TowerDefenseGame/Assets/Scripts/Runtime/AI/EnemyManager/Gobler.cs

using AI.Base;
using NUnit.Framework.Internal.Execution;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;
using UnityEngine;
using UnityEngine.AI;
using static EnemySpawnerData;


public class Gobler : Alive {
  [Header("Mechanics Attributes")]
  [SerializeField] public float ChaseDistance = 10f;
  [SerializeField] public float ChaseDistanceBuffer = 1f;
  [SerializeField] public float AttackDistance = 1f;
  [SerializeField] public float AttackMaskDiameter = 1f;


  [Header("Enemy Attributes")]
  [SerializeField] public float Attack = 10f;
  [SerializeField] public float Speed = 10f;
  [SerializeField] public float Health = 10f;
  [SerializeField] public float Energy = 10f;

  protected FloatingTextSpawner TextPopUp;


  private Player Player { get { return Player.Instance; } }
  private Transform PlayerTransform { get { return Player.transform; } }
  private Vector2 PlayerPos { get { return PlayerTransform.position; } }
  private Vector2 CrystalPos { get { return GameManager.Crystal.transform.position; } }

  private GameObject Owner;
  private Rigidbody2D Rigidbody;
  private Transform MyTransform { get { return Owner.transform; } }
  private Vector2 MyPos { get { return MyTransform.position; } set { MyTransform.position = value; } }

  private NavMeshAgent PathAgent;

  private List<Material> Materials;


  public Gobler(GameObject owner) {
    Owner = owner;
    PathAgent = Owner.GetComponent<NavMeshAgent>();
    PathAgent.updateRotation = false;
    PathAgent.updateUpAxis = false;
    PathAgent.speed = Speed;
    IsUpdating = false;

    MaxHealth = 100;
    CurrentHealth = MaxHealth;
    OnTakeDamage += (damage, direction) => SetState(State.TakeDamage);
    OnDeath += () => SetState(State.Die);

    Rigidbody = Owner.GetComponent<Rigidbody2D>();
    Materials = Owner.GetComponentsInChildren<SpriteRenderer>().Select(x => x.material).ToList();

    TextPopUp = new FloatingTextSpawner(Owner.transform, 1);

    SetState(State.GoToCrystal);
    EnemyManagers[Enemies.Gobler].UpdateTick += Update;
    EnemyManagers[Enemies.Gobler].GizmoTick += OnDrawGizmos;
  }

  public float DistFromPlayer { get; private set; }
  public float DistFromCrystal { get; private set; }


  public State CurrentState;
  public enum State {
    None,
    GoToCrystal,
    AttackCrystal,
    ChasePlayer,
    AttackPlayer,
    PrepareAttack,
    FinalizeAttack,
    TakeDamage,
    Die
  }


  protected void SetPriorityState() {
    if (CurrentState == State.AttackPlayer) return;
    if (CurrentState == State.ChasePlayer) return;
    if (CurrentState == State.TakeDamage) return;
    if (CurrentState == State.Die) return;
    if (DistFromPlayer > ChaseDistance) return;
    SetState(State.ChasePlayer);
  }

  private bool IsUpdating;
  protected void Update() {
    if (Owner == null) return;
    if (GameManager.Crystal == null) return;
    if (IsUpdating) return;
    IsUpdating = true;

    DistFromPlayer = Vector2.Distance(MyPos, PlayerPos);
    DistFromCrystal = Vector2.Distance(MyPos, CrystalPos);
    SetPriorityState();

    switch (CurrentState) {
      case State.None:
        SetState(State.GoToCrystal);
        break;


      case State.GoToCrystal:
        PathAgent.SetDestination(CrystalPos);

        break;


      case State.AttackCrystal:
        break;


      case State.ChasePlayer:
        if (DistFromPlayer > ChaseDistance + ChaseDistanceBuffer)
          SetState(State.GoToCrystal);
        if (DistFromPlayer > ChaseDistance + ChaseDistanceBuffer)
          SetState(State.GoToCrystal);
        else
          PathAgent.SetDestination(PlayerPos);
        break;


      case State.AttackPlayer:
        break;


      case State.TakeDamage:
        Rigidbody.linearVelocity = DirectionOfDamage * Knockback * 10 * InvincibilityLeft;
        Materials.ForEach(x => x.SetFloat("_FlashAmount", InvincibilityLeft));
        if (!IsInvincible) SetState(State.None);
        break;

      case State.PrepareAttack:
        break;


      case State.FinalizeAttack:
        break;


