using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace Dfs.WayneChina.FairbanksRTData.Support
{
    public class FileNameSuffixComparer : IComparer<string>
    {
        #region Logger

        NLog.Logger logger = NLog.LogManager.LoadConfiguration("NLog.config").GetLogger("Fairbanks");

        #endregion

        public int Compare(string x1, string y1)
        {
            var x = Path.GetFileNameWithoutExtension(x1);
            var y = Path.GetFileNameWithoutExtension(y1);
            logger.Debug(string.Format("\tComparing {0} and {1}", x, y));

            if (!x.Contains('[') || !y.Contains('['))
            {
                if (x.Length > y.Length)
                {
                    logger.Debug("\treturn 1");
                    return 1;
                }
                if (x.Length < y.Length)
                {
                    logger.Debug("\treturn -1");
                    return -1;
                }

                logger.Debug("\treturn 0");
                return 0;
            }

            int xNumber = GetSuffixNumber(x);
            int yNumber = GetSuffixNumber(y);

            if (xNumber > yNumber)
                return 1;

            if (xNumber < yNumber)
                return -1;

            return 0;
        }

        private int GetSuffixNumber(string x)
        {
            int xStartIndex = x.IndexOf('[');
            int xEndIndex = x.IndexOf(']');
            int xNumber = Convert.ToInt32(x.Substring(xStartIndex + 1, xEndIndex - xStartIndex - 1));
            return xNumber;
        }
    }
}