using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace DDD
{
    public class UiManager : Singleton<UiManager>, IManager, IEventHandler<OpenPopupUiEvent>, IEventHandler<ClosePopupUiEvent>
    {
        private readonly Dictionary<Type, BasePopupUi> _popupUIs = new();
        private readonly Stack<BasePopupUi> _popupStack = new();
        private InputActionMaps _previousActionMap = InputActionMaps.None;

        private readonly object _uiPauseRequester = new();

        public void PreInit()
        {
            EventBus.Register<OpenPopupUiEvent>(this);
            EventBus.Register<ClosePopupUiEvent>(this);
        }
        
        public Task Init()
        {
            return Task.CompletedTask;
        }

        public void PostInit()
        {
            
        }

        private void OnDestroy()
        {
            EventBus.Unregister<OpenPopupUiEvent>(this);
            EventBus.Unregister<ClosePopupUiEvent>(this);
        }

        public void RegisterPopupUI(BasePopupUi ui)
        {
            var type = ui.GetType();
            _popupUIs.TryAdd(type, ui);
        }

        public void UnregisterPopupUI(BasePopupUi ui)
        {
            var type = ui.GetType();
            if (_popupUIs.TryGetValue(type, out var registered) && registered == ui)
            {
                _popupUIs.Remove(type);
            }
        }

        public void Invoke(OpenPopupUiEvent evt)
        {
            if (_popupUIs.TryGetValue(evt.UiType, out var popup))
            {
                if (!popup.IsOpen)
                {
                    PushPopup(popup);
                    popup.Open();

                    if (popup.IsBlockingTime)
                    {
                        var timeScaleChangeEvent = GameEvents.RequestTimeScaleChangeEvent;
                        timeScaleChangeEvent.Requester = popup;
                        timeScaleChangeEvent.NewTimeScale = 0f;
                        EventBus.Broadcast(timeScaleChangeEvent);
                    }
                }
            }
        }

        public void Invoke(ClosePopupUiEvent evt)
        {
            if (_popupUIs.TryGetValue(evt.UiType, out var popup))
            {
                if (popup.IsOpen)
                {
                    popup.Close();
                    PopPopup(popup);

                    if (popup.IsBlockingTime)
                    {
                        var timeScaleChangeEvent = GameEvents.RequestTimeScaleChangeEvent;
                        timeScaleChangeEvent.Requester = popup;
                        timeScaleChangeEvent.NewTimeScale = 1f;
                        EventBus.Broadcast(timeScaleChangeEvent);
                    }
                }
            }
        }
        
        public bool IsTopPopup(BasePopupUi popup)
        {
            return _popupStack.Count > 0 && _popupStack.Peek() == popup;
        }
        
        public void PushPopup(BasePopupUi popup)
        {
            if (_popupStack.Contains(popup)) return;
            
            if (_popupStack.Count == 0)
            {
                _previousActionMap = InputManager.Instance.GetCurrentActionMap();
            }

            _popupStack.Push(popup);
        }
        
        public void PopPopup(BasePopupUi popup)
        {
            if (_popupStack.Count == 0) return;

            if (_popupStack.Peek() == popup)
            {
                _popupStack.Pop();
            }
            else
            {
                var temp = _popupStack.Reverse().Where(p => p != popup).Reverse().ToList();
                _popupStack.Clear();
                foreach (var p in temp)
                {
                    _popupStack.Push(p);
                }
            }
            
            if (_popupStack.TryPeek(out var topPopup) && topPopup.IsOpen)
            {
                InputManager.Instance.SwitchCurrentActionMap(topPopup.InputActionMaps);
            }
            else
            {
                InputManager.Instance.SwitchCurrentActionMap(_previousActionMap);
            }
        }
    }
}