/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.uima.ruta.ide.ui.documentation;

import org.eclipse.dltk.core.IBuffer;
import org.eclipse.dltk.corext.documentation.SingleCharReader;

public class RutaCommentReader extends SingleCharReader {

  private IBuffer fBuffer;

  private int fCurrPos;

  private int fStartPos;

  private int fEndPos;

  private boolean fWasNewLine;

  public RutaCommentReader(IBuffer buf, int start, int end) {
    fBuffer = buf;
    fStartPos = start;
    fEndPos = end;

    reset();
  }

  @Override
  public int read() {
    if (fCurrPos < fEndPos) {
      char ch;
      if (fWasNewLine) {
        do {
          ch = fBuffer.getChar(fCurrPos++);
        } while (fCurrPos < fEndPos && Character.isWhitespace(ch));
        if (ch == '#') {
          if (fCurrPos < fEndPos) {
            do {
              ch = fBuffer.getChar(fCurrPos++);
            } while (ch == '#');
          } else {
            return -1;
          }
        }
      } else {
        ch = fBuffer.getChar(fCurrPos++);
      }
      fWasNewLine = (ch == '\n' || ch == '\r');

      return ch;
    }
    return -1;
  }

  @Override
  public void close() {
    fBuffer = null;
  }

  @Override
  public void reset() {
    fCurrPos = fStartPos;
    fWasNewLine = true;
  }

  public int getOffset() {
    return fCurrPos;
  }
}
