using System.Collections.Generic;
using UnityEngine;
using BaseGames.Core;

namespace BaseGames.Combat
{
    /// <summary>
    /// 攻击判定盒。挂载在武器 Prefab 或技能 HitBox Prefab 的子节点上。
    /// 直接挂在 Player Prefab 子节点 [HitBoxGround/Up/Down/Air]。
    /// Collider2D 需设 IsTrigger = true，Layer = PlayerHitBox 或 EnemyHitBox。
    ///
    /// 多碰撞体模式：在子节点上挂载 HitBoxColliderProxy + Collider2D 即可组合任意形状。
    /// HitBox 本身可不带 Collider2D（仅代理子节点）或同时拥有直属 Collider2D。
    /// </summary>
    /// <summary>
    /// 命中节奏模式。
    /// <list type="bullet">
    ///   <item><see cref="Single"/>：每次激活对每个目标只判一次（近战挥击、普通投射物）。</item>
    ///   <item><see cref="Interval"/>：对停留在判定盒内的同一目标，每 <c>_hitInterval</c> 秒重判一次
    ///         （接触伤害、持续 AOE、危险区）。靠 Enter/Exit 跟踪占用 + Update 轮询，
    ///         不依赖 OnTriggerEnter 的单次语义。</item>
    /// </list>
    /// </summary>
    public enum HitMode { Single, Interval }

    public class HitBox : MonoBehaviour
    {
        [SerializeField] private DamageSourceSO _defaultSource;
        [SerializeField] private float          _hitCooldown = 0.1f;

        [Header("命中节奏")]
        [Tooltip("Single=每次激活每个目标判一次；Interval=对停留目标按间隔持续重判（接触伤害/持续区域）。")]
        [SerializeField] private HitMode _hitMode = HitMode.Single;
        [Tooltip("Interval 模式下，对同一目标重复造成伤害的间隔（秒）。")]
        [SerializeField] private float   _hitInterval = 0.5f;

        /// <summary>
        /// HitBox 标识符，供 PlayerAnimationEvents / EnemyAnimationEvents 按名称精确激活特定判定盒。
        /// 留空表示"无 Id"；事件 payload 为空时将操作所有 HitBox。
        /// </summary>
        [SerializeField] private string _id = "";
        public string Id => _id;

        /// <summary>
        /// 对立阵营 HitBox 所在的 Layer 掩码（用于拼刀检测）。
        /// Inspector 中将 PlayerHitBox 与 EnemyHitBox 两个 Layer 均勾选。
        /// </summary>
        [SerializeField] private LayerMask _rivalHitBoxMask;

        private DamageSourceSO _currentSource;
        private Transform      _attackerTransform;
        private Rigidbody2D    _ownerRigidbody;
        private bool           _isActive;
        private IClashService  _clashService;

        // 直属碰撞体（本 GameObject 上）
        private Collider2D[]          _directColliders = System.Array.Empty<Collider2D>();
        // 子节点代理碰撞体
        private HitBoxColliderProxy[] _proxies         = System.Array.Empty<HitBoxColliderProxy>();

        // 激活 ID：每次 Activate() 递增，写入 DamageInfo.HitActivationId，
        // HurtBoxOwnerGuard 据此防止多 HurtBox 节点被同一次攻击重复扣血。
        private static uint _nextActivationId  = 1;
        private        uint _currentActivationId;

        /// <summary>HitBox 当前是否激活（供 ClashResolver 查询）。</summary>
        public bool IsActive => _isActive;

        /// <summary>当前 Source 是否携带 CanClash 标记（供 ClashResolver 查询）。</summary>
        public bool CanClash => _currentSource != null && _currentSource.Flags.HasFlag(DamageFlags.CanClash);

        /// <summary>宿主角色的 Rigidbody2D（用于拼刀弹开力计算）。</summary>
        public Rigidbody2D OwnerRigidbody => _ownerRigidbody;

