StoreWeb/Core/MAX.Core/Helpers/EnumHelper.cs

using MAX.Core.Extensions;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;

namespace MAX.Core.Helpers;

/// <summary>
/// 枚举操作
/// </summary>
public static partial class EnumHelper
{
	/// <summary>
	/// 获取实例
	/// </summary>
	/// <typeparam name="TEnum">枚举类型</typeparam>
	/// <param name="member">成员名或值,范例:Enum1枚举有成员A=0,则传入"A"或"0"获取 Enum1.A</param>
	public static TEnum Parse<TEnum>(object member)
	{
		string value = member.SafeString();
		if (string.IsNullOrWhiteSpace(value))
		{
			if (typeof(TEnum).IsGenericType)
			{
				return default;
			}

			throw new ArgumentNullException(nameof(member));
		}
		return (TEnum)Enum.Parse(Common.GetType<TEnum>(), value, true);
	}
	public static object Parse(Type enumObj, object member)
	{
		string value = member.SafeString();
		if (string.IsNullOrWhiteSpace(value))
		{
			if (enumObj.IsGenericType)
			{
				return null;
			}

			throw new ArgumentNullException(nameof(member));
		}
		return Enum.Parse(enumObj, value, true);
	}
	public static TEnum ParseByDescription<TEnum>(string description)
	{
		return (TEnum)ParseByDescription(Common.GetType<TEnum>(), description);
	}
	public static object ParseByDescription(Type enumObj, string description)
	{
		List<EnumItem> listitem = GetItems(enumObj);
		foreach (EnumItem item in listitem)
		{
			if (item.Description == description)
			{
				return Enum.Parse(enumObj, item.Numeric.ToString(), true);
			}
		}
		return null;
	}
	/// <summary>
	/// 获取成员名
	/// </summary>
	/// <typeparam name="TEnum">枚举类型</typeparam>
	/// <param name="member">成员名、值、实例均可,范例:Enum1枚举有成员A=0,则传入Enum1.A或0,获取成员名"A"</param>
	public static string GetName<TEnum>(object member)
	{
		return GetName(Common.GetType<TEnum>(), member);
	}

	/// <summary>
	/// 获取成员名
	/// </summary>
	/// <param name="type">枚举类型</param>
	/// <param name="member">成员名、值、实例均可</param>
	public static string GetName(Type type, object member)
	{
		if (type == null)
		{
			return string.Empty;
		}

		if (member == null)
		{
			return string.Empty;
		}

		if (member is string)
		{
			return member.ToString();
		}

		if (type.GetTypeInfo().IsEnum == false)
		{
			return string.Empty;
		}

		return Enum.GetName(type, member);
	}

	/// <summary>
	/// 获取成员值
	/// </summary>
	/// <typeparam name="TEnum">枚举类型</typeparam>
	/// <param name="member">成员名、值、实例均可，范例:Enum1枚举有成员A=0,可传入"A"、0、Enum1.A，获取值0</param>
	public static int GetValue<TEnum>(object member)
	{
		return GetValue(Common.GetType<TEnum>(), member);
	}

	/// <summary>
	/// 获取成员值
	/// </summary>
	/// <param name="type">枚举类型</param>
	/// <param name="member">成员名、值、实例均可</param>
	public static int GetValue(Type type, object member)
	{
		string value = member.SafeString();
		if (string.IsNullOrWhiteSpace(value))
		{
			throw new ArgumentNullException(nameof(member));
		}

		return (int)Enum.Parse(type, member.ToString(), true);
	}
	/// <summary>
	/// 获取描述,使用System.ComponentModel.Description特性设置描述
	/// </summary>
	/// <typeparam name="TEnum">枚举类型</typeparam>
	/// <param name="member">成员名、值、实例均可</param>
	public static string GetDescription<TEnum>(object member)
	{
		return ReflectionHelper.GetDescription<TEnum>(GetName<TEnum>(member));
	}

	/// <summary>
	/// 获取描述,使用System.ComponentModel.Description特性设置描述
	/// </summary>
	/// <param name="type">枚举类型</param>
	/// <param name="member">成员名、值、实例均可</param>
	public static string GetDescription(Type type, object member)
	{
		return ReflectionHelper.GetDescription(type, GetName(type, member));
	}


	/// <summary>
	/// 获取项集合,文本设置为Description，值为Value
	/// </summary>
	/// <typeparam name="TEnum">枚举类型</typeparam>
	public static List<EnumItem> GetItems<TEnum>()
	{
		return GetItems(typeof(TEnum));
	}

