using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using Voile.Common.DRM;
using Voile.Common.Reflection;

namespace Voile.Patchouli.Reflection
{
	public class VoilePluginInfo
	{
		internal VoilePluginInfo(Type t)
		{
			Type = t;
		}

		private Type Type { get; }

		public string TypeName { get => Type.Name; }
		public int Id { get; internal set; }
		public VoileSubsystemType Subsystem { get; internal set; }

		private object _instance;
		public object GetPluginInstance()
		{
			if (_instance != null)
				return _instance;

			ConstructorInfo? constructorInfo = Type.GetConstructor(new Type[0] { });
			if (constructorInfo == null)
			{
				throw new VoileReflectionException(String.Format("{0} does not provide a parameterless constructor.", TypeName));
			}

			object result = constructorInfo.Invoke(new object[0] { });
			_instance = result;
			return result;
		}

		private bool checkedNeededEntitlement;
		private Guid? _neededEntitlement;
		public Guid? NeededEntitlement
		{
			get
			{
				if (checkedNeededEntitlement)
					return _neededEntitlement;

				NeedsEntitlementAttribute? needsEntitlementAttribute = Type.GetCustomAttribute<NeedsEntitlementAttribute>();
				if (needsEntitlementAttribute != null)
				{
					_neededEntitlement = needsEntitlementAttribute.Guid;
				}
				checkedNeededEntitlement = true;
				return _neededEntitlement;
			}
		}

		private bool checkedAutoconfigurable;
		public bool _autoconfigurable;
		public bool Autoconfigurable
		{
			get
			{
				if (checkedAutoconfigurable)
					return _autoconfigurable;

				AutoconfigurableAttribute autoconfigurableAttribute = Type.GetCustomAttribute<AutoconfigurableAttribute>();
				_autoconfigurable = autoconfigurableAttribute != null;
				checkedAutoconfigurable = true;
				return _autoconfigurable;
			}
		}

		private bool checkedIncomplete;
		private bool _incomplete;
		public bool Incomplete
		{
			get
			{
				if (checkedIncomplete)
					return _incomplete;

				IncompleteAttribute incompleteAttribute = Type.GetCustomAttribute<IncompleteAttribute>();
				_incomplete = incompleteAttribute != null;
				checkedIncomplete = true;
				return _incomplete;
			}
		}

		private string _displayName;
		public string DisplayName
		{
			get
			{
				if (!string.IsNullOrEmpty(_displayName))
					return _displayName;

				DisplayNameAttribute displayNameAttribute = Type.GetCustomAttribute<DisplayNameAttribute>();
				if (displayNameAttribute != null)
				{
					_displayName = displayNameAttribute.DisplayName;
				}
				if (string.IsNullOrEmpty(_displayName))
				{
					_displayName = TypeName;
				}
				return _displayName;
			}
		}

		private string _description;
		public string Description
		{
			get
			{
				if (!string.IsNullOrEmpty(_description))
					return _description;

				DescriptionAttribute descriptionAttribute = Type.GetCustomAttribute<DescriptionAttribute>();
				if (descriptionAttribute != null)
				{
					_description = descriptionAttribute.Desciption;
				}
				if (string.IsNullOrEmpty(_description))
				{
					_description = String.Format("TODO: Add {0} to {1}.", nameof(DescriptionAttribute), TypeName);
				}
				return Description;
			}
		}
	}
}