using UnityEngine;

public class ShieldBarrier : MonoBehaviour
{
    [Header("盾牌状态")]
    [Min(0f)]
    public float maxDurability = 220f;

    [Min(0f)]
    public float currentDurability;

    [Min(0f)]
    public float duration = 6f;

    [Range(-1f, 1f)]
    public float frontDotThreshold = 0.15f;

    private UnitBase owner;
    private Collider barrierCollider;
    private float remainingTime;

    public UnitBase Owner => owner;

    public float CurrentDurability => currentDurability;

    public bool IsActive =>
        isActiveAndEnabled &&
        barrierCollider != null &&
        barrierCollider.enabled &&
        currentDurability > 0f &&
        remainingTime > 0f;

    public void Configure(UnitBase shieldOwner, Collider shieldCollider)
    {
        owner = shieldOwner;
        barrierCollider = shieldCollider;
    }

    public void Refresh(float durability, float activeDuration, Vector3 localPosition, Vector3 localSize)
    {
        if (barrierCollider == null)
        {
            barrierCollider = GetComponent<Collider>();
        }

        if (owner == null)
        {
            owner = GetComponentInParent<UnitBase>();
        }

        transform.localPosition = localPosition;
        transform.localRotation = Quaternion.identity;

        BoxCollider boxCollider = barrierCollider as BoxCollider;
        if (boxCollider != null)
        {
            boxCollider.center = Vector3.zero;
            boxCollider.size = localSize;
            boxCollider.isTrigger = true;
        }

        maxDurability = Mathf.Max(0.01f, durability);
        currentDurability = maxDurability;
        duration = Mathf.Max(0.01f, activeDuration);
        remainingTime = duration;

        gameObject.SetActive(true);
        if (barrierCollider != null)
        {
            barrierCollider.enabled = true;
        }
    }

    public bool TryBlock(GameObject attacker, float damage)
    {
        if (!IsActive || damage <= 0f)
        {
            return false;
        }

        if (attacker != null && !IsIncomingFromFront(attacker))
        {
            return false;
        }

        currentDurability -= damage;
        if (currentDurability <= 0f)
        {
            DisableBarrier();
        }

        return true;
    }

    public void DisableBarrier()
    {
        currentDurability = 0f;
        remainingTime = 0f;

        if (barrierCollider != null)
        {
            barrierCollider.enabled = false;
        }

        gameObject.SetActive(false);
    }

    private void Update()
    {
        if (!IsActive)
        {
            return;
        }

        remainingTime -= Time.deltaTime;
        if (remainingTime <= 0f)
        {
            DisableBarrier();
        }
    }

    private bool IsIncomingFromFront(GameObject attacker)
    {
        if (owner == null)
        {
            return true;
        }

        Vector3 direction = attacker.transform.position - owner.transform.position;
        direction.y = 0f;
        if (direction.sqrMagnitude <= 0.0001f)
        {
            return true;
        }

        return Vector3.Dot(owner.transform.forward, direction.normalized) >= frontDotThreshold;
    }
}