using System.Diagnostics;
using System.IO;
using System;
using System.Collections.Generic;
using System.Threading;
using System.Collections;

namespace FFmpegOut
{
    // A stream pipe class that invokes ffmpeg and connect to it.
    public class FFmpegPipe
    {
        #region Public properties

        public enum Codec { ProRes, H264, VP8 }

        public string Filename { get; private set; }
        public string Error { get; private set; }

        #endregion


        List<byte[]> writeByteList;
        static Thread thread;

        #region Public methods

        public FFmpegPipe(string name, int width, int height, int framerate, Codec codec)
        {
            //name += DateTime.Now.ToString(" yyyy MMdd HHmmss");
            //Filename = name.Replace(" ", "_") + GetSuffix(codec);
            Filename = name + GetSuffix(codec);
            var opt = "-y -f rawvideo -vcodec rawvideo -pixel_format rgb24";
            opt += " -video_size " + width + "x" + height;
            opt += " -framerate " + framerate;
            opt += " -loglevel warning -i - " + GetOptions(codec);
            opt += " " + Filename;

            if (writeByteList == null)
                writeByteList = new List<byte[]>();

            writeByteList.Clear();
            GC.Collect();
            recording = true;

            var info = new ProcessStartInfo(FFmpegConfig.BinaryPath, opt);
            info.UseShellExecute = false;
            info.CreateNoWindow = true;
            info.RedirectStandardInput = true;
            info.RedirectStandardOutput = true;
            info.RedirectStandardError = true;

            _subprocess = Process.Start(info);
            _stdin = new BinaryWriter(_subprocess.StandardInput.BaseStream);
            thread = new Thread(() => WriteStdin());
            thread.Start();
        }

        public void Write(byte[] data)
        {
            if (_subprocess == null) return;

            lock (writeByteList)
                writeByteList.Add(data);

            //_stdin.Write(data);
            //_stdin.Flush();
        }

        private static bool recording;
        public void WriteStdin()
        {
            while (recording)
            {
                lock (_stdin)
                {
                    lock (writeByteList)
                    {
                        while (writeByteList.Count > 0)
                        {
                            _stdin.Write(writeByteList[0]);
                            _stdin.Flush();
                            writeByteList.RemoveAt(0);
                        }
                    }
                }

            }
            Thread.CurrentThread.Abort();
        }

        public IEnumerator Close()
        {
            if (_subprocess == null) yield break;
            recording = false;
            while (thread.IsAlive)
            {
                yield return null;
            }
            _subprocess.StandardInput.Close();
            _subprocess.WaitForExit();

            var outputReader = _subprocess.StandardError;
            Error = outputReader.ReadToEnd();

            _subprocess.Close();
            _subprocess.Dispose();

            outputReader.Close();
            outputReader.Dispose();

            _subprocess = null;
            _stdin = null;
        }

        #endregion

        #region Private members

        Process _subprocess;
        BinaryWriter _stdin;

        static string [] _suffixes = {
            ".mov",
            ".mp4",
            ".webm"
        };

        static string [] _options = {
            "-c:v prores_ks -pix_fmt yuv422p10le",
            "-pix_fmt yuv420p",
            "-c:v libvpx"
        };

        public static string GetSuffix(Codec codec)
        {
            return _suffixes[(int)codec];
        }

        static string GetOptions(Codec codec)
        {
            return _options[(int)codec];
        }

        #endregion
    }
}