using Encoder.Lib;

namespace Encoder;

public static class Program
{
    public static void Main(string[] args)
    {
        var inputDirectory = new DirectoryInfo("input");
        var outputDirectory = new DirectoryInfo("output");

        if (!inputDirectory.Exists)
        {
            inputDirectory.Create();
        }

        if (!outputDirectory.Exists)
        {
            outputDirectory.Create();
        }

        var coreCount = (int) Math.Max(Environment.ProcessorCount / 2, 1);
        var limitedTaskScheduler = new LimitedConcurrencyLevelTaskScheduler(coreCount);
        var limitedTaskFactory = new TaskFactory(limitedTaskScheduler);
        var tasks = new List<Task>();

        foreach (var file in inputDirectory.EnumerateFiles())
        {
            var task = limitedTaskFactory.StartNew(async () => {
                // detect volumes.
                var detectWorker = new DetectWorker("./", file.FullName, "-vn -af volumedetect");
                await detectWorker.Run().ConfigureAwait(false);
                if (string.IsNullOrEmpty(detectWorker.MaxVolume) || string.IsNullOrWhiteSpace(detectWorker.MeanVolume))
                {
                    return;
                }

                var maxVolumeF = float.Parse(detectWorker.MaxVolume.Substring(0, detectWorker.MaxVolume.Length - 2));
                var meanVolumeF = float.Parse(detectWorker.MeanVolume.Substring(0, detectWorker.MeanVolume.Length - 2));
                var gainVolume = $"{Math.Round(meanVolumeF * 10 / 20 * -1)}dB";
                var outputFile = Path.ChangeExtension(Path.Combine(outputDirectory.FullName, file.Name), "m4a");

                // encoding
                EncodeWorker worker = new EncodeWorker("./", file.FullName, outputFile, $"-vn -ac 2 -c:a aac -b:a 256k -ar 48000 -af volume={gainVolume} -f mp4");
                await worker.Run().ConfigureAwait(false);
            });
            tasks.Add(task.Unwrap());
        }

        Task.WhenAll(tasks.ToArray()).ConfigureAwait(false).GetAwaiter().GetResult();
    }
}