/*

  * $Source$

  * $Revision$

  *

  * Copyright (C) 2001 Myles Chippendale

  *

  * Part of Melati (http://melati.org), a framework for the rapid

  * development of clean, maintainable web applications.

  *

  * Melati is free software; Permission is granted to copy, distribute

  * and/or modify this software under the terms either:

  *

  * a) the GNU General Public License as published by the Free Software

  *    Foundation; either version 2 of the License, or (at your option)

  *    any later version,

  *

  *    or

  *

  * b) any version of the Melati Software License, as published

  *    at http://melati.org

  *

  * You should have received a copy of the GNU General Public License and

  * the Melati Software License along with this program;

  * if not, write to the Free Software Foundation, Inc.,

  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the

  * GNU General Public License and visit http://melati.org to obtain the

  * Melati Software License.

  *

  * Feel free to contact the Developers of Melati (http://melati.org),

  * if you would like to work out a different arrangement than the options

  * outlined here.  It is our intention to allow Melati to be used by as

  * wide an audience as possible.

  *

  * This program 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.

  *

  * Contact details for copyright holder:

  *

  *     Myles Chippendale <mylesc@paneris.org>

  */

 package org.melati.poem.csv;

 import java.util.Vector;

 import java.io.File;

 import java.io.Writer;

 import java.io.IOException;

 import org.melati.poem.Database;

 import org.melati.poem.PoemBugPoemException;

 import org.melati.poem.PoemThread;

 import org.melati.poem.Table;

 /**

  * A class to define a sequence of {@link CSVTable}s and process them by

  * parsing the files and writing the data to the database.

  * 

  * @author MylesC AT paneris.org

  *  

  */

 public class CSVFilesProcessor {

   protected Vector<CSVTable> tables = new Vector<CSVTable>();

   Database db = null;

   /**

    * Constructor.

    * 

    * @param db the target database

    */

   public CSVFilesProcessor(Database db) {

     this.db = db;

   }

   /**

    * Convenience method.

    * 

    * @param tablename the name of a POEM table

    * @param file a CSV file, with first line containing field names

    * @return a new CSVTable

    */

   public CSVTable addTable(String tablename, File file) {

     return addTable(db.getTable(tablename), file);

   }

   /**

    * Add a table to this processor.

    * 

    * @param tab a POEM table

    * @param file a CSV file, with first line containing field names

    * @return a new CSVTable

    */

   public CSVTable addTable(Table<?> tab, File file) {

     if (!file.exists())

       throw new RuntimeException("File not found: " + file.getPath());

     CSVTable table = new CSVTable(tab, file);

     tables.addElement(table);

     return table;

   }

   /**

    * Load all the data from the files, empty the tables if necessary and then

    * write the new data into the tables.

    * <p>

    * Write a report of the progress to the Writer.

    * 

    * @param writeOnFly flag whether to write down to db when all files read in

    *          if set then it is the programmers responsibility to ensure that

    *          there are no references to yet to be created fields

    * @param emptyTables flag whether to remove remains from last run

    * @param recordDetails flag passed in to table.report

    * @param fieldDetails flag passed in to table.report

    * @param output to write report to

    * @throws IOException if file stuff goes wrong

    * @throws CSVParseException if csv file has an error

    * @throws NoPrimaryKeyInCSVTableException not thrown

    * @throws CSVWriteDownException thrown when a persistent cannot be created

    */

   public void process(boolean writeOnFly, boolean emptyTables,

       boolean recordDetails, boolean fieldDetails, Writer output)

       throws IOException, CSVParseException, NoPrimaryKeyInCSVTableException,

       CSVWriteDownException {

     output.write("Trying to get exclusive lock on the database\n");

     db.beginExclusiveLock();

     output.write("Got exclusive lock on the database!!!\n");

     // Delete all records from the tables, if necessary

     if (emptyTables) {

       for (int i = 0; i < tables.size(); i++) {

         CSVTable t = (CSVTable) tables.elementAt(i);

         t.emptyTable();

         output.write("Emptied table :" + t.getName() + "\n");

         System.err.println("Emptied table :" + t.getName());

       }

       PoemThread.writeDown();

     }

     // Load in data

     for (int i = 0; i < tables.size(); i++) {

       CSVTable t = ((CSVTable) tables.elementAt(i));

       t.load(writeOnFly);

       output.write("Loaded table :" + t.getName() + "\n");

       System.err.println("Loaded table :" + t.getName());

     }

     // We must have loaded in all the data before we

     // try writing records, otherwise Foreign Key lookups

     // defined in this set of CSVs won't work

     if (!writeOnFly) {

       writeData(output);

       output.write("Written records\n");

     }

     db.endExclusiveLock();

     output.write("Ended exclusive lock on the database!!!\n");

     output.write("***** REPORT ******\n");

     // Write a report about how many records are in each table

     for (int i = 0; i < tables.size(); i++)

       ((CSVTable) tables.elementAt(i)).report(recordDetails, fieldDetails,

           output);

   }

   /**

    * With write on the fly false.

    * <p>

    * Load all the data from the files, empty the tables if necessary and then

    * write the new data into the tables.

    * <p>

    * Write a report of the progress to the Writer.

    * 

    * @param emptyTables flag whether to remove remains from last run

    * @param recordDetails flag passed in to table.report

    * @param fieldDetails flag passed in to table.report

    * @param output to write report to

    * @throws IOException if file stuff goes wrong

    * @throws CSVParseException if csv file has an error

    * @throws NoPrimaryKeyInCSVTableException not thrown

    * @throws CSVWriteDownException thrown when a persistent cannot be created

    */

   public void process(boolean emptyTables, boolean recordDetails,

                       boolean fieldDetails, Writer output) 

       throws IOException,

       CSVParseException, NoPrimaryKeyInCSVTableException, CSVWriteDownException {

     process(false, emptyTables, recordDetails, fieldDetails, output);

   }

   /**

    * @param o output log to write to

    * @throws NoPrimaryKeyInCSVTableException

    * @throws CSVWriteDownException

    */

   protected void writeData(Writer o) throws NoPrimaryKeyInCSVTableException,

       CSVWriteDownException {

     for (int i = 0; i < tables.size(); i++) {

       CSVTable t = (CSVTable) tables.elementAt(i);

       try {

         o.write("Writing " + t.getName() + ".\n");

       } catch (IOException e) {

         throw new PoemBugPoemException("Problem writing log", e);

       }

       t.writeRecords();

     }

   }

 }