﻿// Copyright © 2012, Oracle and/or its affiliates. All rights reserved.
//
// MySQL Connector/NET is licensed under the terms of the GPLv2
// <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most 
// MySQL Connectors. There are special exceptions to the terms and 
// conditions of the GPLv2 as it is applied to this software, see the 
// FLOSS License Exception
// <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
//
// This program is free software; you can redistribute it and/or modify 
// it under the terms of the GNU General Public License as published 
// by the Free Software Foundation; version 2 of the License.
//
// This program 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 
// for more details.
//
// You should have received a copy of the GNU General Public License along 
// with this program; if not, write to the Free Software Foundation, Inc., 
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

using System;
using System.Collections.Generic;
using System.Reflection;
using MySql.Data.MySqlClient.Properties;

namespace MySql.Data.MySqlClient.Authentication {
    internal class AuthenticationPluginManager {
        private static readonly Dictionary<string, PluginInfo> Plugins = new Dictionary<string, PluginInfo>();

        static AuthenticationPluginManager() {
            Plugins[ "mysql_native_password" ] = new PluginInfo( "MySql.Data.MySqlClient.Authentication.MySqlNativePasswordPlugin" );
            Plugins[ "sha256_password" ] = new PluginInfo( "MySql.Data.MySqlClient.Authentication.Sha256AuthenticationPlugin" );
            Plugins[ "authentication_windows_client" ] = new PluginInfo( "MySql.Data.MySqlClient.Authentication.MySqlWindowsAuthenticationPlugin" );
            if ( MySqlConfiguration.Settings?.AuthenticationPlugins == null ) return;
            foreach ( var e in MySqlConfiguration.Settings.AuthenticationPlugins ) Plugins[ e.Name ] = new PluginInfo( e.Type );
        }

        public static MySqlAuthenticationPlugin GetPlugin( string method ) {
            if ( !Plugins.ContainsKey( method ) ) throw new MySqlException( String.Format( Resources.AuthenticationMethodNotSupported, method ) );
            return CreatePlugin( method );
        }

        private static MySqlAuthenticationPlugin CreatePlugin( string method ) {
            var pi = Plugins[ method ];
            try {
                return (MySqlAuthenticationPlugin) Activator.CreateInstance( Type.GetType( pi.Type ) );
            }
            catch ( Exception e ) {
                throw new MySqlException( String.Format( Resources.UnableToCreateAuthPlugin, method ), e );
            }
        }
    }

    internal struct PluginInfo {
        public string Type;
        public Assembly Assembly;

        public PluginInfo( string type ) {
            Type = type;
            Assembly = null;
        }
    }
}