using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.UI;

public class WindowsController : MonoBehaviour
{
    [SerializeField] private Canvas _canvas = null;
    [SerializeField] private GameObject _windowContainer = null;

    [Space]
    [Header("Background:")]
    [SerializeField] private RectTransform _background = null;
    [SerializeField] private BackgroundController _backgroundController = null;
    [SerializeField] private ClickHandlerMediator _backgroundClicker = null;

    public IReadOnlyList<Window> GetVisibleStack() => _visibleWindows;

    private List<Window> _visibleWindows = new List<Window>();
    private readonly Dictionary<Type, Window> _windows = new Dictionary<Type, Window>();
    private readonly List<Window> _hidingWindows = new List<Window>();
    private readonly LinkedList<Action> _windowQueue = new LinkedList<Action>();
    private readonly List<Window> _availableWindows = new List<Window>();

    public Canvas Canvas => _canvas;

    public void Init()
    {
        GetAvailableWindows();
        SetCanvasSettings();

        _backgroundClicker.OnClick += TryCloseActiveWindow;
        _backgroundController.Init();
    }

    private void GetAvailableWindows()
    {
        Window[] windows = Assets.LoadAll<Window>("UI/Windows");
        _availableWindows.AddRange(windows);
    }

    private void SetCanvasSettings()
    {
        _canvas.planeDistance = 1f;
        _canvas.sortingOrder = 10;
    }

    private void TryCloseActiveWindow()
    {
        var window = GetTopmostWindow();

        if (window == null)
            return;

        if (window.CanBeClosedByBackground && window.NeedShowBackground)
            window.Close();
    }

    public T ShowWindow<T>() where T : ParameterlessWindow
    {
        var wnd = GetOrCreateWindow<T>();
        wnd.Show();
        return wnd;
    }

    public T ShowWindow<T, A1>(A1 a1) where T : ParameterWindow<A1>
    {
        var wnd = GetOrCreateWindow<T>();
        wnd.Show(a1);

        return wnd;
    }

    public T ShowWindow<T, A1, A2>(A1 a1, A2 a2) where T : ParameterWindow<A1, A2>
    {
        var wnd = GetOrCreateWindow<T>();
        wnd.Show(a1, a2);
        return wnd;
    }

    public bool IsWindowVisible<T>() where T : Window
    {
        return _visibleWindows.Find(x => x.GetType() == typeof(T)) != null;
    }

    public bool HasAnyVisible()
    {
        return _visibleWindows.Count > 0;
    }

    private void SortWindows()
    {
        if (IsUnsorted(_visibleWindows))
        {
            _visibleWindows = _visibleWindows.OrderByDescending(w => w.ZOrder).ToList();
        }

        for (var i = 0; i < _visibleWindows.Count; i++)
        {
            _visibleWindows[i].transform.SetSiblingIndex(i + 1);
        }
    }

    private static bool IsUnsorted(IList<Window> windows_list)
    {
        var prev_z = int.MinValue;
        for (var index = 0; index < windows_list.Count; index++)
        {
            var current_z = windows_list[index].ZOrder;
            if (current_z > prev_z)
                return true;
            prev_z = current_z;
        }

        return false;
    }

    private void OnWindowShow(Window wnd)
    {
        if (!_visibleWindows.Contains(wnd))
            _visibleWindows.Add(wnd);

        SortWindows();
        Log.Debug($"window show ID={wnd}, sibling_index={wnd.transform.GetSiblingIndex()}");
        UpdateBackground(GetTopmostWindow());
    }

    private void OnWindowHide(Window wnd)
    {
        _visibleWindows.Remove(wnd);
        _hidingWindows.Add(wnd);

        wnd.OnShow += window => _hidingWindows.Remove(wnd); //для тех случаев, когда это же окно будет вновь открыто
        wnd.OnAfterClose += window => _hidingWindows.Remove(wnd);

