/*
 * Copyright (c) 2007-2010 Concurrent, Inc. All Rights Reserved.
 *
 * Project and contact information: http://www.cascading.org/
 *
 * This file is part of the Cascading project.
 *
 * Cascading is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Cascading is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Cascading.  If not, see <http://www.gnu.org/licenses/>.
 */

package cascading.operation.text;

import java.beans.ConstructorProperties;

import cascading.flow.FlowProcess;
import cascading.operation.BaseOperation;
import cascading.operation.Function;
import cascading.operation.FunctionCall;
import cascading.tuple.Fields;
import cascading.tuple.Tuple;

/** Class FieldJoiner joins the values in a Tuple with a given delimiter and stuffs the result into a new field. */
public class FieldJoiner extends BaseOperation implements Function
  {
  /** Field FIELD_NAME */
  public static final String FIELD_NAME = "joined";

  /** Field delimiter */
  private String delimiter = "\t";

  /**
   * Constructor FieldJoiner creates a new FieldJoiner instance.
   *
   * @param delimiter of type String
   */
  @ConstructorProperties({"delimiter"})
  public FieldJoiner( String delimiter )
    {
    this( new Fields( FIELD_NAME ) );
    this.delimiter = delimiter;
    }

  /**
   * Constructor FieldJoiner creates a new FieldJoiner instance.
   *
   * @param fieldDeclaration of type Fields
   */
  @ConstructorProperties({"fieldDeclaration"})
  public FieldJoiner( Fields fieldDeclaration )
    {
    super( fieldDeclaration );
    }

  /**
   * Constructor FieldJoiner creates a new FieldJoiner instance.
   *
   * @param fieldDeclaration of type Fields
   * @param delimiter        of type String
   */
  @ConstructorProperties({"fieldDeclaration", "delimiter"})
  public FieldJoiner( Fields fieldDeclaration, String delimiter )
    {
    super( fieldDeclaration );
    this.delimiter = delimiter;
    }

  /**
   * Method getFormat returns the delimiter of this FieldJoiner object.
   *
   * @return the delimiter (type String) of this FieldJoiner object.
   */
  public String getDelimiter()
    {
    return delimiter;
    }

  /** @see Function#operate(cascading.flow.FlowProcess,cascading.operation.FunctionCall) */
  public void operate( FlowProcess flowProcess, FunctionCall functionCall )
    {
    functionCall.getOutputCollector().add( new Tuple( functionCall.getArguments().getTuple().toString( delimiter ) ) );
    }

  @Override
  public boolean equals( Object object )
    {
    if( this == object )
      return true;
    if( !( object instanceof FieldJoiner ) )
      return false;
    if( !super.equals( object ) )
      return false;

    FieldJoiner that = (FieldJoiner) object;

    if( delimiter != null ? !delimiter.equals( that.delimiter ) : that.delimiter != null )
      return false;

    return true;
    }

  @Override
  public int hashCode()
    {
    int result = super.hashCode();
    result = 31 * result + ( delimiter != null ? delimiter.hashCode() : 0 );
    return result;
    }
  }