using System;
using System.Collections.Generic;
using System.IO;
using Newtonsoft.Json;
using S22.Xmpp;

namespace RhinoReminds
{
	public delegate void OnReminderListUpdateHandler(object sender, Reminder newReminder);

	[JsonObject(MemberSerialization.OptIn)]
	public class ReminderList
	{
		[JsonProperty]
		public int NextId { get; private set; } = 0;
		private object saveLock = new object();

		[JsonProperty]
		public SortedList<DateTime, Reminder> Reminders = new SortedList<DateTime, Reminder>();

		public event OnReminderListUpdateHandler OnReminderListUpdate;


		public ReminderList() {

		}

		public Reminder CreateReminder(Jid inJid, DateTime time, string message) {
			Reminder result = new Reminder(NextId++, $"{inJid.Node}@{inJid.Domain}", time, message);
			Console.WriteLine($"[Rhino/ReminderList] Created reminder {result}");
			Reminders.Add(time, result);
			OnReminderListUpdate(this, result);
			return result;
		}

		public void Save(string filename)
		{
			// Make sure that the reminder thread doesn't try to save the reminders at the exact same time
			// we receive a request for a new reminder
			lock (saveLock) { // FUTURE: We could go lockless here with some work, but it's not worth it for the teeny chance & low overhead 
				File.WriteAllText(filename, JsonConvert.SerializeObject(this));
			}
		}

		public Reminder GetNextReminder()
		{
			if (Reminders.Count == 0)
				return null;

			return Reminders.Values[0];
		}

		public void DeleteReminder(Reminder nextReminder) {
			Reminders.Remove(nextReminder.Time);
		}
	}
}