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

public class ItemGrabber : MonoBehaviour {
    public Transform CameraTransform;
    public Transform HandTransform;
    public CanvasGroup GrabHint;
    public Text GrabText;
    public LayerMask ItemLayer;
    public LayerMask DroppingRaycastMask;
    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.");
        }
        if (GrabText == null) {
            Debug.LogWarning("Player's GrabText is not set, and pick up texts will not necessarily match the object.");
        }
    }

    private void Update() {
        Item Item = null;
        RaycastHit Hit;
        Vector3 From = CameraTransform.position;
        Vector3 Direction = CameraTransform.forward;
        if (GrabbedItem == null) {
            Debug.DrawLine(From, From + Direction * Distance, Color.red);
            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 DropPosition;
            if (Physics.Raycast(From, Direction, out Hit, Distance * 2f, DroppingRaycastMask)) {
                DropPosition = Hit.point + Hit.normal * 0.1f;
            } else {
                DropPosition = From + Direction * Distance;
            }
            GrabbedItem.Drop(DropPosition);
            GrabbedItem = null;
        }

        if (GrabHint != null) {
            GrabHint.alpha = Mathf.Lerp(GrabHint.alpha, Item != null ? 1 : 0, 10f * Time.deltaTime);
        }
        if (Item != null && GrabText != null) {
            GrabText.text = $"Take {Item.name}";
        }
    }
}