using NEG.UI.Area;
using NEG.UI.Popup;
using NEG.UI.UnityUi.Buttons.Reaction;
using NEG.UI.UnityUi.Buttons.Settings;
using NEG.UI.UnityUi.Popup;
using NEG.UI.UnityUi.Window;
using NEG.Utils;
using System;
using UnityEngine;
using UnityEngine.Assertions;
using UnityEngine.EventSystems;
using UnityEngine.SceneManagement;
using Object = UnityEngine.Object;

namespace NEG.UI.UnityUi
{
    /// <summary>
    ///     Implements ui using UnityUI and Unity Event System with New Input System.
    ///     <para>You have to provide prefabs within resources:</para>
    ///     <para> - UI/PopupCanvas - prefab with canvas to create popups (will be created on every scene)</para>
    ///     <para>
    ///         - UI/DefaultPopupPrefab - prefab of default popup with 2 options (has to have
    ///         <see cref="MonoDefaultPopup" /> component)
    ///     </para>
    ///     NEG_UI_DISABLE_WARNING_DEFAULT_SELECTION
    /// </summary>
    public class MonoUiManager : UiManager, IDisposable
    {
        private readonly GameObject canvasPrefab;

        //TODO: editor to auto add slots, buttons 

        private readonly MonoDefaultPopup defaultPopupPrefab;

        private readonly UiInputModule inputModule;

        public MonoUiManager(IArea startArea, Type inputModuleType, ButtonSettings defaultUiSettings) : base(startArea)
        {
            Instance = this;

            var popupCanvas = Resources.Load<GameObject>("UI/PopupCanvas");
            var defaultPopup = Resources.Load<GameObject>("UI/DefaultPopupPrefab");

            Assert.IsNotNull(popupCanvas,
                "No canvas prefab was provided. Please check MonoUiManager class documentation");
            Assert.IsNotNull(defaultPopup,
                "No popup prefab was provided. Please check MonoUiManager class documentation");
            Assert.IsNotNull(popupCanvas.GetComponent<Canvas>());
            Assert.IsNotNull(defaultPopup.GetComponent<MonoDefaultPopup>());

            canvasPrefab = popupCanvas;
            defaultPopupPrefab = defaultPopup.GetComponent<MonoDefaultPopup>();

            SpawnDefaultPopup();

            SceneManager.activeSceneChanged += (_, _) => SpawnDefaultPopup();

            BehavioursFactory = new KeyBasedFactory<string, ButtonElementBehaviour>();
            BehavioursFactory.FireRegistration();

            inputModule = (UiInputModule)Activator.CreateInstance(inputModuleType);
            DefaultUiSettings = defaultUiSettings;
        }

        //TODO: use default unity selection
        //TODO: window snaping to slots
        public static new MonoUiManager Instance { get; private set; }

        public ButtonSettings DefaultUiSettings { get; }
        public KeyBasedFactory<string, ButtonElementBehaviour> BehavioursFactory { get; }

        public override void Dispose()
        {
            base.Dispose();
            Instance = null;
        }

        protected override void UpdatePopupsState(bool forceShow, int priority = 0, PopupData data = null)
        {
            base.UpdatePopupsState(forceShow, priority, data);
            if (inputModule.CurrentSelectionSource != SelectionSource.Direction)
                return;

            if (CurrentPopup == null && (EventSystem.current.currentSelectedGameObject == null ||
                                         !EventSystem.current.currentSelectedGameObject.activeInHierarchy))
            {
                if (((MonoWindow)CurrentMainWindow).DefaultSelectedItem == null)
                    return;
                EventSystem.current.SetSelectedGameObject(((MonoWindow)CurrentMainWindow).DefaultSelectedItem);
            }
        }

        private void SpawnDefaultPopup()
        {
            var canvas = Object.Instantiate(canvasPrefab);
            canvas.name = "DefaultPopupCanvas";
            SetDefaultPopup(Object.Instantiate(defaultPopupPrefab, canvas.transform));
            currentDefaultPopup.Close(true);
        }
    }
}