/*
 * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */
package jdk.internal.net.http.hpack;

import java.nio.ByteBuffer;

abstract class IndexNameValueWriter implements BinaryRepresentationWriter {

    private final int pattern;
    private final int prefix;
    private final IntegerWriter intWriter = new IntegerWriter();
    private final StringWriter nameWriter = new StringWriter();
    private final StringWriter valueWriter = new StringWriter();

    protected boolean indexedRepresentation;

    private static final int NEW               = 0;
    private static final int NAME_PART_WRITTEN = 1;
    private static final int VALUE_WRITTEN     = 2;

    private int state = NEW;

    protected IndexNameValueWriter(int pattern, int prefix) {
        this.pattern = pattern;
        this.prefix = prefix;
    }

    IndexNameValueWriter index(int index) {
        indexedRepresentation = true;
        intWriter.configure(index, prefix, pattern);
        return this;
    }

    IndexNameValueWriter name(CharSequence name, boolean useHuffman) {
        indexedRepresentation = false;
        intWriter.configure(0, prefix, pattern);
        nameWriter.configure(name, useHuffman);
        return this;
    }

    IndexNameValueWriter value(CharSequence value, boolean useHuffman) {
        valueWriter.configure(value, useHuffman);
        return this;
    }

    @Override
    public boolean write(HeaderTable table, ByteBuffer destination) {
        if (state < NAME_PART_WRITTEN) {
            if (indexedRepresentation) {
                if (!intWriter.write(destination)) {
                    return false;
                }
            } else {
                if (!intWriter.write(destination) ||
                        !nameWriter.write(destination)) {
                    return false;
                }
            }
            state = NAME_PART_WRITTEN;
        }
        if (state < VALUE_WRITTEN) {
            if (!valueWriter.write(destination)) {
                return false;
            }
            state = VALUE_WRITTEN;
        }
        return state == VALUE_WRITTEN;
    }

    @Override
    public IndexNameValueWriter reset() {
        intWriter.reset();
        if (!indexedRepresentation) {
            nameWriter.reset();
        }
        valueWriter.reset();
        state = NEW;
        return this;
    }
}
