Artemis/src/Artemis.Core/VisualScripting/Internal/EventDefaultNode.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Artemis.Core.Modules;
using Humanizer;

namespace Artemis.Core.Internal
{
    internal class EventDefaultNode : Node
    {
        private readonly Dictionary<PropertyInfo, OutputPin> _propertyPins;
        private readonly List<OutputPin> _pinBucket = new();
        private IDataModelEvent? _dataModelEvent;

        public EventDefaultNode() : base("Event Arguments", "Contains the event arguments that triggered the evaluation")
        {
            _propertyPins = new Dictionary<PropertyInfo, OutputPin>();
        }

        public override bool IsDefaultNode => true;

        public void CreatePins(IDataModelEvent? dataModelEvent)
        {
            if (_dataModelEvent == dataModelEvent)
                return;

            while (Pins.Any())
                RemovePin((Pin) Pins.First());
            _propertyPins.Clear();

            _dataModelEvent = dataModelEvent;
            if (dataModelEvent == null)
                return;

            foreach (PropertyInfo propertyInfo in dataModelEvent.ArgumentsType.GetProperties(BindingFlags.Instance | BindingFlags.Public)
                         .Where(p => p.CustomAttributes.All(a => a.AttributeType != typeof(DataModelIgnoreAttribute))))
                _propertyPins.Add(propertyInfo, CreateOrAddOutputPin(propertyInfo.PropertyType, propertyInfo.Name.Humanize()));
        }

        public override void Evaluate()
        {
            if (_dataModelEvent?.LastEventArgumentsUntyped == null)
                return;

            foreach ((PropertyInfo propertyInfo, OutputPin outputPin) in _propertyPins)
            {
                if (outputPin.ConnectedTo.Any())
                    outputPin.Value = propertyInfo.GetValue(_dataModelEvent.LastEventArgumentsUntyped) ?? outputPin.Type.GetDefault()!;
            }
        }

        /// <summary>
        ///     Creates or adds an input pin to the node using a bucket.
        ///     The bucket might grow a bit over time as the user edits the node but pins won't get lost, enabling undo/redo in the
        ///     editor.
        /// </summary>
        private OutputPin CreateOrAddOutputPin(Type valueType, string displayName)
        {
            // Grab the first pin from the bucket that isn't on the node yet
            OutputPin? pin = _pinBucket.FirstOrDefault(p => !Pins.Contains(p));

            // If there is none, create a new one and add it to the bucket
            if (pin == null)
            {
                pin = CreateOutputPin(valueType, displayName);
                _pinBucket.Add(pin);
            }
            // If there was a pin in the bucket, update it's type and display name and reuse it
            else
            {
                pin.ChangeType(valueType);
                pin.Name = displayName;
                AddPin(pin);
            }

            return pin;
        }
    }
}