using System.Diagnostics;

namespace ReviewProxy.Lib;

public class StreamEncoder : IEncoder
{
    private Stream stream;
    private string workDirectory;
    private string outputFilePath;

    public StreamEncoder(Stream inputStream, string workDirectory, string outputFilePath)
    {
        this.stream = inputStream;
        this.workDirectory = workDirectory;
        this.outputFilePath = outputFilePath;

        this.Init();
    }

    public async ValueTask EncodeAsync()
    {
        using (var proc = this.CreateEncoder())
        {
            if (proc is null)
            {
                throw new FileNotFoundException("ffmpeg could't execute.");
            }

            Console.WriteLine($"CopyToAsync");
            await this.stream.CopyToAsync(proc.StandardInput.BaseStream).ConfigureAwait(false);
            Console.WriteLine($"Close");
            proc.StandardInput.BaseStream.Close();
            await proc.WaitForExitAsync().ConfigureAwait(false);
        }

        this.BundleToZip();
    }

    private void BundleToZip()
    {
        using (var archive = new ZipArchiver(this.outputFilePath, this.workDirectory))
        {
            archive.Compress();
        }
    }

    private void Init()
    {
        if (!Directory.Exists(workDirectory))
        {
            Directory.CreateDirectory(workDirectory);
        }
    }

    private Process? CreateEncoder()
    {
        string tsFilePath = Path.Combine(workDirectory, "a%03d.ts");
        string plFilePath = Path.Combine(workDirectory, "playlist.m3u8");

        var args = $"-i pipe:0 -c:v libx264 -vf scale=-2:720 -movflags faststart -b:v 1000K -r 24 -c:a aac -b:a 64k -y -pix_fmt yuv420p -crf 23 -f segment -segment_format mpegts -segment_time 5 -segment_list \"{plFilePath}\" \"{tsFilePath}\"";
        var startInfo = new ProcessStartInfo()
        {
            FileName = "ffmpeg",
            Arguments = args,
            RedirectStandardInput = true,
        };

        return Process.Start(startInfo);
    }

    public void Dispose()
    {
        if (Directory.Exists(workDirectory))
        {
            Directory.Delete(workDirectory, true);
        }

        if (File.Exists(outputFilePath))
        {
            File.Delete(outputFilePath);
        }
    }
}