Fruitomation/Assets/Scripts/Game/Items/ItemBehaviour.cs

using Fruitomation.Global;
using PashaBibko.Pacore.Attributes;
using UnityEngine;

namespace Fruitomation.Game.Items
{
    public sealed class ItemBehaviour : MonoBehaviour
    {
        public RectTransform RectTransform { get; private set; }
        public Rigidbody2D Body2D { get; private set; }
        
        private Canvas AttachedCanvas { get; set; }
        private bool EnteredCanvas { get; set; }

        private CustomItemBehaviour CustomBehaviour;
        private GameObject CurrentChild;

        [SerializeField, InspectorReadOnly("Item Type")]
        private ItemType InternalItemType = ItemType.None;

        public ItemType CurrentType
        {
            get => InternalItemType;
            set
            {
                if (InternalItemType != value) // Stops unneeded changes
                {
                    InternalItemType = value;
                    OnUpdateItemType();
                }
            }
        }

        public void InitBehaviour(Canvas canvas, ItemType startType)
        {
            RectTransform = transform.GetComponent<RectTransform>();
            Body2D = transform.GetComponent<Rigidbody2D>();
            
            AttachedCanvas = canvas;
            CurrentType = startType;
            EnteredCanvas = false;
            
            CustomBehaviour?.OnCreation();
        }

        private void OnUpdateItemType()
        {
            if (CurrentChild is not null)
            {
                CustomBehaviour = null;
                Destroy(CurrentChild);
            }
            
            ItemInfo info = ItemInfoRegistry.Get(CurrentType);
            CurrentChild = Instantiate(info.Prefab, transform);

            CustomBehaviour = info.GetCustomBehaviour();
            if (CustomBehaviour is not null)
            {
                CustomBehaviour.AttachedItemBehaviour = this;
                CustomBehaviour.OnCreation();
            }
        }

        private void Update()
        {
            if (!GameStateController.Is(GameState.Simulation))
            {
                TriggerDestruction(false);
            }
        }

        private void FixedUpdate()
        {
            bool contained = IsWithinCanvas(RectTransform, AttachedCanvas.GetComponent<RectTransform>());
            EnteredCanvas = EnteredCanvas || contained;

            if (!contained && EnteredCanvas)
            {
                TriggerDestruction();
            }
        }

        private static bool IsWithinCanvas(RectTransform element, RectTransform canvas)
        {
            Vector3[] elementCorners = new Vector3[4];
            Vector3[] canvasCorners = new Vector3[4];

            element.GetWorldCorners(elementCorners);
            canvas.GetWorldCorners(canvasCorners);

            Rect bounds = new
            (
                canvasCorners[0].x,
                canvasCorners[0].y,
                canvasCorners[2].x - canvasCorners[0].x,
                canvasCorners[2].y - canvasCorners[0].y
            );

            foreach (Vector3 corner in elementCorners)
            {
                if (bounds.Contains(corner))
                {
                    return true;
                }
            }

            return false;
        }

        public void TriggerDestruction(bool harvest = true)
        {
            if (harvest)
            {
                ItemInfo info = ItemInfoRegistry.Get(CurrentType);
                float money = Random.Range(info.MinMoney, info.MaxMoney);
                MoneyController.Add(money);
            }

            Destroy(gameObject);
        }
    }
}