using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Entities.Movies;
using MediaBrowser.Controller.Entities.TV;
using MediaBrowser.Controller.Library;
using MediaBrowser.Model.Logging;
using MediaBrowser.Model.Tasks;

namespace NFOGuard.Emby.Plugin
{
    public class NFOGuardScheduledTask : IScheduledTask
    {
        private readonly ILibraryManager _libraryManager;
        private readonly ILogger _logger;
        private readonly FreeTierManager _freeTierManager;

        public string Name => "DateSync Task";

        public string Key => "NFOGuardSync";

        public string Description => "Synchronizes PremiereDate to DateCreated for all TV episodes and movies";

        public string Category => "Library";

        public NFOGuardScheduledTask(ILibraryManager libraryManager, ILogManager logManager)
        {
            _libraryManager = libraryManager;
            _logger = logManager.GetLogger("NFOGuard");
            _freeTierManager = new FreeTierManager(_logger);
        }

        public async Task Execute(CancellationToken cancellationToken, IProgress<double> progress)
        {
            if (!Plugin.Instance.Configuration.EnableScheduledTask)
            {
                _logger.Info("NFOGuard :: Scheduled task is disabled in configuration");
                return;
            }

            _logger.Info("NFOGuard :: Starting scheduled task execution");

            try
            {
                // Get all TV episodes and movies
                var episodes = _libraryManager.GetItemList(new InternalItemsQuery
                {
                    IncludeItemTypes = new[] { "Episode" },
                    Recursive = true
                }).OfType<Episode>().ToList();

                var movies = _libraryManager.GetItemList(new InternalItemsQuery
                {
                    IncludeItemTypes = new[] { "Movie" },
                    Recursive = true
                }).OfType<Movie>().ToList();

                var totalItems = episodes.Count + movies.Count;
                _logger.Info($"NFOGuard :: Found {episodes.Count} episodes and {movies.Count} movies to process ({totalItems} total)");

                // Calculate items that need processing
                var itemsNeedingSync = episodes.Where(e => e.PremiereDate.HasValue && e.DateCreated != e.PremiereDate.Value).Count() +
                                     movies.Where(m => m.PremiereDate.HasValue && m.DateCreated != m.PremiereDate.Value).Count();
                
                _logger.Info($"NFOGuard :: {itemsNeedingSync} items need date synchronization");

                // Check free tier limits
                if (!_freeTierManager.CanProcessItems(itemsNeedingSync, out string reason))
                {
                    _logger.Info($"NFOGuard :: {reason}");
                    
                    // In free tier, process only what we can
                    var pluginConfig = Plugin.Instance.Configuration;
                    if (pluginConfig.MonthlyProcessingLimit > 0 && !pluginConfig.LicenseValid)
                    {
                        var allowedCount = Math.Max(0, pluginConfig.MonthlyProcessingLimit - pluginConfig.ProcessedThisMonth);
                        _logger.Info($"NFOGuard :: Free tier: Processing {allowedCount} items only");
                        
                        if (allowedCount == 0)
                        {
                            _logger.Info("NFOGuard :: Free tier limit reached. No items will be processed this month.");
                            return;
                        }
                    }
                }

                var processedCount = 0;
                var updatedCount = 0;
                var config = Plugin.Instance.Configuration;
                var remainingQuota = config.MonthlyProcessingLimit > 0 && !config.LicenseValid 
                    ? Math.Max(0, config.MonthlyProcessingLimit - config.ProcessedThisMonth) 
                    : int.MaxValue;

                // Process episodes
                for (int i = 0; i < episodes.Count && (config.LicenseValid || remainingQuota > 0); i++)
                {
                    cancellationToken.ThrowIfCancellationRequested();

                    var episode = episodes[i];
                    try
                    {
                        // Always log detailed info to diagnose the issue
                        if (Plugin.Instance.Configuration.LogVerbose)
                            _logger.Info($"NFOGuard :: Episode: {episode.Name} :: " +
                                       $"PremiereDate: {episode.PremiereDate?.ToString("yyyy-MM-dd HH:mm:ss") ?? "NULL"}, " +
                                       $"DateCreated: {episode.DateCreated.ToString("yyyy-MM-dd HH:mm:ss")}");

