using Comal.Classes;
using InABox.Clients;
using InABox.Core;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Timers;

namespace Comal.TaskScheduler.Shared
{
    public class Scheduler
    {
		private Timer timer;

        public TimeSpan Interval { get; set; }

		public Scheduler()
		{
            CoreUtils.RegisterClasses();
            ComalUtils.RegisterClasses();

            // Set the Interval to 1 minute
            Interval = new TimeSpan(0, 1, 0);
			timer = new System.Timers.Timer(Interval.TotalMilliseconds);
			timer.Elapsed += new ElapsedEventHandler(CheckSchedules);            
        }

        public void Start()
		{
            DoCheckSchedules();
        }

		public void Stop()
		{
			timer.Enabled = false;
		}

		private object? GetEntity(Type type, Guid id)
		{
			if (type == typeof(Equipment))
				return new Client<Equipment>().Load(new Filter<Equipment>(x => x.ID).IsEqualTo(id)).FirstOrDefault();
			else if (type == typeof(Customer))
				return new Client<Customer>().Load(new Filter<Customer>(x => x.ID).IsEqualTo(id)).FirstOrDefault();
			else if (type == typeof(Employee))
				return new Client<Employee>().Load(new Filter<Employee>(x => x.ID).IsEqualTo(id)).FirstOrDefault();
            else if (type == typeof(CustomModule))
                return new Client<CustomModule>().Load(new Filter<CustomModule>(x => x.ID).IsEqualTo(id)).FirstOrDefault();
            else if (type == typeof(ScheduledScript))
                return new Client<ScheduledScript>().Load(new Filter<ScheduledScript>(x => x.ID).IsEqualTo(id)).FirstOrDefault();
            return null;
			//var type = schedule.DocumentType;
			//IClient client = ClientFactory.CreateClient(type);
			//var filter = new Filter<Entity>(x => x.ID).IsEqualTo(schedule.DocumentID);
			//Entity entity = client.Load(filter).FirstOrDefault();
			//var item = entity as ISchedulable;
		}

        private void DoCheckSchedules()
        {
            timer.Enabled = false;

            Logger.Send(LogType.Information, ClientFactory.UserID, "Checking Schedules");
            var scheduleClient = new Client<Schedule>();

            try
            {
                Schedule[] schedules = scheduleClient.Load(
                    new Filter<Schedule>(x => x.DocumentClass).IsNotEqualTo("")
                        .And(x => x.DocumentID).IsNotEqualTo(Guid.Empty)
                        .And(x => x.Active).IsEqualTo(true) //.And(x => x.DueDate).IsLessThan(DateTime.Now)
                    );

                EmployeeRole[] EmployeeRoles = new Client<EmployeeRole>().Load();

                var cache = new Dictionary<string, Entity[]>();
                for (int i = 0; i < schedules.Length; i++)
                {
                    Schedule schedule = schedules[i];

                    if ((schedule.DocumentClass != "") && (schedule.DocumentID != Guid.Empty))
                    {
                        ISchedulePlugin? plugin = SchedulePluginFactory.GetPlugin(schedule.DocumentClass);
                        if(plugin == null)
                        {
                            Logger.Send(LogType.Error, ClientFactory.UserID, $"No plugin for {schedule.DocumentClass}");
                            continue;
                        }

                        //var entity = plugin.LoadEntity(schedule.DocumentID);
                        if (!cache.ContainsKey(schedule.DocumentClass))
                        {
                            Guid[] ids = schedules.Where(x => x.DocumentClass.Equals(schedule.DocumentClass)).Select(x => x.DocumentID).ToArray();
                            cache[schedule.DocumentClass] = plugin.LoadEntities(ids);
                        }
                        var entities = cache[schedule.DocumentClass];
                        var entity = entities.FirstOrDefault(x => x.ID.Equals(schedule.DocumentID));

                        if (entity != null)
                        {
                            Logger.Send(LogType.Information, ClientFactory.UserID, $"- {entity} - {schedule.Title}");
                            try
                            {
                                if (!plugin.Execute(schedule, entity))
                                    Logger.Send(LogType.Information, ClientFactory.UserID, "  * Schedule not yet due");
                            }
                            catch (Exception e)
                            {
                                Logger.Send(LogType.Information, ClientFactory.UserID, $"  * Exception while processing schedule: {e.Message}\n" + String.Join("\n",e.StackTrace));
                            }
                        }
                        else
                            Logger.Send(LogType.Information, ClientFactory.UserID, $"- {schedule.Title}: cannot find linked entity({schedule.DocumentClass})");
                    }
                }
            }
            catch (Exception err)
            {
                Logger.Send(LogType.Information, ClientFactory.UserID, err.Message + "\r\n" + err.StackTrace);
            }

            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();

            timer.Enabled = true;
        }

		private void CheckSchedules(object source, ElapsedEventArgs e)
		{
            DoCheckSchedules();
		}

	
	}
}