    }

    IsUpdating = false;
  }



  protected void SetState(State newState) {
    CurrentState = newState;
    switch (CurrentState) {
      case State.None:
        PathAgent.isStopped = false;
        break;


      case State.GoToCrystal:
        break;


      case State.AttackCrystal:
        break;


      case State.ChasePlayer:
        break;


      case State.AttackPlayer:
        break;


      case State.TakeDamage:
        PathAgent.isStopped = true;
        TextPopUp.SpawnFloatingText(DamageTaken.ToString(), Color.red, 3);
        Materials.ForEach(x => x.SetColor("_FlashColor", Color.white));
        break;


      case State.Die:
        SpawnableEnemyInfo.DestroyEnemy(Owner, Enemies.Gobler);
        SetState(State.None);
        break;


    }
  }



  protected void OnDrawGizmos() {
    if (Owner == null) return;

    DrawChaseDistance();
    DrawAttackDistance();
    DrawAttackReach();
  }

  private void DrawWireSphere(Color color, Vector2 center, float radius) => EnemyManagers[Enemies.Gobler].DrawWireSphere(color, center, radius);


  private void DrawChaseDistance() {
    DrawWireSphere(Color.green, MyPos, ChaseDistance);
  }

  private void DrawAttackDistance() {
    //Gizmos.color = CurrentState == (IState)AttackState ? Color.red : Color.green;
    //Vector2 center = this.transform.position;
    //Gizmos.DrawWireSphere(center, AttackDistance);
  }

  private void DrawAttackReach() {
    //if (CurrentState != (IState)AttackState) return;
    //Gizmos.color = Color.red;

    Vector2 direction2D = (PlayerPos - MyPos).normalized;
    Vector2 point2D = MyPos + direction2D * AttackDistance;
    //Gizmos.DrawWireSphere(point2D, AttackMaskDiameter);
    DrawWireSphere(Color.red, point2D, AttackMaskDiameter);
  }
}


public class Alive {
  public int MaxHealth { get; protected set; }
  public int CurrentHealth { get; protected set; }
  public bool IsDead => CurrentHealth <= 0;

  public bool IsInvincible => Time.time < InvincibleUntil;
  protected float InvincibleUntil = 0f;
  protected float InvincibilityLeft => Math.Max(0, InvincibleUntil - Time.time);
  protected float InvincibilityDuration = 0.1f;

  public event Action<int, Vector2> OnTakeDamage;
  public event Action OnDeath;
  public event Action<int> OnHeal;

  protected int DamageTaken;
  protected Vector2 DirectionOfDamage;
  protected int Knockback;

  public void Damage(int amount, Vector2 hitDirection, int knockback = 1) {
    if (IsDead || IsInvincible) return;

    CurrentHealth -= amount;
    CurrentHealth = Mathf.Max(CurrentHealth, 0);
    InvincibleUntil = Time.time + InvincibilityDuration;
    DamageTaken = amount;
    Knockback = knockback;

    hitDirection = hitDirection.normalized;
    if (hitDirection == Vector2.zero) hitDirection = Vector2.up;
    DirectionOfDamage = hitDirection;
    OnTakeDamage?.Invoke(amount, hitDirection);

    if (CurrentHealth == 0) OnDeath?.Invoke();
  }

  public void Heal(int amount) {
    if (IsDead) return;

    CurrentHealth += amount;
    CurrentHealth = Mathf.Min(CurrentHealth, MaxHealth);
    OnHeal?.Invoke(amount);
  }

  public void Reset() {
    CurrentHealth = MaxHealth;
    InvincibleUntil = 0f;
  }
}