/*
 *
 * MariaDB Client for Java
 *
 * Copyright (c) 2012-2014 Monty Program Ab.
 * Copyright (c) 2015-2017 MariaDB Ab.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this library; if not, write to Monty Program Ab info@montyprogram.com.
 *
 * This particular MariaDB Client for Java file is work
 * derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to
 * the following copyright and notice provisions:
 *
 * Copyright (c) 2009-2011, Marcus Eriksson
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice, this list
 * of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice, this
 * list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 *
 * Neither the name of the driver nor the names of its contributors may not be
 * used to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS  AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 */

package org.mariadb.jdbc.internal.com.send;

import com.sun.jna.Platform;
import org.mariadb.jdbc.internal.com.read.Buffer;
import org.mariadb.jdbc.internal.com.read.ErrorPacket;
import org.mariadb.jdbc.internal.com.send.gssapi.GssapiAuth;
import org.mariadb.jdbc.internal.com.send.gssapi.StandardGssapiAuthentication;
import org.mariadb.jdbc.internal.com.send.gssapi.WindowsNativeSspiAuthentication;
import org.mariadb.jdbc.internal.io.input.PacketInputStream;
import org.mariadb.jdbc.internal.io.output.PacketOutputStream;

import java.io.EOFException;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.sql.SQLException;

import static org.mariadb.jdbc.internal.com.Packet.ERROR;

public class SendGssApiAuthPacket extends AbstractAuthSwitchSendResponsePacket implements InterfaceAuthSwitchSendResponsePacket {
    private final PacketInputStream reader;

    public SendGssApiAuthPacket(PacketInputStream reader, String password, byte[] authData, int packSeq, String passwordCharacterEncoding) {
        super(packSeq, authData, password, passwordCharacterEncoding);
        this.reader = reader;
    }

    /**
     * Send native password stream.
     *
     * @param pos database socket
     * @throws IOException if a connection error occur
     */
    public void send(PacketOutputStream pos) throws IOException, SQLException {
        Buffer buffer = new Buffer(authData);
        final String serverPrincipalName = buffer.readStringNullEnd(StandardCharsets.UTF_8);
        String mechanisms = buffer.readStringNullEnd(StandardCharsets.UTF_8);
        if (mechanisms.isEmpty()) mechanisms = "Kerberos";

        GssapiAuth gssapiAuth = getAuthenticationMethod();
        gssapiAuth.authenticate(pos, serverPrincipalName, mechanisms);
    }


    @Override
    public void handleResultPacket(PacketInputStream reader) throws SQLException, IOException {
        try {
            Buffer buffer = reader.getPacket(true);
            if (buffer.getByteAt(0) == ERROR) {
                ErrorPacket ep = new ErrorPacket(buffer);
                String message = ep.getMessage();
                throw new SQLException("Could not connect: " + message, ep.getSqlState(), ep.getErrorNumber());
            }
        } catch (EOFException e) {
            throw new SQLException("Authentication exception", "28000", 1045, e);
        }
    }

    /**
     * Get authentication method according to classpath.
     * Windows native authentication is using Waffle-jna.
     *
     * @return authentication method
     */
    private GssapiAuth getAuthenticationMethod() {
        try {
            //Waffle-jna has jna as dependency, so if not available on classpath, just use standard authentication
            if (Platform.isWindows()) {
                try {
                    Class.forName("waffle.windows.auth.impl.WindowsAuthProviderImpl");
                    return new WindowsNativeSspiAuthentication(reader, packSeq);
                } catch (ClassNotFoundException cle) {
                    //waffle not in the classpath
                }
            }
        } catch (Throwable cle) {
            //jna jar's are not in classpath
        }
        return new StandardGssapiAuthentication(reader, packSeq);
    }

}

