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.apex.malhar.contrib.parser;
  
  import java.io.IOException;
  import java.util.List;
  import java.util.Map;
  
  import javax.validation.constraints.NotNull;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.supercsv.cellprocessor.ift.CellProcessor;
  import org.supercsv.exception.SuperCsvException;
  import org.supercsv.io.CsvBeanReader;
  import org.supercsv.io.CsvMapReader;
  import org.supercsv.prefs.CsvPreference;
  
  import org.apache.apex.malhar.contrib.parser.DelimitedSchema.Field;
  import org.apache.apex.malhar.lib.parser.Parser;
  import org.apache.apex.malhar.lib.util.KeyValPair;
  import org.apache.apex.malhar.lib.util.ReusableStringReader;
  import org.apache.commons.lang.StringUtils;
  import org.apache.hadoop.classification.InterfaceStability;
  
  import com.google.common.annotations.VisibleForTesting;
  
  import com.datatorrent.api.AutoMetric;
  import com.datatorrent.api.Context.OperatorContext;
  import com.datatorrent.api.DefaultOutputPort;
  import com.datatorrent.netlet.util.DTThrowable;
  
  /**
   * Operator that parses a delimited tuple against a specified schema <br>
   * Schema is specified in a json format as per {@link DelimitedSchema} that
   * contains field information and constraints for each field.<br>
   * Assumption is that each field in the delimited data should map to a simple
   * java type.<br>
   * <br>
   * <b>Properties</b> <br>
   * <b>schema</b>:schema as a string<br>
   * <b>clazz</b>:Pojo class <br>
   * <b>Ports</b> <br>
   * <b>in</b>:input tuple as a byte array. Each tuple represents a record<br>
   * <b>parsedOutput</b>:tuples that are validated against the schema are emitted
   * as Map<String,Object> on this port<br>
   * <b>out</b>:tuples that are validated against the schema are emitted as pojo
   * on this port<br>
   * <b>err</b>:tuples that do not confine to schema are emitted on this port as
   * KeyValPair<String,String><br>
   * Key being the tuple and Val being the reason.
   *
   * @displayName CsvParser
   * @category Parsers
   * @tags csv pojo parser
   * @since 3.2.0
   */
  @InterfaceStability.Evolving
  public class CsvParser extends Parser<byte[], KeyValPair<String, String>>
  {
    /**
     * Map Reader to read delimited records
     */
    private transient CsvMapReader csvMapReader;
    /**
     * Bean Reader to read delimited records
     */
    private transient CsvBeanReader csvBeanReader;
    /**
     * Reader used by csvMapReader and csvBeanReader
     */
    private transient ReusableStringReader csvStringReader;
    /**
     * Contents of the schema.Schema is specified in a json format as per
     * {@link DelimitedSchema}
     */
    @NotNull
    private String schema;
    /**
     * Schema is read into this object to access fields
     */
    private transient DelimitedSchema delimitedParserSchema;
    /**
     * Cell processors are an integral part of reading and writing with Super CSV
     * they automate the data type conversions, and enforce constraints.
     */
    private transient CellProcessor[] processors;
    /**
     * Names of all the fields in the same order of incoming records
     */
    private transient String[] nameMapping;
    /**
     * header-this will be delimiter separated string of field names
     */
    private transient String header;
    /**
     * Reading preferences that are passed through schema
     */
    private transient CsvPreference preference;
  
    /**
     * metric to keep count of number of tuples emitted on {@link #parsedOutput}
     * port
     */
    @AutoMetric
    long parsedOutputCount;
  
    @Override
    public void beginWindow(long windowId)
    {
      super.beginWindow(windowId);
      parsedOutputCount = 0;
    }
  
