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*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS AND ANY
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*/
using System;
using System.Collections.Generic;
using Db4objects.Db4o;
using libsecondlife;

namespace OpenSim.Framework.Data.DB4o
{
    /// <summary>
    /// A Database manager for Db4o
    /// </summary>
    class DB4oGridManager
    {
        /// <summary>
        /// A list of the current regions connected (in-memory cache)
        /// </summary>
        public Dictionary<LLUUID, SimProfileData> simProfiles = new Dictionary<LLUUID, SimProfileData>();
        /// <summary>
        /// Database File Name
        /// </summary>
        string dbfl;

        /// <summary>
        /// Creates a new grid storage manager
        /// </summary>
        /// <param name="db4odb">Filename to the database file</param>
        public DB4oGridManager(string db4odb)
        {
            dbfl = db4odb;
            IObjectContainer database;
            database = Db4oFactory.OpenFile(dbfl);
            IObjectSet result = database.Get(typeof(SimProfileData));
            // Loads the file into the in-memory cache
            foreach(SimProfileData row in result) {
                simProfiles.Add(row.UUID, row);
            }
            database.Close();
        }

        /// <summary>
        /// Adds a new profile to the database (Warning: Probably slow.)
        /// </summary>
        /// <param name="row">The profile to add</param>
        /// <returns>Successful?</returns>
        public bool AddRow(SimProfileData row)
        {
            if (simProfiles.ContainsKey(row.UUID))
            {
                simProfiles[row.UUID] = row;
            }
            else
            {
                simProfiles.Add(row.UUID, row);
            }

            try
            {
                IObjectContainer database;
                database = Db4oFactory.OpenFile(dbfl);
                database.Set(row);
                database.Close();
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }


    }

    /// <summary>
    /// A manager for the DB4o database (user profiles)
    /// </summary>
    class DB4oUserManager
    {
        /// <summary>
        /// A list of the user profiles (in memory cache)
        /// </summary>
        public Dictionary<LLUUID, UserProfileData> userProfiles = new Dictionary<LLUUID, UserProfileData>();
        /// <summary>
        /// Database filename
        /// </summary>
        string dbfl;

        /// <summary>
        /// Initialises a new DB manager
        /// </summary>
        /// <param name="db4odb">The filename to the database</param>
        public DB4oUserManager(string db4odb)
        {
            dbfl = db4odb;
            IObjectContainer database;
            database = Db4oFactory.OpenFile(dbfl);
            // Load to cache
            IObjectSet result = database.Get(typeof(UserProfileData));
            foreach (UserProfileData row in result)
            {
                if (userProfiles.ContainsKey(row.UUID))
                    userProfiles[row.UUID] = row;
                else
                    userProfiles.Add(row.UUID, row);
            }
            database.Close();
        }

        /// <summary>
        /// Adds or updates a record to the user database.  Do this when changes are needed
        /// in the user profile that need to be persistant.
        /// 
        /// TODO: the logic here is not ACID, the local cache will be
        /// updated even if the persistant data is not.  This may lead
        /// to unexpected results.
        /// </summary>
        /// <param name="record">The profile to update</param>
        /// <returns>true on success, false on fail to persist to db</returns>
        public bool UpdateRecord(UserProfileData record)
        { 
            if (userProfiles.ContainsKey(record.UUID))
            {
                userProfiles[record.UUID] = record;
            }
            else
            {
                userProfiles.Add(record.UUID, record);
            }

            try
            {
                IObjectContainer database;
                database = Db4oFactory.OpenFile(dbfl);
                database.Set(record);
                database.Close();
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }
    }
}