using System.Collections.Generic;
using SepCore.Components;
using SepCore.CustomUtility;
using SepCore.Definition;
using DG.Tweening;
using SepCore.Entity;
using UnityEngine;
using UnityGameFramework.Runtime;

namespace SepCore.Entity
{
    public class WeaponLance : WeaponBase
    {
        private Sequence _attackSequence;
        private Transform _attackParent;

        // 前刺动画耗时。
        [SerializeField] private float _attackDuration = 0.12f;
        // 收枪返回耗时。
        [SerializeField] private float _returnDuration = 0.18f;

        [SerializeField] private int _maxHitColliders = 32;

        private IWeaponAttackEffect _attackEffect;
        private Collider[] _hitResults;
        private readonly HashSet<int> _hitEntityIds = new();

        public float HitHalfWidth => WeaponData.GetParamFloat(ParamType.HitHalfWidth);
        public float HitHeight => WeaponData.GetParamFloat(ParamType.HitHeight);
        public float PierceLength => WeaponData.GetParamFloat(ParamType.PierceLength);
        public Vector3 StrikeDirection => _strikeDirection;

        // 本次攻击锁定的前戳方向，避免受位移动画中的武器位置影响。
        private Vector3 _strikeDirection = Vector3.forward;
        // 本次攻击锁定的矩形判定中心。
        private Vector3 _strikeCenter;

        protected override void BuildStates()
        {
            RegisterState(new WeaponLanceIdleState());
            RegisterState(new WeaponLanceAimState());
            RegisterState(new WeaponLanceSeekState());
            RegisterState(new WeaponLanceAttackState());
        }

        public override void Attack()
        {
            StopAttackTween(false);
            FaceTargetImmediately();
            _attackParent = CachedTransform.parent;
            CacheStrikeSnapshot();

            _isAttacking = true;
            CachedTransform.SetParent(null);

            Vector3 targetPos = CachedTransform.position + _strikeDirection * PierceLength;
            _attackSequence = DOTween.Sequence();
            _attackSequence.Append(CachedTransform.DOMove(targetPos, _attackDuration).SetEase(Ease.OutQuad));
            _attackSequence.AppendCallback(() =>
            {
                _attackEffect.Play(this, _strikeCenter, _target, HitHalfWidth);
                ApplyPierceDamage();

                if (_attackParent != null)
                {
                    CachedTransform.SetParent(_attackParent);
                }
            });
            _attackSequence.Append(CachedTransform.DOLocalMove(Vector3.zero, _returnDuration).SetEase(Ease.InQuad));
            _attackSequence.AppendCallback(() =>
            {
                _isAttacking = false;
                _attackSequence = null;
                _attackParent = null;
            });
        }

        private void CacheStrikeSnapshot()
        {
            _strikeDirection = ResolvePlanarForward();
            Vector3 strikeStart = CachedTransform.position;
            strikeStart.y = ResolveStrikePlaneY();
            _strikeCenter = strikeStart + _strikeDirection * (PierceLength * 0.5f);
        }

        private Vector3 ResolvePlanarForward()
        {
            Vector3 forward = CachedTransform.forward;
            forward.y = 0f;
            if (forward.sqrMagnitude <= Mathf.Epsilon)
            {
                forward = Vector3.forward;
            }

            forward.Normalize();
            return forward;
        }

        private void ApplyPierceDamage()
        {
            if (HitHalfWidth <= 0f || PierceLength <= 0f) return;

            Vector3 strikeDirection = _strikeDirection;
            if (strikeDirection.sqrMagnitude <= Mathf.Epsilon) return;

            Vector3 broadPhaseCenter = _strikeCenter;
            Quaternion broadPhaseRotation = Quaternion.LookRotation(strikeDirection, Vector3.up);

            if (TryQueueRectangleCollisionQuery(broadPhaseCenter, HitHalfWidth, PierceLength * 0.5f,
                    strikeDirection, Mathf.Max(1, _maxHitColliders)))
            {
                return;
            }

            if (_hitResults == null || _hitResults.Length == 0) return;

            Vector3 halfExtents = new(HitHalfWidth, HitHeight * 0.5f, PierceLength * 0.5f);
            int hitCount = Physics.OverlapBoxNonAlloc(broadPhaseCenter, halfExtents, _hitResults, broadPhaseRotation,
                _hitMask, QueryTriggerInteraction.Collide);
            _hitEntityIds.Clear();
            for (int i = 0; i < hitCount; i++)
            {
                Collider collider = _hitResults[i];
                if (collider == null) continue;

                TargetableObject targetable = collider.GetComponentInParent<TargetableObject>();
                if (targetable == null || !targetable.Available || targetable.IsDead) continue;
                if (!_hitEntityIds.Add(targetable.Id)) continue;

                if (!IsTargetInsidePierce(targetable, broadPhaseCenter, strikeDirection)) continue;

                AIUtility.PerformCollision(targetable, this);
            }
        }

        private bool IsTargetInsidePierce(TargetableObject targetable, Vector3 strikeCenter, Vector3 strikeDirection)
        {
            Vector3 delta = targetable.CachedTransform.position - strikeCenter;
            delta.y = 0f;

            Vector3 right = Vector3.Cross(Vector3.up, strikeDirection);
            float forwardDistance = Vector3.Dot(delta, strikeDirection);
            float lateralDistance = Vector3.Dot(delta, right);
            float targetRadius = ResolveTargetCollisionRadius(targetable);

            return Mathf.Abs(forwardDistance) <= PierceLength * 0.5f + targetRadius &&
                   Mathf.Abs(lateralDistance) <= HitHalfWidth + targetRadius;
        }

        private static float ResolveTargetCollisionRadius(TargetableObject targetable)
        {
            if (targetable == null)
            {
                return 0f;
            }

            MovementComponent movementComponent = targetable.GetComponent<MovementComponent>();
            return movementComponent != null ? Mathf.Max(0f, movementComponent.EnemyBodyRadius) : 0f;
        }

        private float ResolveStrikePlaneY()
        {
            if (_target != null && _target.Available)
            {
                return _target.CachedTransform.position.y;
            }

            return _attackParent != null ? _attackParent.position.y : CachedTransform.position.y;
        }

        protected override bool OnWeaponShow(object userData)
        {
            int colliderCapacity = Mathf.Max(1, _maxHitColliders);
            if (_hitResults == null || _hitResults.Length != colliderCapacity)
            {
                _hitResults = new Collider[colliderCapacity];
            }

            _attackEffect = new LanceThrustAttackEffect();
            return true;
        }

        protected override void OnWeaponHide(object userData)
        {
            StopAttackTween(true);
            _attackEffect = null;
        }

        protected override void OnWeaponDetach(EntityLogic parentEntity, object userData)
        {
            StopAttackTween(true);
            base.OnWeaponDetach(parentEntity, userData);
        }

        protected override void OnEnabledChanged(bool enabled)
        {
            if (!enabled)
            {
                StopAttackTween(true);
            }
        }

        private void StopAttackTween(bool resetTransform)
        {
            if (_attackSequence != null)
            {
                _attackSequence.Kill();
                _attackSequence = null;
            }

            _isAttacking = false;

            if (resetTransform && _attackParent != null)
            {
                CachedTransform.SetParent(_attackParent);
                CachedTransform.localPosition = Vector3.zero;
                CachedTransform.rotation = _cachedRotation;
            }

            _attackParent = null;
            _hitEntityIds.Clear();
        }
    }
}