using Games.Events;
using UnityEngine;
using UnityEngine.UI;

public class SceneSwitchScreen : MonoBehaviour
{
    public static SceneSwitchScreen instance { get; private set; }
    public float enterTime = 0.5f;
    public float keepTime = 0.5f;
    public float exitTime = 0.5f;
    private float _startTime = -1f;
    private bool _sendEvent;

    private RectTransform _root;
    private Graphic _fillRect;
    private RawImage _rawImage;

    private float _ratio = 2f;

    private void Awake()
    {
        instance = this;
        _root = (RectTransform) transform;
        _fillRect = transform.Find("FillImage").GetComponent<Graphic>();
        _rawImage = _fillRect.rectTransform.Find("RawImage").GetComponent<RawImage>();
        EndAnimation();
    }

    private void Update()
    {
        if (_startTime > 0f)
        {
            var delta = Time.realtimeSinceStartup - _startTime;
            if (delta > enterTime + keepTime + exitTime)
                EndAnimation();
            else if (delta > enterTime + keepTime)
                SetRatio(1f + (delta - enterTime - keepTime) / exitTime);
            else if (delta > enterTime)
                SetRatio(1f);
            else
                SetRatio(delta / enterTime);
            if (_sendEvent && delta > enterTime)
            {
                _sendEvent = false;
                EventDispatcher.Instance.Dispatch(Games.Events.EventId.CameraSpaceBlurMax);
            }
        }
        else
            EndAnimation();
    }

    public float StartAnimation()
    {
        var rect = _root.rect;
        enabled = true;
        _fillRect.gameObject.SetActive(true);
        _fillRect.rectTransform.sizeDelta = new Vector2(rect.width, rect.height);
        var height = (float)_rawImage.texture.height / _rawImage.texture.width * _fillRect.rectTransform.sizeDelta.x;
        _rawImage.rectTransform.sizeDelta = new Vector2(_fillRect.rectTransform.sizeDelta.x, height);
        _startTime = Time.realtimeSinceStartup;
        _sendEvent = true;
        SetRatio(0f);
        return enterTime + keepTime + exitTime;
    }

    public void EndAnimation()
    {
        enabled = false;
        _startTime = -1f;
        _sendEvent = false;
        _fillRect.gameObject.SetActive(false);
    }

    public void SetRatio(float ratio)
    {
        if (_ratio != ratio)
        {
            _ratio = ratio;
            var distance = (1f - Mathf.Max(1f, _ratio)) * _fillRect.rectTransform.sizeDelta.x;
            var alpha = Mathf.Min(1f, _ratio);
            _fillRect.rectTransform.anchoredPosition = new Vector2(distance, 0f);
            _fillRect.color = new Color(0f, 0f, 0f, alpha);
            _rawImage.color = new Color(1f, 1f, 1f, alpha);
        }
    }

    private void OnDestroy()
    {
        if (instance == this)
            instance = null;
    }
}