using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using log4net;
using Taloyhtio.GeneralApi.Common.Extensions;

namespace Taloyhtio.GeneralApi.IntegrationUtility.Services.Impl
{
    public class FileSorter : IFileSorter
    {
        private ILog logger;

        public FileSorter(ILog logger)
        {
            this.logger = logger;
        }

        public List<string> Sort(List<string> files)
        {
            try
            {
                if (files.IsNullOrEmpty())
                {
                    this.logger.Warn("Files list is empty. There is nothing to sort");
                    return new List<string>();
                }

                var regex = new Regex("^(condo|boardmember)_(?<date>\\d{8,8}_\\d{9,9})\\.xml$", RegexOptions.Singleline | RegexOptions.IgnoreCase);
                var list = new List<KeyValuePair<string, DateTime>>();
                foreach (var file in files)
                {
                    var match = regex.Match(Path.GetFileName(file));
                    if (match.Success)
                    {
                        var datePart = match.Result("${date}");
                        //var timePart = match.Result("{$time_part}");
                        DateTime dt;
                        if (DateTime.TryParseExact(datePart, "yyyyMMdd_HHmmssfff", CultureInfo.InvariantCulture, DateTimeStyles.None, out dt))
                        {
                            list.Add(new KeyValuePair<string, DateTime>(file, dt));
                        }
                        else
                        {
                            this.logger.WarnFormat("Unsupported date part in file name '{0}'", file);
                        }
                    }
                }

                if (list.IsNullOrEmpty())
                {
                    this.logger.Warn("Sorter didn't find any matched files");
                    return new List<string>();
                }

                // select by date
                return list.OrderBy(kv => kv.Value).Select(kv => kv.Key).ToList();
            }
            catch (Exception x)
            {
                this.logger.ErrorFormat("{0}\n{1}", x.Message, x.StackTrace);
                return new List<string>();
            }
        }
    }
}