using NAudio.Wave;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml.Linq;

namespace CDSAE3_Lian_Lian_Kan.Sound
{
    internal class AudioPlayer : IDisposable
    {
        readonly byte[] source_obj;
        readonly MemoryStream sound;
        readonly MemoryStream ms;
        readonly Mp3FileReader ws;
        readonly BlockAlignReductionStream blockAlignReductionStream;
        readonly Wave16ToFloatProvider wave16ToFloatProvider;
        readonly WaveOutEvent waveOutEvent;
        readonly Action<string,AudioPlayer>? finished;
        readonly string file_name;
        bool shuting_down = false;
        internal int volume { get; set; }
        internal AudioPlayer(string file_name, int volume)
        {
            this.file_name = file_name;
            this.volume = volume;
            file_name = file_name.Split('.').First().Replace(" ", "_").Replace("-", "_");
            source_obj = Etcs.audio_Res_Manager.Get_Audio_Resources(file_name);
            sound = new MemoryStream(source_obj);
            ms = new MemoryStream(StreamToBytes(sound));
            ws = new Mp3FileReader(ms);
            

            blockAlignReductionStream = new BlockAlignReductionStream(ws);

            wave16ToFloatProvider = new Wave16ToFloatProvider(blockAlignReductionStream);

            wave16ToFloatProvider.Volume = volume / 100f;
            waveOutEvent = new WaveOutEvent();
            waveOutEvent.Init(wave16ToFloatProvider);
            waveOutEvent.PlaybackStopped += WaveOutEvent_PlaybackStopped;
        }
        internal AudioPlayer(string file_name, int volume, Action<string,AudioPlayer> finished)
        {
            this.file_name = file_name;
            this.volume = volume;
            this.finished = finished;
            file_name = file_name.Split('.').First().Replace(" ", "_").Replace("-", "_").Replace(",","_");
            source_obj = Etcs.audio_Res_Manager.Get_Audio_Resources(file_name);
            sound = new MemoryStream(source_obj);
            ms = new MemoryStream(StreamToBytes(sound));
            ws = new Mp3FileReader(ms);
            blockAlignReductionStream = new BlockAlignReductionStream(ws);
            wave16ToFloatProvider = new Wave16ToFloatProvider(blockAlignReductionStream);
            wave16ToFloatProvider.Volume = volume / 100f;
            waveOutEvent = new WaveOutEvent();
            waveOutEvent.Init(wave16ToFloatProvider);
            waveOutEvent.PlaybackStopped += WaveOutEvent_PlaybackStopped;
        }
        public void volume_change(int val)
        {
            volume = val;
            wave16ToFloatProvider.Volume = volume / 100f;
        }
        public void pause_song() => waveOutEvent.Pause();
        public void resume_song() => waveOutEvent.Play();
        private void WaveOutEvent_PlaybackStopped(object? sender, StoppedEventArgs e)
        {
            if(shuting_down) return;
            finished?.Invoke(file_name,this);
            Dispose();
        }
        public void Dispose()
        {
            shuting_down = true;
            waveOutEvent.Stop();
            sound.Dispose();
            ms.Dispose();
            try
            { 
                ws.Dispose();
            }catch(Exception)
            { }
            blockAlignReductionStream.Dispose();
            waveOutEvent.Dispose();
            GC.SuppressFinalize(this);
        }
        internal static byte[] StreamToBytes(Stream stream)
        {
            long originalPosition = 0;

            if (stream.CanSeek)
            {
                originalPosition = stream.Position;
                stream.Position = 0;
            }

            try
            {
                byte[] readBuffer = new byte[4096];

                int totalBytesRead = 0;
                int bytesRead;

                while ((bytesRead = stream.Read(readBuffer, totalBytesRead, readBuffer.Length - totalBytesRead)) > 0)
                {
                    totalBytesRead += bytesRead;

                    if (totalBytesRead == readBuffer.Length)
                    {
                        int nextByte = stream.ReadByte();
                        if (nextByte != -1)
                        {
                            byte[] temp = new byte[readBuffer.Length * 2];
                            Buffer.BlockCopy(readBuffer, 0, temp, 0, readBuffer.Length);
                            Buffer.SetByte(temp, totalBytesRead, (byte)nextByte);
                            readBuffer = temp;
                            totalBytesRead++;
                        }
                    }
                }

                byte[] buffer = readBuffer;
                if (readBuffer.Length != totalBytesRead)
                {
                    buffer = new byte[totalBytesRead];
                    Buffer.BlockCopy(readBuffer, 0, buffer, 0, totalBytesRead);
                }
                return buffer;
            }
            finally
            {
                if (stream.CanSeek)
                {
                    stream.Position = originalPosition;
                }
            }
        }

    }
}