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.asterix.runtime.evaluators.functions;
  
  import static org.apache.asterix.om.types.EnumDeserializer.ATYPETAGDESERIALIZER;
  
  import org.apache.asterix.dataflow.data.nontagged.serde.AOrderedListSerializerDeserializer;
  import org.apache.asterix.dataflow.data.nontagged.serde.AUnorderedListSerializerDeserializer;
  import org.apache.asterix.om.functions.BuiltinFunctions;
  import org.apache.asterix.om.functions.IFunctionDescriptorFactory;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.IAType;
  import org.apache.asterix.om.types.hierachy.ATypeHierarchy;
  import org.apache.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
  import org.apache.asterix.runtime.functions.FunctionTypeInferers;
  import org.apache.asterix.runtime.utils.DescriptorFactoryUtil;
  import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory;
  import org.apache.hyracks.api.context.IEvaluatorContext;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.data.std.api.IPointable;
  import org.apache.hyracks.data.std.primitive.TaggedValuePointable;
  import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
  
  /**
   * <pre>
   * array_insert(list, pos, val1, val2, ...) returns a new list with all values inserted at the specified position.
   * Values can be null (i.e., one can insert nulls). Position can be negative where the last position = -1. When position
   * is positive then the first position = 0. Input list can be empty where the only valid position is 0.
   * For the list [5,6], the valid positions are 0, 1, 2, -1, -2. If position is floating-point, it's casted to integer.
   *
   * It throws an error at compile time if the number of arguments < 3
   *
   * It returns in order:
   * 1. missing, if any argument is missing.
   * 2. null, if
   * - the list arg is null or it's not a list
   * - the position is not numeric or the position is out of bound or it's a floating-point with decimals or NaN or +-INF.
   * 3. otherwise, a new list.
   *
   * </pre>
   */
  public class ArrayInsertDescriptor extends AbstractScalarFunctionDynamicDescriptor {
      private static final long serialVersionUID = 1L;
      private IAType[] argTypes;
  
      public static final IFunctionDescriptorFactory FACTORY =
              DescriptorFactoryUtil.createFactory(ArrayInsertDescriptor::new, FunctionTypeInferers.SET_ARGUMENTS_TYPE);
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.ARRAY_INSERT;
      }
  
      @Override
      public IScalarEvaluatorFactory createEvaluatorFactory(final IScalarEvaluatorFactory[] args)
              throws AlgebricksException {
          return new IScalarEvaluatorFactory() {
              private static final long serialVersionUID = 1L;
  
              @Override
              public IScalarEvaluator createScalarEvaluator(final IEvaluatorContext ctx) throws HyracksDataException {
                  return new ArrayInsertEval(args, ctx);
              }
          };
      }
  
      @Override
      public void setImmutableStates(Object... states) {
          argTypes = (IAType[]) states;
      }
  
      public class ArrayInsertEval extends AbstractArrayAddRemoveEval {
          private final TaggedValuePointable positionArg;
          private final IScalarEvaluator positionArgEval;
  
          ArrayInsertEval(IScalarEvaluatorFactory[] args, IEvaluatorContext ctx) throws HyracksDataException {
              super(args, ctx, 0, 2, args.length - 2, argTypes, true, true);
              positionArg = new TaggedValuePointable();
              positionArgEval = args[1].createScalarEvaluator(ctx);
          }
  
          @Override
          protected int getPosition(IFrameTupleReference tuple, IPointable l, ATypeTag listTag)
                  throws HyracksDataException {
              // TODO(ali): could be optimized to evaluate only once if we know the argument is a constant
              positionArgEval.evaluate(tuple, positionArg);
              if (positionArg.getTag() == ATypeTag.SERIALIZED_MISSING_TYPE_TAG) {
                  return RETURN_MISSING;
              }
  
              double position;
              if (!ATypeHierarchy.isCompatible(ATypeTag.DOUBLE, ATYPETAGDESERIALIZER.deserialize(positionArg.getTag()))
                      || !listTag.isListType()) {
                  return RETURN_NULL;
              } else {
                  String name = getIdentifier().getName();
                  position = ATypeHierarchy.getDoubleValue(name, 1, positionArg.getByteArray(),
                          positionArg.getStartOffset());
                  if (Double.isNaN(position) || Double.isInfinite(position) || Math.floor(position) < position) {
                      return RETURN_NULL;
                  }
                  // list size
                  int size;
                  if (listTag == ATypeTag.ARRAY) {
                      size = AOrderedListSerializerDeserializer.getNumberOfItems(l.getByteArray(), l.getStartOffset());
                  } else {
                      size = AUnorderedListSerializerDeserializer.getNumberOfItems(l.getByteArray(), l.getStartOffset());
                  }
                  // adjust position for negative positions
                  if (position < 0) {
                      position = size + position;
                  }
                  // position should always be positive now and should be within [0-list_size]
                  if (position < 0 || position > size) {
                      return RETURN_NULL;
                  }
                  return (int) position;
              }
          }
      }
  }
  