using Newtonsoft.Json.Linq;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Primitives;

namespace Core.Configurations.SmartConfiguration
{
	public class JsonConfigurationSection : IConfigurationSection
	{
		private readonly JObject _data;
		private readonly string _path;
		private readonly string _normalizedPath;

		public JsonConfigurationSection(JObject data, string path)
		{
			_data = data ?? throw new ArgumentNullException(nameof(data));
			_path = path ?? throw new ArgumentNullException(nameof(path));
			_normalizedPath = NormalizePath(_path);
		}

		public string this[string key]
		{
			get
			{
				if (string.IsNullOrEmpty(key))
					throw new ArgumentNullException(nameof(key));

				var token = _data.SelectToken($"{_normalizedPath}.{NormalizePath(key)}");
				return token?.ToString();
			}
			set => throw new NotImplementedException("Setting values is not supported.");
		}

		public string Key => _path.Split(':').Last();
		public string Path => _path;

		public string Value
		{
			get
			{
				var token = _data.SelectToken(_normalizedPath);
				return token?.ToString();
			}
			set => throw new NotImplementedException("Setting values is not supported.");
		}

		public Microsoft.Extensions.Configuration.IConfigurationSection GetSection(string key)
		{
			if (string.IsNullOrEmpty(key))
				throw new ArgumentNullException(nameof(key));

			return null;// new JsonConfigurationSection(_data, string.IsNullOrEmpty(_path) ? key : $"{_path}:{key}");
		}

		public JToken GetToken() => _data.SelectToken(_normalizedPath);

		public IEnumerable<IConfigurationSection> GetChildren()
		{
			var token = _data.SelectToken(_normalizedPath);
			if (token is JObject obj)
			{
				return obj.Properties()
					.Select(p => new JsonConfigurationSection(_data, string.IsNullOrEmpty(_path) ? p.Name : $"{_path}:{p.Name}"));
			}
			return Enumerable.Empty<IConfigurationSection>();
		}

		public T Get<T>() where T : class
		{
			var token = _data.SelectToken(_normalizedPath);
			return token?.ToObject<T>();
		}

		public IChangeToken GetReloadToken() => new ConfigurationReloadToken();

		private static string NormalizePath(string path)
		{
			return path?.Replace(":", ".", StringComparison.Ordinal) ?? string.Empty;
		}
	}
}