/*

 * Copyright (c) 1994, 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

 * questions.

 */

package sun.net;

import java.io.*;

import java.net.Socket;

import java.net.InetAddress;

import java.net.InetSocketAddress;

import java.net.UnknownHostException;

import java.net.Proxy;

import java.util.Arrays;

import java.security.AccessController;

import java.security.PrivilegedAction;

/**

 * This is the base class for network clients.

 *

 * @author      Jonathan Payne

 */

public class NetworkClient {

    /* Default value of read timeout, if not specified (infinity) */

    public static final int DEFAULT_READ_TIMEOUT = -1;

    /* Default value of connect timeout, if not specified (infinity) */

    public static final int DEFAULT_CONNECT_TIMEOUT = -1;

    protected Proxy     proxy = Proxy.NO_PROXY;

    /** Socket for communicating with server. */

    protected Socket    serverSocket = null;

    /** Stream for printing to the server. */

    public PrintStream  serverOutput;

    /** Buffered stream for reading replies from server. */

    public InputStream  serverInput;

    protected static int defaultSoTimeout;

    protected static int defaultConnectTimeout;

    protected int readTimeout = DEFAULT_READ_TIMEOUT;

    protected int connectTimeout = DEFAULT_CONNECT_TIMEOUT;

    /* Name of encoding to use for output */

    protected static String encoding;

    static {

        final int vals[] = {0, 0};

        final String encs[] = { null };

        AccessController.doPrivileged(

                new PrivilegedAction<>() {

                    public Void run() {

                        vals[0] = Integer.getInteger("sun.net.client.defaultReadTimeout", 0).intValue();

                        vals[1] = Integer.getInteger("sun.net.client.defaultConnectTimeout", 0).intValue();

                        encs[0] = System.getProperty("file.encoding", "ISO8859_1");

                        return null;

            }

        });

        if (vals[0] != 0) {

            defaultSoTimeout = vals[0];

        }

        if (vals[1] != 0) {

            defaultConnectTimeout = vals[1];

        }

        encoding = encs[0];

        try {

            if (!isASCIISuperset (encoding)) {

                encoding = "ISO8859_1";

            }

        } catch (Exception e) {

            encoding = "ISO8859_1";

        }

    }

    /**

     * Test the named character encoding to verify that it converts ASCII

     * characters correctly. We have to use an ASCII based encoding, or else

     * the NetworkClients will not work correctly in EBCDIC based systems.

     * However, we cannot just use ASCII or ISO8859_1 universally, because in

     * Asian locales, non-ASCII characters may be embedded in otherwise

     * ASCII based protocols (e.g. HTTP). The specifications (RFC2616, 2398)

     * are a little ambiguous in this matter. For instance, RFC2398 [part 2.1]

     * says that the HTTP request URI should be escaped using a defined

     * mechanism, but there is no way to specify in the escaped string what

     * the original character set is. It is not correct to assume that

     * UTF-8 is always used (as in URLs in HTML 4.0).  For this reason,

     * until the specifications are updated to deal with this issue more

     * comprehensively, and more importantly, HTTP servers are known to

     * support these mechanisms, we will maintain the current behavior

     * where it is possible to send non-ASCII characters in their original

     * unescaped form.

     */

    private static boolean isASCIISuperset (String encoding) throws Exception {

        String chkS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"+

                        "abcdefghijklmnopqrstuvwxyz-_.!~*'();/?:@&=+$,";

        // Expected byte sequence for string above

        byte[] chkB = { 48,49,50,51,52,53,54,55,56,57,65,66,67,68,69,70,71,72,

                73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,97,98,99,

                100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,

                115,116,117,118,119,120,121,122,45,95,46,33,126,42,39,40,41,59,

                47,63,58,64,38,61,43,36,44};

        byte[] b = chkS.getBytes (encoding);

        return Arrays.equals (b, chkB);

