using System.Collections.Generic;
using UnityEngine;
using Platformer.Mechanics;
using Platformer.Gameplay;
using static Platformer.Core.Simulation;

namespace EerieVillage.Skills.Effectors
{
    /// <summary>
    /// A06 독 늪 Effector — Category C (PlacementPersistent).
    /// PD 지시 2026-05-13:
    ///   - 10초마다 (BaseCooldown 10) 화면 내 가장 가까운 적 위치에 독 늪 spawn
    ///   - 6초 유지 (FX_Venom_Swamp)
    ///   - 독에 한번이라도 닿은 적은 늪을 벗어나도 매 초 10 피해·FX_Venom_Spray 재생 (PoisonedEnemyMarker)
    ///   - 늪 위 적은 marker 지속 시간 5초로 갱신 (상시 5초 유지)
    /// </summary>
    public class PoisonSwampSpawner : IEffector
    {
        public void Trigger(ActiveSkillRuntime runtime, PlayerSkillInventory inventory)
        {
            var data = runtime.ActiveData;
            // 화면 내 가장 가까운 적 검출
            var cam = Camera.main;
            if (cam == null) return;
            float halfH = cam.orthographicSize;
            float halfW = halfH * cam.aspect;
            Vector2 camPos = cam.transform.position;

            EnemyController nearest = null;
            float minDist = float.MaxValue;
            Vector2 playerPos = inventory.transform.position;
            var enemies = Object.FindObjectsByType<EnemyController>(FindObjectsSortMode.None);
            foreach (var e in enemies)
            {
                if (e == null) continue;
                var h = e.GetComponent<Health>();
                if (h == null || !h.IsAlive) continue;
                var p = e.transform.position;
                if (p.x < camPos.x - halfW || p.x > camPos.x + halfW || p.y < camPos.y - halfH || p.y > camPos.y + halfH) continue;
                float d = Vector2.Distance(playerPos, p);
                if (d < minDist) { minDist = d; nearest = e; }
            }

            Vector2 spawnPos = nearest != null ? (Vector2)nearest.transform.position : playerPos;
            spawnPos += data.OffsetXY;

            // 독 늪 GO spawn (OnHitFxPrefab = FX_Venom_Swamp)
            GameObject swampGo;
            if (data.OnHitFxPrefab != null)
            {
                swampGo = Object.Instantiate(data.OnHitFxPrefab, spawnPos, Quaternion.identity);
                swampGo.transform.localScale *= data.HitFxScale;
                // PD 지시 2026-05-13 — ParticleSystem 명시 Play (playOnAwake 영역 정합·재발 안전망)
                foreach (var ps in swampGo.GetComponentsInChildren<ParticleSystem>(true))
                {
                    ps.Play(true);
                }
            }
            else
            {
                swampGo = new GameObject("PoisonSwamp_Fallback");
                swampGo.transform.position = spawnPos;
            }
            swampGo.hideFlags = HideFlags.DontSave;

            // PD 지시 2026-05-13 — BoxCollider2D·Rigidbody2D 영역 자식 GO 분리 (ParticleSystem 영역 root 영향 차단)
            var colliderGo = new GameObject("PoisonSwamp_Collider");
            colliderGo.hideFlags = HideFlags.DontSave;
            colliderGo.transform.SetParent(swampGo.transform, false);
            colliderGo.transform.localPosition = Vector3.zero;

            var instance = colliderGo.AddComponent<PoisonSwampInstance>();
            instance.Init(data, Mathf.Max(data.BaseCooldown, 1f), swampGo);
        }
    }

    /// <summary>
    /// 독 늪 인스턴스 — 6초 유지·BoxCollider2D isTrigger·적 OnTrigger 시 PoisonedEnemyMarker 부착·marker duration 5초 갱신.
    /// </summary>
    public class PoisonSwampInstance : MonoBehaviour
    {
        ActiveSkillData _data;
        float _spawnTime;
        float _duration;
        BoxCollider2D _col;
        GameObject _swampVisualRoot;  // PD 지시 2026-05-13 — FX GO 영역 별도·duration 종료 시 함께 Destroy

        public void Init(ActiveSkillData data, float duration, GameObject visualRoot)
        {
            _data = data;
            _duration = duration;
            _spawnTime = Time.unscaledTime;
            _swampVisualRoot = visualRoot;

