using System;
using System.CodeDom;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.UI;
using EZXR.Glass.Inputs;
using UnityEditor;
using EZXR.Glass.Core;
using UnityEngine.Serialization;
using EZXR.Glass.Inputs;

namespace EZXR.Glass.UI
{
    [ExecuteInEditMode]
    public class SpatialButton : SpatialSelectable
    {
        #region InternalUse
        public BoxCollider _collider;
        #endregion

        [Tooltip("按钮前置触发区的厚度(单位:m)，用户手指进入这个区域将会被认为将要与此Button进行交互，触发OnPointerPotentialInteractChanged事件")]
        /// <summary>
        /// 按钮前置触发区的厚度(单位:m)，用户手指进入这个区域将会被认为将要与此Button进行交互，触发OnPointerPotentialInteractChanged事件
        /// </summary>
        public float preTriggerZoneThickness = 0.15f;
        [Tooltip("按钮后置触发区的厚度(单位:m)，决定了用户手指按过(穿过)按钮后还保持按下状态的距离,当手指离开这个后置触发区的时候按钮将会弹起")]
        /// <summary>
        /// 按钮后置触发区的厚度(单位:m),决定了用户手指按过(穿过)按钮后还保持按下状态的距离,当手指离开这个后置触发区的时候按钮将会弹起
        /// </summary>
        public float rearTriggerZoneThickness = 0.05f;
        /// <summary>
        /// 按钮被按下
        /// </summary>
        public bool pressed;
        /// <summary>
        /// 0是未按下，1是按下但是没按到底，2是按下且按到底
        /// </summary>
        public byte state;
        /// <summary>
        /// 按键高度(单位:m，必须大于heightMin)，从这个高度开始响应按键事件
        /// </summary>
        public float heightMax;
        /// <summary>
        /// 按键按到底的时候的厚度
        /// </summary>
        public float heightMin = 0.001f;
        /// <summary>
        /// 当前是哪个指尖点点击到了按键，用于计算按下的z距离
        /// </summary>
        Transform other;
        /// <summary>
        /// 当前被点击的Button
        /// </summary>
        SpatialButton curButton;
        /// <summary>
        /// 指尖点当前在按键坐标系下的坐标
        /// </summary>
        Vector3 curPos;
        /// <summary>
        /// 当前指尖点距离按键底面的z距离
        /// </summary>
        public float length;
        public float clampLength;
        float lastLength;
        /// <summary>
        /// 是否开始点击，只要有指尖点进入触发区就开始点击判断流程
        /// </summary>
        bool start = false;
        //bool rayStart = false;
        ///// <summary>
        ///// 用于播放按键按下和弹起的音效
        ///// </summary>
        //AudioSource audioSource;
        /// <summary>
        /// 0是按键开始按下的音效，1是按键按下的音效，2是按键弹起的音效
        /// </summary>
        static AudioClip[] clips;
        InputInfoBase handInfo;
        /// <summary>
        /// Button是否响应虚拟键盘的回车键
        /// </summary>
        [SerializeField]
        private bool useEnterKey;

        #region Event
        public enum SpatialButtonEventType
        {
            OnPointerHoverEnter,
            OnPointerStartPress,
            OnPointerPressing,
            OnPointerDown,
            OnPointerUp,
            OnPointerEndPress,
            OnPointerClicked,
            OnPointerHoverExit,
        }
        private static Dictionary<Collider, SpatialObject> All = new Dictionary<Collider, SpatialObject>();

        [Serializable]
        public class SpatialButtonEvent : UnityEvent
        { }

        [Serializable]
        public class Entry
        {
            public SpatialButtonEventType eventID = SpatialButtonEventType.OnPointerHoverEnter;
            public SpatialButtonEvent callback = new SpatialButtonEvent();
        }

        [FormerlySerializedAs("delegates")]
        [SerializeField]
        private List<Entry> m_Delegates;
        public List<Entry> triggers
        {
            get
            {
                if (m_Delegates == null)
                    m_Delegates = new List<Entry>();
                return m_Delegates;
            }
            set { m_Delegates = value; }
        }

        private void Execute(SpatialButtonEventType id)
        {
            var triggerCount = triggers.Count;

            for (int i = 0, imax = triggers.Count; i < imax; ++i)
            {
                var ent = triggers[i];
                if (ent.eventID == id && ent.callback != null)
                    ent.callback.Invoke();
            }
        }

        public void AddEvent(SpatialButtonEventType spatialButtonEventType, UnityAction unityAction)
        {
            var triggerCount = triggers.Count;
            for (int i = 0, imax = triggers.Count; i < imax; ++i)
            {
                var ent = triggers[i];
                if (ent.eventID == spatialButtonEventType && ent.callback != null)
                {
                    ent.callback.AddListener(unityAction);
                    return;
                }
            }
            Entry entry = new Entry();
            entry.eventID = spatialButtonEventType;
            entry.callback.AddListener(unityAction);
            triggers.Add(entry);
        }
        #endregion

        protected override void Awake()
        {
            base.Awake();

