using System.Collections;
using TMPro;
using UnityEngine;

[RequireComponent(typeof(TMP_Text))]
public class MarqueeText : MonoBehaviour
{
    public float speed      = 14f;
    public float pauseStart = 1.8f;
    public float pauseEnd   = 0.9f;

    private TMP_Text      _label;
    private RectTransform _rect;
    private Coroutine     _scrollRoutine;

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

    private IEnumerator Start()
    {
        yield return null;
        Refresh();
    }

    private void OnDisable()
    {
        StopScrolling();
    }

    public void Refresh()
    {
        if (!isActiveAndEnabled || _label == null || _rect == null || transform.parent == null)
            return;

        StopScrolling();
        SetX(0f);

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

        if (dist > 1f)
            _scrollRoutine = 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);

    private void StopScrolling()
    {
        if (_scrollRoutine == null)
            return;

        StopCoroutine(_scrollRoutine);
        _scrollRoutine = null;
    }
}