            // 자식 BoxCollider2D 부착·HitboxSize 영역 정합
            _col = gameObject.AddComponent<BoxCollider2D>();
            _col.isTrigger = true;
            Vector2 size = data.HitboxSize.sqrMagnitude > 0.01f ? data.HitboxSize : new Vector2(3f, 1.5f);
            _col.size = size;
            _col.offset = Vector2.zero;

            // Kinematic Rigidbody2D — Kinematic vs Kinematic OnTriggerStay 발화 정합 (Enemy = KinematicObject)
            var rb = GetComponent<Rigidbody2D>();
            if (rb == null) rb = gameObject.AddComponent<Rigidbody2D>();
            rb.bodyType = RigidbodyType2D.Kinematic;
            rb.simulated = true;
            rb.gravityScale = 0f;
            rb.useFullKinematicContacts = true;
        }

        void Update()
        {
            if (Time.unscaledTime - _spawnTime >= _duration)
            {
                // FX 영역 root 영역 함께 Destroy
                if (_swampVisualRoot != null) Destroy(_swampVisualRoot);
                else Destroy(gameObject);
            }
        }

        void OnTriggerEnter2D(Collider2D other) { TryMark(other); }
        void OnTriggerStay2D(Collider2D other) { TryMark(other); }

        void TryMark(Collider2D other)
        {
            if (other == null || _data == null) return;
            var e = other.GetComponent<EnemyController>();
            if (e == null) return;
            var h = other.GetComponent<Health>();
            if (h == null || !h.IsAlive) return;

            // 마커 부착 또는 duration 5초 갱신 (늪 위 있을 때 상시 5초 유지)
            var marker = e.GetComponent<PoisonedEnemyMarker>();
            if (marker == null) marker = e.gameObject.AddComponent<PoisonedEnemyMarker>();
            marker.Refresh(_data, 5f);
        }
    }

    /// <summary>
    /// 독 마커 — 적 자식 부착·매 초 10 피해·FX_Venom_Spray 자식 spawn·duration 만료 시 자가 Destroy.
    /// </summary>
    public class PoisonedEnemyMarker : MonoBehaviour
    {
        ActiveSkillData _data;
        float _lastTickTime;
        float _expireTime;

        public void Refresh(ActiveSkillData data, float duration)
        {
            _data = data;
            _expireTime = Time.unscaledTime + duration;
        }

        void Update()
        {
            if (_data == null) { Destroy(this); return; }
            if (Time.unscaledTime >= _expireTime) { Destroy(this); return; }
            if (Time.unscaledTime - _lastTickTime >= 1f)
            {
                _lastTickTime = Time.unscaledTime;
                Tick();
            }
        }

        void Tick()
        {
            var h = GetComponent<Health>();
            if (h == null || !h.IsAlive) { Destroy(this); return; }
            int dmg = _data.BaseDamage > 0 ? _data.BaseDamage : 10;
            h.DecrementBypassInvuln(dmg);

            // FX_Venom_Spray 자식 spawn (적 위치)
            if (_data.OnDotFxPrefab != null)
            {
                var fx = Object.Instantiate(_data.OnDotFxPrefab, transform.position, Quaternion.Euler(0f, 0f, _data.FxRotation), transform);
                fx.hideFlags = HideFlags.DontSave;
                fx.transform.localScale *= _data.DotFxScale;
                // PD 지시 2026-05-13 — ParticleSystem 명시 Play (playOnAwake 영역 정합·재발 안전망)
                foreach (var ps in fx.GetComponentsInChildren<ParticleSystem>(true))
                {
                    ps.Play(true);
                }
                FxAutoDestroyUnscaled.Attach(fx, 1.5f);
            }

            if (!h.IsAlive)
            {
                var e = GetComponent<EnemyController>();
                if (e != null) Schedule<EnemyDeath>().enemy = e;
            }
        }
    }
}