/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 2001 The Apache Software Foundation.  
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.apache.org.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.xerces.util;

import java.io.InputStream;
import java.io.IOException;
import java.io.Reader;

import org.apache.xerces.xni.XMLLocator;
import org.apache.xerces.xni.XNIException;
import org.apache.xerces.xni.parser.XMLErrorHandler;
import org.apache.xerces.xni.parser.XMLParseException;

import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

/**
 * This class wraps a SAX error handler in an XNI error handler.
 *
 * @see ErrorHandler
 *
 * @author Andy Clark, IBM
 * 
 * @version $Id$
 */
public class ErrorHandlerWrapper
    implements XMLErrorHandler {

    //
    // Data
    //

    /** The SAX error handler. */
    protected ErrorHandler fErrorHandler;

    //
    // Constructors
    //

    /** Default constructor. */
    public ErrorHandlerWrapper() {}

    /** Wraps the specified SAX error handler. */
    public ErrorHandlerWrapper(ErrorHandler errorHandler) {
        setErrorHandler(errorHandler);
    } // <init>(ErrorHandler)

    //
    // Public methods
    //

    /** Sets the SAX error handler. */
    public void setErrorHandler(ErrorHandler errorHandler) {
        fErrorHandler = errorHandler;
    } // setErrorHandler(ErrorHandler)

    /** Returns the SAX error handler. */
    public ErrorHandler getErrorHandler() {
        return fErrorHandler;
    } // getErrorHandler():ErrorHandler

    //
    // XMLErrorHandler methods
    //

    /**
     * Reports a warning. Warnings are non-fatal and can be safely ignored
     * by most applications.
     *
     * @param domain    The domain of the warning. The domain can be any
     *                  string but is suggested to be a valid URI. The
     *                  domain can be used to conveniently specify a web
     *                  site location of the relevent specification or
     *                  document pertaining to this warning.
     * @param key       The warning key. This key can be any string and
     *                  is implementation dependent.
     * @param exception Exception.
     *
     * @throws XNIException Thrown to signal that the parser should stop
     *                      parsing the document.
     */
    public void warning(String domain, String key, 
                        XMLParseException exception) throws XNIException {

        SAXParseException saxException = createSAXParseException(exception);
        try {
            fErrorHandler.warning(saxException);
        }
        catch (SAXParseException e) {
            throw createXMLParseException(e);
        }
        catch (SAXException e) {
            throw createXNIException(e);
        }

    } // warning(String,String,XMLParseException)

    /**
     * Reports an error. Errors are non-fatal and usually signify that the
     * document is invalid with respect to its grammar(s).
     *
     * @param domain    The domain of the error. The domain can be any
     *                  string but is suggested to be a valid URI. The
     *                  domain can be used to conveniently specify a web
     *                  site location of the relevent specification or
     *                  document pertaining to this error.
     * @param key       The error key. This key can be any string and
     *                  is implementation dependent.
     * @param exception Exception.
     *
     * @throws XNIException Thrown to signal that the parser should stop
     *                      parsing the document.
     */
    public void error(String domain, String key, 
                      XMLParseException exception) throws XNIException {

        SAXParseException saxException = createSAXParseException(exception);
        try {
            fErrorHandler.error(saxException);
        }
        catch (SAXParseException e) {
            throw createXMLParseException(e);
        }
        catch (SAXException e) {
            throw createXNIException(e);
        }

    } // error(String,String,XMLParseException)

    /**
     * Report a fatal error. Fatal errors usually occur when the document
     * is not well-formed and signifies that the parser cannot continue
     * normal operation.
     * <p>
     * <strong>Note:</strong> The error handler should <em>always</em>
     * throw an <code>XNIException</code> from this method. This exception
     * can either be the same exception that is passed as a parameter to
     * the method or a new XNI exception object. If the registered error
     * handler fails to throw an exception, the continuing operation of
     * the parser is undetermined.
     *
     * @param domain    The domain of the fatal error. The domain can be 
     *                  any string but is suggested to be a valid URI. The
     *                  domain can be used to conveniently specify a web
     *                  site location of the relevent specification or
     *                  document pertaining to this fatal error.
     * @param key       The fatal error key. This key can be any string 
     *                  and is implementation dependent.
     * @param exception Exception.
     *
     * @throws XNIException Thrown to signal that the parser should stop
     *                      parsing the document.
     */
    public void fatalError(String domain, String key, 
                           XMLParseException exception) throws XNIException {

        SAXParseException saxException = createSAXParseException(exception);
        try {
            fErrorHandler.fatalError(saxException);
        }
        catch (SAXParseException e) {
            throw createXMLParseException(e);
        }
        catch (SAXException e) {
            throw createXNIException(e);
        }

    } // fatalError(String,String,XMLParseException)

    //
    // Protected methods
    //

    /** Creates a SAXParseException from an XMLParseException. */
    protected static SAXParseException createSAXParseException(XMLParseException exception) {
        return new SAXParseException(exception.getMessage(),
                                     exception.getPublicId(),
                                     exception.getSystemId(),
                                     exception.getLineNumber(),
                                     exception.getColumnNumber(),
                                     exception.getException());
    } // createSAXParseException(XMLParseException):SAXParseException

    /** Creates an XMLParseException from a SAXParseException. */
    protected static XMLParseException createXMLParseException(SAXParseException exception) {
        final String fPublicId = exception.getPublicId();
        final String fSystemId = exception.getSystemId();
        final int fLineNumber = exception.getLineNumber();
        final int fColumnNumber = exception.getColumnNumber();
        XMLLocator location = new XMLLocator() {
            public String getPublicId() { return fPublicId; }
            public String getSystemId() { return fSystemId; }
            public String getBaseSystemId() { return null; }
            public int getColumnNumber() { return fColumnNumber; }
            public int getLineNumber() { return fLineNumber; }
        };
        return new XMLParseException(location, exception.getMessage(),
                                     exception.getException());
    } // createXMLParseException(SAXParseException):XMLParseException

    /** Creates an XNIException from a SAXException. 
        NOTE:  care should be taken *not* to call this with a SAXParseException; this will
        lose information!!! */
    protected static XNIException createXNIException(SAXException exception) {
        return new XNIException(exception.getMessage(),
                                     exception.getException());
    } // createXNIException(SAXException):XMLParseException
} // class ErrorHandlerWrapper