using Cleanuparr.Domain.Entities;
using Cleanuparr.Domain.Entities.Arr.Queue;
using Cleanuparr.Domain.Enums;
using Cleanuparr.Infrastructure.Events.Interfaces;
using Cleanuparr.Infrastructure.Features.Arr.Interfaces;
using Cleanuparr.Infrastructure.Features.Context;
using Cleanuparr.Infrastructure.Features.DownloadClient;
using Cleanuparr.Infrastructure.Features.Files;
using Cleanuparr.Infrastructure.Helpers;
using Cleanuparr.Persistence;
using Cleanuparr.Persistence.Models.Configuration.Arr;
using Cleanuparr.Persistence.Models.Configuration.DownloadCleaner;
using Cleanuparr.Persistence.Models.Configuration.General;
using MassTransit;
using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.Logging;
using LogContext = Serilog.Context.LogContext;

namespace Cleanuparr.Infrastructure.Features.Jobs;

public sealed class DownloadCleaner : GenericHandler
{
    private readonly HashSet<string> _downloadsProcessedByArrs = [];
    private readonly TimeProvider _timeProvider;
    private readonly IHardLinkFileService _hardLinkFileService;

    public DownloadCleaner(
        ILogger<DownloadCleaner> logger,
        DataContext dataContext,
        IMemoryCache cache,
        IBus messageBus,
        IArrClientFactory arrClientFactory,
        IArrQueueIterator arrArrQueueIterator,
        IDownloadServiceFactory downloadServiceFactory,
        IEventPublisher eventPublisher,
        TimeProvider timeProvider,
        IHardLinkFileService hardLinkFileService
    ) : base(
        logger, dataContext, cache, messageBus,
        arrClientFactory, arrArrQueueIterator, downloadServiceFactory, eventPublisher
    )
    {
        _timeProvider = timeProvider;
        _hardLinkFileService = hardLinkFileService;
    }
    
    protected override async Task ExecuteInternalAsync(CancellationToken cancellationToken = default)
    {
        var downloadServices = await GetInitializedDownloadServicesAsync();

        if (downloadServices.Count is 0)
        {
            _logger.LogWarning("Processing skipped because no download clients are configured");
            return;
        }

        var config = ContextProvider.Get<DownloadCleanerConfig>();
        
        bool isUnlinkedEnabled = config.UnlinkedEnabled && !string.IsNullOrEmpty(config.UnlinkedTargetCategory) && config.UnlinkedCategories.Count > 0;
        bool isCleaningEnabled = config.Categories.Count > 0;

        if (!isUnlinkedEnabled && !isCleaningEnabled)
        {
            _logger.LogWarning("No features are enabled for {name}", nameof(DownloadCleaner));
            return;
        }
        
        List<string> ignoredDownloads = ContextProvider.Get<GeneralConfig>(nameof(GeneralConfig)).IgnoredDownloads;
        ignoredDownloads.AddRange(ContextProvider.Get<DownloadCleanerConfig>().IgnoredDownloads);
        
        var downloadServiceToDownloadsMap = new Dictionary<IDownloadService, List<ITorrentItemWrapper>>();

        foreach (var downloadService in downloadServices)
        {
            using var dcType = LogContext.PushProperty(LogProperties.DownloadClientType, downloadService.ClientConfig.Type.ToString());
            using var dcName = LogContext.PushProperty(LogProperties.DownloadClientName, downloadService.ClientConfig.Name);

            try
            {
                await downloadService.LoginAsync();
                List<ITorrentItemWrapper> clientDownloads = await downloadService.GetSeedingDownloads();

                if (clientDownloads.Count > 0)
                {
                    downloadServiceToDownloadsMap[downloadService] = clientDownloads;
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to get seeding downloads from download client {clientName}", downloadService.ClientConfig.Name);
            }
        }

        if (downloadServiceToDownloadsMap.Count is 0)
        {
            _logger.LogInformation("No seeding downloads found");
            return;
        }

        int totalDownloads = downloadServiceToDownloadsMap.Values.Sum(x => x.Count);
        _logger.LogTrace("Found {count} seeding downloads across {clientCount} clients", totalDownloads, downloadServiceToDownloadsMap.Count);

        // wait for the downloads to appear in the arr queue
        await Task.Delay(TimeSpan.FromSeconds(10), _timeProvider, cancellationToken);

        await ProcessArrConfigAsync(ContextProvider.Get<ArrConfig>(nameof(InstanceType.Sonarr)), true);
        await ProcessArrConfigAsync(ContextProvider.Get<ArrConfig>(nameof(InstanceType.Radarr)), true);
        await ProcessArrConfigAsync(ContextProvider.Get<ArrConfig>(nameof(InstanceType.Lidarr)), true);
        await ProcessArrConfigAsync(ContextProvider.Get<ArrConfig>(nameof(InstanceType.Readarr)), true);
        await ProcessArrConfigAsync(ContextProvider.Get<ArrConfig>(nameof(InstanceType.Whisparr)), true);

        foreach (var pair in downloadServiceToDownloadsMap)
        {
            List<ITorrentItemWrapper> filteredDownloads = [];
            
            foreach (ITorrentItemWrapper download in pair.Value)
            {
                if (download.IsIgnored(ignoredDownloads))
                {
                    _logger.LogDebug("skip | download is ignored | {name}", download.Name);
                    continue;
                }
                
                if (_downloadsProcessedByArrs.Any(x => x.Equals(download.Hash, StringComparison.InvariantCultureIgnoreCase)))
                {
                    _logger.LogDebug("skip | download is used by an arr | {name}", download.Name);
                    continue;
                }
        
                filteredDownloads.Add(download);
            }
        
            downloadServiceToDownloadsMap[pair.Key] = filteredDownloads;
        }

        await ChangeUnlinkedCategoriesAsync(isUnlinkedEnabled, downloadServiceToDownloadsMap, config);
        await CleanDownloadsAsync(downloadServiceToDownloadsMap, config);

        foreach (var downloadService in downloadServices)
        {
            downloadService.Dispose();
        }
    }

    protected override async Task ProcessInstanceAsync(ArrInstance instance)
    {
        using var _ = LogContext.PushProperty(LogProperties.Category, instance.ArrConfig.Type.ToString());
        using var _2 = LogContext.PushProperty(LogProperties.InstanceName, instance.Name);

