/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
*
* 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 OpenSim Project 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 DEVELOPERS ``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 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
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* 
*/

using System;
using System.Text;
using System.Timers;

namespace OpenSim.Grid.AssetServer
{
    /// <summary>
    /// Collects and reports information on the requests made to the asset server
    /// </summary>
    public class AssetStatsReporter
    {
        private Timer ageStatsTimer = new Timer(24 * 60 * 60 * 1000);
        private DateTime startTime = DateTime.Now;
        
        private long assetRequestsToday;        
        private long assetRequestsYesterday;
        
        public long AssetRequestsToday { get { return assetRequestsToday; } }        
        public long AssetRequestsYesterday { get { return assetRequestsYesterday; } }       
        
        public AssetStatsReporter()
        {
            ageStatsTimer.Elapsed += new ElapsedEventHandler(OnAgeing);
            ageStatsTimer.Enabled = true;
        }
        
        private void OnAgeing(object source, ElapsedEventArgs e)
        {
            assetRequestsYesterday = assetRequestsToday;
            
            // There is a possibility that an asset request could occur between the execution of these
            // two statements.  But we're better off without the synchronization overhead.
            assetRequestsToday = 0;            
        }
        
        /// <summary>
        /// Record that a request was made to the asset server
        /// </summary>
        public void AddRequest()
        {
            assetRequestsToday++;
        }

        /// <summary>
        /// Report back collected statistical information.
        /// </summary>
        /// <returns></returns>
        public string Report()
        {
            double elapsedHours = (DateTime.Now - startTime).TotalHours;
            if (elapsedHours <= 0) { elapsedHours = 1; }  // prevent divide by zero
            
            long assetRequestsTodayPerHour = (long)Math.Round(AssetRequestsToday / elapsedHours);
            long assetRequestsYesterdayPerHour = (long)Math.Round(AssetRequestsYesterday / 24.0);
            
            return string.Format(
@"Asset requests today     : {0}  ({1} per hour)
Asset requests yesterday : {2}  ({3} per hour)",
                AssetRequestsToday, assetRequestsTodayPerHour,
                AssetRequestsYesterday, assetRequestsYesterdayPerHour);
        }
    }
}