using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
using DG.Tweening;

public class MoveCamra : MonoBehaviour {

static MoveCamra _instance;

public static MoveCamra Instance
{
    get
    {
        return _instance;
    }
}
/// <summary>
/// 移动速度
/// </summary>
public float moveSpeed = 3;
private Ray mouseRay;
private bool mouseChick = true;
private float firstTime = 0;
//private bool isOpenCamMove=false;
private float rotationSpeed = 5F;
/// <summary>
/// 最小高度
/// </summary>
private float minY = -1000F;
/// <summary>
/// 最大高度
/// </summary>
private float maxY = 1000F;
/// <summary>
/// 移动跟随物体（初始坐标旋转角度为0的空物体）
/// </summary>
public GameObject forwardPoint;
/// <summary>
/// 绕着旋转的中心点（初始坐标旋转角度为0）
/// </summary>
public GameObject target;
/// <summary>
/// 是否开启鼠标旋转
/// </summary>
private bool isRotating = false;
/// <summary>
/// 相机和目标物体的距离
/// </summary>
private Vector3 offsetPosition;

//是否聚焦在建筑上
bool focusState = false;
//聚焦建筑物
Transform focusObj;

 void Awake()
{
    _instance = this;
}
 
// Use this for initialization
void Start () {
     
    }

     
    // Update is called once per frame
    void Update () {
    if (!IsTouchedUI())  
    {
         MouseMove();
         KeyMove();
    }

}
void LateUpdate()
{
    if (transform.parent != null)
    {
        transform.parent = null;
        forwardPoint.transform.eulerAngles = new Vector3(0, transform.eulerAngles.y, transform.eulerAngles.z);
    }
    ///限制移动高度和低度
    transform.position = new Vector3(transform.position.x, Mathf.Clamp(transform.position.y, minY, maxY + 6f), transform.position.z);
}
private void KeyMove()
{
    if (Input.GetKeyDown(KeyCode.Space))
    {
        ///复位到初始位置和角度
         
    }
    if (Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift))
    {
        moveSpeed = 2;
        rotationSpeed = 2F;
    }
    else if (Input.GetKeyUp(KeyCode.LeftShift) || Input.GetKeyUp(KeyCode.RightShift))
    {
        moveSpeed = 5f;
        rotationSpeed = 5F;
    }
    //判定是否按住了ctrl，如果按住了，则使用最大移动速度，否则使用正常移动速度
    if (Input.GetKey(KeyCode.LeftControl) || Input.GetKey(KeyCode.RightControl))
    {
        moveSpeed = 15;
    }
    else if (Input.GetKeyUp(KeyCode.LeftControl) || Input.GetKeyUp(KeyCode.RightControl))
    {
        moveSpeed = 5;
    }
    if (Input.GetKeyDown(KeyCode.W))
    {
        MoveCmer(Vector3.forward, KeyCode.W);
    }
    else if (Input.GetKeyDown(KeyCode.S))
    {
        MoveCmer(Vector3.back, KeyCode.S);
    }
    if (Input.GetKeyDown(KeyCode.A))
    {
        MoveCmer(Vector3.left, KeyCode.A);
    }
    else if (Input.GetKeyDown(KeyCode.D))
    {
        MoveCmer(Vector3.right, KeyCode.D);
    }
    else if (Input.GetKey(KeyCode.Q))
    {
        RotCamera(5);
    }
    else if (Input.GetKey(KeyCode.E))
    {
        RotCamera(-5);
    }
    else if (Input.GetKeyDown(KeyCode.UpArrow))
    {
        MoveCmer(Vector3.up, KeyCode.UpArrow);
    }
    else if (Input.GetKeyDown(KeyCode.DownArrow))
    {
        MoveCmer(Vector3.down, KeyCode.DownArrow);
    }
    else if (Input.GetKey(KeyCode.LeftArrow))
    {
        CameraRotation(Vector3.down);
    }
    else if (Input.GetKey(KeyCode.RightArrow))
    {
        CameraRotation(Vector3.up);
    }
}
/// <summary>
/// 旋转相机
/// </summary>
private void RotateView()
{
    //鼠标右键按下可以旋转视野
    if (Input.GetMouseButtonDown(1))
    {
        Ray ray = GetComponent<Camera>().ScreenPointToRay(Input.mousePosition);
        RaycastHit hit;
        if (Physics.Raycast(ray, out hit) && focusState == false)
        {
            target.transform.position = hit.point;
        }
        else
        {
            target.transform.position = focusObj.position;
        }
        isRotating = true;
    }
    if (Input.GetMouseButtonUp(1))
        isRotating = false;

    if (isRotating)
    {
        Vector3 originalPosition = transform.position;
        Quaternion originalRotation = transform.rotation;
        transform.RotateAround(target.transform.position, target.transform.up, rotationSpeed * Input.GetAxis("Mouse X"));
        transform.RotateAround(target.transform.position, transform.right, -rotationSpeed * Input.GetAxis("Mouse Y"));
        float x = transform.eulerAngles.x;
        //旋转的范围为
        if (x > 80 && x < 330)
        {
            transform.position = originalPosition;
            transform.rotation = originalRotation;
        }
    }
    offsetPosition = transform.position - target.transform.position;
}

