Masuit.Tools/Masuit.Tools.Abstractions/Extensions/BaseType/ObjectExtensions.cs

using Newtonsoft.Json;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Masuit.Tools.Dynamics;
using Masuit.Tools.Reflection;
using Newtonsoft.Json.Linq;

namespace Masuit.Tools
{
	public static class ObjectExtensions
	{
		private static readonly MethodInfo CloneMethod = typeof(object).GetMethod("MemberwiseClone", BindingFlags.NonPublic | BindingFlags.Instance);

		public static bool IsPrimitive(this Type type)
		{
			if (type == typeof(string))
			{
				return true;
			}

			return type.IsValueType & type.IsPrimitive;
		}

		public static bool IsDefaultValue(this object value)
		{
			if (value == default)
			{
				return true;
			}

			return value switch
			{
				byte s => s == 0,
				sbyte s => s == 0,
				short s => s == 0,
				char s => s == 0,
				bool s => s == false,
				ushort s => s == 0,
				int s => s == 0,
				uint s => s == 0,
				long s => s == 0,
				ulong s => s == 0,
				decimal s => s == 0,
				float s => s == 0,
				double s => s == 0,
				Enum s => Equals(s, Enum.GetValues(value.GetType()).GetValue(0)),
				DateTime s => s == DateTime.MinValue,
				DateTimeOffset s => s == DateTimeOffset.MinValue,
				_ => false
			};
		}

		public static object DeepClone(this object originalObject)
		{
			return InternalCopy(originalObject, new Dictionary<object, object>(new ReferenceEqualityComparer()));
		}

		public static T DeepClone<T>(this T original)
		{
			return (T)DeepClone((object)original);
		}

		private static object InternalCopy(object originalObject, IDictionary<object, object> visited)
		{
			if (originalObject == null)
			{
				return null;
			}

			var typeToReflect = originalObject.GetType();
			if (IsPrimitive(typeToReflect))
			{
				return originalObject;
			}

			if (visited.ContainsKey(originalObject))
			{
				return visited[originalObject];
			}

			if (typeof(Delegate).IsAssignableFrom(typeToReflect))
			{
				return null;
			}

			var cloneObject = CloneMethod.Invoke(originalObject, null);
			if (typeToReflect.IsArray)
			{
				var arrayType = typeToReflect.GetElementType();
				if (!IsPrimitive(arrayType))
				{
					Array clonedArray = (Array)cloneObject;
					clonedArray.ForEach((array, indices) => array.SetValue(InternalCopy(clonedArray.GetValue(indices), visited), indices));
				}
			}

			visited.Add(originalObject, cloneObject);
			CopyFields(originalObject, visited, cloneObject, typeToReflect);
			RecursiveCopyBaseTypePrivateFields(originalObject, visited, cloneObject, typeToReflect);
			return cloneObject;
		}

		private static void RecursiveCopyBaseTypePrivateFields(object originalObject, IDictionary<object, object> visited, object cloneObject, Type typeToReflect)
		{
			if (typeToReflect.BaseType != null)
			{
				RecursiveCopyBaseTypePrivateFields(originalObject, visited, cloneObject, typeToReflect.BaseType);
				CopyFields(originalObject, visited, cloneObject, typeToReflect.BaseType, BindingFlags.Instance | BindingFlags.NonPublic, info => info.IsPrivate);
			}
		}

		private static void CopyFields(object originalObject, IDictionary<object, object> visited, object cloneObject, Type typeToReflect, BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy, Func<FieldInfo, bool> filter = null)
		{
			foreach (FieldInfo fieldInfo in typeToReflect.GetFields(bindingFlags))
			{
				if (filter != null && !filter(fieldInfo))
				{
					continue;
				}

				if (IsPrimitive(fieldInfo.FieldType) || fieldInfo.IsInitOnly)
				{
					continue;
				}

				var originalFieldValue = fieldInfo.GetValue(originalObject);
				var clonedFieldValue = InternalCopy(originalFieldValue, visited);
				fieldInfo.SetValue(cloneObject, clonedFieldValue);
			}
		}

		/// <summary>
		/// 判断是否为null，null或0长度都返回true
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="value"></param>
		/// <returns></returns>
		public static bool IsNullOrEmpty<T>(this T value)
		  where T : class
		{
			#region 1.对象级别

			//引用为null
			bool isObjectNull = value is null;
			if (isObjectNull)
			{
				return true;
			}

			//判断是否为集合
			var tempEnumerator = (value as IEnumerable)?.GetEnumerator();
			if (tempEnumerator == null) return false;//这里出去代表是对象 且 引用不为null.所以为false

			#endregion 1.对象级别

			#region 2.集合级别

			//到这里就代表是集合且引用不为空，判断长度
			//MoveNext方法返回tue代表集合中至少有一个数据,返回false就代表0长度
			bool isZeroLenth = tempEnumerator.MoveNext() == false;
			if (isZeroLenth) return true;

			return isZeroLenth;

