using ChocolArm64.Memory;
using Ryujinx.Core.OsHle.Handles;
using Ryujinx.Core.OsHle.Ipc;
using OpenTK.Audio;
using OpenTK.Audio.OpenAL;
using System;
using System.Collections.Generic;
using System.IO;

namespace Ryujinx.Core.OsHle.Objects.Aud
{
    class IAudioOut : IIpcInterface
    {
        private Dictionary<int, ServiceProcessRequest> m_Commands;

        public IReadOnlyDictionary<int, ServiceProcessRequest> Commands => m_Commands;

        public IAudioOut()
        {
            m_Commands = new Dictionary<int, ServiceProcessRequest>()
            {
                { 0, GetAudioOutState             },
                { 1, StartAudioOut                },
                { 2, StopAudioOut                 },
                { 3, AppendAudioOutBuffer         },
                { 4, RegisterBufferEvent          },
                { 5, GetReleasedAudioOutBuffer    },
                { 6, ContainsAudioOutBuffer       },
                { 7, AppendAudioOutBuffer_ex      },
                { 8, GetReleasedAudioOutBuffer_ex }
            };
        }

        enum AudioOutState
        {
            Started,
            Stopped
        };

        //IAudioOut
        private AudioOutState State = AudioOutState.Stopped;
        private Queue<long> KeysQueue = new Queue<long>();

        //OpenAL
        private bool OpenALInstalled = true;
        private AudioContext AudioCtx;
        private int Source;
        private int Buffer;

        //Return State of IAudioOut
        public long GetAudioOutState(ServiceCtx Context)
        {
            Context.ResponseData.Write((int)State);

            return 0;
        }

        public long StartAudioOut(ServiceCtx Context)
        {
            if (State == AudioOutState.Stopped)
            {
                State = AudioOutState.Started;

                try
                { 
                    AudioCtx = new AudioContext(); //Create the audio context
                }
                catch (Exception)
                {
                    Logging.Warn("OpenAL Error! PS: Install OpenAL Core SDK!");
                    OpenALInstalled = false;
                }

                if (OpenALInstalled) AL.Listener(ALListenerf.Gain, (float)8.0); //Add more gain to it
            }

            return 0;
        }

        public long StopAudioOut(ServiceCtx Context)
        {
            if (State == AudioOutState.Started)
            {
                if (OpenALInstalled)
                { 
                    if (AudioCtx == null) //Needed to call the instance of AudioContext()
                        return 0;

                    AL.SourceStop(Source);
                    AL.DeleteSource(Source);
                }
                State = AudioOutState.Stopped;
            }

            return 0;
        }

        public long AppendAudioOutBuffer(ServiceCtx Context)
        {
            long BufferId = Context.RequestData.ReadInt64();

            KeysQueue.Enqueue(BufferId);

            byte[] AudioOutBuffer = AMemoryHelper.ReadBytes(Context.Memory, Context.Request.SendBuff[0].Position, sizeof(long) * 5);
            using (MemoryStream MS = new MemoryStream(AudioOutBuffer))
            {
                BinaryReader Reader = new BinaryReader(MS);
                long PointerNextBuffer        = Reader.ReadInt64();
                long PointerSampleBuffer      = Reader.ReadInt64();
                long CapacitySampleBuffer     = Reader.ReadInt64();
                long SizeDataInSampleBuffer   = Reader.ReadInt64();
                long OffsetDataInSampleBuffer = Reader.ReadInt64();

                byte[] AudioSampleBuffer = AMemoryHelper.ReadBytes(Context.Memory, PointerSampleBuffer + OffsetDataInSampleBuffer, (int)SizeDataInSampleBuffer);

                if (OpenALInstalled)
                {
                    if (AudioCtx == null) //Needed to call the instance of AudioContext()
                        return 0;

                    Buffer = AL.GenBuffer();
                    AL.BufferData(Buffer, ALFormat.Stereo16, AudioSampleBuffer, AudioSampleBuffer.Length, 48000);

                    Source = AL.GenSource();
                    AL.SourceQueueBuffer(Source, Buffer);
                }
            }

            return 0;
        }

        public long RegisterBufferEvent(ServiceCtx Context)
        {
            int Handle = Context.Ns.Os.Handles.GenerateId(new HEvent());

            Context.Response.HandleDesc = IpcHandleDesc.MakeCopy(Handle);

            return 0;
        }

        public long GetReleasedAudioOutBuffer(ServiceCtx Context)
        {
            long TempKey = 0;

            if (KeysQueue.Count > 0) TempKey = KeysQueue.Dequeue();

            AMemoryHelper.WriteBytes(Context.Memory, Context.Request.ReceiveBuff[0].Position, BitConverter.GetBytes(TempKey));
            
            int ReleasedBuffersCount = 1;
            Context.ResponseData.Write(ReleasedBuffersCount);

            if (OpenALInstalled)
            {
                if (AudioCtx == null) //Needed to call the instance of AudioContext()
                    return 0;

                AL.SourcePlay(Source);
                int[] FreeBuffers = AL.SourceUnqueueBuffers(Source, 1);
                AL.DeleteBuffers(FreeBuffers);
            }

            return 0;
        }

        public long ContainsAudioOutBuffer(ServiceCtx Context)
        {
            return 0;
        }

        public long AppendAudioOutBuffer_ex(ServiceCtx Context)
        {
            return 0;
        }

        public long GetReleasedAudioOutBuffer_ex(ServiceCtx Context)
        {
            return 0;
        }
    }
}