using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Bowin.Common.Utility;
using System.Text.RegularExpressions;
using System.Globalization;

namespace Bowin.Common.ServiceToken
{
    [Serializable]
    public class TokenCombiner
    {
        public static TokenView CreateToken(string systemCode, string password)
        {
            var timeStamp = DateTime.Now.ToString("yyyyMMddHHmmss");
            TokenView result = new TokenView();

            var validateString = systemCode + password + timeStamp;
            result.Token = validateString.MD5();
            result.TimeStamp = timeStamp;

            return result;
        }

        private static TokenError CheckTimeStamp(string timeStamp)
        {
            DateTime dt;

            if (!DateTime.TryParse(timeStamp, out dt))
            {
                if (!DateTime.TryParseExact(timeStamp, "yyyyMMddHHmmss", CultureInfo.CurrentCulture, DateTimeStyles.None, out dt))
                    return new TokenError(-97, "时间戳格式错误");
            }

            var ts = DateTime.Now - dt;

            if (ts.TotalMinutes >= 15 || ts.TotalMinutes < -1)
            {
                return new TokenError(-98, "令牌超时。");
            }

            return null;
        }

        public static TokenError CheckTokenBySystemCode(string token, string systemCode, string timeStamp, string sysPwd)
        {
            var tokenError = CheckTimeStamp(timeStamp);
            if (tokenError != null)
            {
                return tokenError;
            }

            if (systemCode == null) return new TokenError(-97, "系统代码验证失败");

            var validateString = systemCode + sysPwd + timeStamp;
            var md5String = validateString.MD5();

            if (md5String.ToUpper() != token.ToUpper())
            {
                return new TokenError(-97, "令牌无效");
            }
            else
            {
                return null;
            }
        }
    }
}