/*

 * Copyright (c) 2000, 2021, 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 java.nio;

import java.util.Objects;

// ## If the sequence is a string, use reflection to share its array

class StringCharBuffer                                  // package-private

    extends CharBuffer

{

    CharSequence str;

    StringCharBuffer(CharSequence s, int start, int end) { // package-private

        super(-1, start, end, s.length(), null);

        int n = s.length();

        Objects.checkFromToIndex(start, end, n);

        str = s;

        this.isReadOnly = true;

    }

    public CharBuffer slice() {

        int pos = this.position();

        int lim = this.limit();

        int rem = (pos <= lim ? lim - pos : 0);

        return new StringCharBuffer(str,

                                    -1,

                                    0,

                                    rem,

                                    rem,

                                    offset + pos);

    }

    @Override

    public CharBuffer slice(int index, int length) {

        Objects.checkFromIndexSize(index, length, limit());

        return new StringCharBuffer(str,

                                    -1,

                                    0,

                                    length,

                                    length,

                                    offset + index);

    }

    private StringCharBuffer(CharSequence s,

                             int mark,

                             int pos,

                             int limit,

                             int cap,

                             int offset) {

        super(mark, pos, limit, cap, null, offset, null);

        str = s;

        this.isReadOnly = true;

    }

    public CharBuffer duplicate() {

        return new StringCharBuffer(str, markValue(),

                                    position(), limit(), capacity(), offset);

    }

    public CharBuffer asReadOnlyBuffer() {

        return duplicate();

    }

    public final char get() {

        return str.charAt(nextGetIndex() + offset);

    }

    public final char get(int index) {

        return str.charAt(checkIndex(index) + offset);

    }

    char getUnchecked(int index) {

        return str.charAt(index + offset);

    }

    // ## Override bulk get methods for better performance

    public final CharBuffer put(char c) {

        throw new ReadOnlyBufferException();

    }

    public final CharBuffer put(int index, char c) {

        throw new ReadOnlyBufferException();

    }

    public final CharBuffer compact() {

        throw new ReadOnlyBufferException();

    }

    public final boolean isReadOnly() {

        return true;

    }

    final String toString(int start, int end) {

        return str.subSequence(start + offset, end + offset).toString();

    }

    public final CharBuffer subSequence(int start, int end) {

        try {

            int pos = position();

            return new StringCharBuffer(str,

                                        -1,

                                        pos + checkIndex(start, pos),

                                        pos + checkIndex(end, pos),

                                        capacity(),

                                        offset);

        } catch (IllegalArgumentException x) {

            throw new IndexOutOfBoundsException();

        }

    }

    public boolean isDirect() {

        return false;

    }

    public ByteOrder order() {

        return ByteOrder.nativeOrder();

    }

    ByteOrder charRegionOrder() {

        return null;

    }

    boolean isAddressable() {

        return false;

    }

    public boolean equals(Object ob) {

        if (this == ob)

            return true;

        if (!(ob instanceof CharBuffer that))

            return false;

        int thisPos = this.position();

        int thisRem = this.limit() - thisPos;

        int thatPos = that.position();

        int thatRem = that.limit() - thatPos;

        if (thisRem < 0 || thisRem != thatRem)

            return false;

        return BufferMismatch.mismatch(this, thisPos,

                                       that, thatPos,

                                       thisRem) < 0;

    }

    public int compareTo(CharBuffer that) {

        int thisPos = this.position();

        int thisRem = this.limit() - thisPos;

        int thatPos = that.position();

        int thatRem = that.limit() - thatPos;

        int length = Math.min(thisRem, thatRem);

        if (length < 0)

            return -1;

        int i = BufferMismatch.mismatch(this, thisPos,

                                        that, thatPos,

                                        length);

        if (i >= 0) {

            return Character.compare(this.get(thisPos + i), that.get(thatPos + i));

        }

        return thisRem - thatRem;

    }

}