        Log.Debug($"window hide ID={wnd}, window_stack= {ReportWindowStack()}");

        UpdateBackground(GetTopmostWindow());
    }

    private void OnWindowClose(Window wnd)
    {
        _windows.Remove(wnd.GetType());
        _visibleWindows.Remove(wnd);
    }

    private string ReportWindowStack()
    {
        var stack_report = "";
        foreach (var wnd in _visibleWindows)
        {
            if (stack_report != "")
                stack_report += ", ";
            stack_report += wnd;
        }

        return stack_report == "" ? "EMPTY" : stack_report;
    }

    private Window GetTopmostWindow()
    {
        if (_visibleWindows.Count == 0)
            return null;
        return Enumerable.Last(_visibleWindows);
    }

    public string GetTopmostWindowName()
    {
        return GetTopmostWindow() != null ? GetTopmostWindow().name : null;
    }

    private void UpdateBackground(Window wnd)
    {
        if (wnd == null && _windowQueue.Count > 0)
            return;

        if (wnd == null || !wnd.NeedShowBackground)
        {
            HideBackground();
            return;
        }

        PushBackgroundUnder(wnd);
        StretchBackground();
        ShowBackground();
    }

    private void HideBackground()
    {
        _backgroundController.Hide();
    }

    private void ShowBackground()
    {
        _backgroundController.Show();
    }

    private void StretchBackground()
    {
        const float stretch_overshoot = 100f; //for IPhone X, for other 5f is enough
        _background.offsetMin = new Vector2(-stretch_overshoot, -stretch_overshoot);
        _background.offsetMax = new Vector2(stretch_overshoot, stretch_overshoot);
    }

    private void PushBackgroundUnder(Window wnd)
    {
        _background.SetSiblingIndex(0);
        _background.SetSiblingIndex(Math.Max(0, wnd.transform.GetSiblingIndex() - 1));
        _background.anchoredPosition3D = Vector3.forward * wnd.ZOrder;
    }

    public T GetOrCreateWindow<T>() where T : Window
    {
        var window_type = typeof(T);
        T window;

        if (_windows.ContainsKey(window_type))
            window = _windows[window_type] as T;
        else
        {
            window = CreateWindow<T>();
            window.OnShow += OnWindowShow;
            window.OnHide += OnWindowHide;
            window.OnClose += OnWindowClose;
            window.OnAfterClose += OnAfterWindowClose;
            window.gameObject.SetActive(false);
        }

        if (window == null)
        {
            Log.Error("Failed to create window TYPE={" + window_type + "}");
            return null;
        }

        return window;
    }

    private void OnAfterWindowClose(Window wnd)
    {
        if (_windowQueue.Count == 0 || GetTopmostWindow() != null)
            return;

        var show_next_window = _windowQueue.First.Value;
        _windowQueue.RemoveFirst();
        show_next_window();
    }

    private T CreateWindow<T>() where T : Window
    {
        var resource = _availableWindows.Find(w => w as T);
        var window = Assets.Create(resource as T);

        var id = typeof(T);
        _windows.Add(id, window);
        window.gameObject.SetParent(_windowContainer.transform, false);
        window.name = id.Name;
        window.Init();

        return window;
    }

    public void CloseVisibleStack()
    {
        Window[] to_close = new Window[_visibleWindows.Count];
        _visibleWindows.CopyTo(to_close);

        foreach (var wnd in to_close)
        {
            wnd.OnShow -= OnWindowShow;
            wnd.OnHide -= OnWindowHide;
            wnd.OnClose -= OnWindowClose;
            wnd.OnAfterClose -= OnAfterWindowClose;

            wnd.Close();
        }
    }

    public void HideVisibleStack()
    {
        Window[] to_hide = new Window[_visibleWindows.Count];
        _visibleWindows.CopyTo(to_hide);

