using UnityEngine;
using System.Collections;

///
public class CameraRotateAround : MonoBehaviour
{

    public enum CameraState
    {
        /// <summary>
        /// 战斗默认
        /// </summary>
        BattleDefault,
        /// <summary>
        /// 战斗胜利
        /// </summary>
        BattleWin,
        /// <summary>
        /// 角色准备
        /// </summary>
        Ready,
        /// <summary>
        /// 相机修正（技能相机特效完毕后，同步主相机到最后帧的相机位置）
        /// </summary>
        Correct,
        /// <summary>
        /// 自由移动
        /// </summary>
        Free
    }

    /// <summary>
    /// 是否打包模式
    /// </summary>
    public bool IsAndroidAPK = false;
    /// <summary>
    /// 主相机要围绕其旋转的物体
    /// </summary>
    public Transform target;//
    /// <summary>
    /// 主相机与目标物体之间的距离
    /// </summary>
    public float distance = 7.0f;//

    ///*****************************************水平滚动相关
    /// <summary>
    /// 主相机水平方向旋转速度
    /// </summary>
    public float xSpeed = 70.0f;
    /// <summary>
    /// 主相机纵向旋转速度
    /// </summary>
    public float ySpeed = 70.0f;
    ///****************************************垂直滚动相关
    /// <summary>
    /// 最大y（单位是角度）
    /// </summary>
    public int yMaxLimit = 60;

    /// <summary>
    /// 最小y（单位是角度）
    /// </summary>
    public int yMinLimit = 10;

    /// <summary>
    /// 旋转衰减
    /// </summary>
    public float RotationDamping = 10.0f;

    /// <summary>
    /// 位置衰减
    /// </summary>
    public float PosDamping = 5.0f;

    /// <summary>
    /// 高度
    /// </summary>
    public float Height = 0f;

    /// <summary>
    /// 当前相机状态
    /// </summary>
    public CameraState mState = CameraState.Ready;

    /// <summary>
    /// 当前方向
    /// </summary>
    private Vector3 mWantedPosition = Vector3.zero;

    /// <summary>
    /// 当前角度
    /// </summary>
    private Quaternion mWantedRotation = Quaternion.identity;

    /// <summary>
    /// 
    /// </summary>
    private float eulerAngles_x;

    /// <summary>
    /// 
    /// </summary>
    private float eulerAngles_y;

    /// <summary>
    /// 
    /// </summary>
    public Touch touch;

    /// <summary>
    /// 实例
    /// </summary>
    public static CameraRotateAround Instance = null;

    /// <summary>
    /// Awake
    /// </summary>
    void Awake()
    {
        Instance = this;
    }

    /// <summary>
    /// Start
    /// </summary>
    void Start()
    {
        ChangeState(mState);
    }

    /// <summary>
    /// 修改状态
    /// </summary>
    /// <param name="_state"></param>
    public void ChangeState(CameraState _state)
    {
        ResetAngle();

        switch (_state)
        { 
            case CameraState.BattleDefault:
                mWantedPosition = target.TransformPoint(-6.0f, 6.0f, 14.1f);
                mWantedRotation = Quaternion.Euler(23.1f, 154.6f, 0);
                Invoke("LateFree", 1f);
                break;
            case CameraState.BattleWin:
                mWantedPosition = target.TransformPoint(0f, 1.14f, -1.48f);
                mWantedRotation = Quaternion.Euler(-9.8f, 0, 0);
                break;
            case CameraState.Ready:
                mWantedPosition = target.TransformPoint(0f, 3.0f, -2.0f);
                mWantedRotation = Quaternion.Euler(10, 0, 0);
                break;
            case CameraState.Correct:
                Invoke("LateFree", 1f);
                break;
            case CameraState.Free:
                ResetAngle();
                break;
        }
        mState = _state;

    }

    /// <summary>
    /// 延迟修改为自由状态
    /// </summary>
    private void LateFree()
    {
        ChangeState(CameraState.Free);
    }

    /// <summary>
    /// 修正摄像机位置
    /// </summary>
    public void Correct(Vector3 pos, Quaternion rotate)
    {
        mWantedPosition = target.TransformPoint(pos);
        mWantedRotation = rotate;
        ChangeState(CameraState.Correct);

    }

    /// <summary>
    /// 
    /// </summary>
    private void ResetAngle()
    {     
        ///当前物体的欧拉角
        Vector3 eulerAngles = this.transform.eulerAngles;
        this.eulerAngles_x = eulerAngles.y;
        this.eulerAngles_y = eulerAngles.x;
    }

    /// <summary>
    /// 
    /// </summary>
    private void Update()
    {
        if (Input.GetKeyDown(KeyCode.W))
        {
            ChangeState(CameraState.BattleWin);
        }
    }

    /// <summary>
    /// LateUpdate
    /// </summary>
    private void LateUpdate()
    {
        if (this.target == null)
        {
            return;
        }
        if (mState != CameraState.Free)
        { 
            //Quaternion mWantedRotation = Quaternion.LookRotation(target.position - transform.position, target.up);
            transform.rotation = Quaternion.Slerp(transform.rotation, mWantedRotation, Time.deltaTime * RotationDamping);
            transform.position = Vector3.Lerp(transform.position, mWantedPosition, Time.deltaTime * PosDamping);
            return;
        }
        if (IsAndroidAPK)
        {
            if ((Input.touchCount == 1 && Input.GetTouch(0).phase == TouchPhase.Moved))
            {
                touch = Input.GetTouch(0);
                this.eulerAngles_x += ((touch.deltaPosition.x * this.xSpeed) * this.distance) * 0.02f;
                this.eulerAngles_y -= (touch.deltaPosition.y * this.ySpeed) * 0.02f;
                this.eulerAngles_y = ClampAngle(this.eulerAngles_y, (float)this.yMinLimit, (float)this.yMaxLimit);
                Quaternion quaternion = Quaternion.Euler(this.eulerAngles_y, this.eulerAngles_x, (float)0);
                Vector3 vector = ((Vector3)(quaternion * new Vector3((float)0, (float)0, -this.distance))) + this.target.position;
                ///更改主相机的旋转角度和位置
                this.transform.rotation = quaternion;
                this.transform.position = vector;
                return;
            }
        }
        else
        {
            if (Input.GetMouseButton(0))
            {
                
                this.eulerAngles_x += ((Input.GetAxis("Mouse X") * this.xSpeed) * this.distance) * 0.02f;
                this.eulerAngles_y -= (Input.GetAxis("Mouse Y") * this.ySpeed) * 0.02f;
                this.eulerAngles_y = ClampAngle(this.eulerAngles_y, (float)this.yMinLimit, (float)this.yMaxLimit);
                Quaternion quaternion = Quaternion.Euler(this.eulerAngles_y, this.eulerAngles_x, (float)0);
                Vector3 vector = ((Vector3)(quaternion * new Vector3((float)0, (float)0, -this.distance))) + this.target.position;
                ///更改主相机的旋转角度和位置
                this.transform.rotation = quaternion;
                this.transform.position = vector;
            }
        }
    }


    /// <summary>
    /// 把角度限制到给定范围内
    /// </summary>
    /// <param name="angle"></param>
    /// <param name="min"></param>
    /// <param name="max"></param>
    /// <returns></returns>
    private float ClampAngle(float angle, float min, float max)
    {
        while (angle < -360)
        {
            angle += 360;
        }

        while (angle > 360)
        {
            angle -= 360;
        }

        return Mathf.Clamp(angle, min, max);

    }
}