using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class CameraMove : MonoBehaviour
{

    public static CameraMove instance;
    [Header("模型以及相机初始位置，自动初始化")]
    public Vector3 cameraInitialPos;
    public Vector3 cameraInitialRot;
    public Vector3 modelInitialRot;

    [Header("要控制的物体")]
    [Tooltip("要控制的相机")]
    public Camera myCamera;
    [Tooltip("相机缩放的焦点")]
    public Transform zoomTarget;
    [Tooltip("要观察的模型")]
    public Transform model;

    [Header("设置的参数")]
    [Tooltip("缩放速率")]
    public int zoomRate = 40;
    [Tooltip("最远观察距离")]
    public float maxObservationDis;
    [Tooltip("最近观察距离")]
    public float minObservationDis;
    [Tooltip("水平方向最大移动距离")]
    public float maxDisH = 2f;
    [Tooltip("竖直方向最大移动距离")]
    public float maxDisV = 5f;
    [Tooltip("水平竖直平面移动速度")]
    public float deltaMoveSpeed = 2f;
    [Tooltip("转动时的速度")]
    public float rotSpeed = 2f;
    [Tooltip("竖直方向最大旋转角度")]
    public float maxRotV = 90f;

    [Header("自动获取的变量，不需赋值")]
    public float currentObservationDis;
    public float mouseX;
    public float mouseY;
    public Vector3 zoomDir;
    Vector3 mouseScreenPos;
    Vector3 mouseWorldPos;
    float rotV = 0f;

    /// <summary>
    /// 手指控制的时候各个变量
    /// </summary>
    Touch firstFinger;
    Touch secondFinger;
    TouchType touchType;
    Vector2 deltaPos;
    bool isStartIJudgeLongPress;
    bool isStartIZoomByTwoFinger;
    float twoFingerOldDis;
    float twoFingerNewDis;
    void Awake()
    {
        //Init();
    }
    // Update is called once per frame
    void Update()
    {
        if (UI_manage.inst.FBX_obj.transform.childCount!=0)
        {
            model = UI_manage.inst.FBX_obj.transform.GetChild(0);
            modelInitialRot = model.localEulerAngles;
            MoveByFinger();
        }
        
        //PC端调用Move()方法，功能：鼠标左键控制相机平面移动，按住鼠标右键拖动鼠标相机围绕物体旋转，滚轮相机朝着鼠标位子缩放
        //Move();


        //安卓端调用此方法功能：一个手指活动屏幕模型旋转，一个手指长按屏幕后再滑动模型平面移动，两个手指实现模型朝着两手指中间放大缩小
        //MoveByFinger();
    }
    /// <summary>
    /// 初始化
    /// </summary>
    public void Init()
    {
        instance = this;
        cameraInitialPos = myCamera.transform.position;
        cameraInitialRot = myCamera.transform.localEulerAngles;
        //modelInitialRot = model.localEulerAngles;
    }
    #region PC
    /// <summary>
    /// PC端鼠标控制移动方法
    /// </summary>
    private void Move()
    {
        MoveByMouse0();
        ZoomByScrollWheel();
        RotByMouse1();
    }

    /// <summary>
    /// 鼠标右键按住转动摄像机
    /// </summary>
    public void RotByMouse1()
    {
        if (Input.GetMouseButton(1))
        {

            mouseX = Input.GetAxis("Mouse X");
            mouseY = Input.GetAxis("Mouse Y");
            if (Mathf.Abs(mouseX) > Mathf.Abs(mouseY))
            {
                if (mouseX < 0)
                {
                    model.Rotate(Vector3.up, rotSpeed);
                    //myCamera.transform.RotateAround(model.transform.position, Vector3.up, -rotSpeed);
                }
                else if (mouseX > 0)
                {
                    model.Rotate(Vector3.up, -rotSpeed);
                    //myCamera.transform.RotateAround(model.transform.position, Vector3.up, rotSpeed);

                }
            }
            else if (Mathf.Abs(mouseX) < Mathf.Abs(mouseY))
            {
                if (mouseY < 0)
                {
                    if (rotV < maxRotV)
                    {
                        myCamera.transform.RotateAround(model.transform.position, Vector3.right, rotSpeed);
                        rotV += rotSpeed;
                    }
                }
                else if (mouseY > 0)
                {
                    if (rotV > -maxRotV)
                    {
                        myCamera.transform.RotateAround(model.transform.position, Vector3.right, -rotSpeed);
                        rotV -= rotSpeed;
                    }
                    //if (myCamera.transform.localEulerAngles.x >=90)
                    //{
                    //    myCamera.transform.RotateAround(model.transform.position, Vector3.right, -rotSpeed);
                    //}
                }
            }
        }
    }

    /// <summary>
    /// 滑轮键缩放
    /// </summary>
    public void ZoomByScrollWheel()
    {
        float scrollWheel = Input.GetAxis("Mouse ScrollWheel");
        if (scrollWheel != 0)
        {

