using System.Collections.Immutable;
using System.Linq;
using Robust.Client.AutoGenerated;
using Robust.Client.UserInterface;
using Robust.Client.UserInterface.Controls;
using Robust.Client.UserInterface.XAML;
using Robust.Shared.Toolshed.TypeParsers;
using static Content.Client.Stylesheets.StyleBase;
using static Robust.Shared.Maths.Direction;

namespace Content.Client.UserInterface.Controls;

/// <summary>
///     A simple yet good-looking tab container using normal UI elements with multiple styles
///     <br />
///     Because nobody else could do it better.
///     <br />
///     Yeah, it could be better if you don't shit with linkq
/// </summary>
/// WD EDIT
[GenerateTypedNameReferences]
public sealed partial class NeoTabContainer : BoxContainer
{
    private readonly Dictionary<TabId, BaseButton> _tabs = new();
    private readonly Dictionary<TabId, Control> _controls = new();
    private readonly Dictionary<string, TabId> _tabAliases = new();
    private readonly HashSet<TabId> _idTaken = new();
    private readonly ButtonGroup _tabGroup = new(false);

    private TabId? _selectedTabId;
    private readonly TabIdPool _pool = new();

    public ImmutableHashSet<TabId> TakenIds => _idTaken.ToImmutableHashSet();
    public ImmutableDictionary<string, TabId> TabAliases => _tabAliases.ToImmutableDictionary();

    /// All children within the <see cref="TabContainer"/>
    public OrderedChildCollection Tabs => TabContainer.Children;
    /// All children within the <see cref="TabContainer"/> that are visible
    public List<Control> VisibleTabs => Tabs.Where(c => c.Visible).ToList();

    private Control? _currentControl;

    public Control? CurrentControl
    {
        get => _currentControl;
        private set
        {
            if (_currentControl != null)
                ContentScrollContainer.RemoveChild(_currentControl);

            _currentControl = value;

            if (value != null)
                ContentScrollContainer.AddChild(value);
        }
    }

    public TabId? SelectedTabId
    {
        get => _selectedTabId;
        set
        {
            if (value.HasValue)
            {
                if (_controls.TryGetValue(value.Value, out var control))
                {
                    CurrentControl = control;

                    _selectedTabId = value;
                }
            }
            else
            {
                CurrentControl = null;
                _selectedTabId = value;
            }
        }
    }


    /// <inheritdoc cref="NeoTabContainer"/>
    public NeoTabContainer()
    {
        RobustXamlLoader.Load(this);

        LayoutContainer.SetAnchorPreset(ContentScrollContainer, LayoutContainer.LayoutPreset.Wide);

        LayoutChanged(TabLocation);
        ScrollingChanged(HScrollEnabled, VScrollEnabled);
    }

    /// <summary>
    ///     Adds a tab to this container
    /// </summary>
    /// <param name="control">The tab contents</param>
    /// <param name="title">The title of the tab</param>
    /// <param name="updateTabMerging">Whether the tabs should fix their styling automatically. Useful if you're doing tons of updates at once</param>
    /// <returns>The index of the new tab</returns>
    public TabId AddTab(Control control, string? title, bool updateTabMerging = true)
    {
        var button = new Button
        {
            Group = _tabGroup,
            MinHeight = 32,
            MaxHeight = 32,
            HorizontalExpand = true,
        };
        var id = _pool.Take();
        _idTaken.Add(id);

        button.OnPressed += _ => SelectTab(id);
        if (!string.IsNullOrEmpty(title))
            button.Text = title;

        TabContainer.AddChild(button);
        _controls.Add(id, control);
        _tabs.Add(id, button);

        SelectedTabId ??= id;

        if (updateTabMerging)
            UpdateTabMerging();
        return id;
    }


    /// <summary>
    ///     Removes/Disposes the tab associated with the given index
    /// </summary>
    /// <param name="index">The index of the tab to remove</param>
    /// <param name="updateTabMerging">Whether the tabs should fix their styling automatically. Useful if you're doing tons of updates at once</param>
    /// <returns>True if the tab was removed, false otherwise</returns>
    public bool RemoveTab(TabId index, bool updateTabMerging = true)
    {
        if (!_controls.ContainsKey(index))
            return false;

        if (SelectedTabId == index)
        {
            if (_tabs.Count > 0)
                SelectedTabId = _tabs.Keys.First();
            else
                SelectedTabId = null;
        }

