using UnityEngine;
using UnityEngine.AI;

[RequireComponent(typeof(NavMeshAgent))]
public class EnemyController : MonoBehaviour
{
    public enum State { Idle, Chase, Attack, Dead }
    private State currentState = State.Idle;

    [Header("Stats")]
    [SerializeField] private int maxHealth = 60;
    [SerializeField] private int attackDamage = 15;
    [SerializeField] private float attackRange = 1.8f;
    [SerializeField] private float attackCooldown = 1.2f;
    [SerializeField] private float detectionRadius = 18f;

    [Header("Ranged Attack Settings (Optional)")]
    [SerializeField] private bool isRangedEnemy = false;
    [SerializeField] private GameObject rangedProjectilePrefab;
    [SerializeField] private Transform projectileSpawnPoint;
    [SerializeField] private float projectileSpeed = 25f;

    [Header("References")]
    [SerializeField] private Animator animator;
    [SerializeField] private AudioSource audioSource;
    [SerializeField] private AudioClip attackSound;
    [SerializeField] private AudioClip hitSound;
    [SerializeField] private AudioClip deathSound;

    private NavMeshAgent agent;
    private Transform playerTransform;
    private int currentHealth;
    private float nextAttackTime;

    public State CurrentState => currentState;
    public int CurrentHealth => currentHealth;

    private void Awake()
    {
        agent = GetComponent<NavMeshAgent>();
        if (animator == null)
        {
            animator = GetComponentInChildren<Animator>();
        }
        if (audioSource == null)
        {
            audioSource = GetComponent<AudioSource>();
        }
        currentHealth = maxHealth;
    }

    private void Start()
    {
        GameObject playerObj = GameObject.FindGameObjectWithTag("Player");
        if (playerObj != null)
        {
            playerTransform = playerObj.transform;
        }

        AreaClearanceManager.Instance?.RegisterEnemy(this);
    }

    private void Update()
    {
        if (currentState == State.Dead) return;

        // Re-acquire player reference if it was spawned dynamically
        if (playerTransform == null)
        {
            GameObject playerObj = GameObject.FindGameObjectWithTag("Player");
            if (playerObj != null)
            {
                playerTransform = playerObj.transform;
            }
            return;
        }

        float distanceToPlayer = Vector3.Distance(transform.position, playerTransform.position);

        switch (currentState)
        {
            case State.Idle:
                if (distanceToPlayer <= detectionRadius)
                {
                    currentState = State.Chase;
                }
                break;

            case State.Chase:
                if (agent.isOnNavMesh)
                {
                    agent.SetDestination(playerTransform.position);
                }

                if (animator != null)
                {
                    animator.SetFloat("Speed", agent.velocity.magnitude);
                }

                if (distanceToPlayer <= attackRange)
                {
                    currentState = State.Attack;
                    if (agent.isOnNavMesh)
                    {
                        agent.ResetPath();
                    }
                }
                break;

            case State.Attack:
                Vector3 lookTarget = new Vector3(playerTransform.position.x, transform.position.y, playerTransform.position.z);
                transform.LookAt(lookTarget);

                if (Time.time >= nextAttackTime)
                {
                    PerformAttack();
                    nextAttackTime = Time.time + attackCooldown;
                }

                if (distanceToPlayer > attackRange)
                {
                    currentState = State.Chase;
                }
                break;
        }
    }

    private void PerformAttack()
    {
        if (animator != null)
        {
            animator.SetTrigger("Attack");
        }

        if (attackSound != null && audioSource != null)
        {
            audioSource.PlayOneShot(attackSound);
        }

        if (isRangedEnemy && rangedProjectilePrefab != null)
        {
            // Fire projectile towards player
            Vector3 spawnPos = projectileSpawnPoint != null ? projectileSpawnPoint.position : transform.position + Vector3.up * 1.2f + transform.forward * 0.5f;
            Vector3 aimDir = (playerTransform.position + Vector3.up * 1.0f - spawnPos).normalized;
            GameObject projObj = Instantiate(rangedProjectilePrefab, spawnPos, Quaternion.LookRotation(aimDir));
            if (projObj.TryGetComponent<Projectile>(out var proj))
            {
                proj.Initialize(attackDamage, projectileSpeed, "Enemy");
            }
        }
        else
        {
            // Direct melee strike
            if (PlayerHealthController.Instance != null)
            {
                PlayerHealthController.Instance.TakeDamage(attackDamage);
            }
        }
    }

    public void TakeDamage(int damage)
    {
        if (currentState == State.Dead) return;

        currentHealth -= damage;

        if (hitSound != null && audioSource != null)
        {
            audioSource.PlayOneShot(hitSound);
        }

        if (animator != null)
        {
            animator.SetTrigger("Hit");
        }

        // Auto-aggro when damaged if idle
        if (currentState == State.Idle)
        {
            currentState = State.Chase;
        }

        if (currentHealth <= 0)
        {
            Die();
        }
    }

    private void Die()
    {
        currentState = State.Dead;

        if (agent != null && agent.isOnNavMesh)
        {
            agent.isStopped = true;
        }
        if (agent != null)
        {
            agent.enabled = false;
        }

        if (animator != null)
        {
            animator.SetBool("IsDead", true);
        }

        if (deathSound != null && audioSource != null)
        {
            audioSource.PlayOneShot(deathSound);
        }

        Collider col = GetComponent<Collider>();
        if (col != null)
        {
            col.enabled = false;
        }

        AreaClearanceManager.Instance?.UnregisterEnemy(this);
        Destroy(gameObject, 5f);
    }
}