using JetBrains.Annotations;
using NEG.UI.Area;
using NEG.UI.Popup;
using NEG.UI.Window;
using NEG.Utils;
using NegUtils.NEG.UI;
using System;
using System.Collections.Generic;
using UnityEngine;

namespace NEG.UI
{
    [PublicAPI]
    public abstract class UiManager : IDisposable
    {
        public static UiManager Instance { get; protected set; }
        
        /// <summary>
        /// Current area shown on screen.
        /// </summary>
        public IArea CurrentArea
        {
            get => currentArea;
            set
            {
                currentArea?.Close();

                currentArea = value;

                currentArea?.Open();
            }
        }
        
        /// <summary>
        /// Current window that is considered main (focused, lastly opened). Can be null.
        /// </summary>
        public IWindow CurrentMainWindow { get; protected set; }

        public PopupData CurrentPopup => currentShownPopup.data;
        
        private IArea currentArea;
        private (PopupData data, int priority) currentShownPopup;
        protected IDefaultPopup currentDefaultPopup;

        private PriorityQueue<PopupData, int> popupsToShow = new();

        //TODO: localize
        private string localizedYes = "Yes", localizedNo = "No", localizedOk = "Ok";

        protected UiManager(IArea startArea)
        {
            if (Instance != null)
            {
                Debug.LogError("Only one instance od UiManager is allowed");
                return;
            }

            Instance = this;

            CurrentArea = startArea;
        }

        /// <summary>
        /// Show popup if there is non other currently shown. Otherwise add current popup to ordered queue and show it later. It will be closed after pressing ok button.
        /// </summary>
        /// <param name="title">popup title</param>
        /// <param name="content">popup content</param>
        /// <param name="okText">text to show on ok button, empty for localized "Ok"</param>
        /// <param name="okPressed">additional action on ok pressed</param>
        /// <param name="priority">priority of popup (lower number -> show first)</param>
        /// <param name="forceShow">force show current popup only if currently shown has lower priority</param>
        /// <returns>data for created popup, can be used to invalidate popup (will not show)</returns>
        public PopupData ShowOkPopup(string title, string content, string okText = null, Action okPressed = null, int priority = 0, bool forceShow = false)
        {
            var data = new DefaultPopupData(currentDefaultPopup, title, content,
                new List<(string, Action)>() { (okText ?? localizedOk, okPressed) });
            ShowPopup(data, priority, forceShow);
            return data;
        }
        
        /// <summary>
        /// Show popup if there is non other currently shown. Otherwise add current popup to ordered queue and show it later. It will be closed after pressing yes or no button.
        /// </summary>
        /// <param name="title">popup title</param>
        /// <param name="content">popup content</param>
        /// <param name="yesText">text to show on yes button, empty for localized "Yes"</param>
        /// <param name="noText">text to show on no button, empty for localized "No"</param>
        /// <param name="yesPressed">additional action on yes pressed</param>
        /// <param name="noPressed">additional action on no pressed</param>
        /// <param name="priority">priority of popup (lower number -> show first)</param>
        /// <param name="forceShow">force show current popup only if currently shown has lower priority</param>
        /// <returns>data for created popup, can be used to invalidate popup (will not show)</returns>
        public PopupData ShowYesNoPopup(string title, string content, string yesText = null, string noText = null, Action yesPressed = null, Action noPressed = null, int priority = 0, bool forceShow = false)
        {
            var data = new DefaultPopupData(currentDefaultPopup, title, content,
                new List<(string, Action)>() { (yesText ?? localizedYes, yesPressed), (noText ?? localizedNo, noPressed) });
            ShowPopup(data, priority, forceShow);
            return data;
        }
        
        /// <summary>
        /// Show popup if there is non other currently shown. Otherwise add current popup to ordered queue and show it later. It will be closed after pressing any button.
        /// </summary>
        /// <param name="title">popup title</param>
        /// <param name="content">popup content</param>
        /// <param name="actions">list of actions</param>
        /// <param name="priority">priority of popup (lower number -> show first)</param>
        /// <param name="forceShow">force show current popup only if currently shown has lower priority</param>
        /// <returns>data for created popup, can be used to invalidate popup (will not show)</returns>
        public PopupData ShowPopup(string title, string content, List<(string, Action)> actions, int priority = 0, bool forceShow = false)
        {
            var data = new DefaultPopupData(currentDefaultPopup, title, content, actions);
            ShowPopup(data, priority, forceShow);
            return data;
        }
        
        /// <summary>
        /// Show popup if there is non other currently shown. Otherwise add current popup to ordered queue and show it later.
        /// </summary>
        /// <param name="data">popup data object</param>
        /// <param name="priority">priority of popup (lower number -> show first)</param>
        /// <param name="forceShow">force show current popup only if currently shown has lower priority</param>
        public void ShowPopup(PopupData data, int priority = 0, bool forceShow = false)
        {
            popupsToShow.Enqueue(data, priority);
            UpdatePopupsState(forceShow, priority, data);
        }

        public void UseBack()
        {
            IControllable.BackUsed backUsed = new();

            CurrentMainWindow?.TryUseBack(ref backUsed);
            if(backUsed.Used)
                return;
            CurrentArea.TryUseBack(ref backUsed);
        }
        

        public void RefreshPopups()
        {
            if(currentShownPopup.data is { IsValid: true })
                return;
            UpdatePopupsState(false);
        }

        public virtual void Dispose() => Instance = null;

        public void SetMainWindow(IWindow window) => CurrentMainWindow = window;

        public void OnWindowClosed(IWindow window)
        {
            if(CurrentMainWindow != window)
                return;
            
            //TODO: select new main window
        }

        protected void PopupClosed(PopupData data)
        {
            if (currentShownPopup.data != data)
            {
                //Debug.LogError("Popup was not shown");
                return;
            }
            UpdatePopupsState(false);
        }

        protected void SetDefaultPopup(IDefaultPopup popup) => currentDefaultPopup = popup;


        private void UpdatePopupsState(bool forceShow, int priority = 0, PopupData data = null)
        {
            if (forceShow)
            {
                if(currentShownPopup.data != null && currentShownPopup.priority >= priority)
                    return;
                
                popupsToShow.Enqueue(currentShownPopup.data, currentShownPopup.priority);
                ShowPopup(data, priority);
                return;
            }

            while (popupsToShow.TryDequeue(out var d, out int p))
            {
                if(d == null)
                    continue;
                if(!d.IsValid)
                    continue;
                if(d == currentShownPopup.data)
                    continue;
                ShowPopup(d, p);
                return;
            }

            if (currentShownPopup.data == null) 
                return;
            currentShownPopup.data.PopupClosedEvent -= PopupClosed;
            currentShownPopup.data.Hide();
            currentShownPopup.data = null;
        }

        private void ShowPopup(PopupData data, int priority)
        {
            if (currentShownPopup.data != null)
            {
                currentShownPopup.data.PopupClosedEvent -= PopupClosed;
                currentShownPopup.data.Hide();
            }
            currentShownPopup = (data, priority);
            data.Show();
            data.PopupClosedEvent += PopupClosed;
        }
    }
}