// Author: Gockner, Simon
// Created: 2021-04-09
// Copyright(c) 2021 SimonG. All Rights Reserved.

using System;
using Lib.Midi.Interfaces;
using Lib.Midi.Messages.Factories;
using Lib.Midi.Messages.Interfaces;
using NAudio.Midi;

namespace Lib.Midi
{
    public class MidiCommunication : IMidiCommunication
    {
        private readonly IMidiMessageFactory _midiMessageFactory;
        private readonly MidiIn _midiIn;
        private readonly MidiOut _midiOut;

        public MidiCommunication(IMidiMessageFactory midiMessageFactory)
        {
            _midiMessageFactory = midiMessageFactory;
            _midiIn = new MidiIn(0); //TODO: don't always use device 0?
            _midiOut = new MidiOut(0);
        }
        
        public void Open()
        {
            _midiIn.MessageReceived += OnMidiInMessageReceived;
            _midiIn.ErrorReceived += OnMidiInErrorReceived;
            _midiIn.Start();
        }

        public void Close()
        {
            _midiIn.Stop();
            _midiIn.MessageReceived -= OnMidiInMessageReceived;
            _midiIn.ErrorReceived -= OnMidiInErrorReceived;
            
            _midiIn.Close();
            _midiOut.Close();
        }

        public void Send(IMidiMessage message) => _midiOut.Send(message.RawMessage);
        private void OnMidiInMessageReceived(object? sender, MidiInMessageEventArgs args) => MessageReceived?.Invoke(this, _midiMessageFactory.Create(args));
        private void OnMidiInErrorReceived(object? sender, MidiInMessageEventArgs args) => ErrorReceived?.Invoke(this, _midiMessageFactory.Create(args));

        public event EventHandler<IMidiMessage>? MessageReceived;
        public event EventHandler<IMidiMessage>? ErrorReceived;
    }
}