number of argument names and types don't match (got {} and {}).",
            logPrefix,
            keyspaceId.asInternal(),
            simpleName,
            argumentNames.size(),
            argumentTypes.size());
        return null;
      }
      FunctionSignature signature =
          new FunctionSignature(
              CqlIdentifier.fromInternal(simpleName),
              dataTypeParser.parse(keyspaceId, argumentTypes, userDefinedTypes, context));
      String body = row.getString("body");
      Boolean calledOnNullInput = row.getBoolean("called_on_null_input");
      String language = row.getString("language");
      DataType returnType =
          dataTypeParser.parse(keyspaceId, row.getString("return_type"), userDefinedTypes, context);
  
      return new DefaultFunctionMetadata(
          keyspaceId, signature, argumentNames, body, calledOnNullInput, language, returnType);
    }
  }
  