/*

 * Copyright (c) 2005, 2014, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

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.

 *

 *  <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. */

    public static final Context.Key<JavacMessages> messagesKey = new Context.Key<>();

    /** 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<String> bundleNames;

    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.

     */

    public JavacMessages(Context context) {

        this(defaultBundleName, context.get(Locale.class));

        context.put(messagesKey, this);

    }

    /** 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.

     * @param bundleName the name to identify the resource bundle of localized messages.

     */

    public JavacMessages(String bundleName, Locale locale) throws MissingResourceException {

        bundleNames = List.nil();

        bundleCache = new HashMap<>();

        add(bundleName);

        setCurrentLocale(locale);

    }

    public JavacMessages() throws MissingResourceException {

        this(defaultBundleName);

    }

    public void add(String bundleName) throws MissingResourceException {

        bundleNames = bundleNames.prepend(bundleName);

        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 (String bundleName : bundleNames) {

                try {

                    ResourceBundle rb = ResourceBundle.getBundle(bundleName, locale);

                    bundleList = bundleList.prepend(rb);

                } catch (MissingResourceException e) {

                    throw new InternalError("Cannot find javac resource bundle for locale " + locale);

                }

            }

            bundleCache.put(locale, new SoftReference<>(bundleList));

        }

        return bundleList;

    }

    /** 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);

    }

    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.

     */

    // 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);

    }

}