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 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * This code is free software; you can redistribute it and/or modify it

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 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

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 * 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).

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/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file:

 *

 * Copyright (c) 2011-2012, Stephen Colebourne & Michael Nascimento Santos

 *

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *  * Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *

 *  * 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.

 *

 *  * Neither the name of JSR-310 nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

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 */

package java.time.format;

import static java.time.temporal.ChronoField.AMPM_OF_DAY;

import static java.time.temporal.ChronoField.DAY_OF_WEEK;

import static java.time.temporal.ChronoField.ERA;

import static java.time.temporal.ChronoField.MONTH_OF_YEAR;

import java.time.chrono.Chronology;

import java.time.chrono.IsoChronology;

import java.time.chrono.JapaneseChronology;

import java.time.temporal.ChronoField;

import java.time.temporal.IsoFields;

import java.time.temporal.TemporalField;

import java.util.AbstractMap.SimpleImmutableEntry;

import java.util.ArrayList;

import java.util.Calendar;

import java.util.Collections;

import java.util.Comparator;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Locale;

import java.util.Map;

import java.util.Map.Entry;

import java.util.ResourceBundle;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import sun.util.locale.provider.CalendarDataUtility;

import sun.util.locale.provider.LocaleProviderAdapter;

import sun.util.locale.provider.LocaleResources;

/**

 * A provider to obtain the textual form of a date-time field.

 *

 * @implSpec

 * Implementations must be thread-safe.

 * Implementations should cache the textual information.

 *

 * @since 1.8

 */

class DateTimeTextProvider {

    /** Cache. */

    private static final ConcurrentMap<Entry<TemporalField, Locale>, Object> CACHE = new ConcurrentHashMap<>(16, 0.75f, 2);

    /** Comparator. */

    private static final Comparator<Entry<String, Long>> COMPARATOR = new Comparator<Entry<String, Long>>() {

        @Override

        public int compare(Entry<String, Long> obj1, Entry<String, Long> obj2) {

            return obj2.getKey().length() - obj1.getKey().length();  // longest to shortest

        }

    };

    DateTimeTextProvider() {}

    /**

     * Gets the provider of text.

     *

     * @return the provider, not null

     */

    static DateTimeTextProvider getInstance() {

        return new DateTimeTextProvider();

    }

    /**

     * Gets the text for the specified field, locale and style

     * for the purpose of formatting.

     * <p>

     * The text associated with the value is returned.

     * The null return value should be used if there is no applicable text, or

     * if the text would be a numeric representation of the value.

     *

     * @param field  the field to get text for, not null

     * @param value  the field value to get text for, not null

     * @param style  the style to get text for, not null

     * @param locale  the locale to get text for, not null

     * @return the text for the field value, null if no text found

     */

    public String getText(TemporalField field, long value, TextStyle style, Locale locale) {

        Object store = findStore(field, locale);

        if (store instanceof LocaleStore) {

            return ((LocaleStore) store).getText(value, style);

        }

        return null;

    }

    /**

     * Gets the text for the specified chrono, field, locale and style

     * for the purpose of formatting.

     * <p>

     * The text associated with the value is returned.

     * The null return value should be used if there is no applicable text, or

     * if the text would be a numeric representation of the value.

     *

     * @param chrono  the Chronology to get text for, not null

     * @param field  the field to get text for, not null

     * @param value  the field value to get text for, not null

     * @param style  the style to get text for, not null

     * @param locale  the locale to get text for, not null

     * @return the text for the field value, null if no text found

     */

    public String getText(Chronology chrono, TemporalField field, long value,

                                    TextStyle style, Locale locale) {

        if (chrono == IsoChronology.INSTANCE

                || !(field instanceof ChronoField)) {

            return getText(field, value, style, locale);

        }

        int fieldIndex;

        int fieldValue;

        if (field == ERA) {

            fieldIndex = Calendar.ERA;

            if (chrono == JapaneseChronology.INSTANCE) {

                if (value == -999) {

                    fieldValue = 0;

