using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using NLog;
using NzbDrone.Common.Instrumentation.Extensions;
using NzbDrone.Common.TPL;
using NzbDrone.Core.ImportLists.ImportListMovies;
using NzbDrone.Core.MetadataSource;
using NzbDrone.Core.Movies;

namespace NzbDrone.Core.ImportLists
{
    public interface IFetchAndParseImportList
    {
        ImportListFetchResult Fetch();
        ImportListFetchResult FetchSingleList(ImportListDefinition definition);
    }

    public class FetchAndParseImportListService : IFetchAndParseImportList
    {
        private readonly IImportListFactory _importListFactory;
        private readonly IImportListStatusService _importListStatusService;
        private readonly IImportListMovieService _listMovieService;
        private readonly ISearchForNewMovie _movieSearch;
        private readonly IMovieMetadataService _movieMetadataService;
        private readonly Logger _logger;

        public FetchAndParseImportListService(IImportListFactory importListFactory,
                                              IImportListStatusService importListStatusService,
                                              IImportListMovieService listMovieService,
                                              ISearchForNewMovie movieSearch,
                                              IMovieMetadataService movieMetadataService,
                                              Logger logger)
        {
            _importListFactory = importListFactory;
            _importListStatusService = importListStatusService;
            _listMovieService = listMovieService;
            _movieSearch = movieSearch;
            _movieMetadataService = movieMetadataService;
            _logger = logger;
        }

        public ImportListFetchResult Fetch()
        {
            var result = new ImportListFetchResult();

            var importLists = _importListFactory.Enabled();

            if (!importLists.Any())
            {
                _logger.Debug("No available import lists. check your configuration.");
                return result;
            }

            _logger.Debug("Available import lists {0}", importLists.Count);

            var taskList = new List<Task>();
            var taskFactory = new TaskFactory(TaskCreationOptions.LongRunning, TaskContinuationOptions.None);

            foreach (var importList in importLists)
            {
                _logger.ProgressInfo("Syncing Movies for List: {0}", importList.Name);

                var importListLocal = importList;
                var blockedLists = _importListStatusService.GetBlockedProviders().ToDictionary(v => v.ProviderId, v => v);

                if (blockedLists.TryGetValue(importList.Definition.Id, out ImportListStatus blockedListStatus))
                {
                    _logger.Debug("Temporarily ignoring list {0} till {1} due to recent failures.", importList.Definition.Name, blockedListStatus.DisabledTill.Value.ToLocalTime());
                    result.AnyFailure |= true; //Ensure we don't clean if a list is down
                    continue;
                }

                var task = taskFactory.StartNew(() =>
                {
                    try
                    {
                        var importListReports = importListLocal.Fetch();

                        lock (result)
                        {
                            _logger.Debug("Found {0} from {1}", importListReports.Movies.Count, importList.Name);

                            if (!importListReports.AnyFailure)
                            {
                                // TODO some opportunity to bulk map here if we had the tmdbIds
                                var listMovies = importListReports.Movies.Select(x =>
                                {
                                    // Is it existing in result
                                    var movie = result.Movies.FirstOrDefault(r => r.TmdbId == x.TmdbId);

                                    if (movie != null)
                                    {
                                        movie.ListId = importList.Definition.Id;
                                    }

                                    return movie ?? MapMovieReport(x);
                                }).Where(x => x.TmdbId > 0).ToList();

                                listMovies = listMovies.DistinctBy(x => x.TmdbId).ToList();
                                listMovies.ForEach(m => m.ListId = importList.Definition.Id);

                                result.Movies.AddRange(listMovies);
                                _listMovieService.SyncMoviesForList(listMovies, importList.Definition.Id);
                            }

                            result.AnyFailure |= importListReports.AnyFailure;
                        }
                    }
                    catch (Exception e)
                    {
                        _logger.Error(e, "Error during Import List Sync for list {0}", importList.Name);
                    }
                }).LogExceptions();

                taskList.Add(task);
            }

            Task.WaitAll(taskList.ToArray());

            _logger.Debug("Found {0} reports for all lists", result.Movies.Count);

            return result;
        }

        public ImportListFetchResult FetchSingleList(ImportListDefinition definition)
        {
            var result = new ImportListFetchResult();

            var importList = _importListFactory.GetInstance(definition);

            if (importList == null || !definition.Enable)
            {
                _logger.Debug("Import list {0} is not enabled. No Movies will be added");
                return result;
            }

            var importListLocal = importList;

            try
            {
                var importListReports = importListLocal.Fetch();

                lock (result)
                {
                    _logger.Debug("Found {0} from {1}", importListReports.Movies.Count, importList.Name);

                    if (!importListReports.AnyFailure)
                    {
                        // TODO some opportunity to bulk map here if we had the tmdbIds
                        var listMovies = importListReports.Movies.Select(x =>
                        {
                            return MapMovieReport(x);
                        }).Where(x => x.TmdbId > 0).ToList();

                        listMovies = listMovies.DistinctBy(x => x.TmdbId).ToList();

                        result.Movies.AddRange(listMovies);
                        _listMovieService.SyncMoviesForList(listMovies, importList.Definition.Id);
                    }

                    result.AnyFailure |= importListReports.AnyFailure;
                }
            }
            catch (Exception e)
            {
                _logger.Error(e, "Error during Import List Sync for list {0}", importList.Name);
            }

            _logger.Debug("Found {0} reports for list {1}", result.Movies.Count, importList.Name);

            return result;
        }

        private ImportListMovie MapMovieReport(ImportListMovie report)
        {
            var mappedMovie = _movieSearch.MapMovieToTmdbMovie(new MovieMetadata { Title = report.Title, TmdbId = report.TmdbId, ImdbId = report.ImdbId, Year = report.Year });

            var mappedListMovie = new ImportListMovie { ListId = report.ListId };

            if (mappedMovie != null)
            {
                _movieMetadataService.Upsert(mappedMovie);

                mappedListMovie.MovieMetadata = mappedMovie;
                mappedListMovie.MovieMetadataId = mappedMovie.Id;
            }

            return mappedListMovie;
        }
    }
}