            Vector3 zoomTargetScreenPos = myCamera.WorldToScreenPoint(zoomTarget.position);
            mouseScreenPos = new Vector3(Input.mousePosition.x, Input.mousePosition.y, zoomTargetScreenPos.z);
            zoomTarget.position = myCamera.ScreenToWorldPoint(mouseScreenPos);
            Ray ray = myCamera.ScreenPointToRay(Input.mousePosition);
            RaycastHit hitInfo;
            if (Physics.Raycast(ray, out hitInfo))
            {
                zoomTarget.position = hitInfo.point;
            }
        }
        currentObservationDis = (zoomTarget.position - myCamera.transform.position).magnitude;
        zoomDir = (zoomTarget.position - myCamera.transform.position).normalized;
        Zoom(zoomDir, scrollWheel * Time.deltaTime * zoomRate);
    }

    /// <summary>
    /// 按住鼠标左键拖动
    /// </summary>
    public void MoveByMouse0()
    {
        if (Input.GetMouseButton(0))
        {
            if (Input.GetAxis("Mouse X") < 0)
            {
                //SetMoveSpeed(2.0f);
                MoveByDeltaDistance(true, true);
            }
            else if (Input.GetAxis("Mouse X") > 0)
            {
                //SetMoveSpeed(2.0f);
                MoveByDeltaDistance(true, false);

            }

            if (Input.GetAxis("Mouse Y") < 0)
            {
                //SetMoveSpeed(2.0f);
                MoveByDeltaDistance(false, true);

            }
            else if (Input.GetAxis("Mouse Y") > 0)
            {
                //SetMoveSpeed(2.0f);
                MoveByDeltaDistance(false, false);

            }
        }
    }

    /// <summary>
    /// 通过键盘或者方向键或者点击按钮来移动相机
    /// </summary>
    /// <param name="Hmoving" true表示水平移动></param>
    /// <param name="positiveDir" true表示正向移动></param>
    public void MoveByDeltaDistance(bool Hmoving, bool positiveDir)
    {
        //target.rotation = transform.rotation;
        if (Hmoving)
        {


            if (positiveDir)
            {
                if (myCamera.transform.position.x < maxDisH)
                {
                    myCamera.transform.Translate(Vector3.right * deltaMoveSpeed * Time.deltaTime, Space.Self);
                    //target.Translate(Vector3.right * deltaMoveSpeed * Time.deltaTime);
                }
            }
            else
            {
                if (myCamera.transform.position.x > -maxDisH)
                {
                    myCamera.transform.Translate(Vector3.right * -deltaMoveSpeed * Time.deltaTime, Space.Self);
                    //target.Translate(Vector3.right * -deltaMoveSpeed * Time.deltaTime);
                }
            }
        }
        else
        {
            if (positiveDir)
            {

                if (myCamera.transform.position.y < maxDisH)
                {
                    myCamera.transform.Translate(transform.up * deltaMoveSpeed * Time.deltaTime, Space.World);
                    //target.Translate(transform.up * deltaMoveSpeed * Time.deltaTime, Space.World); 
                }
            }
            else
            {
                if (myCamera.transform.position.y > -maxDisH)
                {
                    myCamera.transform.Translate(transform.up * -deltaMoveSpeed * Time.deltaTime, Space.World);
                    //target.Translate(transform.up * -deltaMoveSpeed * Time.deltaTime, Space.World); 
                }

            }
        }


    }
    #endregion

    /// <summary>
    /// 安卓端通过手指控制
    /// </summary>
    private void MoveByFinger()
    {
        if (Input.touchCount == 0)
        {
            touchType = TouchType.NoneFinger;
            StopAllCoroutines();
            isStartIJudgeLongPress = false;
            isStartIZoomByTwoFinger = false;
        }
        else if (Input.touchCount == 1)
        {

            if (touchType == TouchType.NoneFinger && !isStartIJudgeLongPress)
            {
                isStartIJudgeLongPress = true;
                StartCoroutine(IJudgeLongPress());
                firstFinger = Input.GetTouch(0);
            }
        }
        else if (Input.touchCount == 2)
        {
            touchType = TouchType.TwoFingerZoom;
        }
        switch (touchType)
        {
            case TouchType.NoneFinger:
                break;
            case TouchType.OneFingerMove:
                //MoveByOneFinger();
                break;
            case TouchType.OneFingerRot:
                RotByOneFinger();
                break;
            case TouchType.TwoFingerZoom:
                if (!isStartIZoomByTwoFinger)
                {
                    isStartIZoomByTwoFinger = true;
                    StartCoroutine("IZoomByTwoFinger");
                }
                break;
            default:
                break;
        }

    }
    /// <summary>
    /// 判断是否长按
    /// </summary>
    /// <returns></returns>
    IEnumerator IJudgeLongPress()
    {

        if (Input.touchCount != 0)
        {
            Vector2 firstPos = Input.GetTouch(0).position;
            yield return new WaitForSeconds(0.2f);
            if (Input.touchCount != 0)
            {
                Vector2 secondPos = Input.GetTouch(0).position;
                if ((secondPos - firstPos).magnitude < 2f)
                {
                    touchType = TouchType.OneFingerMove;
                }
                else
                {
                    touchType = TouchType.OneFingerRot;
                }
            }