	/// <summary>
	/// 获取项集合,文本设置为Description，值为Value
	/// </summary>
	/// <param name="type">枚举类型</param>
	public static List<EnumItem> GetItems(Type type)
	{
		type = Common.GetType(type);
		if (type.IsEnum == false)
		{
			throw new InvalidOperationException($"类型 {type} 不是枚举");
		}

		List<EnumItem> result = [];
		foreach (FieldInfo field in type.GetFields())
		{
			AddItem(type, result, field);
		}

		return result.OrderBy(t => t.Numeric).ToList();
	}

	public static CommonItem GetItem(object obj)
	{
		CommonItem item = null;
		if (obj is Enum em)
		{
			//item.Text = em.get
			string text = em.ToString();
			int value = GetValue(obj.GetType(), obj);
			string description = em.ToDescription();
			item = new CommonItem(text, value, des: description);
		}
		return item;
	}

	/// <summary>
	/// 添加描述项
	/// </summary>
	private static void AddItem(Type type, ICollection<EnumItem> result, FieldInfo field)
	{
		if (!field.FieldType.IsEnum)
		{
			return;
		}

		string text = field.Name;
		int value = GetValue(type, field.Name);
		string description = ReflectionHelper.GetDescription(field);
		result.Add(new EnumItem(text, value, description));
	}

	/// <summary>
	/// 获取名称集合
	/// </summary>
	/// <typeparam name="TEnum">枚举类型</typeparam>
	public static List<string> GetNames<TEnum>()
	{
		return GetNames(typeof(TEnum));
	}

	/// <summary>
	/// 获取名称集合
	/// </summary>
	/// <param name="type">枚举类型</param>
	public static List<string> GetNames(Type type)
	{
		type = Common.GetType(type);
		if (type.IsEnum == false)
		{
			throw new InvalidOperationException($"类型 {type} 不是枚举");
		}

		List<string> result = [];
		foreach (FieldInfo field in type.GetFields())
		{
			if (!field.FieldType.IsEnum)
			{
				continue;
			}

			result.Add(field.Name);
		}
		return result;
	}


	/// <summary>
	/// 获取名称集合
	/// </summary>
	/// <typeparam name="TEnum">枚举类型</typeparam>
	public static List<string> GetDescriptions<TEnum>()
	{
		return GetDescriptions(typeof(TEnum));
	}

	/// <summary>
	/// 获取名称集合
	/// </summary>
	/// <param name="type">枚举类型</param>
	public static List<string> GetDescriptions(Type type)
	{
		type = Common.GetType(type);
		if (type.IsEnum == false)
		{
			throw new InvalidOperationException($"类型 {type} 不是枚举");
		}

		List<string> result = [];
		foreach (FieldInfo field in type.GetFields())
		{
			if (!field.FieldType.IsEnum)
			{
				continue;
			}

			string description = ReflectionHelper.GetDescription(field);
			result.Add(description);
		}
		return result;
	}
	/// <summary>
	/// 是否单一标记
	/// </summary>
	/// <param name="obj"></param>
	/// <returns></returns>
	public static bool IsSingleFlag(Enum obj)
	{
		int intValue = GetValue(obj.GetType(), obj);
		return (intValue > 0) && ((intValue & (intValue - 1)) == 0);
	}
	/// <summary>
	/// 获取第一个标记
	/// </summary>
	/// <typeparam name="T"></typeparam>
	/// <param name="value"></param>
	/// <returns></returns>
	public static T GetFirstFlag<T>(T value) where T : Enum
	{
		long v = System.Convert.ToInt64(value);
		long first = v & -v;
		return Enum.GetValues(typeof(T)).Cast<T>().First(flag => System.Convert.ToInt64(flag) == first);
	}
}
/// <summary>
/// Enum展示类型
/// </summary>
public enum EnumDisplayType
{
	Text,
	Value,
	Description,
	CommonItem
}
public class EnumItem
{
	public string Name { get; init; }
	public int Numeric { get; init; }
	public string Description { get; init; }

	public EnumItem(string name, int numeric, string description)
	{
		Name = name;
		Numeric = numeric;
		Description = description;
	}
}
public class EnumItem<TEnum> : EnumItem where TEnum : struct, Enum
{
	public TEnum Value { get; }

	public EnumItem(TEnum value)
		: base(value.ToString(), System.Convert.ToInt32(value), GetDescription(value))
	{
		Value = value;
	}
	private static string GetDescription(TEnum value)
	{
		var field = typeof(TEnum).GetField(value.ToString())!;
		var attr = field.GetCustomAttribute<DescriptionAttribute>();
		return attr?.Description ?? string.Empty;
	}

}