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

[RequireComponent(typeof(NavMeshAgent))]
public class NavController : BaseController
{
    /// <summary>
    /// 单击时显示的光圈对象
    /// </summary>
    [Tooltip("单击时显示的光圈对象")]
    public GameObject preClick;

    /// <summary>
    /// 可点击的地面层
    /// </summary>
    [Tooltip("地面所在的层，需要将地面对象的层设为此")]
    public LayerMask layer;

    /// <summary>
    /// 角色寻路旋转速度
    /// </summary>
    [Tooltip("角色寻路旋转速度")]
    public float rotateSpeed = 50f;

    /// <summary>
    /// 角色寻路移动速度
    /// </summary>
    [Tooltip("角色寻路移动速度")]
    public float moveSpeed = 2f;

    /// <summary>
    /// 角色寻路最远距离
    /// </summary>
    [Tooltip("角色寻路最远距离")]
    public float MaxNavDistance = 10f;

    /// <summary>
    /// 导航代理对象
    /// </summary>
    NavMeshAgent agent;

    GameObject objClick;

    void Start()
    {
        agent = GetComponent<NavMeshAgent>();

        if (agent != null)
        {
            // 初始化移动和旋转速度
            agent.speed = moveSpeed;
            agent.angularSpeed = rotateSpeed;
        }
        if(transform.parent != null)
            objClick = Instantiate(preClick, transform.parent.transform);
        else
            objClick = Instantiate(preClick);
        objClick.SetActive(false);

        layerMask = (1 << 0) | (1 << 6);    // 地面跟默认层（墙）
    }
    // 射线检测
    RaycastHit hit;
    Ray ray;
    int layerMask;
    NavMeshHit meshHit;

    Vector3 mouseDownPos;
    
    void LateUpdate()
    {
        if (CanControl
            && agent.enabled
            && !IsTouchOnControl
            && !IsJoyStickOnControl
            && !IsUIClicked)
        {
            if (Input.GetMouseButtonUp(1) || Input.touchCount == 1)
            {
                if (!EventSystem.current.IsPointerOverGameObject())
                {
                    if (!IsMouseOnControl && Input.touchCount == 1)
                    {
                        ray = CommonData.MainCamera.ScreenPointToRay(Input.touches[0].position);
                    }
                    else
                    {
                        ray = CommonData.MainCamera.ScreenPointToRay(Input.mousePosition);
                    }

                    if (Physics.Raycast(ray, out hit, MaxNavDistance, layerMask))
                    {
                        // Debug.Log(hit.collider.name);
                        // 判断点击的对象所在层与所设置的层是否一致
                        if (Mathf.Pow(2, hit.collider.gameObject.layer) == layer.value)
                        {
                            if (NavMesh.SamplePosition(hit.point, out meshHit, 1.0f, NavMesh.AllAreas))
                            {
                                // agent.enabled = true;

                                // 设置提示对象位置并显示
                                objClick.transform.position = hit.point;
                                objClick.SetActive(true);

                                // 自动寻路到目标位置
                                agent.isStopped = false;
                                agent.SetDestination(hit.point);

                                // 标识自动寻路控制中
                                IsNavOnControl = true;
                            }
                        }
                    }
                }
            }
        }

        // 如果控下键盘或鼠标则停止寻路
        // if (IsMouseOnControl || IsKeyOnControl || IsJoyStickOnControl)
        if (IsKeyOnControl || IsJoyStickOnControl)
        {
            StopNav();
        }

        if (IsNavOnControl && !IsMoving())
        {
            IsNavOnControl = false;
        }
    }

    /// <summary>
    /// 停止寻路
    /// </summary>
    public void StopNav()
    {
        if (agent.enabled)
        {
            agent.isStopped = true;     // 停止自动寻路
        }

        objClick.SetActive(false);  // 隐藏点击图标对象 
        IsNavOnControl = false;

        // agent.enabled = false;
    }

    // Unity导航是否到达目的地的方法，（包括有些不可能到达的目的地）
    public bool IsMoving()
    {
        if (!agent.enabled)
            return false;
        //bool r = agent.pathPending || agent.remainingDistance > agent.stoppingDistance || agent.velocity != Vector3.zero;
        //r = agent.enabled ? r : false;
        //return r;

       return agent.enabled ?
            agent.pathPending || agent.remainingDistance > agent.stoppingDistance || agent.velocity != Vector3.zero
            : 
            false;
    }
}