/*
 * This program is free software; you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 * or from the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * 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 Lesser General Public License for more details.
 *
 * Copyright (c) 2006 - 2009 Object Refinery Ltd, Pentaho Corporation and Contributors.  All rights reserved.
 */

package org.pentaho.reporting.libraries.xmlns.common;

import org.pentaho.reporting.libraries.xmlns.parser.ParseException;
import org.pentaho.reporting.libraries.xmlns.LibXmlBoot;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Basic helper functions to ease up the process of parsing.
 *
 * @author Thomas Morgner
 */
public class ParserUtil
{
  private static final Log logger = LogFactory.getLog(ParserUtil.class);
  private static boolean strictParsing;

  static
  {
    strictParsing = "true".equals(LibXmlBoot.getInstance().getGlobalConfig().getConfigProperty
        ("org.pentaho.reporting.libraries.xmlns.StrictParseMode"));
  }


  /**
   * Private constructors prevent initializations of utility classes.
   */
  private ParserUtil()
  {
  }

  /**
   * Parses the string <code>text</code> into an int. If text is null or does
   * not contain a parsable value, the message given in <code>message</code>
   * is used to throw a SAXException.
   *
   * @param text    the text to parse.
   * @param message the error message if parsing fails.
   * @param locator the SAX locator to print meaningfull error messages.
   * @return the int value.
   * @throws SAXException if there is a problem with the parsing.
   */
  public static int parseInt(final String text,
                             final String message,
                             final Locator locator)
      throws SAXException
  {
    if (text == null)
    {
      throw new SAXException(message);
    }

    try
    {
      return Integer.parseInt(text);
    }
    catch (NumberFormatException nfe)
    {
      throw new ParseException("NumberFormatError: " + message, locator);
    }
  }

  /**
   * Parses the string <code>text</code> into an int. If text is null or does
   * not contain a parsable value, the message given in <code>message</code>
   * is used to throw a SAXException.
   *
   * @param text    the text to parse.
   * @param message the error message if parsing fails.
   * @return the int value.
   * @throws SAXException if there is a problem with the parsing.
   */
  public static int parseInt(final String text, final String message)
      throws SAXException
  {
    if (text == null)
    {
      throw new SAXException(message);
    }

    try
    {
      return Integer.parseInt(text);
    }
    catch (NumberFormatException nfe)
    {
      throw new SAXException("NumberFormatError: " + message);
    }
  }

  /**
   * Parses an integer.
   *
   * @param text       the text to parse.
   * @param defaultVal the default value.
   * @return the integer.
   */
  public static int parseInt(final String text, final int defaultVal)
  {
    if (text == null)
    {
      return defaultVal;
    }

    try
    {
      return Integer.parseInt(text);
    }
    catch (NumberFormatException nfe)
    {
      return defaultVal;
    }
  }

  /**
   * Parses the string <code>text</code> into an float. If text is null or
   * does not contain a parsable value, the message given in
   * <code>message</code> is used to throw a SAXException.
   *
   * @param text    the text to parse.
   * @param message the error message if parsing fails.
   * @param locator the SAX locator to print meaningfull error messages.
   * @return the float value.
   * @throws ParseException if the text is no valid float number.
   */
  public static float parseFloat(final String text,
                                 final String message,
                                 final Locator locator)
      throws ParseException
  {
    if (text == null)
    {
      throw new ParseException(message, locator);
    }
    try
    {
      return Float.parseFloat(text);
    }
    catch (NumberFormatException nfe)
    {
      throw new ParseException("NumberFormatError: " + message, locator);
    }
  }

  /**
   * Parses the string <code>text</code> into an float. If text is null or
   * does not contain a parsable value, the message given in
   * <code>message</code> is used to throw a SAXException.
   *
   * @param text    the text to parse.
   * @param message the error message if parsing fails.
   * @return the float value.
   * @throws SAXException if there is a problem with the parsing.
   */
  public static float parseFloat(final String text, final String message)
      throws SAXException
  {
    if (text == null)
    {
      throw new SAXException(message);
    }
    try
    {
      return Float.parseFloat(text);
    }
    catch (NumberFormatException nfe)
    {
      throw new SAXException("NumberFormatError: " + message);
    }
  }

  /**
   * Parses the string <code>text</code> into an float. If text is null or
   * does not contain a parsable value, the message given in
   * <code>message</code> is used to throw a SAXException.
   *
   * @param text       the text to parse.
   * @param defaultVal the defaultValue returned if parsing fails.
   * @return the float value.
   */
  public static float parseFloat(final String text, final float defaultVal)
  {
    if (text == null)
    {
      return defaultVal;
    }
    try
    {
      return Float.parseFloat(text);
    }
    catch (NumberFormatException nfe)
    {
      return defaultVal;
    }
  }

  /**
   * Parses a boolean. If the string <code>text</code> contains the value of
   * "true", the true value is returned, else false is returned.
   *
   * @param text       the text to parse.
   * @param defaultVal the default value.
   * @return a boolean.
   */
  public static boolean parseBoolean(final String text,
                                     final boolean defaultVal)
  {
    if (text == null)
    {
      return defaultVal;
    }
    if (strictParsing)
    {
      return "true".equals(text);
    }
    else
    {
      if (text.equals("true"))
      {
        return true;
      }
      else if (text.equals("false"))
      {
        return false;
      }

      logger.warn("Invalid value encountered: Expected 'true' or 'false', but got '" + text + "'");
      return "true".equalsIgnoreCase(text);
    }
  }


  /**
   * Translates an boolean string ("true" or "false") into the corresponding Boolean
   * object.
   *
   * @param value   the string that represents the boolean.
   * @param locator the SAX locator to print meaningfull error messages.
   * @return Boolean.TRUE or Boolean.FALSE
   * @throws ParseException if an parse error occured or the string is not
   *                        'true' or 'false'.
   */
  public static Boolean parseBoolean(final String value, final Locator locator)
      throws ParseException
  {
    if (value == null)
    {
      return null;
    }
    if ("true".equals(value))
    {
      return Boolean.TRUE;
    }
    else if ("false".equals(value))
    {
      return Boolean.FALSE;
    }
    if (strictParsing)
    {
      throw new ParseException("Failed to parse: Expected 'true' or 'false'", locator);
    }

    if (locator == null)
    {
      logger.warn("Invalid value encountered for boolean attribute.");
    }
    else
    {
      logger.warn("Invalid value encountered for boolean attribute. [Line: " +
          locator.getLineNumber() + " Column: " + locator.getColumnNumber() + "]");
    }
    return Boolean.FALSE;
  }

  /**
   * Parses a string. If the <code>text</code> is null, defaultval is
   * returned.
   *
   * @param text       the text to parse.
   * @param defaultVal the default value.
   * @return a string.
   */
  public static String parseString(final String text, final String defaultVal)
  {
    if (text == null)
    {
      return defaultVal;
    }
    return text;
  }

}