/** You may copy this example and use it for any purpose, commercial or otherwise. */

import com.ricebridge.xmlman.XmlSpec;
import com.ricebridge.xmlman.RecordSpec;
import com.ricebridge.xmlman.RecordListenerSupport;
import com.ricebridge.xmlman.BeanRecordListener;
import com.ricebridge.xmlman.BadRecord;
import com.ricebridge.data.BeanSpec;

import java.util.*;
import java.io.*;


/** This is a custom RecordListener than can handle streaming data.
 *  It builds on the MultipleBeansRecordListener class, but instead of
 *  storing the data, it creates the HTML directly. Thus, you can use this
 *  class to handle arbitrarily large input files.
 *
 *  To compile this class, you will need to include xmlman.jar
 *  (in the lib folder of the XML Manager distribution) in your CLASSPATH. 
 */
public class StreamingMultipleBeansRecordListener extends MultipleBeansRecordListener {

  // protected instance

  /** This is the PrintWriter for outputing the HTML. */
  protected PrintWriter iPrintWriter = null;

  /** Flag to help create the right HTML table code. */
  protected boolean iLastWasEmployee = false;

  /** Flag to indicate we are on the first record. */
  protected boolean iFirst = true;


  /** Initialise the RecordListener with a PrintWriter. */
  public StreamingMultipleBeansRecordListener( PrintWriter pPrintWriter ) {
    iPrintWriter = pPrintWriter;
  }
  

  /** This method now has no function, as we do not store the Beans. */
  public List getBeans( String pCodeName) {
    return Collections.EMPTY_LIST;
  }



  // protected methods

  /** Start the load process. */
  protected void startProcessImpl() {
    System.out.println( "Using StreamingMultipleBeansRecordListener" );
  }


  /** Handle a data record.
   *    Check the first value and use that as the bean code. Once the bean
   *  is created, it is passed directly to the saveBean method for saving and is not
   *  stored in memory.
   *  @param pRecord       data record fields
   *  @param pRecordNumber number of records of this type seen so far
   */
  protected BadRecord handleRecordImpl( String[] pRecord, long pRecordNumber ) throws Exception {
    String codename = pRecord[0];
    if( iBeanSpecMap.containsKey( codename ) ) {
      BeanSpec bs         = (BeanSpec) iBeanSpecMap.get( codename );
      String[] fieldnames = (String[]) iBeanFieldsMap.get( codename );
      Object   bean       = bs.getBeanClass().newInstance();
    
      for( int fI = 1; fI < fieldnames.length; fI++ ) {
        bs.setStringValue( bean, fieldnames[fI], pRecord[fI], iUseDefault );
      }

      saveBean( bean );

      if( 0 == pRecordNumber % 100 ) {
        long memused = Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();
        System.out.println( codename+" records:"+pRecordNumber+" mem:"+memused );
      }

      return null;
    }
    else {
      return new BadRecord( pRecordNumber, pRecord, "unknown code: "+codename );
    }
  }


  /** End the load process. */
  protected void endProcessImpl() {
    if( !iFirst ) { 
      if( iLastWasEmployee ) {
        MakeTable.outputEndEmployeeTable( iPrintWriter );
      }
      else {
        MakeTable.outputEndProjectTable( iPrintWriter );
      }
    }
  }

  
  /** Save a Java Bean.
   *    Based on the bean type, the correct HTML is output. Note that
   *  cross-referencing is not possible when using the data as a stream.
   *  @param pBean Employee or Project object.
   */
  protected void saveBean( Object pBean ) {
    if( pBean instanceof Project ) {
      if( iLastWasEmployee || iFirst ) {
        if( !iFirst ) { 
          MakeTable.outputEndEmployeeTable( iPrintWriter );
        }
        else {
          iFirst = false;
        }
        MakeTable.outputStartProjectTable( iPrintWriter );
      }
      MakeTable.outputProject( (Project) pBean, null, iPrintWriter );
      iLastWasEmployee = false;
    }
    else if( pBean instanceof Employee ) {
      if( !iLastWasEmployee || iFirst ) {
        if( !iFirst ) { 
          MakeTable.outputEndProjectTable( iPrintWriter );
        }
        else {
          iFirst = false;
        }
        MakeTable.outputStartEmployeeTable( iPrintWriter );
      }
      MakeTable.outputEmployee( (Employee) pBean, null, iPrintWriter );
      iLastWasEmployee = true;
    }
  }

 
}