using System;
using System.ComponentModel;
using System.Security.Cryptography;
using System.Text;

namespace APT.Infrastructure.Core
{
    /// <summary>
    /// Hash工具类
    /// </summary>
    public static class HashUtil
    {
        /// <summary>
        /// 计算字符串MD5值
        /// </summary>
        /// <param name="source">要计算的值</param>
        /// <returns></returns>
        public static string GetMD5(string source)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(source);
            return GetMD5(bytes);
        }

        /// <summary>
        /// 计算byte数组MD5值
        /// </summary>
        /// <param name="bytes">要计算的byte数组</param>
        /// <returns></returns>
        public static string GetMD5(byte[] bytes)
        {
            StringBuilder builder = new StringBuilder();
            MD5 hash = new MD5CryptoServiceProvider();
            bytes = hash.ComputeHash(bytes);
            foreach (byte b in bytes)
            {
                builder.AppendFormat("{0:X2}", b);
            }
            return builder.ToString();
        }

        /// <summary>
        /// 产生随机字串，可用来自动生成密码,默认长度8位16进制
        /// </summary>
        /// <param name="len">长度</param>
        /// <param name="type">字串类型 0 字母 1 数字 2 大写字母 3 小写字母 4 十六进制字母 5 混合</param>
        /// <param name="addChars">额外字符</param> 
        /// <returns></returns>
        public static string rand_string(int len = 8, RandomTypeEnum type = RandomTypeEnum.Hex, string addChars = "")
        {
           string chars = "";
            switch (type) {
        case RandomTypeEnum.Alphabet:
            chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"+addChars;
                break;
        case RandomTypeEnum.Number:
            chars = "0123456789";
                break;
        case RandomTypeEnum.Uppercase:
            chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"+addChars;
                break;
        case RandomTypeEnum.Lowercase:
            chars = "abcdefghijklmnopqrstuvwxyz"+ addChars;
                break;
        case RandomTypeEnum.Hex:
            chars = "0123456789ABCDEF"+addChars;
                break;
                default :
            // 默认去掉了容易混淆的字符oOLl和数字01，要添加请使用addChars参数
            chars = "ABCDEFGHIJKMNPQRSTUVWXYZabcdefghijkmnpqrstuvwxyz23456789"+ addChars;
                break;
            }

            char[] constant = chars.ToCharArray();
            System.Text.StringBuilder newRandom = new System.Text.StringBuilder(constant.Length);
            Random rd = new Random();
            for (int i = 0; i < len; i++)
            {
                newRandom.Append(constant[rd.Next(constant.Length)]);
            }
            return newRandom.ToString();
        }


    }
    /// <summary>
    /// 随机数类型
    /// </summary>
    public enum RandomTypeEnum
    {
        [Description("字母")]
        Alphabet = 0,

        [Description("数字")]
        Number = 1,

        [Description("大写字母")]
        Uppercase = 2,

        [Description("小写字母")]
        Lowercase = 3,

        [Description("十六进制字母")]
        Hex = 4,

        [Description("混合")]
        Mix = 5

    }
}