card

using System.Collections;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace Assets.Scripts.Cards {
    [RequireComponent(typeof(RectTransform), typeof(Image))]
    public class Card : MonoBehaviour,
        IPointerEnterHandler, IPointerExitHandler, IPointerDownHandler,
        IBeginDragHandler, IDragHandler, IEndDragHandler {
        public CardData data;
        private Vector3 offset;
        private Vector3 originalPosition;
        public bool played;
        public bool shouldMoveBack;

        public void OnBeginDrag(PointerEventData eventData) {
        }

        public void OnDrag(PointerEventData eventData) {
            if (played) return;
            var newPos = Input.mousePosition + offset;
            newPos.z = 1.0f;
            transform.position = newPos;
        }

        public void OnEndDrag(PointerEventData eventData) {
            Deck.stoppedDragging = true;
            StartCoroutine(DisableStopppedDragging());
            StartCoroutine(MoveBack());
        }

        public void OnPointerEnter(PointerEventData eventData) {
            if (transform.position != originalPosition) return;
            transform.localScale = new Vector3(1.1f, 1.1f, 1.1f);
        }

        public void OnPointerExit(PointerEventData eventData) {
            if (transform.position != originalPosition) return;
            transform.localScale = new Vector3(1.0f, 1.0f, 1.0f);
        }

        public void OnPointerDown(PointerEventData eventData) {
            // sets the appropriate offset of mouse and position 
            // so the object doesn't jump when it's first moved
            if (played) return;
            offset = transform.position - Input.mousePosition;
            Deck.currentlySelected = this;
        }

        private void Awake() {
            shouldMoveBack = true;
        }

        private void Start() {
            originalPosition = transform.position;
        }

        // Update is called once per frame
        private void Update() {
        }

        private static IEnumerator DisableStopppedDragging() {
            yield return null;
            Deck.stoppedDragging = false;
        }

        private IEnumerator MoveBack() {
            // moves a card back to it's originally position 
            // so long it's supposed to (which it's not when placed in a row)
            yield return new WaitForEndOfFrame();
            if (!shouldMoveBack) yield break;
            while (transform.position != originalPosition)
                transform.position = Vector3.MoveTowards(transform.position, originalPosition,
                    5000.0f);
            transform.localScale = new Vector3(1.0f, 1.0f, 1.0f);
        }
    }
}