// Author: Gockner, Simon
// Created: 2021-04-07
// Copyright(c) 2021 SimonG. All Rights Reserved.

using System.Collections.Generic;
using Lib.Audio.Controls.Buttons.Factories;
using Lib.Audio.Controls.Buttons.Interfaces;
using Lib.Audio.Controls.Factories;
using Lib.Audio.Controls.Interfaces;
using Lib.Audio.Interfaces;
using Lib.Driver.Xml;
using Lib.Midi.Interfaces;
using Lib.Midi.Messages;
using Lib.Midi.Messages.Interfaces;

namespace Lib.Audio
{
    public class Channel : IChannel
    {
        private readonly int _channelNumber;

        private IMidiMessage? _acknowledgeMessage;

        public Channel(XmlChannel xmlChannel,
            IFaderFactory faderFactory,
            IKnobFactory knobFactory,
            IButtonFactory buttonFactory)
        {
            _channelNumber = xmlChannel.ChannelNumber;

            if (xmlChannel.Fader != null)
            {
                Fader = faderFactory.Create(xmlChannel.Fader);
                Fader.PositionChanged += OnFaderPositionChanged;
            }

            if (xmlChannel.Knob != null)
                Knob = knobFactory.Create();

            if (xmlChannel.Buttons != null)
            {
                Buttons = new List<IButton>();
                foreach (var button in xmlChannel.Buttons) 
                    Buttons.Add(buttonFactory.Create(button));
            }
        }

        public IFader? Fader { get; }
        public IKnob? Knob { get; }
        public List<IButton>? Buttons { get; }
        public IControllable? Controllable { get; private set; }
        
        public void AllocateControllable(IControllable controllable) => Controllable = controllable;
        public void HandleMessage(IMidiMessage message)
        {
            if (message is NoteOnMessage noteOnMessage)
            {
                if (Fader?.NoteNumber == noteOnMessage.NoteNumber)
                    Fader.IsTouched = true;
            }
            else if (message is NoteMessage noteMessage)
            {
                if (Fader?.NoteNumber == noteMessage.NoteNumber)
                {
                    Fader.IsTouched = false;
                    _acknowledgeMessage = new PitchWheelChangeMessage(0, _channelNumber, Fader.Position);
                }
            }
            else if (message is PitchWheelChangeMessage pitchWheelChangeMessage)
            {
                if (Fader != null) 
                    Fader.Position = pitchWheelChangeMessage.Pitch;
            }
        }

        public void SendAcknowledge(IMidiCommunication midiCommunication)
        {
            if (_acknowledgeMessage == null)
                return;
            
            midiCommunication.Send(_acknowledgeMessage);
            _acknowledgeMessage = null;
        }

        private void OnFaderPositionChanged(object? sender, int position)
        {
            if (sender is not IFader fader)
                return;
            
            Controllable?.SetVolume(fader.RelativePosition);
        }

        public override string ToString() => $"Channel {_channelNumber}";
    }
}