        }

    }

    /// <summary>
    /// 相机向物体移动
    /// </summary>
    /// <param name="zoomDir">移动方向</param>
    /// <param name="zoomDis">移动距离</param>
    public void Zoom(Vector3 zoomDir, float zoomDis)
    {
        //target.Translate(zoomDir * zoomDis, Space.World);
        if (zoomDis < 0 && currentObservationDis > maxObservationDis)
        {
            return;
        }
        else if (zoomDis > 0 && currentObservationDis < minObservationDis)
        {
            return;
        }
        myCamera.transform.Translate(zoomDir * zoomDis, Space.World);
    }
    
    /// <summary>
    /// 一根手指拖动
    /// </summary>
    public void MoveByOneFinger()
    {

        firstFinger = Input.GetTouch(0);

        if (firstFinger.phase == TouchPhase.Moved)
        {
            deltaPos = firstFinger.deltaPosition;
            if (deltaPos.x < 0)
            {
                //SetMoveSpeed(2.0f);
                MoveByDeltaDistance(true, true);
            }
            else if (deltaPos.x > 0)
            {
                //SetMoveSpeed(2.0f);
                MoveByDeltaDistance(true, false);

            }

            if (deltaPos.y < 0)
            {
                //SetMoveSpeed(2.0f);
                MoveByDeltaDistance(false, true);

            }
            else if (deltaPos.y > 0)
            {
                //SetMoveSpeed(2.0f);
                MoveByDeltaDistance(false, false);

            }
        }
    }

    /// <summary>
    /// 一根手指长按转动
    /// </summary>
    public void RotByOneFinger()
    {
        firstFinger = Input.GetTouch(0);
        if (firstFinger.phase == TouchPhase.Moved)
        {
            deltaPos = firstFinger.deltaPosition;
            mouseX = deltaPos.x;
            mouseY = deltaPos.y;
            if (Mathf.Abs(mouseX) > Mathf.Abs(mouseY))
            {
                if (mouseX < 0)
                {
                    model.Rotate(Vector3.up, rotSpeed);
                }
                else if (mouseX > 0)
                {
                    model.Rotate(Vector3.up, -rotSpeed);

                }
            }
            else if (Mathf.Abs(mouseX) < Mathf.Abs(mouseY))
            {
                if (mouseY < 0)
                {
                    if (rotV < maxRotV)
                    {
                        myCamera.transform.RotateAround(model.transform.position, Vector3.right, rotSpeed);
                        rotV += rotSpeed;
                    }
                }
                else if (mouseY > 0)
                {
                    if (rotV > -maxRotV)
                    {
                        myCamera.transform.RotateAround(model.transform.position, Vector3.right, -rotSpeed);
                        rotV -= rotSpeed;
                    }
                    //if (myCamera.transform.localEulerAngles.x >=90)
                    //{
                    //    myCamera.transform.RotateAround(model.transform.position, Vector3.right, -rotSpeed);
                    //}
                }
            }
        }
    }

    /// <summary>
    /// 两根手指缩放协程
    /// </summary>
    public IEnumerator IZoomByTwoFinger()
    {
        Vector2 centerPos;
        while (true)
        {
            firstFinger = Input.GetTouch(0);
            secondFinger = Input.GetTouch(1);
            twoFingerOldDis = Vector2.Distance(firstFinger.position, secondFinger.position);
            centerPos = (firstFinger.position + secondFinger.position) / 2;
            yield return 0;
            firstFinger = Input.GetTouch(0);
            secondFinger = Input.GetTouch(1);
            twoFingerNewDis = Vector2.Distance(firstFinger.position, secondFinger.position);
            float scrollWheel = twoFingerNewDis - twoFingerOldDis;
            if (scrollWheel != 0)
            {

                Vector3 zoomTargetScreenPos = myCamera.WorldToScreenPoint(zoomTarget.position);
                mouseScreenPos = new Vector3(centerPos.x, centerPos.y, zoomTargetScreenPos.z);
                zoomTarget.position = myCamera.ScreenToWorldPoint(mouseScreenPos);
                Ray ray = myCamera.ScreenPointToRay(centerPos);
                RaycastHit hitInfo;
                if (Physics.Raycast(ray, out hitInfo))
                {
                    zoomTarget.position = hitInfo.point;
                }
            }
            currentObservationDis = (zoomTarget.position - myCamera.transform.position).magnitude;
            zoomDir = (zoomTarget.position - myCamera.transform.position).normalized;
            Zoom(zoomDir, scrollWheel * Time.deltaTime * zoomRate * 0.1f);
            if (Input.touchCount != 2)
            {
                isStartIZoomByTwoFinger = false;
                break;
            }
        }


    }

    /// <summary>
    /// 复位方法
    /// </summary>
    public void Reset()
    {
        myCamera.transform.position = cameraInitialPos;
        myCamera.transform.localEulerAngles = cameraInitialRot;
        model.localEulerAngles = modelInitialRot;
        rotV = 0;
    }
}
public enum TouchType
{
    NoneFinger,
    OneFingerMove,
    OneFingerRot,
    TwoFingerZoom
}