                } else {

                    fieldValue = (int) value + 2;

                }

            } else {

                fieldValue = (int) value;

            }

        } else if (field == MONTH_OF_YEAR) {

            fieldIndex = Calendar.MONTH;

            fieldValue = (int) value - 1;

        } else if (field == DAY_OF_WEEK) {

            fieldIndex = Calendar.DAY_OF_WEEK;

            fieldValue = (int) value + 1;

            if (fieldValue > 7) {

                fieldValue = Calendar.SUNDAY;

            }

        } else if (field == AMPM_OF_DAY) {

            fieldIndex = Calendar.AM_PM;

            fieldValue = (int) value;

        } else {

            return null;

        }

        return CalendarDataUtility.retrieveJavaTimeFieldValueName(

                chrono.getCalendarType(), fieldIndex, fieldValue, style.toCalendarStyle(), locale);

    }

    /**

     * Gets an iterator of text to field for the specified field, locale and style

     * for the purpose of parsing.

     * <p>

     * The iterator must be returned in order from the longest text to the shortest.

     * <p>

     * The null return value should be used if there is no applicable parsable text, or

     * if the text would be a numeric representation of the value.

     * Text can only be parsed if all the values for that field-style-locale combination are unique.

     *

     * @param field  the field to get text for, not null

     * @param style  the style to get text for, null for all parsable text

     * @param locale  the locale to get text for, not null

     * @return the iterator of text to field pairs, in order from longest text to shortest text,

     *  null if the field or style is not parsable

     */

    public Iterator<Entry<String, Long>> getTextIterator(TemporalField field, TextStyle style, Locale locale) {

        Object store = findStore(field, locale);

        if (store instanceof LocaleStore) {

            return ((LocaleStore) store).getTextIterator(style);

        }

        return null;

    }

    /**

     * Gets an iterator of text to field for the specified chrono, field, locale and style

     * for the purpose of parsing.

     * <p>

     * The iterator must be returned in order from the longest text to the shortest.

     * <p>

     * The null return value should be used if there is no applicable parsable text, or

     * if the text would be a numeric representation of the value.

     * Text can only be parsed if all the values for that field-style-locale combination are unique.

     *

     * @param chrono  the Chronology to get text for, not null

     * @param field  the field to get text for, not null

     * @param style  the style to get text for, null for all parsable text

     * @param locale  the locale to get text for, not null

     * @return the iterator of text to field pairs, in order from longest text to shortest text,

     *  null if the field or style is not parsable

     */

    public Iterator<Entry<String, Long>> getTextIterator(Chronology chrono, TemporalField field,

                                                         TextStyle style, Locale locale) {

        if (chrono == IsoChronology.INSTANCE

                || !(field instanceof ChronoField)) {

            return getTextIterator(field, style, locale);

        }

        int fieldIndex;

        switch ((ChronoField)field) {

        case ERA:

            fieldIndex = Calendar.ERA;

            break;

        case MONTH_OF_YEAR:

            fieldIndex = Calendar.MONTH;

            break;

        case DAY_OF_WEEK:

            fieldIndex = Calendar.DAY_OF_WEEK;

            break;

        case AMPM_OF_DAY:

            fieldIndex = Calendar.AM_PM;

            break;

        default:

            return null;

        }

        int calendarStyle = (style == null) ? Calendar.ALL_STYLES : style.toCalendarStyle();

        Map<String, Integer> map = CalendarDataUtility.retrieveJavaTimeFieldValueNames(

                chrono.getCalendarType(), fieldIndex, calendarStyle, locale);

        if (map == null) {

            return null;

        }

        List<Entry<String, Long>> list = new ArrayList<>(map.size());

        switch (fieldIndex) {

        case Calendar.ERA:

            for (Map.Entry<String, Integer> entry : map.entrySet()) {

                int era = entry.getValue();

                if (chrono == JapaneseChronology.INSTANCE) {

                    if (era == 0) {

                        era = -999;

                    } else {

                        era -= 2;

