using System;
using System.Runtime.InteropServices;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Concurrent;

namespace DMX2
{
	public static partial class AlsaSeqLib
	{	public class MidiPort : IDisposable
		{
			internal ConcurrentQueue<snd_seq_event_t> eventqueue = new ConcurrentQueue<snd_seq_event_t> ();

			internal int portid;
			public MidiPort(string portname){
				portid=Invoke.snd_seq_create_simple_port (seq_handle.Handle, 
					portname,
					SND_SEQ_PORT_CAP_WRITE 
					+ SND_SEQ_PORT_CAP_SUBS_WRITE 
					+ SND_SEQ_PORT_CAP_READ
					+ SND_SEQ_PORT_CAP_SUBS_READ
					, 
					SND_SEQ_PORT_TYPE_APPLICATION
				);
				openports[portid]=this;
			}

			bool closed = false;
			public void Close()
			{
				if (closed)
					return;
				closed = true;

				Invoke.snd_seq_delete_simple_port (seq_handle.Handle,
					portid);

				if(openports.ContainsKey(portid))
					if (openports [portid] == this)
						openports.Remove (portid);
			}

			void IDisposable.Dispose(){
				Close ();
			}

			public void SendEvent(snd_seq_event_t ev){
				if (seq_handle == null)
					throw new InvalidOperationException ();
				
				ev.source.client = (byte)clientId;
				ev.source.port = (byte)portid;
				ev.dest.client = SND_SEQ_ADDRESS_SUBSCRIBERS; 
				ev.dest.port = SND_SEQ_ADDRESS_UNKNOWN;
				ev.queue = SND_SEQ_QUEUE_DIRECT;

				Marshal.StructureToPtr (ev, evOutPtr.Pointer, false);
				Invoke.snd_seq_event_output (seq_handle.Handle, evOutPtr.Pointer);
				Invoke.snd_seq_drain_output (seq_handle.Handle);

			}

			public bool GetEvent(out snd_seq_event_t ev){
				return eventqueue.TryDequeue (out ev);
			}

			public bool ConnectTo(Port p){
				if (seq_handle == null)
					throw new InvalidOperationException ();
				return Invoke.snd_seq_connect_to (seq_handle.Handle, portid, p.ClientId, p.PortId) == 0;
			}

			internal bool ConnectTo(int client, int port){
				if (seq_handle == null)
					throw new InvalidOperationException ();
				return Invoke.snd_seq_connect_to (seq_handle.Handle, portid, client, port) == 0;
			}

			public bool ConnectFrom(Port p){
				if (seq_handle == null)
					throw new InvalidOperationException ();
				return Invoke.snd_seq_connect_from (seq_handle.Handle, portid, p.ClientId, p.PortId) == 0;
			}

			public void Deconnecte(Port p){
				if (seq_handle == null)
					throw new InvalidOperationException ();
				snd_seq_addr_t local = new snd_seq_addr_t ();
				local.client = (byte)clientId;
				local.port = (byte)portid;

				snd_seq_addr_t addr;
				using (PointerWrapper subqueryInfo = new PointerWrapper(GetQuerySubscribeInfoSize())) 
				using (PointerWrapper localAddr =new PointerWrapper(local.SndSeqAddrToPtr())) {
					Invoke.snd_seq_query_subscribe_set_root (subqueryInfo.Pointer, localAddr.Pointer);
					Invoke.snd_seq_query_subscribe_set_type (subqueryInfo.Pointer, SND_SEQ_QUERY_SUBS_WRITE);

					for (Invoke.snd_seq_query_subscribe_set_index(subqueryInfo.Pointer,0);
						Invoke.snd_seq_query_port_subscribers (seq_handle.Handle,subqueryInfo.Pointer)>=0;
						Invoke.snd_seq_query_subscribe_set_index(subqueryInfo.Pointer,
							Invoke.snd_seq_query_subscribe_get_index(subqueryInfo.Pointer) +1)
					) {
						addr = Invoke.snd_seq_query_subscribe_get_addr (subqueryInfo.Pointer).PtrToSndSeqAddr ();

						if (addr.client != p.ClientId || addr.port != p.PortId)	
							continue;

						Invoke.snd_seq_disconnect_from (seq_handle.Handle, portid, p.ClientId, p.PortId);
					}

					Invoke.snd_seq_query_subscribe_set_type (subqueryInfo.Pointer, SND_SEQ_QUERY_SUBS_READ);

					for (Invoke.snd_seq_query_subscribe_set_index(subqueryInfo.Pointer,0);
						Invoke.snd_seq_query_port_subscribers (seq_handle.Handle,subqueryInfo.Pointer)>=0;
						Invoke.snd_seq_query_subscribe_set_index(subqueryInfo.Pointer,
							Invoke.snd_seq_query_subscribe_get_index(subqueryInfo.Pointer) +1)
					) {
						addr = Invoke.snd_seq_query_subscribe_get_addr (subqueryInfo.Pointer).PtrToSndSeqAddr ();
						if (addr.client != p.ClientId || addr.port != p.PortId)	
							continue;
						Invoke.snd_seq_disconnect_to (seq_handle.Handle, portid, p.ClientId, p.PortId);
					}
				}
			}

		
		}
	}
}