/*

     StatCvs - CVS statistics generation 

     Copyright (C) 2002  Lukasz Pekacki <lukasz@pekacki.de>

     http://statcvs.sf.net/

     This library is free software; you can redistribute it and/or

     modify it under the terms of the GNU Lesser General Public

     License as published by the Free Software Foundation; either

     version 2.1 of the License, or (at your option) any later version.

     This library 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

     Lesser General Public License for more details.

     You should have received a copy of the GNU Lesser General Public

     License along with this library; if not, write to the Free Software

     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

         $RCSfile: CvsLogfileParser.java,v $ 

         Created on $Date: 2008/04/02 11:22:15 $ 

 */

 package net.sf.statcvs.input;

 import java.io.IOException;

 import java.io.Reader;

 import java.util.logging.Logger;

 import net.sf.statcvs.util.LookaheadReader;

 /**

  * Parses a CVS logfile. A {@link Builder} must be specified which does

  * the construction work.

  * 

  * @author Anja Jentzsch

  * @author Richard Cyganiak

  * @version $Id: CvsLogfileParser.java,v 1.17 2008/04/02 11:22:15 benoitx Exp $

  */

 public class CvsLogfileParser {

     private static Logger logger = Logger.getLogger(CvsLogfileParser.class.getName());

     private final LookaheadReader logReader;

     private final CvsLogBuilder builder;

     /**

      * Default Constructor

      * @param logReader a <tt>Reader</tt> containing the CVS logfile

      * @param builder the builder that will process the log information

      */

     public CvsLogfileParser(final Reader logReader, final CvsLogBuilder builder) {

         this.logReader = new LookaheadReader(logReader);

         this.builder = builder;

     }

     /**

      * Parses the logfile. After <tt>parse()</tt> has finished, the result

      * of the parsing process can be obtained from the builder.

      * @throws LogSyntaxException if syntax errors in log

      * @throws IOException if errors while reading from the log Reader

      */

     public void parse() throws LogSyntaxException, IOException {

         final long startTime = System.currentTimeMillis();

         logger.fine("starting to parse...");

         eatNonCheckedInFileLines();

         if (!this.logReader.hasNextLine()) {

             return;

         }

         if (!"".equals(this.logReader.getCurrentLine())) {

             throw new LogSyntaxException("Expected '?' or empty line at line " + this.logReader.getLineNumber() + ", but found '"

                     + this.logReader.getCurrentLine() + "'");

         }

         eatEmptyLines();

         //                TODO: uncomment when tag/branch reports are added 

         //                boolean isLogWithoutSymbolicNames = false;

         boolean isFirstFile = true;

         do {

             final CvsFileBlockParser parser = new CvsFileBlockParser(this.logReader, this.builder, isFirstFile);

             parser.parse();

             isFirstFile = false;

             //                        if (parser.isLogWithoutSymbolicNames()) {

             //                                isLogWithoutSymbolicNames = true;

             //                        }

             eatEmptyLines();

         } while (this.logReader.hasNextLine());

         //                if (isLogWithoutSymbolicNames) {

         //                        logger.warning("Log was created with '-N' switch of 'cvs log', some reports will be missing!");

         //                }

         logger.fine("parsing finished in " + (System.currentTimeMillis() - startTime) + " ms.");

     }

     private void eatNonCheckedInFileLines() throws IOException {

         while (this.logReader.hasNextLine() && this.logReader.nextLine().startsWith("? ")) {

             // ignore lines starting with "? "

         }

     }

     /**

      * Calls nextLine() on the reader until EOF or a non-empty line

      * is found

      */

     private void eatEmptyLines() throws IOException {

         while (this.logReader.hasNextLine() && "".equals(this.logReader.nextLine())) {

             // ignore empty lines

         }

     }

 }