using System;
using System.Collections.Generic;
using System.Text;
using System.Text.Json;
using System.Timers;
using Telegram.Bot;
using ZaoBot.Config;

namespace ZaoBot.Problems
{
	class StatusManager
	{
		const int DEFAULT_INTERVAL = 2000;

		private OpenHab.OpenHabClient openhab;
		private ITelegramBotClient bot;
		private JsonDocument config;

		private Timer timer;
		private Dictionary<string, Item> statusItems = new Dictionary<string, Item>();

		public IEnumerable<Item> StatusItems => statusItems.Values;

		public StatusManager(OpenHab.OpenHabClient openhab, ITelegramBotClient bot, IConfig config)
		{
			this.bot = bot;
			this.openhab = openhab;
			this.config = config.Data;
			UpdateStatus();
			timer = new Timer(DEFAULT_INTERVAL);
			timer.Elapsed += OnTimer;
			timer.Enabled = true;
		}

		private void OnTimer(object sender, ElapsedEventArgs e)
		{
			UpdateStatus();
		}

		private async void UpdateStatus()
		{
			try
			{
				var items = await openhab.GetItems();
				foreach (var item in items)
				{
					if (!item.name.StartsWith("Problem_")) continue;
					Item statusItem = null;
					lock (statusItems)
					{
						if (statusItems.ContainsKey(item.name)) statusItem = statusItems[item.name];
						else
						{
							statusItem = new Item()
							{
								name = item.name,
								label = item.label,
								status = Status.UNKNOWN
							};
							statusItems[item.name] = statusItem;
						}
					}
					var state = await openhab.GetItemState(item.name);
					lock (statusItems)
					{
						if (state.state == "OFF") statusItem.status = Status.OK;
						else if (state.state == "ON") statusItem.status = Status.PROBLEM;
						else statusItem.status = Status.UNKNOWN;
						if (statusItem.status == Status.PROBLEM && statusItem.notified == false)
						{
							Notify(statusItem);
							statusItem.notified = true;
						}
					}
				}
			}
			catch (Exception ex)
			{
				Console.WriteLine("Exception on getting status: " + ex.ToString());
			}
		}

		private async void Notify(Item item)
		{
			foreach (var element in config.RootElement.GetProperty("notify_user_ids").EnumerateArray())
			{
				await bot.SendTextMessageAsync(
							chatId: element.GetString(),
							text: "Problem appeared: " + item.label
				);
			}
		}
	}
}