        foreach (var wnd in to_hide)
        {
            wnd.Hide();
        }
    }

    public T GetWindow<T>() where T : Window
    {
        var window = GetOr(_windows, typeof(T));
        return window as T;
    }
    public static V GetOr<K, V>(IDictionary<K, V> self, K key, V default_value = default(V))
    {
        V val;
        return self.TryGetValue(key, out val) ? val : default_value;
    }

    public IEnumerator ShowWithDelay<T>(float delay = .2f) where T : ParameterlessWindow
    {
        var window = GetOrCreateWindow<T>();
        yield return new WaitForSeconds(delay);
        window.Show();
    }

    public void CloseWindow<T>() where T : Window
    {
        var window = GetWindow<T>();
        if (window == null)
            return;

        window.Close();
    }

    public IEnumerator WaitForWindowClose<T>() where T : Window
    {
        var window = GetWindow<T>();
        if (window == null)
            yield break;

        var is_closed = false;
        window.OnAfterClose += w => is_closed = true;
        yield return new WaitUntil(() => is_closed);
    }

    public IEnumerator CloseWindowAndWait<T>() where T : Window
    {
        var window = GetWindow<T>();
        if (window == null)
            yield break;

        window.Close();
        yield return WaitForWindowClose<T>();
    }

    public IEnumerator WaitForWindow<T>() where T : Window
    {
        while (GetWindow<T>() == null)
            yield return null;
    }

    public IEnumerator WaitForWindowThenWaitForClose<T>() where T : Window
    {
        yield return WaitForWindow<T>();

        yield return WaitForWindowClose<T>();
    }

    public IEnumerator WaitForWindowForTimeThenWaitForClose<T>(float time_seconds = 2) where T : Window
    {
        yield return WaitForWindowForTime<T>(time_seconds);

        yield return WaitForWindowClose<T>();
    }

    public IEnumerator WaitForWindowForTime<T>(float time_seconds = 2) where T : Window
    {
        var time = 0f;
        while (time < time_seconds && GetWindow<T>() == null)
        {
            time += Time.deltaTime;
            yield return null;
        }
    }

    public void ShowAfter<T>() where T : ParameterlessWindow
    {
        if (HasAnyVisible())
        {
            _windowQueue.AddLast(() => ShowWindow<T>());
            return;
        }

        ShowWindow<T>();
    }

    public void ShowAfter<T>(Action<T> action) where T : ParameterlessWindow
    {
        _windowQueue.AddLast(() =>
        {
            Debug.LogError("ShowAfter invoke");
            var window = GetOrCreateWindow<T>();
            action(window);
            window.Show();
        });
    }

    public void ShowAfter<T, A1>(A1 a1) where T : ParameterWindow<A1>
    {
        if (HasAnyVisible())
        {
            _windowQueue.AddLast(() => ShowWindow<T, A1>(a1));
            return;
        }

        ShowWindow<T, A1>(a1);
    }

    public void ShowAfter<T, A1, A2>(A1 a1, A2 a2) where T : ParameterWindow<A1, A2>
    {
        if (HasAnyVisible())
        {
            _windowQueue.AddLast(() => ShowWindow<T, A1, A2>(a1, a2));
            return;
        }

        ShowWindow<T, A1, A2>(a1, a2);
    }

    public void ShowAfter<T, A1, A2>(A1 a1, A2 a2, Action<Window> on_close) where T : ParameterWindow<A1, A2>
    {
        Action show_window = () =>
        {
            var window = ShowWindow<T, A1, A2>(a1, a2);
            window.OnAfterClose += on_close;
        };

        if (HasAnyVisible())
        {
            _windowQueue.AddLast(show_window);
            return;
        }

        show_window();
    }

    public bool ThereIsNoHidingWindows()
    {
        return _hidingWindows.Count == 0;
    }

    public bool HasAnyOf(List<Type> check_types)
    {
        foreach (var window in _visibleWindows)
        {
            var index = check_types.IndexOf(window.GetType());
            if (index > -1)
                return true;
        }
        return false;
    }
}