public void CameraRotation(Vector3 direction)
{
    transform.Rotate(direction * rotationSpeed, Space.World);
}
/// <summary>
/// 移动相机开启携程
/// </summary>
/// <param name="v"></param>
/// <param name="key"></param>
private void MoveCmer(Vector3 v, KeyCode key)
{
    StartCoroutine(TurnRound(v, key));
}
/// <summary>
/// 移动相机
/// </summary>
/// <param name="v">方向</param>
/// <param name="key">按键</param>
/// <returns></returns>
private IEnumerator TurnRound(Vector3 v, KeyCode key)
{
    bool isPress = true;
    while (isPress && Input.GetKey(key))
    {
        Move(v);
        yield return new WaitForFixedUpdate();
        if (Input.GetKeyUp(key))
        {
            isPress = false;
        }
    }
}
/// <summary>
/// 移动相机通过子父物体关系移动
/// </summary>
/// <param name="direction"></param>
private void Move(Vector3 direction)
{
    transform.parent = forwardPoint.transform;
    forwardPoint.transform.Translate(direction * moveSpeed);
}
/// <summary>
/// 限制相机上下旋转角度
/// </summary>
/// <param name="speed"></param>
private void RotCamera(float speed)
{
    transform.localEulerAngles -= new Vector3(rotationSpeed / speed, 0, 0);
    if (transform.localEulerAngles.x > 85)
        transform.localEulerAngles = new Vector3(85, transform.eulerAngles.y, transform.eulerAngles.z);
    if (transform.localEulerAngles.x < 10)
        transform.localEulerAngles = new Vector3(10, transform.eulerAngles.y, transform.eulerAngles.z);
}
/// <summary>
/// 鼠标控制
/// </summary>
void MouseMove()
{
    if (!Input.GetMouseButtonDown(2))
    {
        if (Input.GetAxis("Mouse ScrollWheel") != 0)
        {
            transform.Translate(Vector3.forward * Input.GetAxis("Mouse ScrollWheel") * moveSpeed * Ray(transform) * 0.1f);
            //Debug.Log("速度："+moveSpeed * Ray(transform) * 0.1f);
        }
    }
    if (Input.GetMouseButton(0) && focusState == false)
    {
        transform.parent = forwardPoint.transform;
        forwardPoint.transform.Translate(-Input.GetAxis("Mouse X") * Ray(transform) * 0.02f * moveSpeed, 0, -Input.GetAxis("Mouse Y") * Ray(transform) * 0.02f * moveSpeed);
    }
    if (Input.GetMouseButtonDown(0))//
    {
        mouseRay = GetComponent<Camera>().ScreenPointToRay(Input.mousePosition);//从摄像机向鼠标点击的位置发射条射线
        RaycastHit hit;
        //双击左键定位
        if (Physics.Raycast(mouseRay, out hit))//当射线碰撞到对象时
        {
            if (Time.time - firstTime > 0.3f)
            {
                mouseChick = true;
            }
            if (mouseChick)
            {
                firstTime = Time.time;
            }
            else
            {
                if (Time.time - firstTime <= 0.3f)
                {
                    if (Vector3.Distance(transform.position, hit.point) >= 5)
                    {
                        //双击定位到物体附近
                        if(hit.collider.tag == "house")
                        {
                            StartCoroutine(FrontTowardPoint(hit.collider.transform.parent.parent.parent));
                        }
                        else
                        {
                            transform.DOMove(GetBetweenPoint(hit.point, transform.position, 40), 1);
                        }
                    }
                }
            }
            mouseChick = !mouseChick;
        }
    }
    RotateView();
}
/// <summary>
/// 返回两点之间distance距离的点
/// </summary>
/// <param name="start">开始的点</param>
/// <param name="end">终点</param>
/// <param name="distance">距离</param>
/// <returns></returns>
private Vector3 GetBetweenPoint(Vector3 start, Vector3 end, float distance)
{
    Vector3 normal = (end - start).normalized;
    return normal * distance + start;
}
/// <summary>
/// 朝向建筑的点
/// </summary>
/// <returns></returns>
IEnumerator FrontTowardPoint(Transform TargetPoint)
{
    focusObj = TargetPoint;
    focusState = true;
    Sequence mySequence = DOTween.Sequence();
    mySequence.Append(transform.DOMove(TargetPoint.position + new Vector3(0, 10, 10), 1f));
    mySequence.Append(transform.DOLookAt(TargetPoint.position, 0.7f));
    yield return new WaitForSeconds(1.7f);
    //开始实例化UI界面
    print("开始实例化UI界面");
}
/// <summary>
/// 判断相机和前方焦点的距离
/// </summary>
/// <param name="point"></param>
/// <returns>返回距离</returns>
private float Ray(Transform point)
{
    Vector3 p = Vector3.zero;
    RaycastHit hit;
    if (Physics.Raycast(point.position, point.forward, out hit))
    {
        p = hit.point;
    }
    float dis = Vector3.Distance(point.transform.position, p);
    if (dis >= 300)
        dis = 300;
    if (dis <= 6)
        dis = 6;
    return dis;
}

//是否在UI上
bool IsTouchedUI()
{
    bool touchedUI = false;
    if (Application.isMobilePlatform)
    {
        if (EventSystem.current.IsPointerOverGameObject(Input.GetTouch(0).fingerId))
        {
            touchedUI = true;
        }
    }
    else if (EventSystem.current.IsPointerOverGameObject())
    {
        touchedUI = true;
    }
    return touchedUI;
}

}