/*
 * 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;

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

import org.apache.uima.internal.util.I18nUtil;

/**
 * The <code>InternationalizedException</code> class adds internationalization support to 
 * the standard functionality provided by <code>java.lang.Exception</code>.
 * <p>
 * To support internationalization, the thrower of an exception must not specify a hardcoded message 
 * string. Instead, the thrower specifies a key that identifies the message. That key is then looked 
 * up in a locale-specific {@link java.util.ResourceBundle ResourceBundle} to find the actual 
 * message associated with this exception.
 * <p>
 * This class also supports arguments to messages. The full message will be constructed using the 
 * {@link java.text.MessageFormat MessageFormat} class. For more information on 
 * internationalization, see the <a href="http://java.sun.com/j2se/1.4/docs/guide/intl/index.html">
 * Java Internationalization Guide</a>.
 * <p>
 * This version of this class works with JDK versions prior to 1.4, since it does not assume support 
 * for exception chaining. The file <code>InternationalizedException.java_1_4</code> is a version 
 * that uses the exception chaining support built-in to JDK1.4.
 * 
 * 
 */
public class InternationalizedException extends Exception {
  
   private static final long serialVersionUID = 2306587442280738385L;

   /**
    * The base name of the resource bundle in which the message for this exception is located.
    */
   private String mResourceBundleName;

   /**
    * An identifier that maps to the message for this exception.
    */
   private String mMessageKey;

   /**
    * The arguments to this exception's message, if any. This allows an
    * <code>InternationalizedException</code> to have a compound message, made up of 
    * multiple parts that are concatenated in a language-neutral way.
    */
   private Object[] mArguments;

   /**
    * The exception that caused this exception to occur.
    */
   private Throwable mCause;
   
   /**
    * the thread local class loader at creation time, see UIMA-4793
    * Transient to allow exceptions to be serialized.
    * Deserialized versions have null as their value, which is handled by the users
    */
   final transient private ClassLoader originalContextClassLoader;
   
   // see https://issues.apache.org/jira/browse/UIMA-5961
   // the resourceBundle associated with the default locale, at the time of creation of this instance
   final transient private ResourceBundle default_localized_resourceBundle;
   // the default locale, at the time of creation of this instance
   final transient private Locale default_locale;
   // a user specified resource bundle, used when the default_locale is not appropriate
   transient private ResourceBundle user_specified_resourceBundle = null;

   /**
    * Creates a new <code>InternationalizedException</code> with a null
    * message.
    */
   public InternationalizedException() {
      this(null, null, null, null);
   }

   /**
    * Creates a new <code>InternationalizedException</code> with the specified cause and a 
    * null message.
    * 
    * @param aCause
    *           the original exception that caused this exception to be thrown, if any
    */
   public InternationalizedException(Throwable aCause) {
      this(null, null, null, aCause);
   }

   /**
    * Creates a new <code>InternationalizedException</code> with the specified message.
    * 
    * @param aResourceBundleName
    *           the base name of the resource bundle in which the message for this exception is 
    *           located.
    * @param aMessageKey
    *           an identifier that maps to the message for this exception. The message may contain 
    *           placeholders for arguments as defined by the 
    *           {@link java.text.MessageFormat MessageFormat} class.
    * @param aArguments
    *           The arguments to the message. <code>null</code> may be used if the message has no 
    *           arguments.
    */
   public InternationalizedException(String aResourceBundleName,
         String aMessageKey, Object[] aArguments) {
      this(aResourceBundleName, aMessageKey, aArguments, null);
   }

   /**
    * Creates a new <code>InternationalizedException</code> with the specified message and 
    * cause.
    * 
    * @param aResourceBundleName
    *           the base name of the resource bundle in which the message for this exception is 
    *           located.
    * @param aMessageKey
    *           an identifier that maps to the message for this exception. The message may contain 
    *           placeholders for arguments as defined by the
    *           {@link java.text.MessageFormat MessageFormat} class.
    * @param aArguments
    *           The arguments to the message. <code>null</code> may be used if the message has no 
    *           arguments.
    * @param aCause
    *           the original exception that caused this exception to be thrown, if any
    */
   public InternationalizedException(String aResourceBundleName, String aMessageKey, 
           Object[] aArguments, Throwable aCause) {
      super();
      originalContextClassLoader = Thread.currentThread().getContextClassLoader();
      try {
        I18nUtil.setTccl(originalContextClassLoader); 
        default_locale = Locale.getDefault();
        default_localized_resourceBundle = (aMessageKey == null) 
            ? null 
            : I18nUtil.resolveResourceBundle(aResourceBundleName, default_locale, null);      
      } finally {
        I18nUtil.removeTccl();        
      }
      mCause = aCause;
      mResourceBundleName = aResourceBundleName;
      mMessageKey = aMessageKey;
      mArguments = aArguments;
      // if null message and mCause is Internationalized exception, "promote" message
      if (mResourceBundleName == null && mMessageKey == null) {
         if (mCause instanceof InternationalizedException) {
            mResourceBundleName = ((InternationalizedException) mCause).getResourceBundleName();
            mMessageKey = ((InternationalizedException) mCause).getMessageKey();
            mArguments = ((InternationalizedException) mCause).getArguments();
         } else if (mCause instanceof InternationalizedRuntimeException) {
            mResourceBundleName = ((InternationalizedRuntimeException) mCause).getResourceBundleName();
            mMessageKey = ((InternationalizedRuntimeException) mCause).getMessageKey();
            mArguments = ((InternationalizedRuntimeException) mCause).getArguments();
         }
      }
   }