        // 拼刀检测所需的对立层掩码（Inspector 配置）

        /// <summary>命中确认委托（PlayerCombat / EnemyCombat 订阅）。</summary>
        public event System.Action<DamageInfo> OnHitConfirmed;

        // 宿主投射物缓存（Activate 时填入，DamageInfo.SourceProjectile 写入用）
        private Projectile _ownerProjectile;

        /// <summary>
        /// 激活 HitBox。source/attacker 均可选，未传则使用 Inspector 默认值。
        /// ⚠️ 不存在 Activate(float duration) 重载。
        /// </summary>
        public void Activate(DamageSourceSO source = null, Transform attacker = null)
        {
            _currentActivationId = _nextActivationId++;
            _currentSource       = source   ?? _defaultSource;
            _attackerTransform   = attacker ?? transform;
            _isActive            = true;
            _ownerRigidbody      = _attackerTransform.GetComponentInParent<Rigidbody2D>();
            foreach (var col in _directColliders) col.enabled = true;
            foreach (var proxy in _proxies)        proxy.SetEnabled(true);
            // 每次激活清空当前激活期已命中目标集合（防止连击连段导致同一阶段多次命中目标）
            _hitThisActivation.Clear();
            _hitCooldownTimers.Clear();
            _intervalTargets.Clear();
        }

        public void Deactivate()
        {
            _isActive = false;
            foreach (var col in _directColliders) col.enabled = false;
            foreach (var proxy in _proxies)        proxy.SetEnabled(false);
            _hitThisActivation.Clear();
            _hitCooldownTimers.Clear();
            _intervalTargets.Clear();
        }

        /// <summary>仅替换当前 DamageSource（不改变激活状态，供 PlayerCombat 连击段切换）。</summary>
        public void SetDamageSource(DamageSourceSO source)
        {
            if (source != null) _currentSource = source;
        }

        private void Awake()
        {
            // 收集本节点上所有直属 Collider2D，并验证 isTrigger
            _directColliders = GetComponents<Collider2D>();
            foreach (var col in _directColliders)
            {
                if (!col.isTrigger)
                    Debug.LogWarning($"[HitBox] {name}: Collider2D ({col.GetType().Name}) isTrigger 应为 true。", this);
                col.enabled = false;
            }
            // 注册所有子代 HitBoxColliderProxy（子节点多形状模式）
            _proxies = GetComponentsInChildren<HitBoxColliderProxy>(true);
            foreach (var proxy in _proxies)
                proxy.Init(this);
            // 缓存 IClashService：OnTriggerEnter2D 为物理热路径，避免每次调用 Dictionary 查找
            _clashService = ServiceLocator.GetOrDefault<IClashService>();
            // 缓存宿主投射物（仅 Projectile GameObject 上挂载的 HitBox 非 null）
            _ownerProjectile = GetComponent<Projectile>();
        }

        private void OnDisable()
        {
            _isActive = false;
            foreach (var col in _directColliders) if (col != null) col.enabled = false;
            foreach (var proxy in _proxies)        proxy.SetEnabled(false);
            _hitThisActivation.Clear();
            _hitCooldownTimers.Clear();
            _intervalTargets.Clear();
        }

        private void Update()
        {
            // 仅 Interval 模式需要轮询：对仍停留在判定盒内的目标按间隔重判
            if (!_isActive || _hitMode != HitMode.Interval || _intervalTargets.Count == 0) return;

            float now = Time.time;
            _intervalTickBuffer.Clear();
            foreach (var kv in _intervalTargets)
                if (now - kv.Value >= _hitInterval) _intervalTickBuffer.Add(kv.Key);

            for (int i = 0; i < _intervalTickBuffer.Count; i++)
            {
                Collider2D col = _intervalTickBuffer[i];
                // 目标被销毁/禁用：移除占用记录（Exit 可能因对象失活而未触发）
                if (col == null || !col.isActiveAndEnabled)
                {
                    _intervalTargets.Remove(col);
                    continue;
                }
                _intervalTargets[col] = now;
                DealDamage(col, null);
            }
        }

        private void OnTriggerEnter2D(Collider2D other) => HandleTriggerEnter(other, null);
        private void OnTriggerExit2D(Collider2D other)  => HandleTriggerExit(other);

