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
   * <p/>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p/>
   * 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.flink.streaming.siddhi.schema;
  
  import org.apache.flink.api.common.typeinfo.AtomicType;
  import org.apache.flink.api.common.typeinfo.TypeInformation;
  import org.apache.flink.api.common.typeutils.CompositeType;
  import org.apache.flink.api.common.typeutils.TypeSerializer;
  import org.apache.flink.api.java.typeutils.PojoTypeInfo;
  import org.apache.flink.api.java.typeutils.TupleTypeInfo;
  import org.apache.flink.api.scala.typeutils.CaseClassTypeInfo;
  import org.apache.flink.util.Preconditions;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.Serializable;
  
  /**
   * Generic Field-based Stream Schema
   *
   * @param <T> Stream element type
   */
  public class StreamSchema<T> implements Serializable {
      private static final Logger LOGGER = LoggerFactory.getLogger(StreamSchema.class);
      private final TypeInformation<T> typeInfo;
      private final int[] fieldIndexes;
      private final String[] fieldNames;
      private TypeInformation[] fieldTypes;
      private final StreamSerializer<T> streamSerializer;
      private TypeSerializer<T> typeSerializer;
  
      public StreamSchema(TypeInformation<T> typeInfo, String... fieldNames) {
          Preconditions.checkNotNull(fieldNames, "Field name is required");
          this.typeInfo = typeInfo;
          this.fieldNames = fieldNames;
          this.fieldIndexes = getFieldIndexes(typeInfo, fieldNames);
          this.fieldTypes = getFieldTypes(typeInfo, fieldIndexes, fieldNames);
          this.streamSerializer = new StreamSerializer<>(this);
      }
  
      public StreamSchema(TypeInformation<T> typeInfo, int[] fieldIndexes, String[] fieldNames) {
          this.typeInfo = typeInfo;
          this.fieldIndexes = fieldIndexes;
          this.fieldNames = fieldNames;
          this.fieldTypes = getFieldTypes(typeInfo, fieldIndexes, fieldNames);
          this.streamSerializer = new StreamSerializer<>(this);
      }
  
      public boolean isAtomicType() {
          return typeInfo instanceof AtomicType;
      }
  
      public boolean isTupleType() {
          return typeInfo instanceof TupleTypeInfo;
      }
  
      public boolean isPojoType() {
          return typeInfo instanceof PojoTypeInfo;
      }
  
      public boolean isCaseClassType() {
          return typeInfo instanceof CaseClassTypeInfo;
      }
  
      public boolean isCompositeType() {
          return typeInfo instanceof CompositeType;
      }
  
      private <E> int[] getFieldIndexes(TypeInformation<E> typeInfo, String... fieldNames) {
          int[] result;
          if (isAtomicType()) {
              result = new int[]{0};
          } else if (isTupleType()) {
              result = new int[fieldNames.length];
              for (int i = 0; i < fieldNames.length; i++) {
                  result[i] = i;
              }
          } else if (isPojoType()) {
              result = new int[fieldNames.length];
              for (int i = 0; i < fieldNames.length; i++) {
                  int index = ((PojoTypeInfo) typeInfo).getFieldIndex(fieldNames[i]);
                  if (index < 0) {
                      throw new IllegalArgumentException(fieldNames[i] + " is not a field of type " + typeInfo);
                  }
                  result[i] = index;
              }
          } else if (isCaseClassType()) {
              result = new int[fieldNames.length];
              for (int i = 0; i < fieldNames.length; i++) {
                  int index = ((CaseClassTypeInfo) typeInfo).getFieldIndex(fieldNames[i]);
                  if (index < 0) {
                      throw new IllegalArgumentException(fieldNames[i] + " is not a field of type " + typeInfo);
                  }
                  result[i] = index;
              }
          } else {
              throw new IllegalArgumentException("Failed to get field index from " + typeInfo);
          }
          return result;
      }
  
  
      private <E> TypeInformation[] getFieldTypes(TypeInformation<E> typeInfo, int[] fieldIndexes, String[] fieldNames) {
          TypeInformation[] fieldTypes;
          if (isCompositeType()) {
              CompositeType cType = (CompositeType) typeInfo;
              if (fieldNames.length != cType.getArity()) {
                  // throw new IllegalArgumentException("Arity of type (" + cType.getFieldNames().length+ ") " +
                  // "not equal to number of field names " + fieldNames.length + ".");
                  LOGGER.warn("Arity of type (" + cType.getFieldNames().length + ") " +
                      "not equal to number of field names " + fieldNames.length + ".");
              }
              fieldTypes = new TypeInformation[fieldIndexes.length];
              for (int i = 0; i < fieldIndexes.length; i++) {
                  fieldTypes[i] = cType.getTypeAt(fieldIndexes[i]);
              }
          } else if (isAtomicType()) {
              if (fieldIndexes.length != 1 || fieldIndexes[0] != 0) {
                  throw new IllegalArgumentException(
                      "Non-composite input type may have only a single field and its index must be 0.");
              }
              fieldTypes = new TypeInformation[]{typeInfo};
          } else {
              throw new IllegalArgumentException(
                  "Illegal input type info"
              );
          }
          return fieldTypes;
      }
  
      public TypeInformation<T> getTypeInfo() {
          return typeInfo;
      }
  
      public int[] getFieldIndexes() {
          return fieldIndexes;
      }
  
      public String[] getFieldNames() {
          return fieldNames;
      }
  
      public TypeInformation[] getFieldTypes() {
          return fieldTypes;
      }
  
      public StreamSerializer<T> getStreamSerializer() {
          return streamSerializer;
      }
  
      public TypeSerializer<T> getTypeSerializer() {
          return typeSerializer;
      }
  
      public void setTypeSerializer(TypeSerializer<T> typeSerializer) {
          this.typeSerializer = typeSerializer;
      }
  }
  