using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace UnityCommon
{
    public class CloseUpState : CameraState
    {
        //private float mouseDragSpeed2 = 1;//鼠标拖动的速度
        private Vector3 m_pFocus;
        private Vector3 m_pOrignal;
        public CloseUpState(Camera camera, Vector3 pFocus, Vector3 pOrignal) : base(camera)
        {
            m_pFocus = pFocus;
            m_pOrignal = pOrignal;
        }
        private Vector3 focus;
        private Vector3 offset;

        float nearClipPlaneOld;
        float farClipPlaneOld;

        public override void Enter()
        {
            base.Enter();
            m_camera.transform.SetParent(null);//保持父节点为空，解决相机漂移问题
            nearClipPlaneOld = m_camera.nearClipPlane;
            farClipPlaneOld = m_camera.farClipPlane;
            m_camera.nearClipPlane = 0.01f;
            m_camera.farClipPlane = 100;
            Quaternion r = Quaternion.LookRotation(m_pFocus - m_pOrignal);
            SetCameraPosition(m_pOrignal, r, () =>
            {
                focus = m_pFocus;
                offset = m_pOrignal - focus;
            });
        }
        public override void Exit()
        {
            base.Exit();
            m_camera.farClipPlane = farClipPlaneOld;
            m_camera.nearClipPlane = nearClipPlaneOld;
        }
        public override void OnMove(Vector3 vecDir)
        {
            if (!m_isAllReady) return;
            if (vecDir.y == 0) return;
            OnZoom(vecDir.y * 0.01f);
        }

        public override void OnRotate(Vector2 vector2)
        {
            if (!m_isAllReady) return;
            if (vector2 == Vector2.zero) return;
            m_camera.transform.RotateAround(focus, Vector3.up, vector2.x * 10);
            m_camera.transform.RotateAround(focus, m_camera.transform.right, -vector2.y * 10);
            offset = m_camera.transform.position - focus;
            //if (Input.GetAxis("Mouse Y") != 0 || Input.GetAxis("Mouse X") != 0)
            //    offset = m_camera.transform.position - focus;
        }
        private float distance;
        private float scrollSpeed = 5;
        private float closeUpMaxDistance = 50;
        private float minDistance = 0.1f;
        public override void OnZoom(float zoom)
        {
            if (!m_isAllReady) return;
            if (zoom == 0) return;
            distance = offset.magnitude;
            //var scrollWheel = Input.GetAxis("Mouse ScrollWheel");
            var scrollWheel = zoom;
            if (scrollWheel != 0)
            {
                distance -= scrollWheel * scrollSpeed;
                distance = Mathf.Clamp(distance, minDistance, closeUpMaxDistance);
                offset = offset.normalized * distance;
            }
            m_camera.transform.position = focus + offset;
            Debug.Log(zoom);
        }
        float m_camHitDistance
        {
            get { return Vector3.Distance(m_pFocus, m_camera.transform.position); }
        }
        public override void OnTranlation(Vector2 vector2)
        {
            if (!m_isAllReady) return;
            if (vector2 == Vector2.zero) return;
            var mousePositionDelta = vector2;
            //mouseLastPosition = Input.mousePosition;
            if (mousePositionDelta.magnitude != 0)
            {
                //var moveDelta = new Vector3(-mousePositionDelta.x * Time.deltaTime * mouseDragSpeed2, -mousePositionDelta.y * Time.deltaTime * mouseDragSpeed2, 0);
                //m_camera.transform.Translate(moveDelta, Space.Self);
                //offset = m_camera.transform.position - focus;

                var m_mouseMoveBegin = m_camera.ScreenToWorldPoint(new Vector3(0, 0, m_camHitDistance));
                var offset_Current2Begin = m_camera.ScreenToWorldPoint(new Vector3(vector2.x, vector2.y, m_camHitDistance)) - m_mouseMoveBegin;
                //相机的移动方向相反
                m_camera.transform.position -= offset_Current2Begin;
                m_pFocus -= offset_Current2Begin;
            }
        }
    }
}