            //将自身注册到ARUIEventSystem中，以在被射线碰到的时候被回调
            SpatialUIEventSystem.RegisterCallBack(GetComponent<Collider>(), this);
        }

        protected override void OnEnable()
        {
            base.OnEnable();

            if (useEnterKey)
            {
                KeyBoard.OnEnterClicked += OnEnterClicked;
            }
        }

        protected override void OnDisable()
        {
            base.OnDisable();

            if (useEnterKey)
            {
                KeyBoard.OnEnterClicked -= OnEnterClicked;
            }
        }

        private void OnEnterClicked()
        {
            if (isActiveAndEnabled)
            {
                ButtonClick();
            }
        }

        // Start is called before the first frame update
        protected override void Start()
        {
            base.Start();

            if (Application.isPlaying)
            {
                //_collider = GetComponent<BoxCollider>();
                heightMax = size.z > heightMin ? size.z : heightMin;
                //material = _visual.GetChild(0).GetComponent<Renderer>().material;
                //audioSource = GetComponent<AudioSource>();
                clips = new AudioClip[3];
                clips[0] = ResourcesManager.Load<AudioClip>("Sounds/ButtonStartPress");
                clips[1] = ResourcesManager.Load<AudioClip>("Sounds/ButtonDown");
                clips[2] = ResourcesManager.Load<AudioClip>("Sounds/ButtonUp");
            }
        }

        // Update is called once per frame
        protected override void Update()
        {
            base.Update();

            if (Application.isPlaying)
            {
                //射线交互
                if (handInfo != null)
                {
                    //如果当前射线射到的物体不再是此按钮
                    if (handInfo.CurRayContactingTarget == null || handInfo.CurRayContactingTarget.gameObject != gameObject)
                    {
                        handInfo = null;
                    }
                    else
                    {
                        if (handInfo.isPinching)
                        {
                            ButtonDown(true);
                        }
                        else
                        {
                            ButtonUp(true);
                        }
                    }
                }
                else//近距离
                {
                    if (start)//直接近距离按压
                    {
                        if (other == null || !other.gameObject.activeInHierarchy)//手丢失了的话直接ButtonUp
                        {
                            ButtonUp(false);
                            start = false;
                            curPos = new Vector3(9999, 9999, 9999);
                            return;
                        }
                        else//手正常存在的话实时算出指尖在Button局部坐标系下的位置
                        {
                            //先算出指尖点当前在按键坐标系下的坐标
                            curPos = transform.InverseTransformPoint(other.position);
                        }

                        //然后算出当前指尖点距离按键底面的z距离，这个0.005是指尖点的半径长度
                        length = curPos.z - 0.005f;
                        clampLength = Mathf.Clamp(length, heightMin, heightMax);

                        //更新按钮状态
                        if (clampLength == heightMax)//按钮已经弹起来
                        {
                            ButtonUp(false);
                        }
                        else if (clampLength == heightMin)//按钮按到底
                        {
                            ButtonDown(false);
                        }
                        else if (clampLength < heightMax)//按钮按下但没到底
                        {
                            ButtonPressing();
                        }

                        lastLength = length;
                    }
                }
            }
            else
            {
#if UNITY_EDITOR
                //_mesh.localScale = size;
                _collider.size = new Vector3(size.x, size.y, /*size.z + */preTriggerZoneThickness + rearTriggerZoneThickness);
                _collider.center = new Vector3(0, 0, preTriggerZoneThickness - _collider.size.z / 2.0f);
#endif
            }
        }

        private void OnTriggerStay(Collider other)
        {
            if (Application.isPlaying)
            {
                if (!start)
                {
                    //对方必须具备rigidbody才会触发ARButton的Tigger
                    if (other.name.Contains("Index_4"))
                    {
                        if (_collider.bounds.Contains(other.transform.position) && (transform.InverseTransformPoint(other.transform.position).z - 0.005f > heightMin /*heightMax*/))//此处用于确保开始触发按钮事件一定是从Hover开始，避免从按钮底部向上移动指尖造成的异常
                        {
                            curButton = this;
                            this.other = other.transform;
                            start = true;

