using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using XdCxRhDW.Entity;

namespace XdCxRhDW.Repostory
{
    public static class XlRepository
    {
        /// <summary>
        /// 获取数据库所有双行根数
        /// </summary>
        /// <returns></returns>
        public static async Task<List<XlInfo>> GetAllAsync()
        {
            try
            {
                using (RHDWContext db = new RHDWContext())
                {
                    var res = await db.XlInfos.OrderByDescending(p => p.TimeUTC).OrderByDescending(p => p.Lon).ToListAsync();
                    return res;
                }
            }
            catch (Exception ex)
            {
                Serilog.Log.Error(ex, "加载星历信息异常");
                return null;
            }
        }


        /// <summary>
        /// 获取某个星某个时刻最近的双行根(可能返回null)
        /// </summary>
        /// <param name="satCode">卫星编号</param>
        /// <param name="sigTime">时刻</param>
        /// <returns></returns>
        public static async Task<XlInfo> GetLatestAsync(int satCode, DateTime sigTime)
        {
            var sql = $"SELECT min(abs(JULIANDAY(TimeUTC)-JULIANDAY('{sigTime:yyyy-MM-dd HH:mm:ss}')))" +
                        $" as NearDaySpan,* FROM XlInfo where satcode={satCode}";
            try
            {
                using (RHDWContext db = new RHDWContext())
                {
                  var res= await db.XlInfos.SqlQuery(sql).FirstOrDefaultAsync();
                    return res;
                }
            }
            catch (Exception ex)
            {
                Serilog.Log.Error(ex, $"获取卫星[{satCode}]--{sigTime:yyyyMMddHHmmss}时刻附近的双行根数出错!Sql={sql}");
                return null;
            }
        }
    }
}