using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using NLog;
using Ninject;
using NzbDrone.Core.Model;
using NzbDrone.Core.Model.Notification;
using NzbDrone.Core.Providers.Core;

namespace NzbDrone.Core.Providers
{
    public class PostDownloadProvider
    {

        private readonly DiskProvider _diskProvider;
        private readonly EpisodeProvider _episodeProvider;
        private readonly DiskScanProvider _diskScanProvider;
        private readonly SeriesProvider _seriesProvider;
        private static readonly Logger Logger = LogManager.GetCurrentClassLogger();

        private static readonly Regex StatusRegex = new Regex(@"^_[\w_]*_", RegexOptions.Compiled);

        [Inject]
        public PostDownloadProvider(DiskProvider diskProvider, EpisodeProvider episodeProvider,
                                    DiskScanProvider diskScanProvider, SeriesProvider seriesProvider)
        {
            _diskProvider = diskProvider;
            _episodeProvider = episodeProvider;
            _diskScanProvider = diskScanProvider;
            _seriesProvider = seriesProvider;
        }

        public PostDownloadProvider()
        {
        }

        public virtual void ProcessDropFolder(string dropFolder)
        {
            foreach (var subfolder in _diskProvider.GetDirectories(dropFolder))
            {
                try
                {
                    ProcessDownload(new DirectoryInfo(subfolder));
                }
                catch (Exception e)
                {
                    Logger.ErrorException("An error has occurred while importing folder" + subfolder, e);
                }
            }
        }

        public virtual void ProcessDownload(DirectoryInfo subfolderInfo)
        {

            if (subfolderInfo.Name.StartsWith("_") && subfolderInfo.LastWriteTimeUtc.AddMinutes(1) > DateTime.UtcNow)
            {
                Logger.Trace("[{0}] is too fresh. skipping", subfolderInfo.Name);
                return;
            }

            var seriesName = Parser.ParseSeriesName(RemoveStatusFromFolderName(subfolderInfo.Name));
            var series = _seriesProvider.FindSeries(seriesName);

            if (series == null)
            {
                Logger.Warn("Unable to Import new download [{0}], Can't find matching series in database.", subfolderInfo.Name);

                //Rename the Directory so it's not processed again.
                TagFolder(subfolderInfo, PostDownloadStatusType.UnknownSeries);
                return;
            }

            var importedFiles = _diskScanProvider.Scan(series, subfolderInfo.FullName);
            importedFiles.ForEach(file => _diskScanProvider.MoveEpisodeFile(file, true));

            //Delete the folder only if folder is small enough
            if (_diskProvider.GetDirectorySize(subfolderInfo.FullName) < 10.Megabytes())
            {
                _diskProvider.DeleteFolder(subfolderInfo.FullName, true);
            }
            else
            {
                //Otherwise rename the folder to say it was already processed once by NzbDrone
                if (importedFiles.Count == 0)
                {
                    Logger.Warn("Unable to Import new download [{0}], no importable files were found..", subfolderInfo.Name);
                    TagFolder(subfolderInfo, PostDownloadStatusType.ParseError);
                }
                    //Unknown Error Importing (Possibly a lesser quality than episode currently on disk)
                else
                {
                    Logger.Warn("Unable to Import new download [{0}].", subfolderInfo.Name);
                    TagFolder(subfolderInfo, PostDownloadStatusType.Unknown);
                }
            }
        }

        public void TagFolder(DirectoryInfo directory, PostDownloadStatusType status)
        {
            _diskProvider.MoveDirectory(directory.FullName, GetFolderNameWithStatus(directory, status));
        }

        public static string GetFolderNameWithStatus(DirectoryInfo directoryInfo, PostDownloadStatusType status)
        {
            if (status == PostDownloadStatusType.NoError)
                throw new InvalidOperationException("Can't tag a folder with a None-error status. " + status);

            var cleanName = RemoveStatusFromFolderName(directoryInfo.Name);

            var newName = string.Format("_{0}_{1}", status, cleanName);

            return Path.Combine(directoryInfo.Parent.FullName, newName);
        }

        public static string RemoveStatusFromFolderName(string folderName)
        {
            return StatusRegex.Replace(folderName, string.Empty);
        }
    }
}