/*

 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * 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 com.sun.org.apache.xml.internal.serialize;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.io.UnsupportedEncodingException;

import java.io.Writer;

import com.sun.org.apache.xerces.internal.util.EncodingMap;

import java.nio.charset.Charset;

import java.nio.charset.CharsetEncoder;

/**

 * This class represents an encoding.

 *

 * @deprecated As of JDK 9, Xerces 2.9.0, Xerces DOM L3 Serializer implementation

 * is replaced by that of Xalan. Main class

 * {@link com.sun.org.apache.xml.internal.serialize.DOMSerializerImpl} is replaced

 * by {@link com.sun.org.apache.xml.internal.serializer.dom3.LSSerializerImpl}.

 */

@Deprecated

public class EncodingInfo {

    // name of encoding as registered with IANA;

    // preferably a MIME name, but aliases are fine too.

    String ianaName;

    String javaName;

    int lastPrintable;

    // The CharsetEncoder with which we test unusual characters.

    CharsetEncoder fCharsetEncoder = null;

    // Is the charset encoder usable or available.

    boolean fHaveTriedCharsetEncoder = false;

    /**

     * Creates new <code>EncodingInfo</code> instance.

     */

    public EncodingInfo(String ianaName, String javaName, int lastPrintable) {

        this.ianaName = ianaName;

        this.javaName = EncodingMap.getIANA2JavaMapping(ianaName);

        this.lastPrintable = lastPrintable;

    }

    /**

     * Returns a MIME charset name of this encoding.

     */

    public String getIANAName() {

        return this.ianaName;

    }

    /**

     * Returns a writer for this encoding based on

     * an output stream.

     *

     * @return A suitable writer

     * @exception UnsupportedEncodingException There is no convertor

     *  to support this encoding

     */

    public Writer getWriter(OutputStream output)

        throws UnsupportedEncodingException {

        // this should always be true!

        if (javaName != null)

            return new OutputStreamWriter(output, javaName);

        javaName = EncodingMap.getIANA2JavaMapping(ianaName);

        if(javaName == null)

            // use UTF-8 as preferred encoding

            return new OutputStreamWriter(output, "UTF8");

        return new OutputStreamWriter(output, javaName);

    }

    /**

     * Checks whether the specified character is printable or not in this encoding.

     *

     * @param ch a code point (0-0x10ffff)

     */

    public boolean isPrintable(char ch) {

        if (ch <= this.lastPrintable) {

            return true;

        }

        return isPrintable0(ch);

    }

    /**

     * Checks whether the specified character is printable or not in this encoding.

     * This method accomplishes this using a java.nio.CharsetEncoder. If NIO isn't

     * available it will attempt use a sun.io.CharToByteConverter.

     *

     * @param ch a code point (0-0x10ffff)

     */

    private boolean isPrintable0(char ch) {

        // Attempt to get a CharsetEncoder for this encoding.

        if (fCharsetEncoder == null && !fHaveTriedCharsetEncoder) {

            // try and create the CharsetEncoder

            try {

                Charset charset = java.nio.charset.Charset.forName(javaName);

                if (charset.canEncode()) {

                    fCharsetEncoder = charset.newEncoder();

                }

                // This charset cannot be used for encoding, don't try it again...

                else {

                    fHaveTriedCharsetEncoder = true;

                }

            }

            catch (Exception e) {

                // don't try it again...

                fHaveTriedCharsetEncoder = true;

            }

        }

        // Attempt to use the CharsetEncoder to determine whether the character is printable.

        if (fCharsetEncoder != null) {

            try {

                return fCharsetEncoder.canEncode(ch);

            }

            catch (Exception e) {

                // obviously can't use this charset encoder; possibly a JDK bug

                fCharsetEncoder = null;

                fHaveTriedCharsetEncoder = false;

            }

        }

        return false;

    }

    // is this an encoding name recognized by this JDK?

    // if not, will throw UnsupportedEncodingException

    public static void testJavaEncodingName(String name)  throws UnsupportedEncodingException {

        final byte [] bTest = {(byte)'v', (byte)'a', (byte)'l', (byte)'i', (byte)'d'};

        String s = new String(bTest, name);

    }

}