/*******************************************************************************
 * Copyright (c) 2008 Innoopract Informationssysteme GmbH.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Innoopract Informationssysteme GmbH - initial API and implementation
 ******************************************************************************/

package org.eclipse.rwt.internal.theme.css;

import java.io.IOException;
import java.io.InputStream;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;

import org.w3c.css.sac.*;


public class CssFileReader {

  private static final String CSS_ENCODING = "UTF-8";

  private List problems;

  private Parser parser;

  /* BEGIN Modification for Theme Editor */
  private List errors;
  private List warnings;
  private String uri;
  /* END Modification for Theme Editor */

  public CssFileReader() {
    try {
      parser = new org.apache.batik.css.parser.Parser();
    } catch( Exception e ) {
      throw new RuntimeException( "Failed to instantiate CSS parser", e );
    }
    problems = new ArrayList();
    /* BEGIN Modification for Theme Editor */
    errors = new ArrayList();
    warnings = new ArrayList();
    /* END Modification for Theme Editor */
  }

  public StyleSheet parse( final InputStream inputStream, final String uri )
    throws CSSException, IOException
  {
    /* BEGIN Modification for Theme Editor */
    this.uri = uri;
    /* END Modification for Theme Editor */
    InputSource source = new InputSource();
    source.setByteStream( inputStream );
    source.setEncoding( CSS_ENCODING );
    source.setURI( uri );
    parser.setConditionFactory( new ConditionFactoryImpl( this ) );
    parser.setSelectorFactory( new SelectorFactoryImpl( this ) );
    DocumentHandlerImpl documentHandler = new DocumentHandlerImpl( this );
    parser.setDocumentHandler( documentHandler );
    parser.setErrorHandler( new ErrorHandlerImpl( this ) );
    parser.parseStyleSheet( source );
    StyleRule[] styleRules = documentHandler.getStyleRules();
    StyleSheet result = new StyleSheet( styleRules );
    /* BEGIN Modification for Theme Editor */
    result.setHeaderComment( documentHandler.getHeaderComment() );
    /* END Modification for Theme Editor */
    return result;
  }

  public CSSException[] getProblems() {
    CSSException[] result = new CSSException[ problems.size() ];
    problems.toArray( result );
    return result;
  }

  void addProblem( final CSSException exception ) {
//    TODO [rst] Logging instead of sysout
    System.err.println( exception );
    problems.add( exception );
  /* BEGIN Modification for Theme Editor */
    if( exception instanceof CSSParseException ) {
      addWarning( ( CSSParseException )exception );
    } else if( parser instanceof org.apache.batik.css.parser.Parser ) {
      CSSParseException parseException = new CSSParseException( exception.getMessage(),
                                                                uri,
                                                                getCurrentLine(),
                                                                0 );
      addWarning( parseException );
    }
  /* END Modification for Theme Editor */
  }

  public CSSParseException[] getErrors() {
    CSSParseException[] result = new CSSParseException[ errors.size() ];
    errors.toArray( result );
    return result;
  }

  public CSSParseException[] getWarnings() {
    CSSParseException[] result = new CSSParseException[ warnings.size() ];
    warnings.toArray( result );
    return result;
  }

  private void addError( final CSSParseException exception ) {
    errors.add( exception );
  }

  private void addWarning( final CSSParseException exception ) {
    warnings.add( exception );
  }

  public int getCurrentLine() {
    int result = -1;
    if( parser instanceof org.apache.batik.css.parser.Parser ) {
      //result = ( ( org.apache.batik.css.parser.Parser )parser ).getLine();
    }
    return result;
  }
  /* END Modification for Theme Editor */


  private static String createProblemDescription( final String type,
                                                  final CSSParseException exception )
  {
    String pattern = "{0}: {1} in {2} at pos [{3}:{4}]";
    Object[] arguments = new Object[] {
      type,
      exception.getMessage(),
      exception.getURI(),
      String.valueOf( exception.getLineNumber() ),
      String.valueOf( exception.getColumnNumber() )
    };
    return MessageFormat.format( pattern, arguments );
  }

  private static class ErrorHandlerImpl implements ErrorHandler {

//    private final List problems;
    private final CssFileReader reader;

    public ErrorHandlerImpl( final CssFileReader reader ) {
//      this.problems = reader.problems;
      this.reader = reader;
    }

    // TODO [rst] decent logging instead of sysout
    public void warning( final CSSParseException exception ) throws CSSException {
//      String problem = createProblemDescription( "WARNING: ", exception );
//      System.err.println( problem );
//      problems.add( exception );
      reader.addWarning( exception );
    }

    public void error( final CSSParseException exception ) throws CSSException {
//      String problem = createProblemDescription( "ERROR: ", exception );
//      System.err.println( problem );
//      problems.add( exception );
      reader.addError( exception );
    }

    public void fatalError( final CSSParseException exception ) throws CSSException {
//      String problem = createProblemDescription( "FATAL ERROR: ", exception );
//      System.err.println( problem );
//      problems.add( exception );
      reader.addError( exception );
      throw exception;
    }
  }
}