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// (C) Copyright 2003-2014 by Autodesk, Inc. All rights reserved.
//
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// object code form for any purpose and without fee is hereby granted
// provided that the above copyright notice appears in all copies and
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// documentation.

//
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// DOES NOT WARRANT THAT THE OPERATION OF THE PROGRAM WILL BE
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// Use, duplication, or disclosure by the U.S. Government is subject to
// restrictions set forth in FAR 52.227-19 (Commercial Computer
// Software - Restricted Rights) and DFAR 252.227-7013(c)(1)(ii)
// (Rights in Technical Data and Computer Software), as applicable. 

using System;
using System.Collections.Generic;

using Autodesk.Revit.DB;
using Autodesk.Revit.DB.Analysis;


namespace Revit.SDK.Samples.WorkThread.CS
{
    /// <summary>
    ///   This class is for exchange of results between the
    ///   analyzer which displays the results and the work-thread
    ///   that calculates them. All operations are thread-safe;
    /// </summary>
    /// 
    class SharedResults
    {
        #region class member variables
        // List of ValueAtPoints
        private IList<ValueAtPoint> m_values = new List<ValueAtPoint>();
        // List of UV points
        private IList<UV> m_points = new List<UV>();
        // lock object
        private Object mylock = new Object();
        // If completed
        private bool m_completed = false;
        // Last read number
        private int m_NumberWhenLastRead = 0;
        #endregion

        #region class member methods
        /// <summary>
        ///   Signaling no more results are needed
        /// </summary>
        /// <remarks>
        ///   This is set by the analyzer if it needs no more data.
        ///   We will let this know to the work-thread when it attempts
        ///   to add more results. When the work-tread results are not
        ///   needed anymore, it will stop even when not finished yet
        ///   and returns (which basically means it will die).
        /// </remarks>
        /// 
        public void SetCompleted()
        {
            lock (mylock)
            {
                m_completed = true;
            }
        }


        /// <summary>
        ///   Returns a list of points and values acquired so far.
        /// </summary>
        /// <returns>
        ///   False if there have been no new results acquired from
        ///   the work-thread since the last time this method was called.
        /// </returns>
        /// 
        public bool GetResults(out IList<UV> points, out IList<ValueAtPoint> values)
        {
            bool hasMoreResults = false;
            points = null;
            values = null;

            lock (mylock)    // lock the access
            {
                hasMoreResults = (m_values.Count != m_NumberWhenLastRead);

                if (hasMoreResults)
                {
                    points = m_points;
                    values = m_values;
                    m_NumberWhenLastRead = m_values.Count;
                }
            }

            return hasMoreResults;
        }


        /// <summary>
        ///   Adding one pair of point/value to the collected
        ///   results for the current analysis.
        /// </summary>
        ///   The work-thread calls this every time it has another result to add.
        /// <returns>
        ///   Returns False if no more values can be accepted, which signals 
        ///   to the work-thread that the analysis was interrupted and
        ///   that the thread is supposed to stop and return immediately.
        /// </returns>
        /// 
        public bool AddResult(UV point, double value)
        {
            bool accepted = false;

            lock (mylock)    // lock the access
            {
                // do nothing if reading has been completed
                if (!m_completed)
                {
                    // First, the double is converted to a one-item
                    // list of ValueAtPoint. Than the list is added
                    // to the list of values, while the UV is added
                    // to the list of points.

                    List<double> doubleList = new List<double>();
                    doubleList.Add(value);
                    m_values.Add(new ValueAtPoint(doubleList));
                    m_points.Add(point);
                    accepted = true;
                }
            }

            return accepted;
        }
        #endregion
    }  // class

}