using System;
using System.Collections.Generic;
using UnityEngine;

namespace NBF
{
    public class FishingLineNode : MonoBehaviour
    {
        public enum NodeType
        {
            Start,
            Float,
            Weight,
            Tail
        }

        [SerializeField] private FLine _solver;

        [Header("Node")] [SerializeField] private NodeType nodeType = NodeType.Tail;
        [SerializeField] public Rigidbody body;
        public Rope Rope;
        [SerializeField] private MonoBehaviour interaction;
        [SerializeField] private ConfigurableJoint _joint;

        [Header("Segment To Next Logical Node")] [Min(0f)] [SerializeField]
        private float segmentLengthToNext = 0.5f;

        [SerializeField] private int runtimeChainIndex = -1;


        [SerializeField] private List<FishingLineNodeFeature> features = new();
        [SerializeField] private List<FishingLineNodeMotionFeature> motionFeatures = new();
        private bool featureCacheReady;
        [SerializeField] private FishingLineNodeMotionFeature activeMotionFeature;

        /// <summary>
        /// 当前正在接管节点运动的组件。
        /// </summary>
        public FishingLineNodeMotionFeature ActiveMotionFeature => activeMotionFeature;

        public NodeType Type
        {
            get => nodeType;
            set => nodeType = value;
        }

        public float Lenght { get; private set; }

        /// <summary>
        /// 真实实际长度
        /// </summary>
        public float RealLength { get; private set; }

        /// <summary>
        /// 当前逻辑链总长度超出配置总长度的部分，小于等于零时记为 0。
        /// </summary>
        public float StretchLength { get; private set; }

        public Rigidbody Body => body;

        public MonoBehaviour Interaction => interaction;
        public ConfigurableJoint Joint => _joint;

        public int RuntimeChainIndex => runtimeChainIndex;

        public Vector3 Position => transform.position;


        private void Reset()
        {
            TryGetComponent(out body);
        }

        private void Awake()
        {
            if (!_solver) _solver = GetComponentInParent<FLine>();
            if (!_joint) _joint = GetComponent<ConfigurableJoint>();
            EnsureFeatureCache();
        }

        private void Start()
        {
            BindFeatures(_solver);
        }

        private void FixedUpdate()
        {
            EnsureFeatureCache();
            UpdateMotionControl(Time.fixedDeltaTime);
            UpdateLenght();
        }

        private void OnValidate()
        {
            if (body == null)
            {
                TryGetComponent(out body);
            }

            segmentLengthToNext = Mathf.Max(0f, segmentLengthToNext);
            
        }

        private void UpdateLenght()
        {
            //更新长度
            Lenght = 0;
            RealLength = 0;
            StretchLength = 0;
            if (_joint)
            {
                Lenght = _joint.linearLimit.limit;
                if (_joint && _joint.connectedBody)
                {
                    RealLength = Vector3.Distance(transform.position, _joint.connectedBody.transform.position);
                }
            }

            if (RealLength > Lenght)
            {
                StretchLength = RealLength - Lenght;
            }
        }

        #region Line

        public void SetLenght(float lenght)
        {
            if (!_joint) return;
            if (!Mathf.Approximately(lenght, _joint.linearLimit.limit))
            {
                _joint.linearLimit = new SoftJointLimit() { limit = lenght };
                Rope.SetTargetLength(lenght - 0.1f);
            }
        }

        #endregion

        #region Feature

        /// <summary>
        /// 获取节点上的第一个指定类型功能组件。
        /// </summary>
        public T GetFeature<T>() where T : FishingLineNodeFeature
        {
            EnsureFeatureCache();
            for (var i = 0; i < features.Count; i++)
            {
                if (features[i] is T result)
                {
                    return result;
                }
            }

            return null;
        }

        /// <summary>
        /// 尝试获取节点上的指定类型功能组件。
        /// </summary>
        public bool TryGetFeature<T>(out T feature) where T : FishingLineNodeFeature
        {
            feature = GetFeature<T>();
            return feature != null;
        }

        /// <summary>
        /// 刷新并重新绑定当前节点上的功能组件。
        /// </summary>
        public void BindFeatures(FLine solver)
        {
            EnsureFeatureCache();
            foreach (var t in features)
            {
                t.Bind(this, solver);
            }

            ResolveMotionFeature(forceRefresh: true);
        }

        /// <summary>
        /// 通知当前节点上的所有功能组件，鱼线已重建完成。
        /// </summary>
        public void NotifyLineBuilt()
        {
            EnsureFeatureCache();
            foreach (var t in features)
            {
                t.OnLineBuilt();
            }

            ResolveMotionFeature(forceRefresh: true);
        }

        /// <summary>
        /// 通知当前节点上的所有功能组件，鱼线已经达到断线条件。
        /// </summary>
        public void NotifyLineBreakRequested()
        {
            EnsureFeatureCache();
            foreach (var t in features)
            {
                t.OnLineBreakRequested();
            }
        }


        private void EnsureFeatureCache()
        {
            if (!featureCacheReady)
            {
                RefreshFeatures();
            }
        }

        private void RefreshFeatures()
        {
            features.Clear();
            motionFeatures.Clear();
            GetComponents(features);
            for (var i = 0; i < features.Count; i++)
            {
                if (features[i] is FishingLineNodeMotionFeature motionFeature)
                {
                    motionFeatures.Add(motionFeature);
                }
            }

            activeMotionFeature = null;
            featureCacheReady = true;
        }

        private void UpdateMotionControl(float deltaTime)
        {
            var motionFeature = ResolveMotionFeature(forceRefresh: false);
            if (motionFeature == null)
            {
                return;
            }

            motionFeature.TickMotion(deltaTime);
        }

        private FishingLineNodeMotionFeature ResolveMotionFeature(bool forceRefresh)
        {
            EnsureFeatureCache();

            var bestMotionFeature = default(FishingLineNodeMotionFeature);
            var bestPriority = int.MinValue;

            foreach (var motionFeature in motionFeatures)
            {
                var r = !motionFeature.IsSupportedNode(this);
                var n = !motionFeature.CanControl();
                if (motionFeature == null || !motionFeature.IsSupportedNode(this) || !motionFeature.CanControl())
                {
                    continue;
                }

                if (bestMotionFeature != null && motionFeature.Priority <= bestPriority)
                {
                    continue;
                }

                bestMotionFeature = motionFeature;
                bestPriority = motionFeature.Priority;
            }

            if (!forceRefresh && ReferenceEquals(activeMotionFeature, bestMotionFeature))
            {
                return activeMotionFeature;
            }

            if (activeMotionFeature != null && !ReferenceEquals(activeMotionFeature, bestMotionFeature))
            {
                activeMotionFeature.OnMotionDeactivated();
            }

            activeMotionFeature = bestMotionFeature;
            if (activeMotionFeature != null)
            {
                activeMotionFeature.OnMotionActivated();
            }

            return activeMotionFeature;
        }

        #endregion

        private void OnDrawGizmos()
        {
        }
    }
}