        /// <summary>代理入口：由 HitBoxColliderProxy 或本节点 OnTriggerEnter2D 转发。</summary>
        internal void HandleTriggerEnter(Collider2D other, Collider2D sourceCollider)
        {
            if (!_isActive) return;
            if (_currentSource == null)
            {
                Debug.LogWarning($"[HitBox] {name}: 无 DamageSourceSO，跳过命中。", this);
                return;
            }
            if (_hitMode == HitMode.Interval)
            {
                // 周期接触模式：记录占用并立即结算一次；后续由 Update 按间隔对仍停留的目标重判。
                _intervalTargets[other] = Time.time;
                DealDamage(other, sourceCollider);
                return;
            }

            // Single 模式：同一激活期同一 Collider 只命中一次（一次攻击每个目标至多命中一次）+ 抖动冷却
            if (!_hitThisActivation.Add(other)) return;
            if (!CheckCooldown(other)) return;
            DealDamage(other, sourceCollider);
        }

        /// <summary>
        /// 实际伤害结算：自身排除 → 拼刀 → HurtBox → IBreakable。
        /// 由 Single 模式 Enter、Interval 模式 Enter 与 Update 共同调用。
        /// </summary>
        private void DealDamage(Collider2D other, Collider2D sourceCollider)
        {
            // 排除自身：攻击方与受击方属于同一根 GameObject 时跳过（防止近战 EnemyHitBox 命中同一敌人的 EnemyHurtBox）
            if (other.transform.root == _attackerTransform.root) return;

            Vector2 knockDir = ((Vector2)other.bounds.center
                               - (Vector2)_attackerTransform.position).normalized;

            // ⚡ 零 GC：struct 工厂，运行时字段内联传入
            var info = DamageInfo.From(
                _currentSource,
                knockDir,
                _attackerTransform.position,
                _attackerTransform.gameObject.layer,
                _ownerProjectile);
            info.HitActivationId = _currentActivationId;

            // ① 拼刀检测：当前 HitBox 携带 CanClash 标记，且碰到对立阵营的 HitBox 层
            int otherLayer = other.gameObject.layer;
            bool isRivalHitBoxLayer = (_rivalHitBoxMask.value & (1 << otherLayer)) != 0;
            if (isRivalHitBoxLayer && CanClash)
            {
                if (other.TryGetComponent<HitBox>(out var rivalHitBox) &&
                    rivalHitBox.IsActive && rivalHitBox.CanClash)
                {
                    _clashService?.ResolveClash(this, rivalHitBox);
                    return; // 拼刀，中止伤害流水线
                }
            }

            // ② 命中 HurtBox
            if (other.TryGetComponent<HurtBox>(out var hurtBox))
            {
                // hitPoint：优先使用触发命中的碰撞体中心在 HurtBox 表面的最近点；
                // 无 sourceCollider（直属碰撞体）时回退到 HitBox 节点坐标。
                Vector2 hitOrigin = sourceCollider != null
                    ? (Vector2)sourceCollider.bounds.center
                    : (Vector2)transform.position;
                Vector3 hitPoint = other.ClosestPoint(hitOrigin);
                hurtBox.ReceiveDamage(info, hitPoint);
                OnHitConfirmed?.Invoke(info);
                return;
            }

            // ③ 命中 IBreakable（机关/障碍物）
            if (other.TryGetComponent<IBreakable>(out var breakable))
                breakable.TryInteract(info);
        }