			#endregion 2.集合级别
		}

		/// <summary>
		/// 转成非null
		/// </summary>
		/// <param name="s"></param>
		/// <param name="value">为空时的替换值</param>
		/// <returns></returns>
		public static T IfNull<T>(this T s, in T value)
		{
			return s ?? value;
		}

		/// <summary>
		/// 转换成json字符串
		/// </summary>
		/// <param name="obj"></param>
		/// <param name="setting"></param>
		/// <returns></returns>
		public static string ToJsonString(this object obj, JsonSerializerSettings setting = null)
		{
			if (obj == null) return string.Empty;
			return JsonConvert.SerializeObject(obj, setting);
		}

		/// <summary>
		/// 链式操作
		/// </summary>
		/// <typeparam name="T1"></typeparam>
		/// <typeparam name="T2"></typeparam>
		/// <param name="source"></param>
		/// <param name="action"></param>
		public static T2 Next<T1, T2>(this T1 source, Func<T1, T2> action)
		{
			return action(source);
		}

		/// <summary>
		/// 将对象转换成字典
		/// </summary>
		/// <param name="value"></param>
		public static Dictionary<string, object> ToDictionary(this object value)
		{
			var dictionary = new Dictionary<string, object>();
			if (value != null)
			{
				foreach (var property in value.GetType().GetProperties())
				{
					var obj = property.GetValue(value, null);
					dictionary.Add(property.Name, obj);
				}
			}

			return dictionary;
		}

		/// <summary>
		/// 将对象转换成字典
		/// </summary>
		/// <param name="value"></param>
		public static Dictionary<string, string> ToDictionary(this JObject value)
		{
			var dictionary = new Dictionary<string, string>();
			if (value != null)
			{
				var enumerator = value.GetEnumerator();
				while (enumerator.MoveNext())
				{
					var obj = enumerator.Current.Value ?? string.Empty;
					dictionary.Add(enumerator.Current.Key, obj + string.Empty);
				}
			}

			return dictionary;
		}

		/// <summary>
		/// 对象转换成动态类型
		/// </summary>
		/// <param name="obj"></param>
		/// <returns></returns>
		public static dynamic ToDynamic(this object obj)
		{
			return DynamicFactory.WithObject(obj);
		}

		/// <summary>
		/// 多个对象的属性值合并
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="a"></param>
		/// <param name="b"></param>
		/// <param name="others"></param>
		public static T Merge<T>(this T a, T b, params T[] others) where T : class
		{
			foreach (var item in new[] { b }.Concat(others))
			{
				var dic = item.ToDictionary();
				foreach (var p in dic.Where(p => a.GetProperty(p.Key).IsDefaultValue()))
				{
					a.SetProperty(p.Key, p.Value);
				}
			}

			return a;
		}

		/// <summary>
		/// 多个对象的属性值合并
		/// </summary>
		/// <typeparam name="T"></typeparam>
		public static T Merge<T>(this IEnumerable<T> objects) where T : class
		{
			var list = objects as List<T> ?? objects.ToList();
			if (list.Count == 0)
			{
				return null;
			}

			if (list.Count == 1)
			{
				return list[0];
			}

			foreach (var item in list.Skip(1))
			{
				var dic = item.ToDictionary();
				foreach (var p in dic.Where(p => list[0].GetProperty(p.Key).IsDefaultValue()))
				{
					list[0].SetProperty(p.Key, p.Value);
				}
			}

			return list[0];
		}
	}

	internal class ReferenceEqualityComparer : EqualityComparer<object>
	{
		public override bool Equals(object x, object y)
		{
			return ReferenceEquals(x, y);
		}

		public override int GetHashCode(object obj)
		{
			if (obj is null) return 0;
			return obj.GetHashCode();
		}
	}

	internal static class ArrayExtensions
	{
		public static void ForEach(this Array array, Action<Array, int[]> action)
		{
			if (array.LongLength == 0)
			{
				return;
			}

			ArrayTraverse walker = new ArrayTraverse(array);
			do action(array, walker.Position);
			while (walker.Step());
		}

		internal class ArrayTraverse
		{
			public int[] Position;
			private readonly int[] _maxLengths;

			public ArrayTraverse(Array array)
			{
				_maxLengths = new int[array.Rank];
				for (int i = 0; i < array.Rank; ++i)
				{
					_maxLengths[i] = array.GetLength(i) - 1;
				}
				Position = new int[array.Rank];
			}

			public bool Step()
			{
				for (int i = 0; i < Position.Length; ++i)
				{
					if (Position[i] < _maxLengths[i])
					{
						Position[i]++;
						for (int j = 0; j < i; j++)
						{
							Position[j] = 0;
						}
						return true;
					}
				}
				return false;
			}
		}
	}
}