PGiZ3/Assets/Code/Gameplay/Enemy/SimpleEnemy.cs

using Code.Gameplay.Character.Core;
using UnityEngine;
using Code.Gameplay.Core;
using Code.Gameplay.Character.Stats;
using Code.Gameplay.Weapons;

namespace Code.Gameplay.Enemy
{
    public class SimpleEnemy : MonoBehaviour, IDamageable
    {
        [SerializeField] private HealthSystem healthSystem;
        [SerializeField] private WeaponBase weapon;
        [SerializeField] private Transform firePoint;
        [SerializeField] private Transform target;
        
        [SerializeField] private float moveSpeed = 3f;
        [SerializeField] private float rotationSpeed = 5f;
        [SerializeField] private float detectionRange = 20f;
        [SerializeField] private float attackRange = 15f;
        [SerializeField] private float stopDistance = 5f;
        
        [SerializeField] private float attackCooldown = 1f;
        [SerializeField] private LayerMask obstacleMask;
        
        private float lastAttackTime;
        private bool isAttacking;
        private CharacterController characterController;

        public bool IsAlive => healthSystem != null && healthSystem.IsAlive;

        private void Awake()
        {
            characterController = GetComponent<CharacterController>();
            if (characterController == null)
                characterController = gameObject.AddComponent<CharacterController>();
                
            if (healthSystem == null)
                healthSystem = GetComponent<HealthSystem>();
        }

        private void Start()
        {
            if (healthSystem != null)
            {
                healthSystem.OnDied += HandleDeath;
            }

            if (target != null) return;
            
            var player = FindFirstObjectByType<CharacterProvider>();
            if (player != null)
                target = player.transform;
        }

        private void Update()
        {
            if (!IsAlive || target == null) return;
            
            var distanceToTarget = Vector3.Distance(transform.position, target.position);

            if (!(distanceToTarget <= detectionRange)) return;
            
            RotateTowardsTarget();
                
            if (distanceToTarget <= attackRange)
            {
                Attack();

                if (distanceToTarget < stopDistance)
                {
                    MoveAway();
                }
            }
            else
            {
                MoveTowardsTarget();
            }
        }

        private void RotateTowardsTarget()
        {
            var direction = (target.position - transform.position).normalized;
            direction.y = 0;
            
            var lookRotation = Quaternion.LookRotation(direction);
            transform.rotation = Quaternion.Slerp(transform.rotation, lookRotation, Time.deltaTime * rotationSpeed);
        }

        private void MoveTowardsTarget()
        {
            var direction = (target.position - transform.position).normalized;
            direction.y = 0;
            
            characterController.Move(direction * (moveSpeed * Time.deltaTime));
        }

        private void MoveAway()
        {
            var direction = (transform.position - target.position).normalized;
            direction.y = 0;
            
            characterController.Move(direction * (moveSpeed * Time.deltaTime));
        }

        private void Attack()
        {
            if (Time.time - lastAttackTime < attackCooldown) return;
            if (weapon == null) return;

            if (!HasLineOfSight()) return;
            
            lastAttackTime = Time.time;
            weapon.Shoot();
        }

        private bool HasLineOfSight()
        {
            if (target == null) return false;
            
            var direction = (target.position - firePoint.position).normalized;
            var distance = Vector3.Distance(firePoint.position, target.position);

            if (Physics.Raycast(firePoint.position, direction, out var hit, distance, obstacleMask))
            {
                return hit.collider.transform == target;
            }
            
            return true;
        }

        private void HandleDeath()
        {
            enabled = false;

            Destroy(gameObject, 2f);
        }

        public void TakeDamage(float damage)
        {
            healthSystem?.TakeDamage(damage);
        }

        public Transform GetTransform() => transform;
    }
}