using System.Collections;
using UnityEngine;

/// <summary>
/// 盾卫技能：坚固壁垒
/// 1级：生成相当于自身 25% 最大生命值的护盾（持续 5 秒），播放 MagicShield 护盾特效
/// 3级：护盾值提升至 35% 最大生命值，护盾期间减伤 +15%
/// </summary>
public class ShieldGuardSkill : UnitSkill
{
    [Header("护盾配置")]
    [Tooltip("护盾持续时间(秒)")]
    public float shieldDuration = 5.0f;

    [Tooltip("护盾特效预制体")]
    public GameObject shieldVfxPrefab;

    private GameObject activeVfxInstance;
    private Coroutine activeShieldCoroutine;

    private void EnsureUnit()
    {
        if (unit == null)
        {
            unit = GetComponent<UnitBase>();
        }
    }

    public override void ReleaseSkill()
    {
        EnsureUnit();
        if (unit == null) return;

        WorldHealthBar healthBar = unit.GetComponent<WorldHealthBar>();
        if (healthBar == null || healthBar.IsDead) return;

        int level = unit.level; // 从 UnitBase 字段读取 level
        // 1级：25% maxHealth，3级+：35% maxHealth
        float ratio = level >= 3 ? 0.35f : 0.25f;
        float shieldAmount = healthBar.maxHealth * ratio;

        // 1. 添加护盾值
        healthBar.AddShield(shieldAmount);

        // 2. 播放 MagicShield 护盾特效
        PlayShieldVfx();

        // 3. 开启超时自动清盾协程
        if (activeShieldCoroutine != null)
        {
            StopCoroutine(activeShieldCoroutine);
        }
        activeShieldCoroutine = StartCoroutine(ShieldTimeoutRoutine(shieldDuration, shieldAmount));

        Debug.Log($"<color=cyan>盾卫释放技能【坚固壁垒】</color> 获得 {shieldAmount:F1} 护盾（比例: {ratio * 100}%，等级: {level}）");
    }

    public override float ModifyIncomingDamage(float damage, GameObject attacker)
    {
        EnsureUnit();
        // 3级解锁：护盾激活期间享受额外 15% 减伤
        if (unit != null && unit.level >= 3)
        {
            WorldHealthBar healthBar = unit.GetComponent<WorldHealthBar>();
            if (healthBar != null && healthBar.currentShield > 0f)
            {
                return damage * (1f - 0.15f);
            }
        }
        return damage;
    }

    private void PlayShieldVfx()
    {
        if (activeVfxInstance != null)
        {
            Destroy(activeVfxInstance);
        }

        GameObject prefab = shieldVfxPrefab;
        if (prefab == null)
        {
            prefab = Resources.Load<GameObject>("Prefabs/Combat/Magic/Shield/MagicShieldBlue");
        }
#if UNITY_EDITOR
        if (prefab == null)
        {
            prefab = UnityEditor.AssetDatabase.LoadAssetAtPath<GameObject>("Assets/TJGeneratorLibEffects/Prefabs/Combat/Magic/Shield/MagicShieldBlue.prefab");
        }
#endif

        if (prefab != null)
        {
            activeVfxInstance = Instantiate(prefab, unit.transform.position + Vector3.up * 1.0f, Quaternion.identity);
            activeVfxInstance.transform.SetParent(unit.transform, true);
        }
    }

    private IEnumerator ShieldTimeoutRoutine(float duration, float amount)
    {
        float timer = duration;
        WorldHealthBar healthBar = unit != null ? unit.GetComponent<WorldHealthBar>() : null;

        while (timer > 0f)
        {
            if (unit == null || healthBar == null || healthBar.IsDead || healthBar.currentShield <= 0f)
            {
                break;
            }
            timer -= Time.deltaTime;
            yield return null;
        }

        // 超时或护盾为 0 清理特效与护盾值
        if (activeVfxInstance != null)
        {
            Destroy(activeVfxInstance);
            activeVfxInstance = null;
        }

        if (healthBar != null && healthBar.currentShield > 0f && timer <= 0f)
        {
            healthBar.RemoveShield(amount);
        }
    }

    private void OnDestroy()
    {
        if (activeVfxInstance != null)
        {
            Destroy(activeVfxInstance);
        }
    }
}