                    }

                }

                list.add(createEntry(entry.getKey(), (long)era));

            }

            break;

        case Calendar.MONTH:

            for (Map.Entry<String, Integer> entry : map.entrySet()) {

                list.add(createEntry(entry.getKey(), (long)(entry.getValue() + 1)));

            }

            break;

        case Calendar.DAY_OF_WEEK:

            for (Map.Entry<String, Integer> entry : map.entrySet()) {

                list.add(createEntry(entry.getKey(), (long)toWeekDay(entry.getValue())));

            }

            break;

        default:

            for (Map.Entry<String, Integer> entry : map.entrySet()) {

                list.add(createEntry(entry.getKey(), (long)entry.getValue()));

            }

            break;

        }

        return list.iterator();

    }

    private Object findStore(TemporalField field, Locale locale) {

        Entry<TemporalField, Locale> key = createEntry(field, locale);

        Object store = CACHE.get(key);

        if (store == null) {

            store = createStore(field, locale);

            CACHE.putIfAbsent(key, store);

            store = CACHE.get(key);

        }

        return store;

    }

    private static int toWeekDay(int calWeekDay) {

        if (calWeekDay == Calendar.SUNDAY) {

            return 7;

        } else {

            return calWeekDay - 1;

        }

    }

    private Object createStore(TemporalField field, Locale locale) {

        Map<TextStyle, Map<Long, String>> styleMap = new HashMap<>();

        if (field == ERA) {

            for (TextStyle textStyle : TextStyle.values()) {

                if (textStyle.isStandalone()) {

                    // Stand-alone isn't applicable to era names.

                    continue;

                }

                Map<String, Integer> displayNames = CalendarDataUtility.retrieveJavaTimeFieldValueNames(

                        "gregory", Calendar.ERA, textStyle.toCalendarStyle(), locale);

                if (displayNames != null) {

                    Map<Long, String> map = new HashMap<>();

                    for (Entry<String, Integer> entry : displayNames.entrySet()) {

                        map.put((long) entry.getValue(), entry.getKey());

                    }

                    if (!map.isEmpty()) {

                        styleMap.put(textStyle, map);

                    }

                }

            }

            return new LocaleStore(styleMap);

        }

        if (field == MONTH_OF_YEAR) {

            for (TextStyle textStyle : TextStyle.values()) {

                Map<String, Integer> displayNames = CalendarDataUtility.retrieveJavaTimeFieldValueNames(

                        "gregory", Calendar.MONTH, textStyle.toCalendarStyle(), locale);

                Map<Long, String> map = new HashMap<>();

                if (displayNames != null) {

                    for (Entry<String, Integer> entry : displayNames.entrySet()) {

                        map.put((long) (entry.getValue() + 1), entry.getKey());

                    }

                } else {

                    // Narrow names may have duplicated names, such as "J" for January, Jun, July.

                    // Get names one by one in that case.

                    for (int month = Calendar.JANUARY; month <= Calendar.DECEMBER; month++) {

                        String name;

                        name = CalendarDataUtility.retrieveJavaTimeFieldValueName(

                                "gregory", Calendar.MONTH, month, textStyle.toCalendarStyle(), locale);

                        if (name == null) {

                            break;

                        }

                        map.put((long) (month + 1), name);

                    }

                }

                if (!map.isEmpty()) {

                    styleMap.put(textStyle, map);

                }

            }

            return new LocaleStore(styleMap);

        }

        if (field == DAY_OF_WEEK) {

            for (TextStyle textStyle : TextStyle.values()) {

                Map<String, Integer> displayNames = CalendarDataUtility.retrieveJavaTimeFieldValueNames(

                        "gregory", Calendar.DAY_OF_WEEK, textStyle.toCalendarStyle(), locale);

                Map<Long, String> map = new HashMap<>();

                if (displayNames != null) {

                    for (Entry<String, Integer> entry : displayNames.entrySet()) {

                        map.put((long)toWeekDay(entry.getValue()), entry.getKey());

                    }

                } else {

                    // Narrow names may have duplicated names, such as "S" for Sunday and Saturday.

