using System;
using UniRx;
using UniRx.Triggers;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class UIButton : Button
{
    [SerializeField]private float _holdThresh = 0.5f;
    private ButtonClickedEvent m_OnDown = new ButtonClickedEvent();
    private ButtonClickedEvent m_OnUp = new ButtonClickedEvent();
    private ButtonClickedEvent m_OnLongPress = new ButtonClickedEvent();
    private ButtonClickedEvent m_OnShortClick = new ButtonClickedEvent();
    private IDisposable clickStream, longPressStream;
    private DateTimeOffset _lastDownTime, _lastUpTime;
    //private CompositeDisposable _pressTimer;
    //private float ci;
    PointerEventData pointerEventData;
    protected override void Start()
    {
        var pointerDownStream = this.OnPointerDownAsObservable().Timestamp();
        var pointerUpStream = this.OnPointerUpAsObservable().Timestamp();
        //Logic of long press: delayed.Timestamp - delayThreshold - lastButtonUpTime > 0
        longPressStream = pointerDownStream
            .SelectMany(_ => Observable.Timer(TimeSpan.FromSeconds(_holdThresh)))
            .Timestamp()
            .Where(_ => (_.Timestamp - _lastUpTime ).TotalSeconds > _holdThresh)
            .Subscribe(_ => m_OnLongPress.Invoke())
            .AddTo(this);
        clickStream = pointerUpStream
            .CombineLatest(pointerDownStream, (eUp, eDown) => eUp.Timestamp - eDown.Timestamp)
            .Where(interval => interval.TotalSeconds > 0 && interval.TotalSeconds <= _holdThresh)
            .Subscribe(_ => m_OnShortClick.Invoke())
            .AddTo(this);
    }
    public ButtonClickedEvent onDown
    {
        get { return m_OnDown; }
        set { m_OnDown = value; }
    }

    public ButtonClickedEvent onUp
    {
        get { return m_OnUp; }
        set { m_OnUp = value; }
    }

    public ButtonClickedEvent onLongPress
    {
        get { return m_OnLongPress; }
        set { m_OnLongPress = value; }
    }

    public new ButtonClickedEvent onClick
    {
        get { return m_OnShortClick; }
        set { m_OnShortClick = value; }
    }

    public override void OnPointerDown(PointerEventData eventData)
    {
        base.OnPointerDown(eventData);
        m_OnDown.Invoke();
        pointerEventData = eventData;
        _lastDownTime = DateTimeOffset.Now;
    }
    public override void OnPointerUp(PointerEventData eventData)
    {
        base.OnPointerUp(eventData);
        m_OnUp.Invoke();
        _lastUpTime = DateTimeOffset.Now;
    }
    public void Up()
    {
        OnPointerUp(pointerEventData);
    }
    public bool IsDowning => IsPressed();
}