using MeshSplitting.Splitters;
using System;
using UnityEngine;

namespace MeshSplitting.Examples
{
    [AddComponentMenu("Mesh Splitting/Examples/Camera Line Splitter")]
    [RequireComponent(typeof(Camera))]
    [RequireComponent(typeof(LineRenderer))]
    public class CameraLineSplitter : MonoBehaviour
    {
#if UNITY_EDITOR
        [NonSerialized]
        public bool ShowDebug = false;
#endif

        public float CutPlaneDistance = 1f;
        public float CutPlaneSize = 2f;

        private LineRenderer _lineRenderer;
        private Camera _camera;
        private Transform _transform;

        private bool _inCutMode = false;
        private bool _hasStartPos = false;
        private Vector3 _startPos;
        private Vector3 _endPos;

        private void Awake()
        {
            _transform = transform;
            _lineRenderer = GetComponent<LineRenderer>();
            _camera = GetComponent<Camera>();

            _lineRenderer.enabled = false;
        }

        private void Update()
        {
            if (Input.GetMouseButtonDown(0))
            {
                _startPos = GetMousePosInWorld();
                _hasStartPos = true;
            }
            else if (_hasStartPos && Input.GetMouseButtonUp(0))
            {
                _endPos = GetMousePosInWorld();
                if (_startPos != _endPos)
                    CreateCutPlane();

                _hasStartPos = false;
                _lineRenderer.enabled = false;
            }

            if (_hasStartPos)
            {
                _lineRenderer.enabled = true;
                _startPos = new Vector3(_startPos.x, _startPos.y, transform.position.z + CutPlaneDistance);
                _lineRenderer.SetPosition(0, _startPos);
                _lineRenderer.SetPosition(1, GetMousePosInWorld());
            }
        }

        private Vector3 GetMousePosInWorld()
        {
            Ray ray = _camera.ScreenPointToRay(Input.mousePosition);
            return ray.origin + ray.direction * CutPlaneDistance;
        }

        private void CreateCutPlane()
        {
            Vector3 center = Vector3.Lerp(_startPos, _endPos, .5f);
            Vector3 cut = (_endPos - _startPos).normalized;
            Vector3 fwd = (center - _transform.position).normalized;
            Vector3 normal = Vector3.Cross(fwd, cut).normalized;

            GameObject goCutPlane = new GameObject("CutPlane", typeof(BoxCollider), typeof(Rigidbody), typeof(SplitterSingleCut));

            goCutPlane.GetComponent<Collider>().isTrigger = true;
            Rigidbody bodyCutPlane = goCutPlane.GetComponent<Rigidbody>();
            bodyCutPlane.useGravity = false;
            bodyCutPlane.isKinematic = true;

            Transform transformCutPlane = goCutPlane.transform;
            transformCutPlane.position = _camera.transform.position;
            transformCutPlane.localScale = new Vector3(Vector3.Distance(_startPos, _endPos), .01f, CutPlaneSize);
            transformCutPlane.up = normal;
            float angleFwd = Vector3.Angle(transformCutPlane.forward, fwd);
            //transformCutPlane.position -= Vector3.up * (Camera.main.ScreenToWorldPoint(center).y - transform.position.y);
            transformCutPlane.LookAt(center, normal);
            //transformCutPlane.up = normal;
            //transformCutPlane.RotateAround(center, normal, normal.y < 0f ? -angleFwd : angleFwd);
        }
    }
}