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

public class Yeji : TargetAnimal
{
    //动画播放器
    Animator animator;
    //寻路代理
    NavMeshAgent agent;
    //血量
    [System.NonSerialized] public int hp = 3;
    [System.NonSerialized] public TreeAreaRecorder treeAreaRecorder;
    [System.NonSerialized] public float flyPlaneHeight = 5;
    float currentHeight = 0;
    public void SetFlyHeight(float value) {
        currentHeight = value;
        float agentBaseOffset = value - flyPlaneHeight;
        this.agent.baseOffset = agentBaseOffset / 1.2f;//因为agent的baseoffset会受节点的scale影响
        state.flying = currentHeight > 0;
    }

    void Awake()
    {
        state.animal = this;
        animator = GetComponent<Animator>();
        agent = GetComponent<NavMeshAgent>();
        this.agent.avoidancePriority = avoidancePriority;
    }
    static int _avoidancePriority = 0;
    static int avoidancePriority {
        get {
            if (_avoidancePriority < 50) {
                _avoidancePriority++;
            } else {
                _avoidancePriority = 1;
            }
            return _avoidancePriority;
        }
    }

    void OnDestroy() {
        tryReleaseOccupyTree();
    }

    void Update()
    {
        //寻路过程监测
        if (HasCloseToDestination()) {
            OnReachDestination();
        } else {
            OnMovingToDestination();
        }
        UpdateAutoStrategy();
    }

    #region 被击触发
        public override void OnHit(Arrow arrow, Vector3 hitPoint, string partName)
        {
            arrow.Head().position = hitPoint + arrow.transform.forward * 0.1f;
            arrow.Hit();
            if (partName == "Wing") {
                hp -= 1;
                this.agent.speed /= 2f;
            }
            else if (partName == "Body") hp -= 2;
            else if (partName == "Head") hp -= 3;
            if (hp <= 0) {
                Die(arrow);
            } else {
                Hurt();
            }
        }

        void Die(Arrow arrow) {
            if (state.dead) return;
            arrow.onDoNextShoot += delegate() {
                Destroy(this.gameObject);
            };
            this.animator.speed = 1;
            state.dead = true;
            this.agent.enabled = false;
            onDie?.Invoke(this);
            AudioMgr.ins.PlayAnimalEffect("bird_injured", AudioMgr.GetAudioSource(this.gameObject));
            if (currentHeight < 1.5f) {
                arrow.arrowCameraComp.arrowCameraTemplate.SendMsg(0, null);
            }
        }

        void Hurt() {
            CancelStand();
            CancelFlyStay();
            AudioMgr.ins.PlayAnimalEffect("bird_injured", AudioMgr.GetAudioSource(this.gameObject));
        }
    #endregion

    #region 寻路导航
        bool _moving;
        bool moving {
            get { return _moving; }
            set {
                movingTime = 0;
                _moving = value;
            }
        } 
        float movingTime;
        //启动寻路
        void SetDestination(Vector3 pos) {
            moving = true;
            this.agent.destination = pos;
        }
        //寻路过程
        void OnMovingToDestination() {
            if (!moving) return;
            movingTime += Time.deltaTime;
        }
        //寻路结束
        void OnReachDestination() {
            if (!moving) return;
            moving = false;
        }
        //是否已经接近目的地（寻路完成判断）
        bool HasCloseToDestination() {
            if (!moving) return true;
            return movingTime > 0.1 && this.agent.velocity.magnitude < 0.05f;
        }
        //停止寻路
        void StopNavigation() {
            if (!moving) return;
            this.agent.destination = this.agent.nextPosition;
            this.agent.velocity = Vector3.zero;
            this.transform.position = this.agent.destination;
            OnReachDestination();
        }
    #endregion

    #region 自动逻辑
        //自动策略的更新逻辑
        void UpdateAutoStrategy() {
            if (state.dead) return;
            UpdateFlyUpDown();
            UpdateBehavior();
        }
        
        float toFlyHeight = 2f;
        float canStandTime = 3f;
        float canFlyStayTime = 3f;
        //能够在前几棵树徘徊
        [System.NonSerialized] public int canFlyTreeCount = 4;
        const float downSpeed = 2.0f;
        //更新逻辑-起飞降落
        void UpdateFlyUpDown() {
            if (state.up && state.landing) { //起飞阶段
                AnimatorStateInfo animatorStateInfo = animator.GetCurrentAnimatorStateInfo(0);
                bool isTakeOff = animatorStateInfo.IsName("FlyFromGround");
                if (isTakeOff) {
                    if (animatorStateInfo.normalizedTime >= 1.0) {
                        state.landing = false;
                        state.flying = true;
                    }
                }
                return;
            }
            if (state.up && state.flying) { //上升阶段
                float surplusHeight = toFlyHeight - currentHeight;
                float smoothValue = surplusHeight / toFlyHeight;
                float nextFlyHeight = currentHeight + Time.deltaTime * (1f + 2.5f * smoothValue);
                this.animator.speed = 1f + 2f * smoothValue;
                if (nextFlyHeight >= toFlyHeight) { //上升完成
                    nextFlyHeight = toFlyHeight;
                    this.animator.speed = 1;
                    state.up = false;
                }
                SetFlyHeight(nextFlyHeight);
                return;
            }
            if (state.down && state.flying) { //下降阶段
                float nextH = currentHeight - Time.deltaTime * downSpeed;
                if (nextH <= 0) { //下降完成
                    nextH = 0;
                    state.landing = true;
                    state.flying = false;
                    StopNavigation();
                }
                SetFlyHeight(nextH);
                return;
            }
            if (state.down && state.landing) { //着落阶段
                AnimatorStateInfo animatorStateInfo = animator.GetCurrentAnimatorStateInfo(0);
                bool isLand = animatorStateInfo.IsName("LandOnGround");
                if (isLand) {
                    if (animatorStateInfo.normalizedTime >= 1.0) {
                        state.down = false;
                        //进入站立状态
                        state.standing = true;
                        canStandTime = 8f + Random.value * 2f;
                        animator.CrossFade("IdleOnGround2", 0.2f);
                    }
                }
                return;
            }
        }

