BGJ-2022.1/Assets/Scripts/AI/BasicPatrollingEnemyAI.cs

using Movement;
using Pausable;
using UnityEngine;

namespace AI
{
    public class BasicPatrollingEnemyAI : MonoBehaviour, IPausable
    {
        [SerializeField] protected bool isMovingRightInitially = false;
        protected bool isMovingRight = false;

        protected IMovement movement = null;
        protected SpriteRenderer spriteRenderer = null;

        protected CollisionChecker leftWallChecker = null;
        protected CollisionChecker rightWallChecker = null;
        protected CollisionChecker leftGroundChecker = null;
        protected CollisionChecker rightGroundChecker = null;

        #region IPausable
        public bool IsPaused { get; protected set; } = false;
        public virtual void Pause() => IsPaused = true;
        public virtual void Resume() => IsPaused = false;
        #endregion


        // If moving Right, and either there's no more ground to move into or there is a wall at the Right side of the enemy OR
        // If moving Left, and either there's no more ground to move into or there is a wall at the Left side of the enemy
        // We should change directions
        protected bool ShouldChangeDirection
            => (isMovingRight && (rightWallChecker.IsCollided || !rightGroundChecker.IsCollided)) ||
                (!isMovingRight && (leftWallChecker.IsCollided || !leftGroundChecker.IsCollided));

        protected virtual void Awake()
        {
            movement = gameObject.AddComponent<EnemyMovement>();
            spriteRenderer = gameObject.GetComponent<SpriteRenderer>();
            leftWallChecker = GetCollisionCheckerOnChild("Collision Checkers/Left Wall");
            rightWallChecker = GetCollisionCheckerOnChild("Collision Checkers/Right Wall");
            leftGroundChecker = GetCollisionCheckerOnChild("Collision Checkers/Left Ground");
            rightGroundChecker = GetCollisionCheckerOnChild("Collision Checkers/Right Ground");
            isMovingRight = isMovingRightInitially;
            spriteRenderer.flipX = !isMovingRightInitially;
        }

        protected virtual void FixedUpdate()
        {
            if (IsPaused)
                return;

            if (ShouldChangeDirection)
            {
                isMovingRight = !isMovingRight;
                spriteRenderer.flipX = !isMovingRight;
            }

            movement.Move(isMovingRight ? 1f : -1f);
        }

        protected CollisionChecker GetCollisionCheckerOnChild(string childName)
            => transform.Find(childName).GetComponent<CollisionChecker>();
    }
}