/*

 * Copyright (c) 2015, 2018, 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 jdk.internal.net.http.hpack;

import java.io.IOException;

import java.nio.ByteBuffer;

//

// Custom implementation of ISO/IEC 8859-1:1998

//

// The rationale behind this is not to deal with CharsetEncoder/CharsetDecoder,

// basically because it would require wrapping every single CharSequence into a

// CharBuffer and then copying it back.

//

// But why not to give a CharBuffer instead of Appendable? Because I can choose

// an Appendable (e.g. StringBuilder) that adjusts its length when needed and

// therefore not to deal with pre-sized CharBuffers or copying.

//

// The encoding is simple and well known: 1 byte <-> 1 char

//

final class ISO_8859_1 {

    private ISO_8859_1() { }

    public static final class Reader {

        public void read(ByteBuffer source, Appendable destination)

                throws IOException {

            for (int i = 0, len = source.remaining(); i < len; i++) {

                char c = (char) (source.get() & 0xff);

                try {

                    destination.append(c);

                } catch (IOException e) {

                    throw new IOException(

                            "Error appending to the destination", e);

                }

            }

        }

        public Reader reset() {

            return this;

        }

    }

    public static final class Writer {

        private CharSequence source;

        private int pos;

        private int end;

        public Writer configure(CharSequence source, int start, int end) {

            this.source = source;

            this.pos = start;

            this.end = end;

            return this;

        }

        public boolean write(ByteBuffer destination) {

            for (; pos < end; pos++) {

                char c = source.charAt(pos);

                if (c > '\u00FF') {

                    throw new IllegalArgumentException(

                            "Illegal ISO-8859-1 char: " + (int) c);

                }

                if (destination.hasRemaining()) {

                    destination.put((byte) c);

                } else {

                    return false;

                }

            }

            return true;

        }

        public Writer reset() {

            source = null;

            pos = -1;

            end = -1;

            return this;

        }

    }

}