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.ATypeTag.BIGINT;
  import static org.apache.asterix.om.types.ATypeTag.MISSING;
  import static org.apache.asterix.om.types.ATypeTag.NULL;
  import static org.apache.asterix.om.types.ATypeTag.VALUE_TYPE_MAPPING;
  
  import java.io.DataOutput;
  import java.io.IOException;
  import java.util.Arrays;
  
  import org.apache.asterix.common.annotations.MissingNullInOutFunction;
  import org.apache.asterix.dataflow.data.nontagged.serde.AOrderedListSerializerDeserializer;
  import org.apache.asterix.om.exceptions.ExceptionUtil;
  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.hierachy.ATypeHierarchy;
  import org.apache.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
  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.VoidPointable;
  import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
  import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
  import org.apache.hyracks.util.string.UTF8StringUtil;
  
  @MissingNullInOutFunction
  public class CodePointToStringDescriptor extends AbstractScalarFunctionDynamicDescriptor {
  
      private static final long serialVersionUID = 1L;
      public static final IFunctionDescriptorFactory FACTORY = CodePointToStringDescriptor::new;
  
      @Override
      public IScalarEvaluatorFactory createEvaluatorFactory(final IScalarEvaluatorFactory[] args) {
          return new IScalarEvaluatorFactory() {
  
              private static final long serialVersionUID = 1L;
  
              @Override
              public IScalarEvaluator createScalarEvaluator(IEvaluatorContext ctx) throws HyracksDataException {
                  return new IScalarEvaluator() {
  
                      private final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
                      private final DataOutput out = resultStorage.getDataOutput();
                      private final IScalarEvaluatorFactory listEvalFactory = args[0];
                      private final IPointable inputArgList = new VoidPointable();
                      private final IScalarEvaluator evalList = listEvalFactory.createScalarEvaluator(ctx);
                      private final byte[] currentUTF8 = new byte[6];
                      private final byte[] tempStoreForLength = new byte[5];
                      private final FunctionIdentifier fid = getIdentifier();
                      private final char[] tempCharPair = new char[2];
  
                      @Override
                      public void evaluate(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
                          try {
                              resultStorage.reset();
                              Arrays.fill(tempStoreForLength, (byte) 0);
                              Arrays.fill(currentUTF8, (byte) 0);
                              evalList.evaluate(tuple, inputArgList);
  
                              if (PointableHelper.checkAndSetMissingOrNull(result, inputArgList)) {
                                  return;
                              }
  
                              byte[] serOrderedList = inputArgList.getByteArray();
                              int offset = inputArgList.getStartOffset();
                              if (serOrderedList[offset] != ATypeTag.SERIALIZED_ORDEREDLIST_TYPE_TAG) {
                                  PointableHelper.setNull(result);
                                  ExceptionUtil.warnTypeMismatch(ctx, sourceLoc, fid, serOrderedList[offset], 0,
                                          ATypeTag.ARRAY);
                                  return;
                              }
                              int itemTagPosition = offset + 1;
                              ATypeTag itemTag = VALUE_TYPE_MAPPING[serOrderedList[itemTagPosition]];
                              boolean isItemTagged = itemTag == ATypeTag.ANY;
                              int size = AOrderedListSerializerDeserializer.getNumberOfItems(serOrderedList, offset);
                              // calculate length first
                              int utf_8_len = 0;
                              boolean returnNull = false;
                              ATypeTag invalidTag = null;
                              for (int i = 0; i < size; i++) {
                                  int itemOffset =
                                          AOrderedListSerializerDeserializer.getItemOffset(serOrderedList, offset, i);
                                  if (isItemTagged) {
                                      itemTag = VALUE_TYPE_MAPPING[serOrderedList[itemOffset]];
                                      itemTagPosition = itemOffset;
                                      itemOffset++;
                                  }
                                  if (itemTag == MISSING) {
                                      PointableHelper.setMissing(result);
                                      return;
                                  }
                                  if (itemTag == NULL) {
                                      returnNull = true;
                                      invalidTag = null;
                                  } else if (!returnNull && !ATypeHierarchy.canPromote(itemTag, BIGINT)) {
                                      returnNull = true;
                                      invalidTag = itemTag;
                                  }
                                  if (!returnNull) {
                                      int codePoint = ATypeHierarchy.getIntegerValueWithDifferentTypeTagPosition(
                                              fid.getName(), 0, serOrderedList, itemOffset, itemTagPosition);
                                      utf_8_len += UTF8StringUtil.codePointToUTF8(codePoint, tempCharPair, currentUTF8);
                                  }
                              }
                              if (returnNull) {
                                  PointableHelper.setNull(result);
                                  if (invalidTag != null) {
                                      ExceptionUtil.warnUnsupportedType(ctx, sourceLoc, fid.getName(), invalidTag);
                                  }
                                  return;
                              }
                              out.writeByte(ATypeTag.SERIALIZED_STRING_TYPE_TAG);
                              UTF8StringUtil.writeUTF8Length(utf_8_len, tempStoreForLength, out);
                              for (int i = 0; i < size; i++) {
                                  int itemOffset =
                                          AOrderedListSerializerDeserializer.getItemOffset(serOrderedList, offset, i);
                                  if (isItemTagged) {
                                      itemTagPosition = itemOffset;
                                      itemOffset++;
                                  }
                                  int codePoint = ATypeHierarchy.getIntegerValueWithDifferentTypeTagPosition(
                                          fid.getName(), 0, serOrderedList, itemOffset, itemTagPosition);
                                  utf_8_len = UTF8StringUtil.codePointToUTF8(codePoint, tempCharPair, currentUTF8);
                                  for (int j = 0; j < utf_8_len; j++) {
                                      out.writeByte(currentUTF8[j]);
                                  }
                              }
                              result.set(resultStorage);
                          } catch (IOException e) {
                              throw HyracksDataException.create(e);
                          }
                      }
                  };
              }
          };
      }
  
      @Override
      public FunctionIdentifier getIdentifier() {
          return BuiltinFunctions.CODEPOINT_TO_STRING;
      }
  }
  