using System;
using System.Runtime.InteropServices;

namespace DMX2
{
	public static partial class AlsaSeqLib
	{
		public const int SND_SEQ_NONBLOCK = 1;
		public const int SND_SEQ_OPEN_INPUT = 1;
		public const int SND_SEQ_OPEN_OUTPUT = 2;
		public const int SND_SEQ_OPEN_DUPLEX = 3;
		public const int SND_SEQ_PORT_CAP_NO_EXPORT = (1 << 7);
		public const int SND_SEQ_PORT_CAP_READ = (1 << 0);
		public const int SND_SEQ_PORT_CAP_WRITE = (1 << 1);
		public const int SND_SEQ_PORT_CAP_DUPLEX = (1 << 4);
		public const int SND_SEQ_PORT_CAP_SUBS_READ = (1 << 5);
		public const int SND_SEQ_PORT_CAP_SUBS_WRITE = (1 << 6);
		public const int SND_SEQ_USER_CLIENT = 1;
		public const int SND_SEQ_PORT_SYSTEM_TIMER = 0;
		public const int SND_SEQ_PORT_SYSTEM_ANNOUNCE = 1;
		public const int SND_SEQ_QUERY_SUBS_READ = 0;
		public const int SND_SEQ_QUERY_SUBS_WRITE = 1;
		public const int SND_SEQ_PORT_TYPE_APPLICATION = (1 << 20);
		public const byte SND_SEQ_CLIENT_SYSTEM = 0;
		public const byte SND_SEQ_ADDRESS_UNKNOWN = 253;
		public const byte SND_SEQ_ADDRESS_SUBSCRIBERS = 254;
		public const byte SND_SEQ_ADDRESS_BROADCAST = 255;
		public const byte SND_SEQ_QUEUE_DIRECT = 253;

		public enum snd_seq_client_type_t : int {
			SND_SEQ_USER_CLIENT = 1,
			SND_SEQ_KERNEL_CLIENT = 2
		}

		public enum snd_seq_event_type_t : byte
		{
			SND_SEQ_EVENT_SYSTEM = 0,
			/** returned result status; event data type = #snd_seq_result_t */
			SND_SEQ_EVENT_RESULT,

			/** note on and off with duration; event data type = #snd_seq_ev_note_t */
			SND_SEQ_EVENT_NOTE = 5,
			/** note on; event data type = #snd_seq_ev_note_t */
			SND_SEQ_EVENT_NOTEON,
			/** note off; event data type = #snd_seq_ev_note_t */
			SND_SEQ_EVENT_NOTEOFF,
			/** key pressure change (aftertouch); event data type = #snd_seq_ev_note_t */
			SND_SEQ_EVENT_KEYPRESS,
	        
			/** controller; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_CONTROLLER = 10,
			/** program change; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_PGMCHANGE,
			/** channel pressure; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_CHANPRESS,
			/** pitchwheel; event data type = #snd_seq_ev_ctrl_t; data is from -8192 to 8191) */
			SND_SEQ_EVENT_PITCHBEND,
			/** 14 bit controller value; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_CONTROL14,
			/** 14 bit NRPN;  event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_NONREGPARAM,
			/** 14 bit RPN; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_REGPARAM,

			/** SPP with LSB and MSB values; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_SONGPOS = 20,
			/** Song Select with song ID number; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_SONGSEL,
			/** midi time code quarter frame; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_QFRAME,
			/** SMF Time Signature event; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_TIMESIGN,
			/** SMF Key Signature event; event data type = #snd_seq_ev_ctrl_t */
			SND_SEQ_EVENT_KEYSIGN,
			/** MIDI Real Time Start message; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_START = 30,
			/** MIDI Real Time Continue message; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_CONTINUE,
			/** MIDI Real Time Stop message; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_STOP,
			/** Set tick queue position; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_SETPOS_TICK,
			/** Set real-time queue position; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_SETPOS_TIME,
			/** (SMF) Tempo event; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_TEMPO,
			/** MIDI Real Time Clock message; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_CLOCK,
			/** MIDI Real Time Tick message; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_TICK,
			/** Queue timer skew; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_QUEUE_SKEW,
			/** Sync position changed; event data type = #snd_seq_ev_queue_control_t */
			SND_SEQ_EVENT_SYNC_POS,

			/** Tune request; event data type = none */
			SND_SEQ_EVENT_TUNE_REQUEST = 40,
			/** Reset to power-on state; event data type = none */
			SND_SEQ_EVENT_RESET,
			/** Active sensing event; event data type = none */
			SND_SEQ_EVENT_SENSING,

			/** Echo-back event; event data type = any type */
			SND_SEQ_EVENT_ECHO = 50,
			/** OSS emulation raw event; event data type = any type */
			SND_SEQ_EVENT_OSS,

