// Copyright (c) 2014, Outercurve Foundation.
// All rights reserved.
//
// 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  Outercurve Foundation  nor   the   names  of  its
//   contributors may 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
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// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)  HOWEVER  CAUSED AND ON
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using System;
using System.Configuration;

namespace WebsitePanel.AWStats.Viewer
{
	/// <summary>
	/// Summary description for AuthenticationProvider.
	/// </summary>
	public abstract class AuthenticationProvider
	{
		private static AuthenticationProvider objProvider;

		public static AuthenticationProvider Instance
		{
			get
			{
				if (objProvider == null)
				{
                    string providerType = ConfigurationManager.AppSettings["AWStats.AuthenticationProvider"];
					if (providerType == null || providerType == "")
						throw new Exception("AuthenticationProvider implementation type is not specified");

					try
					{
						// instantiate provider
						objProvider = (AuthenticationProvider)Activator.CreateInstance(Type.GetType(providerType));
					}
					catch (Exception ex)
					{
						throw new Exception(String.Format("Can not instantiate '{0}' authentication provider",
							providerType), ex);
					}
				}
				return objProvider;
			}
		}

		public abstract AuthenticationResult AuthenticateUser(string domain, string username, string password);
	}

	public enum AuthenticationResult
	{
		OK,
		WrongUsername,
		WrongPassword,
		DomainNotFound
	}
}