using System;
using PrimeTween;
using UnityEngine.UIElements;

namespace DanieleMarotta.RiversongCodeShowcase
{
    public class UIVisibilityAnimation
    {
        private VisualElement _element;

        private Action<bool> _onCompleted;

        private Sequence _visibilityAnimation;

        public UIVisibilityAnimation(VisualElement element, Action<bool> onCompleted)
        {
            _element = element;
            _onCompleted = onCompleted;

            IsOpen = element.resolvedStyle.display != DisplayStyle.None;
            TargetIsOpen = IsOpen;

            ApplyCommittedState(IsOpen);
        }

        public bool IsOpen { get; private set; }

        public bool TargetIsOpen { get; private set; }

        public bool IsAnimating => _visibilityAnimation.isAlive;

        public void Show(bool show, bool animate = false)
        {
            TargetIsOpen = show;

            if (IsAnimating) return;
            if (IsOpen == TargetIsOpen) return;

            if (!animate)
            {
                ApplyCommittedState(TargetIsOpen);
                IsOpen = TargetIsOpen;
                _onCompleted?.Invoke(IsOpen);
                return;
            }

            TryAdvance();
        }

        private void TryAdvance()
        {
            if (IsAnimating) return;
            if (IsOpen == TargetIsOpen) return;

            if (TargetIsOpen)
                PlayOpenAnimation();
            else
                PlayCloseAnimation();
        }

        private void PlayOpenAnimation()
        {
            _element.style.display = DisplayStyle.Flex;
            _visibilityAnimation = PlayShowTween(_element).OnComplete(() => CompleteTransition(true));
        }

        private void PlayCloseAnimation()
        {
            _element.style.display = DisplayStyle.Flex;
            _visibilityAnimation = PlayHideTween(_element).OnComplete(() => CompleteTransition(false));
        }

        private void CompleteTransition(bool isOpen)
        {
            _visibilityAnimation = default;
            ApplyCommittedState(isOpen);
            IsOpen = isOpen;
            _onCompleted?.Invoke(IsOpen);
            TryAdvance();
        }

        private void ApplyCommittedState(bool isOpen)
        {
            _element.style.display = isOpen ? DisplayStyle.Flex : DisplayStyle.None;
            _element.style.opacity = isOpen ? 1 : 0;
            if (isOpen)
                _element.style.scale = StyleKeyword.Null;
            else
                _element.SetScale(0.8f);
        }

        public static Sequence PlayShowTween(VisualElement element, float duration = 0.3f)
        {
            element.style.opacity = 0;
            element.SetScale(0.8f);

            return Sequence.Create(useUnscaledTime: true)
                .Group(Tween.Custom(0.8f, 1, duration, element.SetScale, Ease.OutQuad))
                .Group(Tween.Custom(0, 1, duration, value => element.style.opacity = value, Ease.OutQuad));
        }

        public static Sequence PlayHideTween(VisualElement element, float duration = 0.2f)
        {
            element.style.opacity = 1;
            element.SetScale(1);

            return Sequence.Create(useUnscaledTime: true)
                .Group(Tween.Custom(1, 0.8f, duration, value => element.SetScale(value), Ease.OutQuad))
                .Group(Tween.Custom(1, 0, duration, value => element.style.opacity = value, Ease.OutQuad));
        }
    }
}