using UnityEngine;

public class EnemyVision : MonoBehaviour
{
    [Header("References")]
    public EnemyStateMachine stateMachine;
    public Transform player;

    [Header("Vision")]
    public float viewRadius = 14f;
    [Range(1f, 180f)]
    public float viewAngle = 65f;
    public LayerMask obstacleMask;
    public LayerMask targetMask;
    public float eyeHeight = 1.4f;
    public float standingDetectionDelay = 0.12f;
    public float crouchDetectionDelay = 0.35f;

    private bool hadLineOfSight;
    private float visibleTimer;

    private void Awake()
    {
        stateMachine = stateMachine != null ? stateMachine : GetComponent<EnemyStateMachine>();
    }

    private void Update()
    {
        AcquirePlayer();
        if (player == null || stateMachine == null)
        {
            return;
        }

        bool canSeePlayer = CanSeePlayer(out Vector3 eyePosition, out Vector3 targetPosition, out Color debugColor);
        Debug.DrawRay(eyePosition, targetPosition - eyePosition, debugColor);

        if (canSeePlayer)
        {
            PlayerStealth stealth = player.GetComponent<PlayerStealth>();
            float requiredTime = stealth != null && stealth.IsCrouching ? crouchDetectionDelay : standingDetectionDelay;
            visibleTimer += Time.deltaTime;

            if (visibleTimer >= requiredTime)
            {
                hadLineOfSight = true;
                stateMachine.OnPlayerDetected(player.position);
            }
        }
        else
        {
            visibleTimer = 0f;
            if (hadLineOfSight)
            {
                hadLineOfSight = false;
                stateMachine.OnPlayerLost();
            }
        }
    }

    public float GetViewRadiusForCurrentTarget()
    {
        if (player == null)
        {
            return viewRadius;
        }

        PlayerStealth stealth = player.GetComponent<PlayerStealth>();
        return viewRadius * (stealth != null ? stealth.VisibilityMultiplier : 1f);
    }

    private bool CanSeePlayer(out Vector3 eyePosition, out Vector3 targetPosition, out Color debugColor)
    {
        eyePosition = transform.position + Vector3.up * eyeHeight;
        targetPosition = player.position + Vector3.up * 0.9f;
        debugColor = Color.gray;

        float effectiveRadius = GetViewRadiusForCurrentTarget();
        Vector3 directionToPlayer = targetPosition - eyePosition;
        float distanceToPlayer = directionToPlayer.magnitude;

        if (distanceToPlayer > effectiveRadius)
        {
            return false;
        }

        float angleToPlayer = Vector3.Angle(transform.forward, directionToPlayer);
        if (angleToPlayer > viewAngle * 0.5f)
        {
            return false;
        }

        int combinedMask = obstacleMask | targetMask;
        if (Physics.Raycast(eyePosition, directionToPlayer.normalized, out RaycastHit hit, distanceToPlayer, combinedMask, QueryTriggerInteraction.Ignore))
        {
            // Если первым попался не игрок, значит между врагом и игроком есть укрытие или стена.
            bool isPlayerHit = hit.transform == player || hit.transform.IsChildOf(player);
            debugColor = isPlayerHit ? Color.green : Color.red;
            return isPlayerHit;
        }

        debugColor = Color.red;
        return false;
    }

    private void AcquirePlayer()
    {
        if (player != null)
        {
            return;
        }

        GameObject playerObject = GameObject.FindGameObjectWithTag("Player");
        if (playerObject != null)
        {
            player = playerObject.transform;
        }
    }
}