/*

 * 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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 */

import java.net.http.HttpClient;

import java.net.http.WebSocket;

import java.net.http.WebSocket.Builder;

import java.net.http.WebSocket.Listener;

import java.net.ProxySelector;

import java.net.URI;

import java.time.Duration;

import java.util.Collection;

import java.util.LinkedList;

import java.util.List;

import java.util.Optional;

import java.util.concurrent.CompletableFuture;

import static java.util.Objects.requireNonNull;

public final class BuilderImpl implements Builder {

    private final HttpClient client;

    private URI uri;

    private Listener listener;

    private final Optional<ProxySelector> proxySelector;

    private final Collection<Pair<String, String>> headers;

    private final Collection<String> subprotocols;

    private Duration timeout;

    public BuilderImpl(HttpClient client, ProxySelector proxySelector)

    {

        this(client, null, null, Optional.ofNullable(proxySelector),

             new LinkedList<>(), new LinkedList<>(), null);

    }

    private BuilderImpl(HttpClient client,

                        URI uri,

                        Listener listener,

                        Optional<ProxySelector> proxySelector,

                        Collection<Pair<String, String>> headers,

                        Collection<String> subprotocols,

                        Duration timeout) {

        this.client = client;

        this.uri = uri;

        this.listener = listener;

        this.proxySelector = proxySelector;

        // If a proxy selector was supplied by the user, it should be present

        // on the client and should be the same that what we got as an argument

        assert !client.proxy().isPresent()

                || client.proxy().equals(proxySelector);

        this.headers = headers;

        this.subprotocols = subprotocols;

        this.timeout = timeout;

    }

    @Override

    public Builder header(String name, String value) {

        requireNonNull(name, "name");

        requireNonNull(value, "value");

        headers.add(pair(name, value));

        return this;

    }

    @Override

    public Builder subprotocols(String mostPreferred, String... lesserPreferred)

    {

        requireNonNull(mostPreferred, "mostPreferred");

        requireNonNull(lesserPreferred, "lesserPreferred");

        List<String> subprotocols = new LinkedList<>();

        subprotocols.add(mostPreferred);

        for (int i = 0; i < lesserPreferred.length; i++) {

            String p = lesserPreferred[i];

            requireNonNull(p, "lesserPreferred[" + i + "]");

            subprotocols.add(p);

        }

        this.subprotocols.clear();

        this.subprotocols.addAll(subprotocols);

        return this;

    }

    @Override

    public Builder connectTimeout(Duration timeout) {

        this.timeout = requireNonNull(timeout, "timeout");

        return this;

    }

    @Override

    public CompletableFuture<WebSocket> buildAsync(URI uri, Listener listener) {

        this.uri = requireNonNull(uri, "uri");

        this.listener = requireNonNull(listener, "listener");

        // A snapshot of builder inaccessible for further modification

        // from the outside

        BuilderImpl copy = immutableCopy();

        return WebSocketImpl.newInstanceAsync(copy);

    }

    HttpClient getClient() { return client; }

    URI getUri() { return uri; }

    Listener getListener() { return listener; }

    Collection<Pair<String, String>> getHeaders() { return headers; }

    Collection<String> getSubprotocols() { return subprotocols; }

    Duration getConnectTimeout() { return timeout; }

    Optional<ProxySelector> getProxySelector() { return proxySelector; }

    private BuilderImpl immutableCopy() {

        @SuppressWarnings({"unchecked", "rawtypes"})

        BuilderImpl copy = new BuilderImpl(

                client,

                uri,

                listener,

                proxySelector,

                List.of(this.headers.toArray(new Pair[0])),

                List.of(this.subprotocols.toArray(new String[0])),

                timeout);

        return copy;

    }

}