/*
 * Copyright (C) 2003-2007 eXo Platform SAS.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see<http://www.gnu.org/licenses/>.
 */
package org.exoplatform.services.document.impl;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import org.exoplatform.container.xml.InitParams;
import org.exoplatform.container.xml.ValuesParam;
import org.exoplatform.services.document.DocumentReadException;

/**
 * Created by The eXo Platform SAS A reader of text files.
 * 
 * @author <a href="mailto:zagrebin_v@mail.ru">Victor Zagrebin</a>
 * @version March 04, 2006
 */
public class TextPlainDocumentReader extends BaseDocumentReader {

  public static final String DEFAULT_ENCODING = "defaultEncoding";

  private String             defaultEncoding;

  /**
   * Initializes a newly created object for text/plain files format parsing.
   * 
   * @param params the container parameters.
   */
  public TextPlainDocumentReader(InitParams params) {

    ValuesParam encoding = (ValuesParam) params.getParameter(DEFAULT_ENCODING);

    if (encoding != null && encoding.getValue() != null
        && !encoding.getValue().equalsIgnoreCase("")) {
      defaultEncoding = encoding.getValue();
    } else {
      defaultEncoding = null;
    }
  }

  /**
   * Get the text/plain mime type.
   * 
   * @return The text/plain mime type.
   */
  public String[] getMimeTypes() {
    return new String[] { "text/plain" };
  }

  /**
   * Returns a text from file content.
   * 
   * @param is an input stream with a file content.
   * @return The string with text from file content.
   */
  public String getContentAsText(InputStream is) throws IOException, DocumentReadException {
    if (this.defaultEncoding != null) {
      return getContentAsText(is, defaultEncoding);
    } else {
      return getContentAsText(is, null); // system encoding will be used
    }
  }

  /**
   * Returns a text from file content. If encoding parameter is null - system
   * encoding will be used.
   * 
   * @param is an input stream with a file content.
   * @param encoding file content encoding.
   * @return The string with text from file content.
   */
  public String getContentAsText(InputStream is, String encoding) throws IOException,
                                                                 DocumentReadException {
    if (is == null) {
      throw new NullPointerException("InputStream is null.");
    }

    try {
      byte[] buffer = new byte[2048];
      int len;
      ByteArrayOutputStream bos = new ByteArrayOutputStream();
      while ((len = is.read(buffer)) > 0)
        bos.write(buffer, 0, len);
      bos.close();

      if (bos.size() == 0)
        return "";
      else if (encoding != null)
        return new String(bos.toByteArray(), encoding);
      else
        return new String(bos.toByteArray());
    } finally {
      if (is != null)
        try {
          is.close();
        } catch (IOException e) {
        }
    }
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.exoplatform.services.document.DocumentReader#getProperties(java.io.
   *      InputStream)
   */
  public Properties getProperties(InputStream is) throws IOException, DocumentReadException {

    try {
      is.close();
    } catch (IOException e) {
    }
    return new Properties();
  }

}