/*
 * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package com.sun.tools.javac.util;

import com.sun.tools.javac.api.Messages;
import java.lang.ref.SoftReference;
import java.util.ResourceBundle;
import java.util.MissingResourceException;
import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

 Support for formatted localized messages.
 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
/**
 *  Support for formatted localized messages.
 *
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class JavacMessages implements Messages {
    
The context key for the JavacMessages object. /** The context key for the JavacMessages object. */
    public static final Context.Key<JavacMessages> messagesKey = new Context.Key<>();

    
Get the JavacMessages instance for this context. /** Get the JavacMessages instance for this context. */
    public static JavacMessages instance(Context context) {
        JavacMessages instance = context.get(messagesKey);
        if (instance == null)
            instance = new JavacMessages(context);
        return instance;
    }

    private Map<Locale, SoftReference<List<ResourceBundle>>> bundleCache;

    private List<ResourceBundleHelper> bundleHelpers;

    private Locale currentLocale;
    private List<ResourceBundle> currentBundles;

    public Locale getCurrentLocale() {
        return currentLocale;
    }

    public void setCurrentLocale(Locale locale) {
        if (locale == null) {
            locale = Locale.getDefault();
        }
        this.currentBundles = getBundles(locale);
        this.currentLocale = locale;
    }

    
Creates a JavacMessages object.
/** Creates a JavacMessages object.
     */
    public JavacMessages(Context context) {
        this(defaultBundleName, context.get(Locale.class));
        context.put(messagesKey, this);
    }

    
Creates a JavacMessages object.
Params:
bundleName – the name to identify the resource bundle of localized messages./** Creates a JavacMessages object.
     * @param bundleName the name to identify the resource bundle of localized messages.
     */
    public JavacMessages(String bundleName) throws MissingResourceException {
        this(bundleName, null);
    }

    
Creates a JavacMessages object.
Params:
bundleName – the name to identify the resource bundle of localized messages./** Creates a JavacMessages object.
     * @param bundleName the name to identify the resource bundle of localized messages.
     */
    public JavacMessages(String bundleName, Locale locale) throws MissingResourceException {
        bundleHelpers = List.nil();
        bundleCache = new HashMap<>();
        add(bundleName);
        setCurrentLocale(locale);
    }

    public JavacMessages() throws MissingResourceException {
        this(defaultBundleName);
    }

    @Override
    public void add(String bundleName) throws MissingResourceException {
        add(locale -> ResourceBundle.getBundle(bundleName, locale));
    }

    public void add(ResourceBundleHelper ma) {
        bundleHelpers = bundleHelpers.prepend(ma);
        if (!bundleCache.isEmpty())
            bundleCache.clear();
        currentBundles = null;
    }

    public List<ResourceBundle> getBundles(Locale locale) {
        if (locale == currentLocale && currentBundles != null)
            return currentBundles;
        SoftReference<List<ResourceBundle>> bundles = bundleCache.get(locale);
        List<ResourceBundle> bundleList = bundles == null ? null : bundles.get();
        if (bundleList == null) {
            bundleList = List.nil();
            for (ResourceBundleHelper helper : bundleHelpers) {
                try {
                    ResourceBundle rb = helper.getResourceBundle(locale);
                    bundleList = bundleList.prepend(rb);
                } catch (MissingResourceException e) {
                    throw new InternalError("Cannot find requested resource bundle for locale " +
                            locale, e);
                }
            }
            bundleCache.put(locale, new SoftReference<>(bundleList));
        }
        return bundleList;
    }

    
Gets the localized string corresponding to a key, formatted with a set of args.
/** Gets the localized string corresponding to a key, formatted with a set of args.
     */
    public String getLocalizedString(String key, Object... args) {
        return getLocalizedString(currentLocale, key, args);
    }

    @Override
    public String getLocalizedString(Locale l, String key, Object... args) {
        if (l == null)
            l = getCurrentLocale();
        return getLocalizedString(getBundles(l), key, args);
    }

    /* Static access:
     * javac has a firmly entrenched notion of a default message bundle
     * which it can access from any static context. This is used to get
     * easy access to simple localized strings.
     */

    private static final String defaultBundleName = "com.sun.tools.javac.resources.compiler";
    private static ResourceBundle defaultBundle;
    private static JavacMessages defaultMessages;


    
Returns a localized string from the compiler's default bundle.
/**
     * Returns a localized string from the compiler's default bundle.
     */
    // used to support legacy Log.getLocalizedString
    static String getDefaultLocalizedString(String key, Object... args) {
        return getLocalizedString(List.of(getDefaultBundle()), key, args);
    }

    // used to support legacy static Diagnostic.fragment
    @Deprecated
    static JavacMessages getDefaultMessages() {
        if (defaultMessages == null)
            defaultMessages = new JavacMessages(defaultBundleName);
        return defaultMessages;
    }

    public static ResourceBundle getDefaultBundle() {
        try {
            if (defaultBundle == null)
                defaultBundle = ResourceBundle.getBundle(defaultBundleName);
            return defaultBundle;
        }
        catch (MissingResourceException e) {
            throw new Error("Fatal: Resource for compiler is missing", e);
        }
    }

    private static String getLocalizedString(List<ResourceBundle> bundles,
                                             String key,
                                             Object... args) {
       String msg = null;
       for (List<ResourceBundle> l = bundles; l.nonEmpty() && msg == null; l = l.tail) {
           ResourceBundle rb = l.head;
           try {
               msg = rb.getString(key);
           }
           catch (MissingResourceException e) {
               // ignore, try other bundles in list
           }
       }
       if (msg == null) {
           msg = "compiler message file broken: key=" + key +
               " arguments={0}, {1}, {2}, {3}, {4}, {5}, {6}, {7}";
       }
       return MessageFormat.format(msg, args);
    }

    
This provides a way for the JavacMessager to retrieve a
ResourceBundle from another module such as jdk.javadoc.
/**
     * This provides a way for the JavacMessager to retrieve a
     * ResourceBundle from another module such as jdk.javadoc.
     */
    public interface ResourceBundleHelper {
        
Gets the ResourceBundle.
Params:
locale – the requested bundle's locale
Returns:
ResourceBundle/**
         * Gets the ResourceBundle.
         * @param locale the requested bundle's locale
         * @return ResourceBundle
         */
        ResourceBundle getResourceBundle(Locale locale);
    }
}