using System;
using System.Collections.Generic;
using System.Linq;
using NLog;
using NzbDrone.Common.Extensions;
using NzbDrone.Common.Instrumentation.Extensions;
using NzbDrone.Common.Serializer;
using NzbDrone.Core.Configuration;
using NzbDrone.Core.IndexerSearch.Definitions;
using NzbDrone.Core.Parser;
using NzbDrone.Core.Parser.Model;

namespace NzbDrone.Core.DecisionEngine
{
    public interface IMakeDownloadDecision
    {
        List<DownloadDecision> GetRssDecision(List<ReleaseInfo> reports);
        List<DownloadDecision> GetSearchDecision(List<ReleaseInfo> reports, SearchCriteriaBase searchCriteriaBase);
    }

    public class DownloadDecisionMaker : IMakeDownloadDecision
    {
        private readonly IEnumerable<IDecisionEngineSpecification> _specifications;
        private readonly IParsingService _parsingService;
	private readonly IConfigService _configService;
        private readonly Logger _logger;

        public DownloadDecisionMaker(IEnumerable<IDecisionEngineSpecification> specifications, IParsingService parsingService, IConfigService configService, Logger logger)
        {
            _specifications = specifications;
            _parsingService = parsingService;
		_configService = configService;
            _logger = logger;
        }

        public List<DownloadDecision> GetRssDecision(List<ReleaseInfo> reports)
        {
            return GetMovieDecisions(reports).ToList();
        }

        public List<DownloadDecision> GetSearchDecision(List<ReleaseInfo> reports, SearchCriteriaBase searchCriteriaBase)
        {
            if (searchCriteriaBase.Movie != null)
            {
                return GetMovieDecisions(reports, searchCriteriaBase).ToList();
            }

            return GetDecisions(reports, searchCriteriaBase).ToList();
        }

        private IEnumerable<DownloadDecision> GetMovieDecisions(List<ReleaseInfo> reports, SearchCriteriaBase searchCriteria = null)
        {
            if (reports.Any())
            {
                _logger.ProgressInfo("Processing {0} releases", reports.Count);
            }

            else
            {
                _logger.ProgressInfo("No results found");
            }

            var reportNumber = 1;

            foreach (var report in reports)
            {
                DownloadDecision decision = null;
                _logger.ProgressTrace("Processing release {0}/{1}", reportNumber, reports.Count);

                try
                {
                    var parsedMovieInfo = Parser.Parser.ParseMovieTitle(report.Title);

					if (parsedMovieInfo != null && !parsedMovieInfo.MovieTitle.IsNullOrWhiteSpace())
					{
						RemoteMovie remoteMovie = _parsingService.Map(parsedMovieInfo, report.ImdbId.ToString(), searchCriteria);
						remoteMovie.Release = report;

						if (remoteMovie.Movie == null)
						{
							decision = new DownloadDecision(remoteMovie, new Rejection("Unknown movie. Movie found does not match wanted movie."));
						}
						else
						{
							if (parsedMovieInfo.Quality.HardcodedSubs.IsNotNullOrWhiteSpace())
							{
								remoteMovie.DownloadAllowed = true;
								if (_configService.AllowHardcodedSubs)
								{
									decision = GetDecisionForReport(remoteMovie, searchCriteria);
								}
								else
								{
									var whitelisted = _configService.WhitelistedHardcodedSubs.Split(',');
									_logger.Debug("Testing: {0}", whitelisted);
									if (whitelisted != null && whitelisted.Any(t => (parsedMovieInfo.Quality.HardcodedSubs.ToLower().Contains(t.ToLower()) && t.IsNotNullOrWhiteSpace())))
									{
										decision = GetDecisionForReport(remoteMovie, searchCriteria);
									}
									else
									{
										decision = new DownloadDecision(remoteMovie, new Rejection("Hardcoded subs found: " + parsedMovieInfo.Quality.HardcodedSubs));
									}
								}
							}
							else
							{
								remoteMovie.DownloadAllowed = true;
								decision = GetDecisionForReport(remoteMovie, searchCriteria);
							}

						}
					}
					else
					{
						_logger.Trace("{0} could not be parsed :(.", report.Title);
					}
                }
                catch (Exception e)
                {
                    _logger.Error(e, "Couldn't process release.");

                    var remoteMovie = new RemoteMovie { Release = report };
                    decision = new DownloadDecision(remoteMovie, new Rejection("Unexpected error processing release"));
                }

                reportNumber++;

                if (decision != null)
                {
                    if (decision.Rejections.Any())
                    {
                        _logger.Debug("Release rejected for the following reasons: {0}", string.Join(", ", decision.Rejections));
                    }

                    else
                    {
                        _logger.Debug("Release accepted");
                    }

                    yield return decision;
                }
            }
        }

        private IEnumerable<DownloadDecision> GetDecisions(List<ReleaseInfo> reports, SearchCriteriaBase searchCriteria = null)
        {
            if (reports.Any())
            {
                _logger.ProgressInfo("Processing {0} releases", reports.Count);
            }

            else
            {
                _logger.ProgressInfo("No results found");
            }

            var reportNumber = 1;

            foreach (var report in reports)
            {
                DownloadDecision decision = null;
                _logger.ProgressTrace("Processing release {0}/{1}", reportNumber, reports.Count);

                try
                {
                    var parsedEpisodeInfo = Parser.Parser.ParseTitle(report.Title);

                    if (parsedEpisodeInfo == null || parsedEpisodeInfo.IsPossibleSpecialEpisode)
                    {
                        var specialEpisodeInfo = _parsingService.ParseSpecialEpisodeTitle(report.Title, report.TvdbId, report.TvRageId, searchCriteria);

