/*
 * 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.xerces.dom;

import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;

/**
 * Used to format DOM error messages, using the system locale.
 * 
 * @xerces.internal
 *
 * @author Sandy Gao, IBM
 * @version $Id$
 */
public class DOMMessageFormatter {
    
    public static final String DOM_DOMAIN = "http://www.w3.org/dom/DOMTR";
    public static final String XML_DOMAIN = "http://www.w3.org/TR/1998/REC-xml-19980210";
    public static final String SERIALIZER_DOMAIN = "http://apache.org/xml/serializer";
    
    private static ResourceBundle domResourceBundle = null;
    private static ResourceBundle xmlResourceBundle = null;
    private static ResourceBundle serResourceBundle = null;
    private static Locale locale = null;
    
    DOMMessageFormatter() {
        locale = Locale.getDefault();
    }
    
    /**
     * Formats a message with the specified arguments using the given
     * locale information.
     *
     * @param domain    domain from which error string is to come.
     * @param key       The message key.
     * @param arguments The message replacement text arguments. The order
     *                  of the arguments must match that of the placeholders
     *                  in the actual message.
     *
     * @return          the formatted message.
     *
     * @throws MissingResourceException Thrown if the message with the
     *                                  specified key cannot be found.
     */
    public static String formatMessage(String domain,
    String key, Object[] arguments)
    throws MissingResourceException {
        ResourceBundle resourceBundle = getResourceBundle(domain);
        if(resourceBundle == null){
            init();
            resourceBundle = getResourceBundle(domain);
            if(resourceBundle == null)
                throw new MissingResourceException("Unknown domain" + domain, null, key);
        }
        // format message
        String msg;
        try {
            msg = key + ": " + resourceBundle.getString(key);
            if (arguments != null) {
                try {
                    msg = java.text.MessageFormat.format(msg, arguments);
                }
                catch (Exception e) {
                    msg = resourceBundle.getString("FormatFailed");
                    msg += " " + resourceBundle.getString(key);
                }
            }
        } // error
        catch (MissingResourceException e) {
            msg = resourceBundle.getString("BadMessageKey");
            throw new MissingResourceException(key, msg, key);
        }
        
        // no message
        if (msg == null) {
            msg = key;
            if (arguments.length > 0) {
                StringBuffer str = new StringBuffer(msg);
                str.append('?');
                for (int i = 0; i < arguments.length; i++) {
                    if (i > 0) {
                        str.append('&');
                    }
                    str.append(String.valueOf(arguments[i]));
                }
            }
        }
        
        return msg;
    }
    
    static ResourceBundle getResourceBundle(String domain) {
        if (domain == DOM_DOMAIN || domain.equals(DOM_DOMAIN)) {
            return domResourceBundle;
        }
        else if (domain == XML_DOMAIN || domain.equals(XML_DOMAIN)) {
            return xmlResourceBundle;
        }
        else if (domain == SERIALIZER_DOMAIN || domain.equals(SERIALIZER_DOMAIN)) {
            return serResourceBundle;
        }
        return null;
    }
    
    /**
     * Initialize Message Formatter.
     */
    public static void init() {
        Locale _locale = locale;
        if (_locale == null) {
            _locale = Locale.getDefault();
        }
        domResourceBundle = ResourceBundle.getBundle("org.apache.xerces.impl.msg.DOMMessages", _locale);
        serResourceBundle = ResourceBundle.getBundle("org.apache.xerces.impl.msg.XMLSerializerMessages", _locale);
        xmlResourceBundle = ResourceBundle.getBundle("org.apache.xerces.impl.msg.XMLMessages", _locale);
    }
    
    /**
     * Set Locale to be used by the formatter.
     * @param dlocale
     */
    public static void setLocale(Locale dlocale) {
        locale = dlocale;
    }
}
