/*

 * Copyright (c) 2009, 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.www.protocol.http;

import java.net.URL;

import java.net.PasswordAuthentication;

import java.lang.reflect.Constructor;

import java.lang.reflect.Method;

import sun.util.logging.PlatformLogger;

/**

 * Proxy class for loading NTLMAuthentication, so as to remove static

 * dependancy.

 */

class NTLMAuthenticationProxy {

    private static Method supportsTA;

    private static final String clazzStr = "sun.net.www.protocol.http.ntlm.NTLMAuthentication";

    private static final String supportsTAStr = "supportsTransparentAuth";

    static final NTLMAuthenticationProxy proxy = tryLoadNTLMAuthentication();

    static final boolean supported = proxy != null ? true : false;

    static final boolean supportsTransparentAuth = supported ? supportsTransparentAuth(supportsTA) : false;

    private final Constructor<? extends AuthenticationInfo> threeArgCtr;

    private final Constructor<? extends AuthenticationInfo> fiveArgCtr;

    private NTLMAuthenticationProxy(Constructor<? extends AuthenticationInfo> threeArgCtr,

                                    Constructor<? extends AuthenticationInfo> fiveArgCtr) {

        this.threeArgCtr = threeArgCtr;

        this.fiveArgCtr = fiveArgCtr;

    }

    AuthenticationInfo create(boolean isProxy,

                              URL url,

                              PasswordAuthentication pw) {

        try {

            return threeArgCtr.newInstance(isProxy, url, pw);

        } catch (ReflectiveOperationException roe) {

            finest(roe);

        }

        return null;

    }

    AuthenticationInfo create(boolean isProxy,

                              String host,

                              int port,

                              PasswordAuthentication pw) {

        try {

            return fiveArgCtr.newInstance(isProxy, host, port, pw);

        } catch (ReflectiveOperationException roe) {

            finest(roe);

        }

        return null;

    }

    /* Returns true if the NTLM implementation supports transparent

     * authentication (try with the current users credentials before

     * prompting for username and password, etc).

     */

    private static boolean supportsTransparentAuth(Method method) {

        try {

            return (Boolean)method.invoke(null);

        } catch (ReflectiveOperationException roe) {

            finest(roe);

        }

        return false;

    }

    /**

     * Loads the NTLM authentiation implementation through reflection. If

     * the class is present, then it must have the required constructors and

     * method. Otherwise, it is considered an error.

     */

    @SuppressWarnings("unchecked")

    private static NTLMAuthenticationProxy tryLoadNTLMAuthentication() {

        Class<? extends AuthenticationInfo> cl;

        Constructor<? extends AuthenticationInfo> threeArg, fiveArg;

        try {

            cl = (Class<? extends AuthenticationInfo>)Class.forName(clazzStr, true, null);

            if (cl != null) {

                threeArg = cl.getConstructor(boolean.class,

                                             URL.class,

                                             PasswordAuthentication.class);

                fiveArg = cl.getConstructor(boolean.class,

                                            String.class,

                                            int.class,

                                            PasswordAuthentication.class);

                supportsTA = cl.getDeclaredMethod(supportsTAStr);

                return new NTLMAuthenticationProxy(threeArg,

                                                   fiveArg);

            }

        } catch (ClassNotFoundException cnfe) {

            finest(cnfe);

        } catch (ReflectiveOperationException roe) {

            throw new AssertionError(roe);

        }

        return null;

    }

    static void finest(Exception e) {

        PlatformLogger logger = HttpURLConnection.getHttpLogger();

        logger.finest("NTLMAuthenticationProxy: " + e);

    }

}