        IArrClient arrClient = _arrClientFactory.GetClient(instance.ArrConfig.Type, instance.Version);

        await _arrArrQueueIterator.Iterate(arrClient, instance, async items =>
        {
            var groups = items
                .Where(x => !string.IsNullOrEmpty(x.DownloadId))
                .GroupBy(x => x.DownloadId)
                .ToList();

            foreach (QueueRecord record in groups.Select(group => group.First()))
            {
                _downloadsProcessedByArrs.Add(record.DownloadId.ToLowerInvariant());
            }
        });
    }

    private async Task ChangeUnlinkedCategoriesAsync(bool isUnlinkedEnabled, Dictionary<IDownloadService, List<ITorrentItemWrapper>> downloadServiceToDownloadsMap, DownloadCleanerConfig config)
    {
        if (!isUnlinkedEnabled)
        {
            return;
        }

        if (config.UnlinkedIgnoredRootDirs.Count > 0)
        {
            _hardLinkFileService.PopulateFileCounts(config.UnlinkedIgnoredRootDirs);
        }

        Dictionary<IDownloadService, List<ITorrentItemWrapper>> downloadServiceWithDownloads = [];
        
        foreach (var (downloadService, clientDownloads) in downloadServiceToDownloadsMap)
        {
            try
            {
                var downloadsToChangeCategory = downloadService
                    .FilterDownloadsToChangeCategoryAsync(clientDownloads, config.UnlinkedCategories);
                
                if (downloadsToChangeCategory?.Count > 0)
                {
                    downloadServiceWithDownloads.Add(downloadService, downloadsToChangeCategory);
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(
                    ex, 
                    "Failed to filter downloads for hardlinks evaluation for download client {clientName}",
                    downloadService.ClientConfig.Name
                );
            }
        }

        if (downloadServiceWithDownloads.Count is 0)
        {
            _logger.LogInformation("No downloads found to evaluate for hardlinks");
            return;
        }

        _logger.LogInformation(
            "Evaluating {count} downloads for hardlinks",
            downloadServiceWithDownloads.Sum(x => x.Value.Count)
        );
        
        // Process each client with its own filtered downloads
        foreach (var (downloadService, downloadsToChangeCategory) in downloadServiceWithDownloads)
        {
            using var dcType = LogContext.PushProperty(LogProperties.DownloadClientType, downloadService.ClientConfig.Type.ToString());
            using var dcName = LogContext.PushProperty(LogProperties.DownloadClientName, downloadService.ClientConfig.Name);

            try
            {
                await downloadService.CreateCategoryAsync(config.UnlinkedTargetCategory);
            }
            catch (Exception ex)
            {
                _logger.LogError(
                    ex,
                    "Failed to create category {category} for download client {clientName}",
                    config.UnlinkedTargetCategory,
                    downloadService.ClientConfig.Name
                );
            }

            try
            {
                await downloadService.ChangeCategoryForNoHardLinksAsync(downloadsToChangeCategory);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to change category for download client {clientName}", downloadService.ClientConfig.Name);
            }
        }

        _logger.LogInformation("Finished hardlinks evaluation");
    }
    
    private async Task CleanDownloadsAsync(Dictionary<IDownloadService, List<ITorrentItemWrapper>> downloadServiceToDownloadsMap, DownloadCleanerConfig config)
    {
        if (config.Categories.Count is 0)
        {
            return;
        }
        
        Dictionary<IDownloadService, List<ITorrentItemWrapper>> downloadServiceWithDownloads = [];

        foreach (var (downloadService, clientDownloads) in downloadServiceToDownloadsMap)
        {
            try
            {
                var downloadsToClean = downloadService
                    .FilterDownloadsToBeCleanedAsync(clientDownloads, config.Categories);
                
                if (downloadsToClean?.Count > 0)
                {
                    downloadServiceWithDownloads.Add(downloadService, downloadsToClean);
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(
                    ex,
                    "Failed to filter downloads for cleaning for download client {clientName}",
                    downloadService.ClientConfig.Name
                );
            }
        }
        
        _logger.LogInformation(
            "Evaluating {count} downloads for cleanup",
            downloadServiceWithDownloads.Sum(x => x.Value.Count)
        );
        
        // Process cleaning for each client
        foreach (var (downloadService, downloadsToClean) in downloadServiceWithDownloads)
        {
            using var dcType = LogContext.PushProperty(LogProperties.DownloadClientType, downloadService.ClientConfig.Type.ToString());
            using var dcName = LogContext.PushProperty(LogProperties.DownloadClientName, downloadService.ClientConfig.Name);

            try
            {
                await downloadService.CleanDownloadsAsync(downloadsToClean, config.Categories);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to clean downloads for download client {clientName}", downloadService.ClientConfig.Name);
            }
        }
        
        _logger.LogInformation("Finished cleanup evaluation");
    }
}