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

public class ItemGrabber : MonoBehaviour {
    public Transform CameraTransform;
    public Transform HandTransform;
    public CanvasGroup GrabHint;
    public LayerMask ItemLayer;
    public float Distance;
    public float ThrowVelocity;

    [Header("Runtime values")]
    public Item GrabbedItem;

    private void Awake() {
        if (GrabHint == null) {
            Debug.LogWarning("Player's GrabHint is not set, and pick ups will not be indicated.");
        }
    }

    private void Update() {
        Item Item = null;
        RaycastHit Hit;
        Vector3 From = CameraTransform.position;
        Vector3 Direction = CameraTransform.forward;
        if (GrabbedItem == null) {
            if (Physics.Raycast(From, Direction, out Hit, Distance, ItemLayer) &&
                    Hit.collider.attachedRigidbody != null) {
                Item = Hit.collider.attachedRigidbody.GetComponent<Item>();
            }

            if (Item != null && Input.GetButtonDown("Grab")) {
                Item.PickUp(HandTransform);
                GrabbedItem = Item;
            }
        } else if (Input.GetButtonDown("Grab")) {
            Vector3 Forward = CameraTransform.forward;
            if (Physics.Raycast(From, Direction, out Hit, 10f)) {
                // Throw direction should be where we're pointign, but slightly upwards
                Forward = (Hit.point - From).normalized + Vector3.up;
            }
            GrabbedItem.Drop(Forward * ThrowVelocity);
            GrabbedItem = null;
        }

        if (GrabHint != null) {
            GrabHint.alpha = Mathf.Lerp(GrabHint.alpha, Item != null ? 1 : 0, 10f * Time.deltaTime);
        }
    }
}