/*

 * 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.common;

import java.net.http.HttpHeaders;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.Map;

import java.util.TreeMap;

/**

 * Implementation of HttpHeaders.

 *

 * The public HttpHeaders API provides a read-only view, while the

 * non-HttpHeaders members allow for implementation specific mutation, e.g.

 * during creation, etc.

 */

public class HttpHeadersImpl extends HttpHeaders {

    private final TreeMap<String, List<String>> headers;

    public HttpHeadersImpl() {

        headers = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);

    }

    @Override

    public Map<String, List<String>> map() {

        return Collections.unmodifiableMap(headersMap());

    }

    // non-HttpHeaders private mutators

    public HttpHeadersImpl deepCopy() {

        HttpHeadersImpl h1 = newDeepCopy();

        for (Map.Entry<String, List<String>> entry : headersMap().entrySet()) {

            List<String> valuesCopy = new ArrayList<>(entry.getValue());

            h1.headersMap().put(entry.getKey(), valuesCopy);

        }

        return h1;

    }

    public void addHeader(String name, String value) {

        headersMap().computeIfAbsent(name, k -> new ArrayList<>(1))

                    .add(value);

    }

    public void setHeader(String name, String value) {

        // headers typically have one value

        List<String> values = new ArrayList<>(1);

        values.add(value);

        headersMap().put(name, values);

    }

    public void clear() {

        headersMap().clear();

    }

    protected HttpHeadersImpl newDeepCopy() {

        return new HttpHeadersImpl();

    }

    protected Map<String, List<String>> headersMap() {

        return headers;

    }

}