[SpaceShooter] Monster 공격과 피격 구현

using System.Collections;
using System.Collections.Generic;
using UnityEditor.Experimental.GraphView;
using UnityEngine;
using UnityEngine.AI;
using UnityEngine.UIElements;

public class MonsterController : MonoBehaviour
{
    private Transform monsterTr;
    private Transform playerTr;
    private NavMeshAgent agent;
    private Animator animator;
    private float attackDelay = 2.0f;
    public enum State { 
        Idle,
        Trace,
        Attack,
        Die
    }
    public State state = State.Idle;
    public float tranceDist = 10.0f;
    public float attckDist = 2.0f;
    public bool isDie = false;
    public int EnemyHP = 3;
    private GameObject bloodEffect;


    void Start()
    {
        animator = GetComponent<Animator>();
        monsterTr = GetComponent<Transform>();
        playerTr = GameObject.FindWithTag("Player").GetComponent<Transform>();
        agent = GetComponent<NavMeshAgent>();
        bloodEffect = Resources.Load<GameObject>("BloodSprayEffect");
        Debug.Log(bloodEffect + "로드완료");
        StartCoroutine(CheckMonsterState());
    }

    IEnumerator CheckMonsterState()
    {
        while (!isDie)
        {
            yield return new WaitForSeconds(0.3f);
            float distance = Vector3.Distance(playerTr.position, monsterTr.position);

            if (distance <= attckDist && state != State.Attack)
            {
                LookAtPlayer();
                state = State.Attack;
                animator.SetInteger("state", (int)state);
                agent.SetDestination(transform.position);

                yield return new WaitForSeconds(attackDelay);  // 공격 후 지정한 시간만큼 대기

                state = State.Idle;  // 대기 시간 후 Idle 상태로 변경
                animator.SetInteger("state", (int)state);
            }
            else if (distance <= tranceDist)
            {
                state = State.Trace;
                animator.SetInteger("state", (int)state);
                LookAtPlayer();
                agent.destination = playerTr.position;
            }
            else
            {
                state = State.Idle;
                animator.SetInteger("state", (int)state);
            }
        }
    }

    private void OnTriggerEnter(Collider other)
    {
        if (other.CompareTag("BULLET"))
        {
            Destroy(other.gameObject);

            // Blood effect logic
            Vector3 pos = other.ClosestPointOnBounds(transform.position); 
            Quaternion rot = Quaternion.LookRotation(-other.transform.forward); // 방향을 역으로 설정
            ShowBloodEffect(pos, rot);

            EnemyHP--;
            // 넉백 효과 추가
            Vector3 knockbackDirection = (monsterTr.position - playerTr.position).normalized; // 플레이어와의 반대 방향 계산
            float knockbackDistance = 2.0f; // 넉백 거리
            Vector3 knockbackPosition = monsterTr.position + knockbackDirection * knockbackDistance;
            this.transform.position = knockbackPosition; // 넉백 위치로 이동

            if (EnemyHP <= 0)
            {
                isDie = true;
                state = State.Die;
                animator.SetInteger("state", (int)state);
                Destroy(this.gameObject,2f);

                // NavMeshAgent 비활성화
                agent.enabled = false;

                // 코루틴 정지
                StopAllCoroutines();
            }
        }
    }

    void ShowBloodEffect(Vector3 pos, Quaternion rot)
    {
        GameObject blood = Instantiate<GameObject>(bloodEffect, pos, rot, monsterTr);
        Destroy(blood,1f);
    }

    private void LookAtPlayer()
    {
        Vector3 direction = (playerTr.position - transform.position).normalized; // 플레이어 방향 계산
        Quaternion lookRotation = Quaternion.LookRotation(new Vector3(direction.x, 0, direction.z)); // 회전값
        transform.rotation = Quaternion.Slerp(transform.rotation, lookRotation, Time.deltaTime * 5f); //회전
    }

    private void OnDrawGizmos()
    {
        if(state == State.Trace)
        {
            Gizmos.color = Color.blue;
            Gizmos.DrawWireSphere(transform.position, tranceDist);
        }

        if(state == State.Attack)
        {
            Gizmos.color = Color.red;
            Gizmos.DrawWireSphere(transform.position, attckDist);
        }
    }
}