			/** New client has connected; event data type = #snd_seq_addr_t */
			SND_SEQ_EVENT_CLIENT_START = 60,
			/** Client has left the system; event data type = #snd_seq_addr_t */
			SND_SEQ_EVENT_CLIENT_EXIT,
			/** Client status/info has changed; event data type = #snd_seq_addr_t */
			SND_SEQ_EVENT_CLIENT_CHANGE,
			/** New port was created; event data type = #snd_seq_addr_t */
			SND_SEQ_EVENT_PORT_START,
			/** Port was deleted from system; event data type = #snd_seq_addr_t */
			SND_SEQ_EVENT_PORT_EXIT,
			/** Port status/info has changed; event data type = #snd_seq_addr_t */
			SND_SEQ_EVENT_PORT_CHANGE,

			/** Ports connected; event data type = #snd_seq_connect_t */
			SND_SEQ_EVENT_PORT_SUBSCRIBED,
			/** Ports disconnected; event data type = #snd_seq_connect_t */
			SND_SEQ_EVENT_PORT_UNSUBSCRIBED,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR0 = 90,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR1,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR2,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR3,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR4,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR5,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR6,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR7,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR8,
			/** user-defined event; event data type = any (fixed size) */
			SND_SEQ_EVENT_USR9,

			/** system exclusive data (variable length);  event data type = #snd_seq_ev_ext_t */
			SND_SEQ_EVENT_SYSEX = 130,
			/** error event;  event data type = #snd_seq_ev_ext_t */
			SND_SEQ_EVENT_BOUNCE,
			/** reserved for user apps;  event data type = #snd_seq_ev_ext_t */
			SND_SEQ_EVENT_USR_VAR0 = 135,
			/** reserved for user apps; event data type = #snd_seq_ev_ext_t */
			SND_SEQ_EVENT_USR_VAR1,
			/** reserved for user apps; event data type = #snd_seq_ev_ext_t */
			SND_SEQ_EVENT_USR_VAR2,
			/** reserved for user apps; event data type = #snd_seq_ev_ext_t */
			SND_SEQ_EVENT_USR_VAR3,
			/** reserved for user apps; event data type = #snd_seq_ev_ext_t */
			SND_SEQ_EVENT_USR_VAR4,

			/** NOP; ignored in any case */
			SND_SEQ_EVENT_NONE = 255

		}

		[StructLayout(LayoutKind.Sequential)]
		public struct snd_seq_addr_t
		{
			public byte client;
			public byte port;
		}

		[StructLayout(LayoutKind.Sequential)]
		public struct snd_seq_ev_ctrl_t
		{
			public byte channel;
			public byte unused1;
			public byte unused2;
			public byte unused3;
			public uint param;
			public int value;
		}

		[StructLayout(LayoutKind.Sequential)]
		public struct snd_seq_ev_note_t
		{
			public byte channel;
			public byte note;
			public byte velocity;
			public byte off_velocity;
			public uint duration;
		}

		[StructLayout(LayoutKind.Sequential)]
		public struct snd_seq_connect_t
		{
			public snd_seq_addr_t sender;
			public snd_seq_addr_t dest;
		}

		[StructLayout(LayoutKind.Sequential)]
		public struct snd_seq_result_t
		{
			public int eventt;
			public int result;
		}

		public const int sizeof_snd_seq_event_t = 24;

		[StructLayout(LayoutKind.Explicit)]
		public struct snd_seq_event_t
		{
			[FieldOffset(0)]
			public snd_seq_event_type_t
				type;
			[FieldOffset(1)]
			public byte
				flags;
			[FieldOffset(2)]
			public byte
				tag;
			[FieldOffset(3)]
			public byte
				queue;
			[FieldOffset(4)]
			public uint
				time;
			[FieldOffset(12)]
			public snd_seq_addr_t
				source;
			[FieldOffset(14)]
			public snd_seq_addr_t
				dest;
			[FieldOffset(16)]
			public snd_seq_ev_ctrl_t
				data_ev_ctrl;
			[FieldOffset(16)]
			public snd_seq_ev_note_t
				data_ev_note;
			[FieldOffset(16)]
			public snd_seq_connect_t
				data_connect;
			[FieldOffset(16)]
			public snd_seq_result_t
				data_result;
			[FieldOffset(16)]
			public snd_seq_addr_t
				data_addr;
		}

		static int _clientInfoSize;
		static int _portInfoSize;
		static int _subscriberInfoSize;
		static int _query_subscribeInfoSize;

		static int GetClientInfoSize ()
		{
			if (_clientInfoSize == 0) {
				_clientInfoSize = Invoke.snd_seq_client_info_sizeof ();
			}
			return _clientInfoSize;
		}

		static int GetPortInfoSize ()
		{
			if (_portInfoSize == 0) {
				_portInfoSize = Invoke.snd_seq_port_info_sizeof ();
			}
			return _portInfoSize;
		}

		static int GetSubscriberInfoSize ()
		{
			if (_subscriberInfoSize == 0) {
				_subscriberInfoSize = Invoke.snd_seq_port_subscribe_sizeof ();
			}
			return _subscriberInfoSize;
		}
		static int GetQuerySubscribeInfoSize ()
		{
			if (_query_subscribeInfoSize == 0) {
				_query_subscribeInfoSize = Invoke.snd_seq_query_subscribe_sizeof ();
			}
			return _query_subscribeInfoSize;
		}
	}
}