/* 
 * Copyright (c) 2008 Intel Corporation
 * 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 Intel Corporation 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 INTEL OR ITS
 * 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.
 */

using System;
using System.Collections.Generic;
using ExtensionLoader;
using OpenMetaverse;

namespace GridServer.Extensions
{
    public class SimpleSessions : IExtension<GridServer>, ISessionProvider
    {
        GridServer server;
        ExpiringCache<UUID, UUID> authTokenToAvatar = new ExpiringCache<UUID, UUID>();
        Dictionary<UUID, UUID> avatarToAuthToken = new Dictionary<UUID, UUID>();
        object syncRoot = new object();

        public SimpleSessions()
        {
        }

        public void Start(GridServer server)
        {
            this.server = server;
        }

        public void Stop()
        {
        }

        public UUID CreateSession(UUID avatarID)
        {
            lock (syncRoot)
            {
                Avatar avatar;
                if (server.AvatarProvider.TryGetAvatar(avatarID, out avatar))
                {
                    UUID authToken = UUID.Random();

                    authTokenToAvatar.AddOrUpdate(authToken, avatarID, TimeSpan.FromMinutes(30));
                    avatarToAuthToken[avatarID] = authToken;

                    return authToken;
                }
                else
                {
                    return UUID.Zero;
                }
            }
        }

        public bool RemoveSession(UUID authToken)
        {
            lock (syncRoot)
            {
                UUID avatarID;
                if (authTokenToAvatar.TryGetValue(authToken, out avatarID))
                {
                    avatarToAuthToken.Remove(avatarID);
                    return authTokenToAvatar.Remove(authToken);
                }
                else
                {
                    return false;
                }
            }
        }

        public bool RemoveSessionByAvatarID(UUID avatarID)
        {
            lock (syncRoot)
            {
                UUID authToken;
                if (avatarToAuthToken.TryGetValue(avatarID, out authToken))
                {
                    authTokenToAvatar.Remove(authToken);
                    return avatarToAuthToken.Remove(avatarID);
                }
                else
                {
                    return false;
                }
            }
        }

        public bool TryGetAvatar(UUID authToken, out Avatar avatar)
        {
            lock (syncRoot)
            {
                UUID avatarID;
                if (authTokenToAvatar.TryGetValue(authToken, out avatarID))
                {
                    return server.AvatarProvider.TryGetAvatar(avatarID, out avatar);
                }
                else
                {
                    avatar = null;
                    return false;
                }
            }
        }

        public bool TryGetSession(UUID avatarID, out UUID authToken)
        {
            lock (syncRoot)
                return avatarToAuthToken.TryGetValue(avatarID, out authToken);
        }

        public int CurrentSessionCount()
        {
            return authTokenToAvatar.Count;
        }
    }
}