Fruitomation/Assets/Scripts/UI/GameCursor.cs

using PashaBibko.Pacore.Attributes;
using System.Collections.Generic;
using Fruitomation.Global;
using Fruitomation.Game;
using UnityEngine.UI;
using UnityEngine;
using System;

namespace Fruitomation.UI
{
    public class GameCursor : MonoBehaviour
    {
        private const float MIN_STRENGTH = 0.5f;
        private const float MAX_STRENGTH = 1.7f;
        
        [Header("References")]
        [SerializeField] private Camera ActiveCamera;
        [SerializeField] private CircleCollider2D CursorCollider;
        [SerializeField] private RectTransform RectTransform;
        [SerializeField] private Image BuildingPreview;
        [SerializeField] private Image CursorImage;
        [SerializeField] private BuildingManager BuildingManager;
        
        [Header("Read Only")]
        [SerializeField, InspectorReadOnly] private float CurrentMouseClickStrength;
        [SerializeField, InspectorReadOnly] private Vector2Int GridPosition;
        [SerializeField, InspectorReadOnly] private GameObject SelectedBuildingToBuild;
        
        private readonly ContactFilter2D ContactFilter = new();
        private readonly List<Collider2D> Colliders = new();

        private BuildingBase SelectedBuildingsBuildingBase;
        
        private float StartOfMouseClick;
        private bool MouseOnGrid;

        public void SetSelectedBuildingToBuild(GameObject prefab)
        {
            SelectedBuildingsBuildingBase = prefab.GetComponent<BuildingBase>();
            SelectedBuildingToBuild = prefab;
        }

        private void UpdatePosition()
        {
            Ray ray = ActiveCamera.ScreenPointToRay(Input.mousePosition);
            
            float t = -ray.origin.z / ray.direction.z;
            Vector2 position = ray.origin + t * ray.direction;
            transform.position = position;
        }

        private void CalculateGridPosition()
        {
            Vector2 p0 = RectTransform.anchoredPosition;
            Vector2 p1 = p0 - new Vector2(0, 100f); // Offset of the grid from the middle of the screen
            Vector2 p2 = p1 / 40f;
            Vector2 p3 = p2 + new Vector2(48f, 24f); // Half size of the grid
            Vector2Int p4 = Vector2Int.FloorToInt(p3);
            GridPosition = new Vector2Int
            (
                Math.Clamp(p4.x, 0, 95), // size.x - 1
                Math.Clamp(p4.y, 0, 48) // size.y - 1
            );

            MouseOnGrid = GridPosition == p4;
        }

        private void Update()
        {
            UpdatePosition();

            CursorImage.enabled = false;
            BuildingPreview.enabled = false;
            
            CurrentMouseClickStrength = MIN_STRENGTH;
            switch (GameStateController.State)
            {
                case GameState.Simulation:
                    UpdateMouseStateSimulation();
                    break;
                 
                case GameState.Building:
                    UpdateMouseStateBuilding();
                    break;
                
                case GameState.UpgradeMenu:
                case GameState.Paused:
                case GameState.Default:
                case GameState.BuildingMenu:
                    break; // No extra logic needed

                default:
                    throw new ArgumentOutOfRangeException();
            }
            
            CurrentMouseClickStrength = Mathf.Clamp(CurrentMouseClickStrength, MIN_STRENGTH, MAX_STRENGTH);
            
            CalculateGridPosition();

            RectTransform.localScale = new Vector3(CurrentMouseClickStrength, CurrentMouseClickStrength, 1f);
        }
        
        private void UpdateMouseStateSimulation()
        {
            CursorImage.enabled = true;
            
            if (Input.GetMouseButtonUp(0))
            {
                CurrentMouseClickStrength = MIN_STRENGTH;
                
                CursorCollider.radius = CurrentMouseClickStrength * 30f;
                Physics2D.OverlapCollider(CursorCollider, ContactFilter, Colliders);
                
                foreach (Collider2D col in Colliders)
                {
                    if (col.transform.name == "Sprite")
                    {
                        FruitBehaviour fruit = col.GetComponentInParent<FruitBehaviour>();
                        Debug.Assert(fruit, "Couldn't find FruitBehaviour");
                        
                        fruit.TriggerDestruction();
                    }
                }
            }
            
            if (Input.GetMouseButton(0))
            {
                if (Input.GetMouseButtonDown(0))
                {
                    StartOfMouseClick = Time.time;
                    CurrentMouseClickStrength = MIN_STRENGTH;
                    return;
                }
                
                CurrentMouseClickStrength = Time.time - StartOfMouseClick;
            }

            else
            {
                CurrentMouseClickStrength = MIN_STRENGTH;
            }
        }

        private void UpdateMouseStateBuilding()
        {
            BuildingPreview.enabled = true;
            
            BuildingPreview.material = new Material(Shader.Find("UI/Default"))
            {
                mainTexture = SelectedBuildingsBuildingBase.Texture
            };
            
            BuildingPreview.rectTransform.sizeDelta = SelectedBuildingsBuildingBase.SizeOnGrid * 40;
            
            //
            Vector2Int p0 = new
            (
                Math.Clamp(GridPosition.x, 0, 96 - SelectedBuildingsBuildingBase.SizeOnGrid.x),
                Math.Clamp(GridPosition.y, 0, 49 - SelectedBuildingsBuildingBase.SizeOnGrid.y)
            );
            Vector2Int p1 = p0 - new Vector2Int(48, 24);
            Vector2Int p2 = p1 * 40;
            Vector2Int p3 = p2 + new Vector2Int(20, 100);
            
            Vector2 o0 = SelectedBuildingsBuildingBase.SizeOnGrid - Vector2.one;
            Vector2 o1 = o0 * 20;
            Vector2 p4 = p3 + o1;
            BuildingPreview.rectTransform.anchoredPosition = p4;
            
            //
            if (Input.GetMouseButtonDown(0) && MouseOnGrid)
            {
                BuildingManager.AddBuildingAt(p1, SelectedBuildingToBuild);
            }
        }
    }
}