        // ── 当前激活期已命中目标集合（防止复合子 Collider 导致同帧多次命中）────────────
        private readonly HashSet<Collider2D>           _hitThisActivation = new(8);
        // ── 同目标多帧命中冷却（防止 Trigger 处于重叠状态时重入等殊情导致的连击）──
        private readonly Dictionary<Collider2D, float> _hitCooldownTimers = new(8);
        // ── Interval 模式：当前停留在判定盒内的目标 → 上次命中时间（Enter 加入 / Exit 移除）──
        private readonly Dictionary<Collider2D, float> _intervalTargets   = new(8);
        // Update 轮询时的临时缓冲（避免遍历字典时修改 + 降低 GC）
        private readonly List<Collider2D>              _intervalTickBuffer = new(8);

        /// <summary>
        /// 配置为周期接触伤害模式（BodyContactDamage 等持续接触源在 OnEnable 时调用）。
        /// 使持续接触的判定盒按 <paramref name="interval"/> 对停留目标重复造成伤害，
        /// 而不依赖 OnTriggerEnter 的单次语义。
        /// </summary>
        public void SetIntervalMode(float interval)
        {
            _hitMode = HitMode.Interval;
            if (interval > 0f) _hitInterval = interval;
        }

        /// <summary>代理出口：由 HitBoxColliderProxy 或本节点 OnTriggerExit2D 转发。</summary>
        internal void HandleTriggerExit(Collider2D other)
        {
            // 目标离开判定区域时清除其冷却记录与占用记录，防止持续激活的 HitBox（环境危险等）
            // 因有效目标持续流动而无限积累已离场对象。
            // 注意：_hitThisActivation 刻意保留，确保同一激活期内不重复命中。
            _hitCooldownTimers.Remove(other);
            _intervalTargets.Remove(other);
        }

        private bool CheckCooldown(Collider2D other)
        {
            float now = Time.time;
            if (_hitCooldownTimers.TryGetValue(other, out float last) && now - last < _hitCooldown)
                return false;
            _hitCooldownTimers[other] = now;
            return true;
        }

#if UNITY_EDITOR
        private void OnDrawGizmos()
        {
            Color fill    = _isActive ? new Color(1f, 0.15f, 0.15f, 0.25f) : new Color(1f, 0.15f, 0.15f, 0.05f);
            Color outline = _isActive ? new Color(1f, 0.15f, 0.15f, 0.90f) : new Color(1f, 0.15f, 0.15f, 0.25f);
            // 直属碰撞体
            foreach (var col in GetComponents<Collider2D>())
                DrawCollider2DFilled(col, fill, outline);
            // 子代代理碰撞体
            foreach (var proxy in GetComponentsInChildren<HitBoxColliderProxy>(true))
            {
                var proxyCol = proxy.GetComponent<Collider2D>();
                if (proxyCol != null) DrawCollider2DFilled(proxyCol, fill, outline);
            }
        }

        // ── Gizmo 辅助（填充 + 轮廓，不依赖外部工具类）──────────────────────────

        /// <summary>根据 Collider2D 类型绘制带填充色和轮廓的 2D Gizmo（供 HurtBox 等复用）。</summary>
        public static void DrawCollider2DFilled(Collider2D col, Color fill, Color outline)
        {
            var prevMatrix = UnityEditor.Handles.matrix;
            UnityEditor.Handles.matrix = col.transform.localToWorldMatrix;

            switch (col)
            {
                case BoxCollider2D box:
                    DrawFilledRect2D(box.offset, box.size, fill, outline);
                    break;

                case CircleCollider2D circle:
                    DrawFilledCircle2D(circle.offset, circle.radius, fill, outline);
                    break;

                case CapsuleCollider2D caps:
                    DrawFilledCapsule2D(caps.offset, caps.size, caps.direction, fill, outline);
                    break;

                case PolygonCollider2D poly:
                    for (int p = 0; p < poly.pathCount; p++)
                        DrawFilledPolygonPath2D(poly.GetPath(p), fill, outline);
                    break;

                default:
                    UnityEditor.Handles.matrix = Matrix4x4.identity;
                    DrawFilledRect2D(col.bounds.center, col.bounds.size, fill, outline);
                    break;
            }

