using CommonUnit.Base;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CommonUnit.IDGenerator
{
    /// <summary>
    /// 主键生成接口
    /// </summary>
    public interface IIDGenerator
    {
        /// <summary>
        /// 生成新主键
        /// </summary>
        /// <param name="parm">生成主键参数</param>
        /// <returns>生成后新主键</returns>
        string GeneratNewID(IDGenerateParm parm);
    }

    /// <summary>
    /// 主键生成参数
    /// </summary>
    public class IDGenerateParm{
        /// <summary>
        /// 主键基值(新主键在此基础上按规则增加)
        /// </summary>
        public string BaseValue { get; set; }
        /// <summary>
        /// 主键长度
        /// </summary>
        public int IDLength { get; set; }
    }

    /// <summary>
    /// 简单主键生成器
    /// </summary>
    public class SampleIDGenerator : IIDGenerator
    {
        /// <summary>
        /// 生成新主键
        /// </summary>
        /// <param name="parm">生成主键参数</param>
        /// <returns>生成后新主键</returns>
        string IIDGenerator.GeneratNewID(IDGenerateParm parm)
        {
            var ret = "";
            if (StringHelper.IsNullOrEmpty(parm.BaseValue)) parm.BaseValue = "0";
            int li_bv;
            if (!int.TryParse(parm.BaseValue,out li_bv)) throw new Exception("参数错误,简单生成器仅能生成数字字符串!");
            if (parm.IDLength == 0) parm.IDLength = 5;

            var li_id=(int)Math.Pow(10, parm.IDLength);
            li_id = li_id + li_bv + 1;

            return li_id.ToString().Substring(1);
        }
    }
}