// Copyright (c) 2022 - schick Informatik
// bsmd.AIS2Service [AISZoneMonitor.cs]: %UserDisplayName%
// Description: Background Thread Controller class for comparing AIS Targets 
// to monitor zones
// 

using log4net;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Security.Policy;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace bsmd.AIS2Service
{
    internal class AISZoneMonitor : IAISThread
    {

        #region Fields

        ConcurrentDictionary<int, AIS_Target> _sitRepDict;
        AIS_SQLiteStorage _storage;
        private Thread _thread;
        private bool _stopFlag = false;
        private static readonly ILog _log = LogManager.GetLogger(typeof(AISZoneMonitor));

        #endregion

        #region Construction

        public AISZoneMonitor(ConcurrentDictionary<int, AIS_Target> sitRepDict, AIS_SQLiteStorage sqliteStorage)
        {
            _sitRepDict = sitRepDict;
            _storage = sqliteStorage;
        }

        #endregion

        #region private methods

        private void Monitor()
        {
            // load zones from storage
            List<MonitorZone> allZones = _storage.LoadMonitorZones();
            Dictionary<int, List<MonitorZone>> testZones = new Dictionary<int, List<MonitorZone>>();
            foreach(MonitorZone zone in allZones)
            {
                // load up Zone list for all assignment mmsi's (to check)
                foreach(MonitorAssignment ma in zone.Assignments)
                {
                    if(!testZones.ContainsKey(ma.MMSI)) testZones[ma.MMSI] = new List<MonitorZone>();
                    testZones[ma.MMSI].Add(zone);
                }
            }


            // loop
            while(!_stopFlag)
            {
                // check all "current" AIS Targets against the zones

                foreach(int mmsi in _sitRepDict.Keys)
                {
                    if(testZones.ContainsKey(mmsi))
                    {
                        AIS_Target target = _sitRepDict[mmsi];
                        foreach(MonitorZone zone in testZones[mmsi]) {
                            if(zone.IsPointInPolygon4(target.Position))
                            {
                                _log.InfoFormat("{0} is in zone {1}", target.ToString(), zone.Name);
                            }
                        }
                    }
                }

                int currentSaturationSecs = 0; // (DateTime.Now - alarm.FirstDetected).TotalSeconds;
                if(currentSaturationSecs > Properties.Settings.Default.MonitorTargetSaturationSecs)
                {
                    // trigger alarm, this thing was "hot" long enough

                }

                Thread.Sleep(Properties.Settings.Default.MonitorTestIntervalSecs * 1000);
            }
        }

        #endregion

        #region IAISThread implementation

        public string Name { get { return "Zone monitor"; } }

        public event EventHandler FatalErrorOccurred;

        public void Start()
        {
            if (_thread != null) return; // may not run twice            
            ThreadStart runReader = new ThreadStart(this.Monitor);
            _thread = new Thread(runReader);
            _thread.Start();
        }

        public void Stop()
        {
            if (_thread == null) return;
            _stopFlag = true;
            _thread.Join();
            _thread = null;
        }

        #endregion


    }
}