using System.Collections;
using TMPro;
using UnityEngine;

[RequireComponent(typeof(TMP_Text))]
public class MarqueeText : MonoBehaviour
{
    public float speed      = 35f;
    public float pauseStart = 1.5f;
    public float pauseEnd   = 0.6f;

    private TMP_Text      _label;
    private RectTransform _rect;

    private void Awake()
    {
        _label = GetComponent<TMP_Text>();
        _rect  = GetComponent<RectTransform>();
    }

    private IEnumerator Start()
    {
        yield return null; // layout 완료 후 실행

        _label.ForceMeshUpdate();
        float textW      = _label.preferredWidth;
        float containerW = ((RectTransform)transform.parent).rect.width;
        float dist       = textW - containerW;

        if (dist > 1f)
            StartCoroutine(ScrollLoop(dist));
    }

    private IEnumerator ScrollLoop(float dist)
    {
        while (true)
        {
            SetX(0f);
            yield return new WaitForSeconds(pauseStart);

            float x = 0f;
            while (x > -dist)
            {
                x = Mathf.MoveTowards(x, -dist, speed * Time.deltaTime);
                SetX(x);
                yield return null;
            }

            yield return new WaitForSeconds(pauseEnd);
        }
    }

    private void SetX(float x) =>
        _rect.anchoredPosition = new Vector2(x, _rect.anchoredPosition.y);
}