using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace Common
{
    public static class StringExtension
    {
        /// <summary>
        /// 字符空判断
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool IsEmpty(this string str)
        {
            if (string.IsNullOrEmpty(str))
                return true;
            return false;
        }

        /// <summary>
        /// 直接格式化字符串
        /// </summary>
        /// <param name="str"></param>
        /// <param name="args"></param>
        /// <returns></returns>
        public static string FormatMe(this string str, params object[] args)
        {
            return string.Format(str, args);
        }

        /// <summary>
        /// 转化为32位int
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static int TryToInt32(this string str)
        {
            return Int32.Parse(str);
        }

        /// <summary>
        /// 转换时间
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static DateTime ToDateTime(this string str)
        {
            return DateTime.Parse(str);
        }

        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="myString">加密字符串</param>
        /// <param name="salt">随机加密码</param>
        /// <returns></returns>
        public static string GetMD5(this string str, string salt)
        {
            MD5 md5 = new MD5CryptoServiceProvider();
            byte[] fromData = System.Text.Encoding.Unicode.GetBytes(str + salt);
            byte[] targetData = md5.ComputeHash(fromData);
            string byte2String = null;

            for (int i = 0; i < targetData.Length; i++)
            {
                byte2String += targetData[i].ToString("x");
            }

            return byte2String;
        }


        /// <summary>
        /// 将对象转换为Int32类型,转换失败返回0
        /// </summary>
        /// <param name="str">要转换的字符串</param>
        /// <returns>转换后的int类型结果</returns>
        public static int StrToInt(this string str)
        {
            return StrToInt(str, 0);
        }

        /// <summary>
        /// 将对象转换为Int32类型
        /// </summary>
        /// <param name="str">要转换的字符串</param>
        /// <param name="defValue">缺省值</param>
        /// <returns>转换后的int类型结果</returns>
        public static int StrToInt(this string str, int defValue)
        {
            if (string.IsNullOrEmpty(str) || str.Trim().Length >= 11 || !Regex.IsMatch(str.Trim(), @"^([-]|[0-9])[0-9]*(\.\w*)?$"))
                return defValue;

            int rv;
            if (Int32.TryParse(str, out rv))
                return rv;

            return Convert.ToInt32(StrToFloat(str, defValue));
        }

        /// <summary>
        /// string型转换为float型
        /// </summary>
        /// <param name="strValue">要转换的字符串</param>
        /// <param name="defValue">缺省值</param>
        /// <returns>转换后的int类型结果</returns>
        public static float StrToFloat(this string strValue, float defValue)
        {
            if ((strValue == null) || (strValue.Length > 10))
                return defValue;

            float intValue = defValue;
            if (strValue != null)
            {
                bool IsFloat = Regex.IsMatch(strValue, @"^([-]|[0-9])[0-9]*(\.\w*)?$");
                if (IsFloat)
                    float.TryParse(strValue, out intValue);
            }
            return intValue;
        }

        /// <summary>
        /// 把特定字符删除
        /// </summary>
        /// <param name="value"></param>
        /// <param name="zf"></param>
        /// <returns></returns>
        public static string RemoveValue(this string value, string zf= "zx95")
        {
            return value.Replace(zf, "");
        }

        /// <summary>
        /// 值是否是存在枚举中
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="value"></param>
        /// <returns></returns>
        public static bool IsEnum<T>(this string value)
           where T : struct
        {
            T a;
            if (Enum.TryParse<T>(value, out a))
            {
                return true;
            }
            return false;
        }
    }
}