                            OnPointerHoverEnter(Spatial.InteractiveMode.Touch);
                        }
                    }
                }
            }
        }

        private void OnTriggerExit(Collider other)
        {
            if (Application.isPlaying)
            {
                if (other.name.Contains("Index_4"))
                {
                    //只有按钮正在被按的状态下，指尖离开触发区才会触发ButtonUp
                    if (state != 0)
                    {
                        ButtonUp(false);
                    }
                    start = false;
                    curButton = null;
                    this.other = null;

                    OnPointerHoverExit();
                }
            }
        }

        /// <summary>
        /// handInfo如果为null表示没有手在与此Button交互
        /// </summary>
        /// <param name="handInfo"></param>
        public override void OnRayCastHit(InputInfoBase handInfo)
        {
            if (this.handInfo != handInfo)
            {
                if (handInfo == null)
                {
                    OnPointerHoverExit();
                }
                else
                {
                    OnPointerHoverEnter(Spatial.InteractiveMode.Raycast);
                }

                this.handInfo = handInfo;
            }
        }

        /// <summary>
        /// 按钮按到底的时候调用，播放按键按下的音效，并更新此按键的pressed状态为true
        /// </summary>
        /// <param name="isRay">是否是射线交互</param>
        void ButtonDown(bool isRay)
        {
            if (state != 2)
            {
                if (isRay)
                {
                    OnPointerStartPress();
                }
            }

            //按到底也属于Pressing的一种情况，所以应该调用OnPointerPressing
            OnPointerPressing();

            if (state != 2)
            {
                state = 2;
                pressed = true;

                //播放按键按下的音效
                AudioSource.PlayClipAtPoint(clips[/*isRay ? 0 : 1*/0], Vector3.zero);

                OnPointerDown();
            }
        }

        /// <summary>
        /// 按钮被按住的时候调用
        /// </summary>
        void ButtonPressing()
        {
            if (state == 0)
            {
                ////播放按键开始按下的音效
                //AudioSource.PlayClipAtPoint(clips[0], Vector3.zero);

                OnPointerStartPress();
            }
            state = 1;

            OnPointerPressing();
        }

        /// <summary>
        /// 按键完全弹起的时候调用，播放按键弹起的音效，并更新此按键的pressed状态为false
        /// </summary>
        void ButtonUp(bool isRay)
        {
            if (state != 0)
            {
                if (isRay)
                {
                    //播放按键弹起的音效
                    AudioSource.PlayClipAtPoint(clips[2], Vector3.zero);
                }

                OnPointerUp();

                OnPointerEndPress();
            }

            if (pressed)//按到底然后弹起来才算是一次点击
            {
                ButtonClick();
            }

            state = 0;
            pressed = false;
        }

        void ButtonClick()
        {
            OnPointerClicked();
        }

        #region Pointer Event
        /// <inheritdoc/>
        public override void OnPointerHoverEnter(Spatial.InteractiveMode interactiveMode = Spatial.InteractiveMode.None)
        {
            base.OnPointerHoverEnter(interactiveMode);
            Execute(SpatialButtonEventType.OnPointerHoverEnter);
        }
        /// <inheritdoc/>
        public override void OnPointerStartPress()
        {
            base.OnPointerStartPress();
            Execute(SpatialButtonEventType.OnPointerStartPress);
        }
        /// <inheritdoc/>
        public override void OnPointerPressing()
        {
            base.OnPointerPressing();
            Execute(SpatialButtonEventType.OnPointerPressing);
        }
        /// <inheritdoc/>
        public override void OnPointerDown()
        {
            base.OnPointerDown();
            Execute(SpatialButtonEventType.OnPointerDown);
        }
        /// <inheritdoc/>
        public override void OnPointerUp()
        {
            base.OnPointerUp();
            Execute(SpatialButtonEventType.OnPointerUp);
        }
        /// <inheritdoc/>
        public override void OnPointerEndPress()
        {
            base.OnPointerEndPress();
            Execute(SpatialButtonEventType.OnPointerEndPress);
        }
        /// <inheritdoc/>
        public override void OnPointerClicked()
        {
            base.OnPointerClicked();
            Execute(SpatialButtonEventType.OnPointerClicked);
        }
        /// <inheritdoc/>
        public override void OnPointerHoverExit()
        {
            base.OnPointerHoverExit();
            Execute(SpatialButtonEventType.OnPointerHoverExit);
        }
        #endregion
    }
}