    @Override
    public void setup(OperatorContext context)
    {
      delimitedParserSchema = new DelimitedSchema(schema);
      preference = new CsvPreference.Builder(delimitedParserSchema.getQuoteChar(),
          delimitedParserSchema.getDelimiterChar(), delimitedParserSchema.getLineDelimiter()).build();
      nameMapping = delimitedParserSchema.getFieldNames().toArray(
          new String[delimitedParserSchema.getFieldNames().size()]);
      header = StringUtils.join(nameMapping, (char)delimitedParserSchema.getDelimiterChar() + "");
      processors = getProcessor(delimitedParserSchema.getFields());
      csvStringReader = new ReusableStringReader();
      csvMapReader = new CsvMapReader(csvStringReader, preference);
      csvBeanReader = new CsvBeanReader(csvStringReader, preference);
    }
  
    @Override
    public Object convert(byte[] tuple)
    {
      throw new UnsupportedOperationException("Not supported");
    }
  
    @Override
    public void processTuple(byte[] tuple)
    {
      if (tuple == null) {
        if (err.isConnected()) {
          err.emit(new KeyValPair<String, String>(null, "Blank/null tuple"));
        }
        errorTupleCount++;
        return;
      }
      String incomingString = new String(tuple);
      if (StringUtils.isBlank(incomingString) || StringUtils.equals(incomingString, header)) {
        if (err.isConnected()) {
          err.emit(new KeyValPair<String, String>(incomingString, "Blank/header tuple"));
        }
        errorTupleCount++;
        return;
      }
      try {
        if (parsedOutput.isConnected()) {
          csvStringReader.open(incomingString);
          Map<String, Object> map = csvMapReader.read(nameMapping, processors);
          parsedOutput.emit(map);
          parsedOutputCount++;
        }
  
        if (out.isConnected() && clazz != null) {
          csvStringReader.open(incomingString);
          Object obj = csvBeanReader.read(clazz, nameMapping, processors);
          out.emit(obj);
          emittedObjectCount++;
        }
  
      } catch (SuperCsvException | IOException | IllegalArgumentException e) {
        if (err.isConnected()) {
          err.emit(new KeyValPair<String, String>(incomingString, e.getMessage()));
        }
        errorTupleCount++;
        logger.error("Tuple could not be parsed. Reason {}", e.getMessage());
      }
    }
  
    @Override
    public KeyValPair<String, String> processErrorTuple(byte[] input)
    {
      throw new UnsupportedOperationException("Not supported");
    }
  
    /**
     * Returns array of cellprocessors, one for each field
     */
    private CellProcessor[] getProcessor(List<Field> fields)
    {
      CellProcessor[] processor = new CellProcessor[fields.size()];
      int fieldCount = 0;
      for (Field field : fields) {
        processor[fieldCount++] = CellProcessorBuilder.getCellProcessor(field.getType(), field.getConstraints());
      }
      return processor;
    }
  
    @Override
    public void teardown()
    {
      try {
        csvMapReader.close();
      } catch (IOException e) {
        logger.error("Error while closing csv map reader {}", e.getMessage());
        DTThrowable.wrapIfChecked(e);
      }
      try {
        csvBeanReader.close();
      } catch (IOException e) {
        logger.error("Error while closing csv bean reader {}", e.getMessage());
        DTThrowable.wrapIfChecked(e);
      }
    }
  
    /**
     * Get the schema
     *
     * @return
     */
    public String getSchema()
    {
      return schema;
    }
  
    /**
     * Set the schema
     *
     * @param schema
     */
    public void setSchema(String schema)
    {
      this.schema = schema;
    }
  
    /**
     * Get errorTupleCount
     *
     * @return errorTupleCount
     */
    @VisibleForTesting
    public long getErrorTupleCount()
    {
      return errorTupleCount;
    }
  
    /**
     * Get emittedObjectCount
     *
     * @return emittedObjectCount
     */
    @VisibleForTesting
    public long getEmittedObjectCount()
    {
      return emittedObjectCount;
    }
  
    /**
     * Get incomingTuplesCount
     *
     * @return incomingTuplesCount
     */
    @VisibleForTesting
    public long getIncomingTuplesCount()
    {
      return incomingTuplesCount;
    }
  
    /**
     * output port to emit validate records as map
     */
    public final transient DefaultOutputPort<Map<String, Object>> parsedOutput = new DefaultOutputPort<Map<String, Object>>();
    private static final Logger logger = LoggerFactory.getLogger(CsvParser.class);
  
  }
  