#if UNITY_3_3 || UNITY_3_4 || UNITY_3_5 || UNITY_4 || UNITY_4_7 || UNITY_5 || UNITY_5_3_OR_NEWER
#define UNITY
#endif
using System;
using System.Collections.Generic;
using System.Reflection;

// ReSharper disable once CheckNamespace
namespace GameDevWare.Serialization
{
	internal static class ReflectionExtensions
	{
		private static readonly Dictionary<Type, MethodInfo> GetNameMethods = new Dictionary<Type, MethodInfo>();
		private static readonly object[] EmptyArgs = new object[0];

		public static bool IsInstantiationOf(this Type type, Type openGenericType)
		{
			if (type == null)
				throw new ArgumentNullException("type");
			if (openGenericType == null)
				throw new ArgumentNullException("openGenericType");

			if (openGenericType.IsGenericType && !openGenericType.IsGenericTypeDefinition)
				throw new ArgumentException(string.Format("Type should be open generic type '{0}'.", openGenericType));

			var genericType = type;
			if (type.IsGenericType)
			{
				if (type.IsGenericType && !type.IsGenericTypeDefinition)
					genericType = type.GetGenericTypeDefinition();

				if (genericType == openGenericType || genericType.IsSubclassOf(openGenericType))
					return true;
			}
			// clean
			genericType = null;

			// check interfaces
			foreach (var interfc in type.GetInterfaces())
			{
				genericType = interfc;

				if (!interfc.IsGenericType)
					continue;

				if (!interfc.IsGenericTypeDefinition)
					genericType = interfc.GetGenericTypeDefinition();

				if (genericType == openGenericType || genericType.IsSubclassOf(openGenericType))
					return true;
			}

			if (type.BaseType != null && type.BaseType != typeof (object))
				return IsInstantiationOf(type.BaseType, openGenericType);

			return false;
		}

		public static bool HasMultipleInstantiations(this Type type, Type openGenericType)
		{
			if (type == null)
				throw new ArgumentNullException("type");
			if (openGenericType == null)
				throw new ArgumentNullException("openGenericType");

			if (openGenericType.IsGenericType && !openGenericType.IsGenericTypeDefinition)
				throw new ArgumentException(string.Format("Type should be open generic type '{0}'.", openGenericType));

			// can't has multiple implementations of class
			if (!openGenericType.IsInterface)
				return false;

			var found = 0;

			var genericType = type;
			if (type.IsGenericType)
			{
				if (type.IsGenericType && !type.IsGenericTypeDefinition)
					genericType = type.GetGenericTypeDefinition();

				if (genericType == openGenericType || genericType.IsSubclassOf(openGenericType))
					found++;
			}
			// clean
			genericType = null;

			// check interfaces
			foreach (var interfc in type.GetInterfaces())
			{
				genericType = interfc;

				if (!interfc.IsGenericType)
					continue;

				if (!interfc.IsGenericTypeDefinition)
					genericType = interfc.GetGenericTypeDefinition();

				if (genericType == openGenericType || genericType.IsSubclassOf(openGenericType))
					found++;
			}


			return found > 1;
		}

		public static Type[] GetInstantiationArguments(this Type type, Type openGenericType)
		{
			if (type == null)
				throw new ArgumentNullException("type");
			if (openGenericType == null)
				throw new ArgumentNullException("openGenericType");

			if (openGenericType.IsGenericType && !openGenericType.IsGenericTypeDefinition)
				throw new ArgumentException(string.Format("Type should be open generic type '{0}'.", openGenericType));

			var genericType = type;
			if (type.IsGenericType)
			{
				if (type.IsGenericType && !type.IsGenericTypeDefinition)
					genericType = type.GetGenericTypeDefinition();

				if (genericType == openGenericType || genericType.IsSubclassOf(openGenericType))
					return type.GetGenericArguments();
			}

			// clean
			genericType = null;

			// check interfaces
			foreach (var _interface in type.GetInterfaces())
			{
				genericType = _interface;

				if (!_interface.IsGenericType)
					continue;

				if (!_interface.IsGenericTypeDefinition)
					genericType = _interface.GetGenericTypeDefinition();


				if (genericType == openGenericType || genericType.IsSubclassOf(openGenericType))
					return _interface.GetGenericArguments();
			}


			if (type.BaseType != null && type.BaseType != typeof (object))
				return GetInstantiationArguments(type.BaseType, openGenericType);

			return null;
		}

		public static string GetDataMemberName(object dataMemberAttribute)
		{
			if (dataMemberAttribute == null) throw new ArgumentNullException("dataMemberAttribute");

			var type = dataMemberAttribute.GetType();
			var getName = default(MethodInfo);

			lock (GetNameMethods)
			{
				if (!GetNameMethods.TryGetValue(type, out getName))
				{
					getName = type.GetMethod("get_Name", BindingFlags.Instance | BindingFlags.Public, null, Type.EmptyTypes, null);

					if (getName == null || getName.ReturnType != typeof (string) || getName.GetParameters().Length != 0)
						getName = null;

					if (getName == null)
					{
						var getNameProperty = type.GetProperty("Name", BindingFlags.Instance | BindingFlags.Public, null, typeof (string),
							Type.EmptyTypes, null);
						if (getNameProperty != null)
							getName = getNameProperty.GetGetMethod(nonPublic: false);
					}

					GetNameMethods.Add(type, getName);
				}
			}

			if (getName != null)
				return (string) getName.Invoke(dataMemberAttribute, EmptyArgs);
			else
				return null;
		}

#if NET35 || UNITY
		public static Type GetTypeInfo(this Type type)
		{
			return type;
		}
#endif
	}
}