using Ips.Library.Entity;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;

namespace Ips.Eph.ResolveUtil
{
    public static class TleResolveUtil
    {
        public static Tle ParseTle(string tleLine1, string tleLine2, string tleName = null)
        {
            int count = 0;
            int epochYear;
            double epochDay;

            Tle ret;
            try
            {
                string[] line1 = new string[9];
                try
                {
                    string[] s1 = tleLine1.Split(' ');

                    for (int i = 0; i < s1.Length; i++)
                    {
                        if (s1[i].Length > 0)
                        {
                            line1[count] = s1[i];
                            count++;
                        }
                    }
                    int noID = 0;
                    epochYear = Convert.ToInt32(line1[3 + noID].Substring(0, 2));
                    string epDay = line1[3 + noID].Substring(2);
                    epochDay = double.Parse(epDay, CultureInfo.GetCultureInfo("en-US"));
                }
                catch (Exception ex)
                {
                    throw new InvalidDataException("Could not parse Line 1.", ex);
                }

                int satNumber = 0;
                //Start Line2 
                try
                {
                    string[] s2 = tleLine2.Split(' ');
                    string[] line2 = new string[9];
                    count = 0;
                    for (int i = 0; i < s2.Length; i++)
                    {
                        if (s2[i].Length > 0)
                        {
                            line2[count] = s2[i];
                            count++;
                        }
                    }

                    satNumber = Convert.ToInt32(line2[1]);
                }
                catch (Exception ex)
                {
                    throw new InvalidDataException("Could not parse Line 2.", ex);
                }

                ret = new Tle(tleName, satNumber, epochYear, epochDay);
                ret.TleName = tleName.Trim();
                if (ret.TleName.StartsWith("0 "))
                    ret.TleName = ret.TleName.Substring(2);
                ret.Line1 = tleLine1;
                ret.Line2 = tleLine2;
            }
            catch (Exception ex)
            {
                throw new InvalidDataException("Data contained parse error(s).", ex);
            }
            return ret;
        }

        public static List<Tle> ParseFile(string filename, string satName = null)
        {
            List<Tle> results = new List<Tle>();
            string name = satName ?? Path.GetFileNameWithoutExtension(filename);

            using (var reader = new StreamReader(filename))
            {
                string line;
                string line1 = null;

                while ((line = reader.ReadLine()) != null)
                {
                    var lineNr = line.Split(' ')[0];
                    if (lineNr != "1" && lineNr != "2")
                    {
                        name = line;
                        line1 = null;
                    }
                    else
                    {
                        if (lineNr == "1")
                        {
                            line1 = line;
                        }
                        if (lineNr == "2" && (line1 != null))
                        {
                            if (name.Contains("TBA")) continue;//TBA表示还未发射的卫星
                            results.Add(ParseTle(line1, line, name));
                        }
                    }
                }
            }
            return results;
        }
    }
}