   /**
    * Gets the base name of the resource bundle in which the message for this exception is located.
    * 
    * @return the resource bundle base name. May return <code>null</code> if this exception has no 
    * message.
    */
   public String getResourceBundleName() {
      return mResourceBundleName;
   }

   /**
    * Gets the identifier for this exception's message. This identifier can be looked up in this 
    * exception's {@link java.util.ResourceBundle ResourceBundle} to get the locale-specific message 
    * for this exception.
    * 
    * @return the resource identifier for this exception's message. May return <code>null</code> if 
    *         this exception has no message.
    */
   public String getMessageKey() {
      return mMessageKey;
   }

   /**
    * Gets the arguments to this exception's message. Arguments allow a
    * <code>InternationalizedException</code> to have a compound message, made up of 
    * multiple parts that are concatenated in a language-neutral way.
    * 
    * @return the arguments to this exception's message.
    */
   public Object[] getArguments() {
      if (mArguments == null)
         return new Object[0];

      Object[] result = new Object[mArguments.length];
      System.arraycopy(mArguments, 0, result, 0, mArguments.length);
      return result;
   }

   /**
    * Gets the <i>English</i> detail message for this exception. For the localized message use 
    * {@link #getLocalizedMessage()}.
    * 
    * @return the English detail message for this exception.
    */
   public String getMessage() {
      return getLocalizedMessage(Locale.ENGLISH);
   }

   /**
    * Gets the localized detail message for this exception. This uses the default Locale for this 
    * JVM. A Locale may be specified using {@link #getLocalizedMessage(Locale)}.
    * 
    * @return this exception's detail message, localized for the default Locale.
    */
   public String getLocalizedMessage() {
      return getLocalizedMessage(Locale.getDefault());
   }

   /**
    * Gets the localized detail message for this exception using the specified <code>Locale</code>.
    * 
    * @param aLocale
    *           the locale to use for localizing the message
    * 
    * @return this exception's detail message, localized for the specified <code>Locale</code>.
    */
   public String getLocalizedMessage(Locale aLocale) {
      // check for null message
      if (getMessageKey() == null) {
         return null;
      }
      
      if (default_localized_resourceBundle != null && aLocale == default_locale) {
        return I18nUtil.localizeMessage(default_localized_resourceBundle, aLocale, getMessageKey(), getArguments());
      }
      
      if (user_specified_resourceBundle != null) {
        return I18nUtil.localizeMessage(user_specified_resourceBundle, aLocale, getMessageKey(), getArguments());
      }
      
      try {
        I18nUtil.setTccl(originalContextClassLoader);       
        return I18nUtil.localizeMessage(getResourceBundleName(), aLocale, getMessageKey(), getArguments());
      } finally {
        I18nUtil.removeTccl();        
      }
//      try {
//         // locate the resource bundle for this exception's messages
//         // turn over the classloader of the current object explicitly, so that the
//         // message resolving also works for derived exception classes
//         ResourceBundle bundle = ResourceBundle.getBundle(
//               getResourceBundleName(), aLocale, this.getClass()
//                     .getClassLoader());
//         // retrieve the message from the resource bundle
//         String message = bundle.getString(getMessageKey());
//         // if arguments exist, use MessageFormat to include them
//         if (getArguments().length > 0) {
//            MessageFormat fmt = new MessageFormat(message);
//            fmt.setLocale(aLocale);
//            return fmt.format(getArguments());
//         } else
//            return message;
//      } catch (Exception e) {
//         return "EXCEPTION MESSAGE LOCALIZATION FAILED: " + e.toString();
//      }
   }
   
   /**
    * Gets the cause of this Exception.
    * 
    * @return the Throwable that caused this Exception to occur, if any. Returns <code>null</code> 
    *         if there is no such cause.
    */
   public Throwable getCause() {
      return mCause;
   }

   /**
    * Checks if this exception, or any of its root causes, has a particular UIMA
    * message key. This allows checking for particular error condition
    * 
    * @param messageKey
    *           to search for in the exception chain
    * @return true if this exception or any of its root causes has a particular UIMA message key.
    */
   public boolean hasMessageKey(String messageKey) {
      if (messageKey.equals(this.getMessageKey())) {
         return true;
      }
      Throwable cause = getCause();
      if (cause != null && cause instanceof InternationalizedException) {
         return ((InternationalizedException) cause).hasMessageKey(messageKey);
      }
      return false;
   }

   public synchronized Throwable initCause(Throwable cause) {
      mCause = cause;
      return this;
   }

   /**
    * For the case where the default locale is not being used for getting messages,
    * and the lookup path in the classpath for the resource bundle needs to be set 
    * at a specific point, call this method to set the resource bundle at that point in the call stack.
    * 
    * Example: If in a Pear, and you are throwing an exception, which is defined in a bundle
    * in the Pear context, but the catcher of the throw is up the stack above where the pear context
    * exists (and therefore, is no longer present at "catch" time), and
    * you don't want to use the default-locale for getting the message out of the message bundle,
    * 
    * then do something like this
    *   Exception e = new AnalysisEngineProcessException(MESSAGE_BUNDLE, "TEST_KEY", objects);
    *   e.setResourceBundle(my_locale);  // call this method, pass in the needed locale object
    *   throw e;  // or whatever should be done with it
    * @param aLocale the locale to use when getting the message from the message bundle at a later time
    */
   public void setResourceBundle(Locale aLocale) {
     user_specified_resourceBundle = I18nUtil.resolveResourceBundle(mResourceBundleName, aLocale, null);
   }
}