//
//  ========================================================================
//  Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.jaas.spi;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import javax.security.auth.Subject;
import javax.security.auth.callback.CallbackHandler;

import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
import org.eclipse.jetty.util.security.Credential;

/**
 * AbstractDatabaseLoginModule
 *
 * Abstract base class for LoginModules that interact with a
 * database to retrieve authentication and authorization information.
 * Used by the JDBCLoginModule and DataSourceLoginModule.
 *
 */
public abstract class AbstractDatabaseLoginModule extends AbstractLoginModule
{
    private static final Logger LOG = Log.getLogger(AbstractDatabaseLoginModule.class);

    private String userQuery;
    private String rolesQuery;
    private String dbUserTable;
    private String dbUserTableUserField;
    private String dbUserTableCredentialField;
    private String dbUserRoleTable;
    private String dbUserRoleTableUserField;
    private String dbUserRoleTableRoleField;


    /**
     * @return a java.sql.Connection from the database
     * @throws Exception
     */
    public abstract Connection getConnection () throws Exception;


    /* ------------------------------------------------ */
    /** Load info from database
     * @param userName user info to load
     * @exception SQLException
     */
    public UserInfo getUserInfo (String userName)
        throws Exception
    {
        try (Connection connection = getConnection())
        {

            //query for credential
            String dbCredential = null;
            try (PreparedStatement statement = connection.prepareStatement (userQuery))
            {
                statement.setString (1, userName);
                try (ResultSet results = statement.executeQuery())
                {
                    if (results.next())
                    {
                        dbCredential = results.getString(1);
                    }
                }
            }

            if (dbCredential==null)
            {
                return null;
            }

            //query for role names
            List<String> roles = new ArrayList<String>();
            try (PreparedStatement statement = connection.prepareStatement (rolesQuery))
            {
                statement.setString (1, userName);
                try (ResultSet results = statement.executeQuery())
                {
                    while (results.next())
                    {
                        String roleName = results.getString (1);
                        roles.add (roleName);
                    }
                }
            }

            return new UserInfo (userName, Credential.getCredential(dbCredential), roles);
        }
    }


    public void initialize(Subject subject,
            CallbackHandler callbackHandler,
            Map<String,?> sharedState,
            Map<String,?> options)
    {
        super.initialize(subject, callbackHandler, sharedState, options);

        //get the user credential query out of the options
        dbUserTable = (String)options.get("userTable");
        dbUserTableUserField = (String)options.get("userField");
        dbUserTableCredentialField = (String)options.get("credentialField");

        userQuery = "select "+dbUserTableCredentialField+" from "+dbUserTable+" where "+dbUserTableUserField+"=?";


        //get the user roles query out of the options
        dbUserRoleTable = (String)options.get("userRoleTable");
        dbUserRoleTableUserField = (String)options.get("userRoleUserField");
        dbUserRoleTableRoleField = (String)options.get("userRoleRoleField");

        rolesQuery = "select "+dbUserRoleTableRoleField+" from "+dbUserRoleTable+" where "+dbUserRoleTableUserField+"=?";

        if(LOG.isDebugEnabled())LOG.debug("userQuery = "+userQuery);
        if(LOG.isDebugEnabled())LOG.debug("rolesQuery = "+rolesQuery);
    }
}