                    // Get names one by one in that case.

                    for (int wday = Calendar.SUNDAY; wday <= Calendar.SATURDAY; wday++) {

                        String name;

                        name = CalendarDataUtility.retrieveJavaTimeFieldValueName(

                            "gregory", Calendar.DAY_OF_WEEK, wday, textStyle.toCalendarStyle(), locale);

                        if (name == null) {

                            break;

                        }

                        map.put((long)toWeekDay(wday), name);

                    }

                }

                if (!map.isEmpty()) {

                    styleMap.put(textStyle, map);

                }

            }

            return new LocaleStore(styleMap);

        }

        if (field == AMPM_OF_DAY) {

            for (TextStyle textStyle : TextStyle.values()) {

                if (textStyle.isStandalone()) {

                    // Stand-alone isn't applicable to AM/PM.

                    continue;

                }

                Map<String, Integer> displayNames = CalendarDataUtility.retrieveJavaTimeFieldValueNames(

                        "gregory", Calendar.AM_PM, textStyle.toCalendarStyle(), locale);

                if (displayNames != null) {

                    Map<Long, String> map = new HashMap<>();

                    for (Entry<String, Integer> entry : displayNames.entrySet()) {

                        map.put((long) entry.getValue(), entry.getKey());

                    }

                    if (!map.isEmpty()) {

                        styleMap.put(textStyle, map);

                    }

                }

            }

            return new LocaleStore(styleMap);

        }

        if (field == IsoFields.QUARTER_OF_YEAR) {

            // The order of keys must correspond to the TextStyle.values() order.

            final String[] keys = {

                "QuarterNames",

                "standalone.QuarterNames",

                "QuarterAbbreviations",

                "standalone.QuarterAbbreviations",

                "QuarterNarrows",

                "standalone.QuarterNarrows",

            };

            for (int i = 0; i < keys.length; i++) {

                String[] names = getLocalizedResource(keys[i], locale);

                if (names != null) {

                    Map<Long, String> map = new HashMap<>();

                    for (int q = 0; q < names.length; q++) {

                        map.put((long) (q + 1), names[q]);

                    }

                    styleMap.put(TextStyle.values()[i], map);

                }

            }

            return new LocaleStore(styleMap);

        }

        return "";  // null marker for map

    }

    /**

     * Helper method to create an immutable entry.

     *

     * @param text  the text, not null

     * @param field  the field, not null

     * @return the entry, not null

     */

    private static <A, B> Entry<A, B> createEntry(A text, B field) {

        return new SimpleImmutableEntry<>(text, field);

    }

    /**

     * Returns the localized resource of the given key and locale, or null

     * if no localized resource is available.

     *

     * @param key  the key of the localized resource, not null

     * @param locale  the locale, not null

     * @return the localized resource, or null if not available

     * @throws NullPointerException if key or locale is null

     */

    @SuppressWarnings("unchecked")

    static <T> T getLocalizedResource(String key, Locale locale) {

        LocaleResources lr = LocaleProviderAdapter.getResourceBundleBased()

                                    .getLocaleResources(locale);

        ResourceBundle rb = lr.getJavaTimeFormatData();

        return rb.containsKey(key) ? (T) rb.getObject(key) : null;

    }

    /**

     * Stores the text for a single locale.

     * <p>

     * Some fields have a textual representation, such as day-of-week or month-of-year.

     * These textual representations can be captured in this class for printing

     * and parsing.

     * <p>

     * This class is immutable and thread-safe.

     */

    static final class LocaleStore {

        /**

         * Map of value to text.

         */

        private final Map<TextStyle, Map<Long, String>> valueTextMap;

        /**

         * Parsable data.

         */

        private final Map<TextStyle, List<Entry<String, Long>>> parsable;

        /**

         * Constructor.

         *

         * @param valueTextMap  the map of values to text to store, assigned and not altered, not null