/*

 * Copyright (c) 2015, 2016, 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

 */

package java.net.http;

import java.io.IOException;

import java.net.InetSocketAddress;

import java.net.URI;

import java.util.concurrent.CompletableFuture;

import java.util.Collections;

import java.util.LinkedList;

import java.util.List;

/**

 * Encapsulates one HTTP/1.1 request/responseAsync exchange.

 */

class Http1Exchange extends ExchangeImpl {

    final HttpRequestImpl request;        // main request

    final List<CompletableFuture<?>> operations; // used for cancel

    final Http1Request requestAction;

    volatile Http1Response response;

    final HttpConnection connection;

    final HttpClientImpl client;

    final ExecutorWrapper executor;

    @Override

    public String toString() {

        return request.toString();

    }

    HttpRequestImpl request() {

        return request;

    }

    Http1Exchange(Exchange exchange, HttpConnection connection)

        throws IOException

    {

        super(exchange);

        this.request = exchange.request();

        this.client = request.client();

        this.executor = client.executorWrapper();

        this.operations = Collections.synchronizedList(new LinkedList<>());

        if (connection != null) {

            this.connection = connection;

        } else {

            InetSocketAddress addr = Utils.getAddress(request);

            this.connection = HttpConnection.getConnection(addr, request);

        }

        this.requestAction = new Http1Request(request, this.connection);

    }

    HttpConnection connection() {

        return connection;

    }

    @Override

    <T> T responseBody(HttpResponse.BodyProcessor<T> processor)

        throws IOException

    {

        return responseBody(processor, true);

    }

    <T> T responseBody(HttpResponse.BodyProcessor<T> processor,

                       boolean return2Cache)

        throws IOException

    {

        try {

            T body = response.readBody(processor, return2Cache);

            return body;

        } catch (Throwable t) {

            connection.close();

            throw t;

        }

    }

    @Override

    <T> CompletableFuture<T> responseBodyAsync(HttpResponse.BodyProcessor<T> processor) {

        CompletableFuture<T> cf = new CompletableFuture<>();

        request.client()

               .executorWrapper()

               .execute(() -> {

                            try {

                                T body = responseBody(processor);

                                cf.complete(body);

                            } catch (Throwable e) {

                                cf.completeExceptionally(e);

                            }

                        },

                        () -> response.response.getAccessControlContext()); // TODO: fix

        return cf;

    }

    @Override

    void sendHeadersOnly() throws IOException, InterruptedException {

        try {

            if (!connection.connected()) {

                connection.connect();

            }

            requestAction.sendHeadersOnly();

        } catch (Throwable e) {

            connection.close();

            throw e;

        }

    }

    @Override

    void sendBody() throws IOException {

        try {

            requestAction.continueRequest();

        } catch (Throwable e) {

            connection.close();

            throw e;

        }

    }

    @Override

    HttpResponseImpl getResponse() throws IOException {

        try {

            response = new Http1Response(connection, this);

            response.readHeaders();

            return response.response();

        } catch (Throwable t) {

            connection.close();

            throw t;

        }

    }

    @Override

    void sendRequest() throws IOException, InterruptedException {

        try {

            if (!connection.connected()) {

                connection.connect();

            }

            requestAction.sendRequest();

        } catch (Throwable t) {

            connection.close();

            throw t;

        }

    }

    private void closeConnection() {

        connection.close();

    }

    @Override

    CompletableFuture<Void> sendHeadersAsync() {

        if (!connection.connected()) {

            CompletableFuture<Void> op = connection.connectAsync()

                    .thenCompose(this::sendHdrsAsyncImpl)

                    .whenComplete((Void b, Throwable t) -> {

                        if (t != null)

                            closeConnection();

                    });

            operations.add(op);

            return op;

        } else {

            return sendHdrsAsyncImpl(null);

        }

    }

    private CompletableFuture<Void> sendHdrsAsyncImpl(Void v) {

        CompletableFuture<Void> cf = new CompletableFuture<>();

        executor.execute(() -> {

                            try {

                                requestAction.sendHeadersOnly();

                                cf.complete(null);

                            } catch (Throwable e) {

                                cf.completeExceptionally(e);

                                connection.close();

                            }

                         },

                request::getAccessControlContext);

        operations.add(cf);

        return cf;

    }

    /**

     * Cancel checks to see if request and responseAsync finished already.

     * If not it closes the connection and completes all pending operations

     */

    @Override

    synchronized void cancel() {

        if (requestAction != null && requestAction.finished()

                && response != null && response.finished()) {

            return;

        }

        connection.close();

        IOException e = new IOException("Request cancelled");

        int count = 0;

        for (CompletableFuture<?> cf : operations) {

            cf.completeExceptionally(e);

            count++;

        }

        Log.logError("Http1Exchange.cancel: count=" + count);

    }

    CompletableFuture<HttpResponseImpl> getResponseAsyncImpl(Void v) {

        CompletableFuture<HttpResponseImpl> cf = new CompletableFuture<>();

        try {

            response = new Http1Response(connection, Http1Exchange.this);

            response.readHeaders();

            cf.complete(response.response());

        } catch (IOException e) {

            cf.completeExceptionally(e);

        }

        return cf;

    }

    @Override

    CompletableFuture<HttpResponseImpl> getResponseAsync(Void v) {

        CompletableFuture<HttpResponseImpl> cf =

            connection.whenReceivingResponse()

                      .thenCompose(this::getResponseAsyncImpl);

        operations.add(cf);

        return cf;

    }

    @Override

    CompletableFuture<Void> sendBodyAsync() {

        final CompletableFuture<Void> cf = new CompletableFuture<>();

        executor.execute(() -> {

            try {

                requestAction.continueRequest();

                cf.complete(null);

            } catch (Throwable e) {

                cf.completeExceptionally(e);

                connection.close();

            }

        }, request::getAccessControlContext);

        operations.add(cf);

        return cf;

    }

    @Override

    CompletableFuture<Void> sendRequestAsync() {

        CompletableFuture<Void> op;

        if (!connection.connected()) {

            op = connection.connectAsync()

                .thenCompose(this::sendRequestAsyncImpl)

                .whenComplete((Void v, Throwable t) -> {

                    if (t != null) {

                        closeConnection();

                    }

                });

        } else {

            op = sendRequestAsyncImpl(null);

        }

        operations.add(op);

        return op;

    }

    CompletableFuture<Void> sendRequestAsyncImpl(Void v) {

        CompletableFuture<Void> cf = new CompletableFuture<>();

        executor.execute(() -> {

            try {

                requestAction.sendRequest();

                cf.complete(null);

            } catch (Throwable e) {

                cf.completeExceptionally(e);

                connection.close();

            }

        }, request::getAccessControlContext);

        operations.add(cf);

        return cf;

    }

}