using Base62;
using Domain.Events;
using Domain.SeedWork;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace Domain.AggregateModel.LinkAggregate
{
    public class Link:Entity,IAggregateRoot
    {
        /// <summary>
        /// 非自增主键
        /// </summary>
        public string ShortCode { get; private set; }
        public string BaseUrl { get; private set; }
        public string SuffixUrl { get; private set; }
        public string FullUrl { get; private set; }
        public int AppId { get; private set; }
        public DateTime Time { get; private set; }

        private Link()
        {

        }
        /// <summary>
        /// 创建一条新的短链接
        /// </summary>
        /// <param name="baseUrl"></param>
        /// <param name="suffixUrl"></param>
        /// <param name="appId">分配的应用id</param>
        public Link(string baseUrl,string suffixUrl,string fullUrl,int appId,string shortCode)
        {
            BaseUrl = baseUrl;
            SuffixUrl = suffixUrl;
            FullUrl = fullUrl;
            ShortCode = shortCode;
            AppId = appId;
            Time = DateTime.Now;
            AddDomainEvent(new LinkCreatedDomainEvent(this));
        }
        /// <summary>
        /// 根据值计算短链字段
        /// </summary>
        /// <returns></returns>
        private void CalculateShortCode()
        {
            string code;
            using (var md5 = MD5.Create())
            {
                var result = md5.ComputeHash(Encoding.UTF8.GetBytes(FullUrl));
                var res = new[] { BitConverter.ToInt64(result, 0) ,BitConverter.ToInt64(result,8)};
                //任意取其中一条即可
                code = res[0].ToBase62();
            }
            ShortCode = code;
        }
    }
}