    }

    /** Open a connection to the server. */

    public void openServer(String server, int port)

        throws IOException, UnknownHostException {

        if (serverSocket != null)

            closeServer();

        serverSocket = doConnect (server, port);

        try {

            serverOutput = new PrintStream(new BufferedOutputStream(

                                        serverSocket.getOutputStream()),

                                        true, encoding);

        } catch (UnsupportedEncodingException e) {

            throw new InternalError(encoding +"encoding not found", e);

        }

        serverInput = new BufferedInputStream(serverSocket.getInputStream());

    }

    /**

     * Return a socket connected to the server, with any

     * appropriate options pre-established

     */

    protected Socket doConnect (String server, int port)

    throws IOException, UnknownHostException {

        Socket s;

        if (proxy != null) {

            if (proxy.type() == Proxy.Type.SOCKS) {

                s = AccessController.doPrivileged(

                    new PrivilegedAction<>() {

                        public Socket run() {

                                       return new Socket(proxy);

                                   }});

            } else if (proxy.type() == Proxy.Type.DIRECT) {

                s = createSocket();

            } else {

                // Still connecting through a proxy

                // server & port will be the proxy address and port

                s = new Socket(Proxy.NO_PROXY);

            }

        } else {

            s = createSocket();

        }

        // Instance specific timeouts do have priority, that means

        // connectTimeout & readTimeout (-1 means not set)

        // Then global default timeouts

        // Then no timeout.

        if (connectTimeout >= 0) {

            s.connect(new InetSocketAddress(server, port), connectTimeout);

        } else {

            if (defaultConnectTimeout > 0) {

                s.connect(new InetSocketAddress(server, port), defaultConnectTimeout);

            } else {

                s.connect(new InetSocketAddress(server, port));

            }

        }

        if (readTimeout >= 0)

            s.setSoTimeout(readTimeout);

        else if (defaultSoTimeout > 0) {

            s.setSoTimeout(defaultSoTimeout);

        }

        return s;

    }

    /**

     * The following method, createSocket, is provided to allow the

     * https client to override it so that it may use its socket factory

     * to create the socket.

     */

    protected Socket createSocket() throws IOException {

        return new java.net.Socket(Proxy.NO_PROXY);  // direct connection

    }

    protected InetAddress getLocalAddress() throws IOException {

        if (serverSocket == null)

            throw new IOException("not connected");

        return  AccessController.doPrivileged(

                        new PrivilegedAction<>() {

                            public InetAddress run() {

                                return serverSocket.getLocalAddress();

                            }

                        });

    }

    /** Close an open connection to the server. */

    public void closeServer() throws IOException {

        if (! serverIsOpen()) {

            return;

        }

        serverSocket.close();

        serverSocket = null;

        serverInput = null;

        serverOutput = null;

    }

    /** Return server connection status */

    public boolean serverIsOpen() {

        return serverSocket != null;

    }

    /** Create connection with host <i>host</i> on port <i>port</i> */

    public NetworkClient(String host, int port) throws IOException {

        openServer(host, port);

    }

    public NetworkClient() {}

    public void setConnectTimeout(int timeout) {

        connectTimeout = timeout;

    }

    public int getConnectTimeout() {

        return connectTimeout;

    }

    /**

     * Sets the read timeout.

     *

     * Note: Public URLConnection (and protocol specific implementations)

     * protect against negative timeout values being set. This implementation,

     * and protocol specific implementations, use -1 to represent the default

     * read timeout.

     *

     * This method may be invoked with the default timeout value when the

     * protocol handler is trying to reset the timeout after doing a

     * potentially blocking internal operation, e.g. cleaning up unread

     * response data, buffering error stream response data, etc

     */

    public void setReadTimeout(int timeout) {

        if (timeout == DEFAULT_READ_TIMEOUT)

            timeout = defaultSoTimeout;

        if (serverSocket != null && timeout >= 0) {

            try {

                serverSocket.setSoTimeout(timeout);

            } catch(IOException e) {

                // We tried...

            }

        }

        readTimeout = timeout;

    }

    public int getReadTimeout() {

        return readTimeout;

    }

}