                        if (specialEpisodeInfo != null)
                        {
                            parsedEpisodeInfo = specialEpisodeInfo;
                        }
                    }

                    if (parsedEpisodeInfo != null && !parsedEpisodeInfo.SeriesTitle.IsNullOrWhiteSpace())
                    {
                        var remoteEpisode = _parsingService.Map(parsedEpisodeInfo, report.TvdbId, report.TvRageId, searchCriteria);
                        remoteEpisode.Release = report;

                        if (remoteEpisode.Series == null)
                        {
                            //remoteEpisode.DownloadAllowed = true; //Fuck you :)
                            //decision = GetDecisionForReport(remoteEpisode, searchCriteria);
                            decision = new DownloadDecision(remoteEpisode, new Rejection("Unknown release. Series not Found."));
                        }
                        else if (remoteEpisode.Episodes.Empty())
                        {
                            decision = new DownloadDecision(remoteEpisode, new Rejection("Unable to parse episodes from release name"));                            
                        }
                        else
                        {
                            remoteEpisode.DownloadAllowed = remoteEpisode.Episodes.Any();
                            decision = GetDecisionForReport(remoteEpisode, searchCriteria);
                        }
                    }
                }
                catch (Exception e)
                {
                    _logger.Error(e, "Couldn't process release.");

                    var remoteEpisode = new RemoteEpisode { Release = report };
                    decision = new DownloadDecision(remoteEpisode, new Rejection("Unexpected error processing release"));
                }

                reportNumber++;

                if (decision != null)
                {
                    if (decision.Rejections.Any())
                    {
                        _logger.Debug("Release rejected for the following reasons: {0}", string.Join(", ", decision.Rejections));
                    }

                    else
                    {
                        _logger.Debug("Release accepted");
                    }

                    yield return decision;
                }
            }
        }

        private DownloadDecision GetDecisionForReport(RemoteMovie remoteEpisode, SearchCriteriaBase searchCriteria = null)
        {
            var reasons = _specifications.Select(c => EvaluateSpec(c, remoteEpisode, searchCriteria))
                                         .Where(c => c != null);

            return new DownloadDecision(remoteEpisode, reasons.ToArray());
        }

        private DownloadDecision GetDecisionForReport(RemoteEpisode remoteEpisode, SearchCriteriaBase searchCriteria = null)
        {
            var reasons = _specifications.Select(c => EvaluateSpec(c, remoteEpisode, searchCriteria))
                                         .Where(c => c != null);

            return new DownloadDecision(remoteEpisode, reasons.ToArray());
        }

        private Rejection EvaluateSpec(IDecisionEngineSpecification spec, RemoteEpisode remoteEpisode, SearchCriteriaBase searchCriteriaBase = null)
        {
            try
            {
                var result = spec.IsSatisfiedBy(remoteEpisode, searchCriteriaBase);

                if (!result.Accepted)
                {
                    return new Rejection(result.Reason, spec.Type);
                }
            }
            catch (Exception e)
            {
                e.Data.Add("report", remoteEpisode.Release.ToJson());
                e.Data.Add("parsed", remoteEpisode.ParsedEpisodeInfo.ToJson());
                _logger.Error(e, "Couldn't evaluate decision on " + remoteEpisode.Release.Title + ", with spec: " + spec.GetType().Name);
                //return new Rejection(string.Format("{0}: {1}", spec.GetType().Name, e.Message));//TODO UPDATE SPECS!
                //return null;
            }

            return null;
        }

        private Rejection EvaluateSpec(IDecisionEngineSpecification spec, RemoteMovie remoteMovie, SearchCriteriaBase searchCriteriaBase = null)
        {
            try
            {
                var result = spec.IsSatisfiedBy(remoteMovie, searchCriteriaBase);

                if (!result.Accepted)
                {
                    return new Rejection(result.Reason, spec.Type);
                }
            }
            catch (NotImplementedException e)
            {
                _logger.Trace("Spec " + spec.GetType().Name + " does not care about movies.");
            }
            catch (Exception e)
            {
                e.Data.Add("report", remoteMovie.Release.ToJson());
                e.Data.Add("parsed", remoteMovie.ParsedMovieInfo.ToJson());
                _logger.Error(e, "Couldn't evaluate decision on " + remoteMovie.Release.Title + ", with spec: " + spec.GetType().Name);
                return new Rejection(string.Format("{0}: {1}", spec.GetType().Name, e.Message));//TODO UPDATE SPECS!
            }

            return null;
        }
    }
}