using System;
using System.Collections;
using UnityEngine;

public class WorldSwitcher : MonoBehaviour
{
    private const float _SCALE_DURATION = 0.5f;
    private const float _SCALE_FACTOR = 100.0f;

    [SerializeField]
    private GameObject _spriteMask;
    [SerializeField]
    private GameObject _world1;
    [SerializeField]
    private GameObject _world2;

    private int _currentWorldIndex = 0;

    public IEnumerator ScaleOverTime(Transform target, Vector3 from, Vector3 to, float duration, Action onComplete)
    {
        var elapsed = 0f;
        target.localScale = from;
        while (elapsed < duration)
        {
            elapsed += Time.deltaTime;
            var t = Mathf.Clamp01(elapsed / duration);
            target.localScale = Vector3.Lerp(from, to, t);
            yield return null;
        }
        target.localScale = to;
        onComplete?.Invoke();
    }

    private void Start()
    {
        _spriteMask.transform.localScale = Vector3.zero;
        SwitchWorld(0);
    }

    private void SwitchWorld(int newIndex)
    {
        var currentScale = _spriteMask.transform.localScale;
        var from = _currentWorldIndex == 0 ? currentScale : new Vector3(_SCALE_FACTOR, _SCALE_FACTOR, 1);
        var to = newIndex == 0 ? Vector3.zero : new Vector3(_SCALE_FACTOR, _SCALE_FACTOR, 1);
        StartCoroutine(ScaleOverTime(_spriteMask.transform, from, to, _SCALE_DURATION, () =>
        {
            _currentWorldIndex = newIndex;
            _spriteMask.transform.localScale = to;
            _world1.SetActive(_currentWorldIndex == 0);
            _world2.SetActive(_currentWorldIndex == 1);
        }));
    }

    public void SwitchNext()
    {
        var newIndex = _currentWorldIndex == 0 ? 1 : 0;
        SwitchWorld(newIndex);
    }
}