/*
 * Copyright (c) 2000, 2017, 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.
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 */

// -- This file was mechanically generated: Do not edit! -- //

package sun.nio.cs;

import java.nio.charset.Charset;
import java.nio.charset.spi.CharsetProvider;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import jdk.internal.vm.annotation.Stable;
import sun.security.action.GetPropertyAction;

public class StandardCharsets extends CharsetProvider {

    _INCLUDE_ALIASES_TABLES_
    _INCLUDE_ALIASES_MAP_
    _INCLUDE_CLASSES_MAP_
    _INCLUDE_CACHE_MAP_

    // Maps canonical names to class names
    private @Stable Map<String,String> classMap;

    // Maps alias names to canonical names
    private @Stable Map<String,String> aliasMap;

    // Maps canonical names to cached instances
    private @Stable Map<String,Charset> cache;

    private static final String packagePrefix = "sun.nio.cs.";

    public StandardCharsets() {
    }

    private String canonicalize(String csn) {
        String acn = aliasMap().get(csn);
        return (acn != null) ? acn : csn;
    }

    private Map<String,String> aliasMap() {
        Map<String,String> map = aliasMap;
        if (map == null) {
            aliasMap = map = new Aliases();
        }
        return map;
    }

    private Map<String,String> classMap() {
        Map<String,String> map = classMap;
        if (map == null) {
            classMap = map = new Classes();
        }
        return map;
    }

    private Map<String,Charset> cache() {
        Map<String,Charset> map = cache;
        if (map == null) {
            map = new Cache();
            map.put("utf-8", java.nio.charset.StandardCharsets.UTF_8);
            map.put("iso-8859-1", java.nio.charset.StandardCharsets.ISO_8859_1);
            map.put("us-ascii", java.nio.charset.StandardCharsets.US_ASCII);
            map.put("utf-16", java.nio.charset.StandardCharsets.UTF_16);
            map.put("utf-16be", java.nio.charset.StandardCharsets.UTF_16BE);
            map.put("utf-16le", java.nio.charset.StandardCharsets.UTF_16LE);
            cache = map;
        }
        return map;
    }

    // Private ASCII-only version, optimized for interpretation during startup
    //
    private static String toLower(String s) {
        int n = s.length();
        boolean allLower = true;
        for (int i = 0; i < n; i++) {
            int c = s.charAt(i);
            if (((c - 'A') | ('Z' - c)) >= 0) {
                allLower = false;
                break;
            }
        }
        if (allLower)
            return s;
        StringBuilder sb = new StringBuilder(n);
        for (int i = 0; i < n; i++) {
            int c = s.charAt(i);
            if (((c - 'A') | ('Z' - c)) >= 0)
                sb.append((char)(c + 0x20));
            else
                sb.append((char)c);
        }
        return sb.toString();
    }

    private Charset lookup(String charsetName) {
        init();

        // By checking these built-ins we can avoid initializing Aliases and
        // Classes eagerly during bootstrap
        String csn;
        if (charsetName.equals("UTF-8")) {
            return java.nio.charset.StandardCharsets.UTF_8;
        } else if (charsetName.equals("US-ASCII")) {
            return java.nio.charset.StandardCharsets.US_ASCII;
        } else if (charsetName.equals("ISO-8859-1")) {
            return java.nio.charset.StandardCharsets.ISO_8859_1;
        } else {
            csn = canonicalize(toLower(charsetName));
        }

        // Check cache first
        Charset cs = cache().get(csn);
        if (cs != null)
            return cs;

        // Do we even support this charset?
        String cln = classMap().get(csn);
        if (cln == null)
            return null;

        // Instantiate the charset and cache it
        try {
            @SuppressWarnings("deprecation")
            Object o = Class.forName(packagePrefix + cln,
                                     true,
                                     this.getClass().getClassLoader()).newInstance();
            return cache(csn, (Charset)o);
        } catch (ClassNotFoundException |
                 IllegalAccessException |
                 InstantiationException x) {
            return null;
        }
    }

    private Charset cache(String csn, Charset cs) {
        cache().put(csn, cs);
        return cs;
    }

    public final Charset charsetForName(String charsetName) {
        synchronized (this) {
            return lookup(charsetName);
        }
    }

    public final Iterator<Charset> charsets() {
        Set<String> charsetNames;
        synchronized (this) {
            init();
            // Ensure initialized in synchronized block
            charsetNames = classMap().keySet();
            aliasMap();
            cache();
        }
        return new Iterator<Charset>() {

                Iterator<String> i = charsetNames.iterator();

                public boolean hasNext() {
                    return i.hasNext();
                }

                public Charset next() {
                    String csn = i.next();
                    return lookup(csn);
                }

                public void remove() {
                    throw new UnsupportedOperationException();
                }

            };
    }

    private boolean initialized = false;

    /*   provider the sun.nio.cs.map property fir sjis/ms932 mapping hack
     */
    private void init() {
        if (initialized)
            return;
        if (!jdk.internal.misc.VM.isBooted())
            return;
        initialized = true;

        String map = GetPropertyAction.privilegedGetProperty("sun.nio.cs.map");
        if (map != null) {
            Map<String,String> aliasMap = aliasMap();
            Map<String,String> classMap = classMap();
            String[] maps = map.split(",");
            for (int i = 0; i < maps.length; i++) {
                if (maps[i].equalsIgnoreCase("Windows-31J/Shift_JIS")) {
                    // if we dont have both sjis and ms932, do nothing
                    if (classMap.get("shift_jis") == null ||
                        classMap.get("windows-31j") == null) {
                        break;
                    }
                    aliases_MS932 = new String[] {
                        "MS932",        // JDK historical
                        "windows-932",
                        "csWindows31J",
                        "shift-jis",
                        "ms_kanji",
                        "x-sjis",
                        "csShiftJIS",
                        // This alias takes precedence over the actual
                        // Shift_JIS charset itself since aliases are always
                        // resolved first, before looking up canonical names.
                        "shift_jis"
                    };
                    aliases_SJIS = new String[] { "sjis" };

                    for (String alias : aliases_MS932) {
                        aliasMap.put(toLower(alias), "windows-31j");
                    }
                    cache().put("shift_jis", null);
                    break;
                }
            }
        }
    }

}