        TreeAreaRecorder.AreaInfo targetAreaInfo;
        bool hasCheckFlyDown = false;
        void UpdateBehavior() {
            if (state.flyStaying) {
                canFlyStayTime -= Time.deltaTime;
                if (canFlyStayTime <= 0) {
                    state.flyStaying = false;
                }
                return;
            }

            if (state.standing) {
                canStandTime -= Time.deltaTime;
                if (canStandTime <= 0) {
                    CancelStand();
                }
                return;
            }

            if (state.landing) return;

            if (state.flying && !state.down && !state.up) {
                if (!hasCheckFlyDown) {
                    float downNeedTime = flyPlaneHeight / downSpeed;
                    float keyDistance = this.agent.speed * downNeedTime; //触发下降的水平距离阈值
                    if (Vector3.Distance(this.transform.position, this.agent.destination) < keyDistance) {
                        hasCheckFlyDown = true;
                        if (Random.value < 0.6 && tryOccupyTree()) {
                            state.down = true;
                        } else {
                            state.flyStaying = true;
                            canFlyStayTime = 4f + Random.value * 2f;
                        }
                    }
                }
            }
            
            if (moving) return;

            //飞向别的树
            #region 
                Vector3 myPos = this.transform.position; 
                TreeAreaRecorder.AreaInfo[] areaInfos = treeAreaRecorder.copyAreaInfos(canFlyTreeCount); 
                for (int i = 0; i < canFlyTreeCount; i++) {
                    areaInfos[i].teamCompareValue = areaInfos[i].distanceInHorizontal(myPos);
                }
                System.Array.Sort(areaInfos, new ComparerAreaInfosByDistance());
                TreeAreaRecorder.AreaInfo areaInfo = areaInfos[Random.Range(1, canFlyTreeCount)];
                Vector3 newPos = YejiHuntGameMode.CalculateNewPosByTreePos(animalsBaseT, flyPlaneHeight, areaInfo);
                SetDestination(newPos);
                targetAreaInfo = areaInfo;
                hasCheckFlyDown = false;
            #endregion
        }

        class ComparerAreaInfosByDistance : IComparer {
            public int Compare(object x, object y) {
                TreeAreaRecorder.AreaInfo a = (TreeAreaRecorder.AreaInfo)x;
                TreeAreaRecorder.AreaInfo b = (TreeAreaRecorder.AreaInfo)y;
                if (a.teamCompareValue - b.teamCompareValue > 0) return 1;
                if (a.teamCompareValue - b.teamCompareValue < 0) return -1;
                else return 0;
            }
        }
        void CancelStand() {
            if (!state.standing) return;
            state.standing = false;
            state.up = true;
            toFlyHeight = RandomOnePreHeight();
            animator.CrossFade("FlyFromGround", 0.1f);
            tryReleaseOccupyTree();
        }

        void CancelFlyStay() {
            if (!state.flyStaying) return;
            canFlyStayTime = 0;
        }

        bool tryOccupyTree() {
            if (targetAreaInfo == null) return false;
            if (targetAreaInfo.occupy != null) return false;
            else {
                targetAreaInfo.occupy = this;
                return true;
            }
        }

        void tryReleaseOccupyTree() {
            if (targetAreaInfo != null && targetAreaInfo.occupy != null && targetAreaInfo.occupy.Equals(this)) {
                targetAreaInfo.occupy = null;
            }
        }

        static float[] preFlyHeights;
        static bool[] preFlyHeightCools;
        public static void InitPreHeights() {
            preFlyHeights = new float[]{1.7f, 2.2f};
            preFlyHeightCools = new bool[]{false, false};
        }
        public static float RandomOnePreHeight() {
            List<int> indexes = new List<int>();
            for (int i = 0; i < preFlyHeightCools.Length; i++) {
                if (!preFlyHeightCools[i]) {
                    indexes.Add(i);
                }
                if (preFlyHeightCools[i]) preFlyHeightCools[i] = false;
            }
            int index = indexes[Random.Range(0, indexes.Count)];
            preFlyHeightCools[index] = true;
            return preFlyHeights[index];
        }
    #endregion

    //状态
    [System.Serializable]
    public class State {
        public bool standing = false;
        public bool flyStaying = false;
        [SerializeField] private bool _dead;
        public bool dead {
            get { return _dead; }
            set {
                _dead = value;
                animal.animator.SetBool("dead", value);
            }
        }
        [SerializeField] private bool _down;
        public bool down {
            get { return _down; }
            set {
                _down = value;
                animal.animator.SetBool("down", value);
            }
        }
        [SerializeField] private bool _landing;
        public bool landing {
            get { return _landing; }
            set {
                _landing = value;
                animal.animator.SetBool("landing", value);
            }
        }
        [SerializeField] private bool _up;
        public bool up {
            get { return _up; }
            set {
                _up = value;
                animal.animator.SetBool("up", value);
            }
        }
        [SerializeField] private bool _flying;
        public bool flying {
            get { return _flying; }
            set {
                _flying = value;
                animal.animator.SetBool("flying", value);
            }
        }
        public Yeji animal;
    }
    [SerializeField] public State state = new State();

    //委托
    public System.Action<Yeji> onDie;
}