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

public class GrappleHook : MonoBehaviour
{

    [SerializeField]
    private float maxGrappleDist = 200;
    [SerializeField]
    private float grappleExtendSpeed = 20;
    [SerializeField]
    private LayerMask grappleableLayer;
    [SerializeField]
    private Transform gunPos;
    private Vector3 hitPosLocal;
    private SpringJoint joint;
    private LineRenderer lr;
    RaycastHit hit;
    private bool grappled = false;
    private Vector3 currGrappleEndPos;
    [SerializeField]
    private RectTransform canvasRect;
    [SerializeField]
    private RectTransform hitMarkerRect;
    // Start is called before the first frame update
    void Start()
    {
        lr = gameObject.GetComponentInChildren<LineRenderer>();
        lr.enabled = false;
        hitMarkerRect.gameObject.SetActive(false);
    }

    // Update is called once per frame
    void Update()
    {
        
        if(Input.GetMouseButtonUp(0)){//TODO Change to correct input system
            EndGrapple();
        }
        if(grappled){
            DrawRope(Time.deltaTime);
            if(Input.GetMouseButtonDown(1)){
                joint.minDistance = 0f;
                joint.maxDistance = 0f;
            }
            return; 
        }
        Aim();

        // TODO extend and retract rope
    }

    private void Aim(){
        Vector3 mousePos;
        mousePos = Input.mousePosition;
        mousePos.z = Mathf.Abs(Camera.main.transform.position.z);
        mousePos = Camera.main.ScreenToWorldPoint(mousePos);
        Vector3 aimDir = (mousePos - gameObject.transform.position).normalized;
        
        if(!hitMarkerRect.gameObject.activeSelf)hitMarkerRect.gameObject.SetActive(true);
        hitMarkerRect.anchoredPosition = WorldToUI(gameObject.transform.position + aimDir * maxGrappleDist);

        if(Physics.Raycast(gameObject.transform.position, aimDir, out hit, maxGrappleDist, grappleableLayer)){
            hitMarkerRect.anchoredPosition = WorldToUI(hit.point);
            hitMarkerRect.gameObject.GetComponent<Image>().color = Color.green;
            if(Input.GetMouseButtonDown(0)){
                StartGrapple(hit);
            }
        }else{
            hitMarkerRect.gameObject.GetComponent<Image>().color = Color.red;
        }
    }

    private void DrawRope(float deltaTime){
        // TODO animate a wiggle on the rope
        if(!grappled)return;
        lr.SetPosition(0, gunPos.position);
        Vector3 endPoint;
        if(hit.rigidbody != null){
            endPoint = hit.transform.TransformPoint(hitPosLocal);
            
        }else{
            endPoint = hit.point;
        }
        currGrappleEndPos = Vector3.Lerp(currGrappleEndPos, endPoint, deltaTime * grappleExtendSpeed);
        lr.SetPosition(1, currGrappleEndPos);
        if(!lr.enabled)lr.enabled = true;
        
    }
    private void StartGrapple(RaycastHit hit){
        grappled = true;

        //Display 
        hitMarkerRect.gameObject.SetActive(false);

        // Rope phys
        joint = gameObject.AddComponent<SpringJoint>();
        joint.anchor = transform.InverseTransformPoint(gunPos.position);
        joint.autoConfigureConnectedAnchor = false;
        joint.maxDistance = hit.distance * 0.8f;
        joint.minDistance = hit.distance * 0.25f;
        if(hit.rigidbody != null){
            Rigidbody hitRb = hit.rigidbody;
            joint.connectedBody = hitRb;
            joint.connectedAnchor = hit.transform.InverseTransformPoint(hit.point);
            hitPosLocal = hit.transform.InverseTransformPoint(hit.point);
        }else{
            joint.connectedAnchor = hit.point;
        }
        joint.spring = 4.5f * 5f;
        joint.damper = 7f;
        joint.massScale = 4.5f;

        currGrappleEndPos = transform.position;
    }

    private void EndGrapple(){
        grappled = false;
        lr.enabled = false;
        
        Destroy(joint);
    }

    private Vector2 WorldToUI(Vector3 point){
        Vector2 viewPortPos = Camera.main.WorldToViewportPoint(point);
        Vector2 pointScreenPos = new Vector2(((viewPortPos.x*canvasRect.sizeDelta.x)-(canvasRect.sizeDelta.x*0.5f)), ((viewPortPos.y*canvasRect.sizeDelta.y)-(canvasRect.sizeDelta.y*0.5f)));
        return pointScreenPos;
    }

}