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;
        RandomWillFlyTime();
    }
    static int _avoidancePriority = 0;
    static int avoidancePriority {
        get {
            if (_avoidancePriority < 50) {
                _avoidancePriority++;
            } else {
                _avoidancePriority = 1;
            }
            return _avoidancePriority;
        }
    }

    void OnDestroy() {
        ReleaseLandLock();
    }

    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_die", AudioMgr.GetAudioSource(this.gameObject));
            AudioMgr.ins.PlayCheer(true);
            if (currentHeight < 1.5f) {
                arrow.arrowCameraComp.arrowCameraTemplate.SendMsg(0, null);
            }
        }

        void Hurt() {
            CancelStand();
            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;
        //能够在前几棵树徘徊
        [System.NonSerialized] public int canFlyTreeCount = 4;
        //将会绕树转
        bool willMoveRoundTree = false;
        Queue<Vector3> roundTreePostions = new Queue<Vector3>();
        //随机移动
        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;
                        Invoke("ReleaseLandLock", Random.value * 3f + 1.0f);
                    }
                }
                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 * 2f;
                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 = 2f + Random.value * 3f;
                        animator.CrossFade("IdleOnGround2", 0.2f);
                    }
                }
                return;
            }
        }
        float willFlyTime;
        float flyingTime;
        void UpdateBehavior() {
            if (state.standing) {
                canStandTime -= Time.deltaTime;
                if (canStandTime <= 0) {
                    CancelStand();
                }
                return;
            }

            if (state.landing) return;

            if (state.flying && !state.down && !state.up) {
                flyingTime += Time.deltaTime;
                if (flyingTime >= willFlyTime && DoLandLock()) {
                    flyingTime = 0;
                    state.down = true;
                }
            }
            
            if (moving) return;

            if (willMoveRoundTree && roundTreePostions.Count > 0) {
                Vector3 pos = roundTreePostions.Dequeue();
                SetDestination(pos);
                return;
            } else {
                willMoveRoundTree = false;
            }

            //规划下一次行动路线
            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());
            //如果离这棵树比较近，有几率使其绕着树转
            TreeAreaRecorder.AreaInfo firstAreaInfo = areaInfos[0];
            bool isNearTree4th = areaInfos.Length == 4 && firstAreaInfo == treeAreaRecorder.getValidAreaInfo(3);
            if (!isNearTree4th && firstAreaInfo.teamCompareValue < firstAreaInfo.radius + 1.5f && Random.value < 0.5) {
                willMoveRoundTree = true;
                Vector3 treePos = areaInfos[0].transform.position; 
                treePos.y = myPos.y;
                Vector3 pointer = myPos - treePos;
                roundTreePostions.Clear();
                int direction = Random.value >= 0.5 ? 1 : -1;
                for (int i = 1; i <= 6; i++) {
                    roundTreePostions.Enqueue(treePos + Quaternion.AngleAxis(i * 60 * direction, Vector3.up) * pointer);
                }
                return;
            }
            TreeAreaRecorder.AreaInfo areaInfo = areaInfos[Random.Range(1, canFlyTreeCount)];
            Vector3 newPos = YejiHuntGameMode.CalculateNewPosByTreePos(animalsBaseT, flyPlaneHeight, areaInfo);
            SetDestination(newPos);
        }

        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);
            RandomWillFlyTime();
        }
        void RandomWillFlyTime() {
            willFlyTime = 4 + Random.value * 3f;
        }
        static float[] preFlyHeights;
        static int[] preFlyHeightCools;
        public static void InitPreHeights() {
            preFlyHeights = new float[]{2, 2.5f, 3, 3.5f, 4f};
            preFlyHeightCools = new int[]{0, 0, 0, 0, 0};
        }
        public static float RandomOnePreHeight() {
            List<int> indexes = new List<int>();
            for (int i = 0; i < preFlyHeightCools.Length; i++) {
                if (preFlyHeightCools[i] > 0) preFlyHeightCools[i] = preFlyHeightCools[i] - 1;
                if (preFlyHeightCools[i] == 0) {
                    indexes.Add(i);
                }
            }
            int index = indexes[Random.Range(0, indexes.Count)];
            preFlyHeightCools[index] = 3;
            return preFlyHeights[index];
        }
        public static bool landLocked = false; //着陆锁，禁止地上同时存在两只鸟，避免穿模
        private bool myLandLocked = false;
        public bool DoLandLock() {
            if (landLocked) return false;
            return myLandLocked = landLocked = true;
        }
        public void ReleaseLandLock() {
            if (!myLandLocked) return;
            myLandLocked = landLocked = false;
        }
    #endregion

    //状态
    [System.Serializable]
    public class State {
        public bool standing = 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;
}