dotnet_dbsync/Services/Loader.cs

using dbsync.Config;
using Serilog;
using TvSyncApp;

namespace dbsync.Services
{
    public class Loader
    {
        private readonly Downloader _downloader;

        public Loader()
        {
            _downloader = new Downloader();
        }

        public async Task<(int Success, int Failed)> LoadJsonAsync(
            Dictionary<string, string> directories,
            List<string> updateList,
            Dictionary<string, long> updateDict,
            Settings settings)
            
        {
            int success = 0;
            int failed = 0;
            int completed = 0;
            int maxParallelDownloads = settings.Global!.MaxParallelDownloads!.Value;

            var semaphore = new System.Threading.SemaphoreSlim(maxParallelDownloads);

            var filesNeeded = new List<(string Directory, string FileName)>();
            
            foreach (var seriesId in updateList)
            {
                foreach (var dir in directories.Values)
                {
                    string filePath = Path.Combine(dir, $"{seriesId}.json");
                    if (!File.Exists(filePath))
                        filesNeeded.Add((dir, $"{seriesId}.json"));
                }
            }

            Log.Information("Downloading {Count} files...", filesNeeded.Count);
            var totalFiles = filesNeeded.Count;
            var progress = new Progress<int>(value =>
            {
                completed += value;
                Console.Write($"\rDownloading files: {completed}/{totalFiles}");
            });

            var tasks = new List<Task>();
            foreach (var file in filesNeeded)
            {
                tasks.Add(DownloadWithThrottleAsync(
                    file.Directory,
                    file.FileName,
                    directories,
                    settings,
                    semaphore,
                    progress));

            }

            await Task.WhenAll(tasks);
            Console.WriteLine("\nDownload complete.");

            foreach (var file in filesNeeded)
            {
                string path = Path.Combine(file.Directory, file.FileName);
                if (File.Exists(path)) success++;
                else failed++;
            }

            return (success, failed);
        }

        private async Task DownloadWithThrottleAsync(
            string directory,
            string fileName,
            Dictionary<string, string> directories,
            Settings settings,
            SemaphoreSlim semaphore,
            IProgress<int> progress)

        {
            List<string> episodeIds = new List<string>();
            await semaphore.WaitAsync();
            try
            {
                string seriesId = Path.GetFileNameWithoutExtension(fileName);
                string url;

                if (directory.Contains("series", StringComparison.OrdinalIgnoreCase))
                    url = settings.Json!.ShowApi!.Replace("<tvmazeid>", seriesId);
                else if (directory.Contains("episodes", StringComparison.OrdinalIgnoreCase))
                    url = settings.Json!.EpisodeApi!.Replace("<tvmazeid>", seriesId);
                else if (directory.Contains("cast", StringComparison.OrdinalIgnoreCase))
                    url = settings.Json!.CastApi!.Replace("<tvmazeid>", seriesId);
                else if (directory.Contains("crew", StringComparison.OrdinalIgnoreCase))
                    url = settings.Json!.CrewApi!.Replace("<tvmazeid>", seriesId);
                else
                    url = $"https://api.tvmaze.com/shows/{seriesId}";

                // Download the file
                var epids = await Task.Run(() =>
                    _downloader.DownloadAsync(url, directory, fileName, Log.Logger));

                if (epids.Count > 0)
                {
                    // await _downloader.DownloadEpisodeExtrasAsync(
                    //    epids,
                    //    directories,
                    //    Log.Logger);
                }

                // Report progress
                progress?.Report(1);
            }
            catch (Exception ex)
            {
                Log.Error(ex, "Failed to download {FileName}", fileName);
                progress?.Report(1); // still report so progress moves forward
            }
            finally
            {
                semaphore.Release();
            }
        }
    }
}