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 org.apache.cassandra.cql3.functions;
  
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  import java.util.function.Supplier;
  
  import com.google.common.base.Suppliers;
  
  import org.apache.cassandra.cql3.functions.types.DataType;
  import org.apache.cassandra.cql3.functions.types.TupleType;
  import org.apache.cassandra.cql3.functions.types.TupleValue;
  import org.apache.cassandra.cql3.functions.types.UDTValue;
  import org.apache.cassandra.cql3.functions.types.UserType;
  
  import org.apache.cassandra.cql3.ColumnIdentifier;
  import org.apache.cassandra.db.marshal.AbstractType;
  import org.apache.cassandra.schema.CQLTypeParser;
  import org.apache.cassandra.schema.KeyspaceMetadata;
  import org.apache.cassandra.schema.Schema;
  import org.apache.cassandra.utils.ByteBufferUtil;
  import org.apache.cassandra.utils.JavaDriverUtils;
  
  /**
   * Package private implementation of {@link UDFContext}
   */
  public final class UDFContextImpl implements UDFContext
  {
      private final Map<String, UDFDataType> byName = new HashMap<>();
      private final List<UDFDataType> argTypes;
      private final UDFDataType returnType;
      private final String keyspace;
  
      /*
          metadata can not be retrieved within the constructor as the keyspace itself may be being
          constructed and an NPE will result.
       */
      private final Supplier<KeyspaceMetadata> metadata;
  
      UDFContextImpl(List<ColumnIdentifier> argNames,
                     List<UDFDataType> argTypes,
                     UDFDataType returnType,
                     String keyspace)
      {
          for (int i = 0; i < argNames.size(); i++)
              byName.put(argNames.get(i).toString(), argTypes.get(i));
          this.argTypes = argTypes;
          this.returnType = returnType;
          this.keyspace = keyspace;
          this.metadata = Suppliers.memoize(() -> Schema.instance.getKeyspaceMetadata(keyspace));
      }
  
      public UDTValue newArgUDTValue(String argName)
      {
          return newUDTValue(getArgumentTypeByName(argName).toDataType());
      }
  
      public UDTValue newArgUDTValue(int argNum)
      {
          return newUDTValue(getArgumentTypeByIndex(argNum).toDataType());
      }
  
      public UDTValue newReturnUDTValue()
      {
          return newUDTValue(returnType.toDataType());
      }
  
      public UDTValue newUDTValue(String udtName)
      {
          Optional<org.apache.cassandra.db.marshal.UserType> udtType = metadata.get().types.get(ByteBufferUtil.bytes(udtName));
          DataType dataType = JavaDriverUtils.driverType(udtType.orElseThrow(
                  () -> new IllegalArgumentException("No UDT named " + udtName + " in keyspace " + keyspace)
          ));
          return newUDTValue(dataType);
      }
  
      public TupleValue newArgTupleValue(String argName)
      {
          return newTupleValue(getArgumentTypeByName(argName).toDataType());
      }
  
      public TupleValue newArgTupleValue(int argNum)
      {
          return newTupleValue(getArgumentTypeByIndex(argNum).toDataType());
      }
  
      public TupleValue newReturnTupleValue()
      {
          return newTupleValue(returnType.toDataType());
      }
  
      public TupleValue newTupleValue(String cqlDefinition)
      {
          AbstractType<?> abstractType = CQLTypeParser.parse(keyspace, cqlDefinition, metadata.get().types);
          DataType dataType = JavaDriverUtils.driverType(abstractType);
          return newTupleValue(dataType);
      }
  
      private static UDTValue newUDTValue(DataType dataType)
      {
          if (!(dataType instanceof UserType))
              throw new IllegalStateException("Function argument is not a UDT but a " + dataType.getName());
          UserType userType = (UserType) dataType;
          return userType.newValue();
      }
  
      private static TupleValue newTupleValue(DataType dataType)
      {
          if (!(dataType instanceof TupleType))
              throw new IllegalStateException("Function argument is not a tuple type but a " + dataType.getName());
          TupleType tupleType = (TupleType) dataType;
          return tupleType.newValue();
      }
  
      private UDFDataType getArgumentTypeByIndex(int index)
      {
          if (index < 0 || index >= argTypes.size())
              throw new IllegalArgumentException("Function does not declare an argument with index " + index);
          return argTypes.get(index);
      }
  
      private UDFDataType getArgumentTypeByName(String argName)
      {
          UDFDataType arg = byName.get(argName);
          if (arg == null)
              throw new IllegalArgumentException("Function does not declare an argument named '" + argName + '\'');
          return arg;
      }
  }
  