            UnityEditor.Handles.matrix = prevMatrix;
        }

        /// <summary>向后兼容的线框接口（内部改调 DrawCollider2DFilled）。</summary>
        public static void DrawCollider2DWire(Collider2D col)
            => DrawCollider2DFilled(col, new Color(1f, 1f, 1f, 0.05f), new Color(1f, 1f, 1f, 0.8f));

        private static void DrawFilledRect2D(Vector2 center, Vector2 size, Color fill, Color outline)
        {
            float hx = size.x * 0.5f, hy = size.y * 0.5f;
            var verts = new Vector3[]
            {
                new Vector3(center.x - hx, center.y + hy, 0f),
                new Vector3(center.x + hx, center.y + hy, 0f),
                new Vector3(center.x + hx, center.y - hy, 0f),
                new Vector3(center.x - hx, center.y - hy, 0f),
            };
            UnityEditor.Handles.DrawSolidRectangleWithOutline(verts, fill, outline);
        }

        private static void DrawFilledCircle2D(Vector2 center, float radius, Color fill, Color outline)
        {
            Vector3 c = new Vector3(center.x, center.y, 0f);
            UnityEditor.Handles.color = fill;
            UnityEditor.Handles.DrawSolidDisc(c, Vector3.back, radius);
            UnityEditor.Handles.color = outline;
            UnityEditor.Handles.DrawWireDisc(c, Vector3.back, radius);
        }

        private static readonly System.Collections.Generic.List<Vector3> _capsuleVertsBuf
            = new System.Collections.Generic.List<Vector3>(64);

        private static void DrawFilledCapsule2D(Vector2 offset, Vector2 size,
                                                 CapsuleDirection2D dir, Color fill, Color outline)
        {
            bool    vert   = dir == CapsuleDirection2D.Vertical;
            float   radius = vert ? size.x * 0.5f : size.y * 0.5f;
            float   half   = Mathf.Max(0f, (vert ? size.y : size.x) * 0.5f - radius);
            Vector2 axis   = vert ? Vector2.up : Vector2.right;
            Vector2 capA   = offset + axis * half;   // 顶部（竖向）或右端（横向）圆心
            Vector2 capB   = offset - axis * half;   // 底部（竖向）或左端（横向）圆心

            const int segs = 12;
            _capsuleVertsBuf.Clear();

            float baseA = vert ? 0f : -Mathf.PI * 0.5f;
            for (int i = 0; i <= segs; i++)
            {
                float a = baseA + (float)i / segs * Mathf.PI;
                _capsuleVertsBuf.Add(new Vector3(capA.x + Mathf.Cos(a) * radius,
                                                  capA.y + Mathf.Sin(a) * radius, 0f));
            }

            float baseB = vert ? Mathf.PI : Mathf.PI * 0.5f;
            for (int i = 0; i <= segs; i++)
            {
                float a = baseB + (float)i / segs * Mathf.PI;
                _capsuleVertsBuf.Add(new Vector3(capB.x + Mathf.Cos(a) * radius,
                                                  capB.y + Mathf.Sin(a) * radius, 0f));
            }

            var arr = _capsuleVertsBuf.ToArray();
            UnityEditor.Handles.color = fill;
            UnityEditor.Handles.DrawAAConvexPolygon(arr);
            UnityEditor.Handles.color = outline;
            for (int i = 0; i < arr.Length; i++)
                UnityEditor.Handles.DrawLine(arr[i], arr[(i + 1) % arr.Length]);
        }

        private static void DrawFilledPolygonPath2D(Vector2[] path, Color fill, Color outline)
        {
            if (path == null || path.Length < 3) return;
            var verts = System.Array.ConvertAll(path, p => new Vector3(p.x, p.y, 0f));
            UnityEditor.Handles.color = fill;
            UnityEditor.Handles.DrawAAConvexPolygon(verts); // 凹多边形仅轮廓准确，填充近似
            UnityEditor.Handles.color = outline;
            for (int i = 0; i < verts.Length; i++)
                UnityEditor.Handles.DrawLine(verts[i], verts[(i + 1) % verts.Length]);
        }
#endif
    }
}