                        if (episode.PremiereDate.HasValue && 
                            episode.DateCreated != episode.PremiereDate.Value)
                        {
                            _logger.Info($"NFOGuard :: SYNCING episode: {episode.Name} :: " +
                                       $"PremiereDate: {episode.PremiereDate.Value}, DateCreated: {episode.DateCreated}");

                            episode.DateCreated = episode.PremiereDate.Value;
                            episode.UpdateToRepository(ItemUpdateType.MetadataEdit);
                            updatedCount++;
                            
                            // Track usage and decrement quota
                            _freeTierManager.RecordProcessedItems(1);
                            if (!config.LicenseValid && config.MonthlyProcessingLimit > 0)
                            {
                                remainingQuota--;
                            }
                        }
                        else if (!episode.PremiereDate.HasValue)
                        {
                            if (Plugin.Instance.Configuration.LogVerbose)
                                _logger.Info($"NFOGuard :: Episode {episode.Name} has no PremiereDate - skipping");
                        }
                        else
                        {
                            if (Plugin.Instance.Configuration.LogVerbose)
                                _logger.Info($"NFOGuard :: Episode {episode.Name} dates already match - no sync needed");
                        }

                        processedCount++;
                        var progressPercentage = (double)processedCount / totalItems * 100;
                        progress?.Report(progressPercentage);

                    }
                    catch (Exception ex)
                    {
                        _logger.ErrorException($"NFOGuard :: Error processing episode {episode.Name}", ex);
                    }
                }

                // Process movies
                for (int i = 0; i < movies.Count && (config.LicenseValid || remainingQuota > 0); i++)
                {
                    cancellationToken.ThrowIfCancellationRequested();

                    var movie = movies[i];
                    try
                    {
                        // Always log detailed info to diagnose the issue
                        if (Plugin.Instance.Configuration.LogVerbose)
                            _logger.Info($"NFOGuard :: Movie: {movie.Name} :: " +
                                       $"PremiereDate: {movie.PremiereDate?.ToString("yyyy-MM-dd HH:mm:ss") ?? "NULL"}, " +
                                       $"DateCreated: {movie.DateCreated.ToString("yyyy-MM-dd HH:mm:ss")}");

                        if (movie.PremiereDate.HasValue && 
                            movie.DateCreated != movie.PremiereDate.Value)
                        {
                            _logger.Info($"NFOGuard :: SYNCING movie: {movie.Name} :: " +
                                       $"PremiereDate: {movie.PremiereDate.Value}, DateCreated: {movie.DateCreated}");

                            movie.DateCreated = movie.PremiereDate.Value;
                            movie.UpdateToRepository(ItemUpdateType.MetadataEdit);
                            updatedCount++;
                            
                            // Track usage and decrement quota
                            _freeTierManager.RecordProcessedItems(1);
                            if (!config.LicenseValid && config.MonthlyProcessingLimit > 0)
                            {
                                remainingQuota--;
                            }
                        }
                        else if (!movie.PremiereDate.HasValue)
                        {
                            if (Plugin.Instance.Configuration.LogVerbose)
                                _logger.Info($"NFOGuard :: Movie {movie.Name} has no PremiereDate - skipping");
                        }
                        else
                        {
                            if (Plugin.Instance.Configuration.LogVerbose)
                                _logger.Info($"NFOGuard :: Movie {movie.Name} dates already match - no sync needed");
                        }

                        processedCount++;
                        var progressPercentage = (double)processedCount / totalItems * 100;
                        progress?.Report(progressPercentage);

                    }
                    catch (Exception ex)
                    {
                        _logger.ErrorException($"NFOGuard :: Error processing movie {movie.Name}", ex);
                    }
                }

                _logger.Info($"NFOGuard :: Scheduled task completed. Processed: {processedCount} items ({episodes.Count} episodes, {movies.Count} movies), Updated: {updatedCount}");
            }
            catch (Exception ex)
            {
                _logger.ErrorException("NFOGuard :: Scheduled task failed", ex);
                throw;
            }
        }

        public IEnumerable<TaskTriggerInfo> GetDefaultTriggers()
        {
            // Default to run weekly at 3 AM on Sunday
            return new[]
            {
                new TaskTriggerInfo
                {
                    Type = TaskTriggerInfo.TriggerWeekly,
                    DayOfWeek = DayOfWeek.Sunday,
                    TimeOfDayTicks = TimeSpan.FromHours(3).Ticks
                }
            };
        }
    }
}