using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using ZaoBot.Config;

namespace ZaoBot.OpenHab
{
	class OpenHabClient
	{
		private string url;
		private string token = "";
		HttpClient http = new HttpClient();

		public OpenHabClient(IConfig config)
		{
			this.url = config.Data.RootElement.GetProperty("openhab_url").GetString();
			if (!string.IsNullOrEmpty(token))
			{
				http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", token + ":");
			}
		}

		public async Task<ItemState> GetItemState(string item)
		{
			var result = await http.GetAsync(url + "/rest/items/" + item);
			var content = await result.Content.ReadAsStringAsync();
			return ParseState(content);
		}

		private ItemState ParseState(string content)
		{
			var doc = JsonDocument.Parse(content);

			var pattern = "";
			JsonElement stateDescription;
			if (doc.RootElement.TryGetProperty("stateDescription", out stateDescription))
			{
				pattern = stateDescription.GetProperty("pattern").GetString();
			}
			var result = new ItemState()
			{
				state = doc.RootElement.GetProperty("state").GetString(),
				pattern = pattern,
			};
			return result;
		}

		public async Task<string> PostItemState(string item, string state)
		{
			return await Post(url + "/rest/items/" + item, state);
		}

		private async Task<string> Post(string url, string v)
		{
			var content = new ByteArrayContent(Encoding.UTF8.GetBytes(v));
			content.Headers.Add("Content-Type", "text/plain");
			var result = await http.PostAsync(url, content);
			if (result.IsSuccessStatusCode) return "OK";
			else return "Fail. " + result.ReasonPhrase;
		}

		public async Task<List<Item>> GetItems()
		{
			var result = await http.GetAsync(url + "/rest/items/?fields=name,type,label");
			var content = await result.Content.ReadAsStringAsync();
			var doc = JsonDocument.Parse(content);
			var items = new List<Item>();
			foreach (var element in doc.RootElement.EnumerateArray())
			{
				var label = "";
				JsonElement l;
				if (element.TryGetProperty("label", out l))
				{
					label = l.GetString();
				}
				items.Add(new Item()
				{
					name = element.GetProperty("name").GetString(),
					type = element.GetProperty("type").GetString(),
					label = label,
				});
			}
			return items;
		}
	}
}