        _controls[index].Dispose();
        _controls.Remove(index);

        _tabs[index].Dispose();
        _tabs.Remove(index);

        var alias =
            _tabAliases
                .Where(p => p.Value == index)
                .Select(p => p.Key)
                .FirstOrDefault();
        if (alias is not null)
            _tabAliases.Remove(alias);

        if (updateTabMerging)
            UpdateTabMerging();

        _idTaken.Remove(index);
        _pool.Free(index);

        return true;
    }


    public T? GetControl<T>(TabId tabId) where T : Control
    {
        if (!_controls.TryGetValue(tabId, out var control))
            return null;

        return control as T;
    }

    public IEnumerable<T> GetControls<T>() where T : Control
    {
        foreach (var control in _controls)
        {
            if(control.Value is T t)
                yield return t;
        }
    }

    public bool TryFindTabByAlias(string alias, out TabId tabId)
    {
        tabId = default;
        if (string.IsNullOrEmpty(alias))
            return false;
        return _tabAliases.TryGetValue(alias, out tabId);
    }

    public void SetTabAlias(TabId tabId, string name)
    {
        if(!_controls.ContainsKey(tabId))
            return;

        _tabAliases[name] = tabId;
    }

    /// Sets the title of the tab associated with the given index
    public void SetTabTitle(TabId index, string title)
    {
        if(!_tabs.TryGetValue(index, out var tab))
            return;

        if (tab is Button button)
            button.Text = title;
    }

    /// Shows or hides the tab associated with the given index
    public void SetTabVisible(TabId index, bool visible)
    {
        if (!_tabs.TryGetValue(index, out var button))
            return;

        button.Visible = visible;
        UpdateTabMerging();
    }

    /// Selects the tab associated with the control
    public void SelectTab(TabId tabId) => SelectedTabId = tabId;

    /// Sets the style of every visible tab's Button to be Open to Right, Both, or Left depending on position
    public void UpdateTabMerging()
    {
        var visibleTabs = VisibleTabs;

        if (visibleTabs.Count == 0)
            return;

        if (visibleTabs.Count == 1)
        {
            var button = visibleTabs[0];
            button.RemoveStyleClass(ButtonOpenRight);
            button.RemoveStyleClass(ButtonOpenBoth);
            button.RemoveStyleClass(ButtonOpenLeft);

            if (FirstTabOpenBoth)
                button.AddStyleClass(ButtonOpenBoth);

            return;
        }

        string GetDirection(Direction direction, int position)
        {
            return position switch
            {
                // First
                0 => direction switch
                {
                    North => ButtonOpenRight,
                    South => ButtonOpenRight,
                    East => ButtonOpenLeft,
                    West => ButtonOpenLeft,
                    _ => ButtonOpenRight,
                },
                // Middle
                1 => ButtonOpenBoth,
                // Last
                2 => direction switch
                {
                    North => ButtonOpenLeft,
                    South => ButtonOpenLeft,
                    East => ButtonOpenRight,
                    West => ButtonOpenRight,
                    _ => ButtonOpenLeft,
                },
                _ => ButtonOpenBoth,
            };
        }

        for (var i = 0; i < visibleTabs.Count; i++)
        {
            var button = visibleTabs[i];
            button.RemoveStyleClass(ButtonOpenRight);
            button.RemoveStyleClass(ButtonOpenBoth);
            button.RemoveStyleClass(ButtonOpenLeft);

            if (FirstTabOpenBoth && i == 0)
            {
                button.AddStyleClass(ButtonOpenBoth);
                continue;
            }
            if (LastTabOpenBoth && i == visibleTabs.Count - 1)
            {
                button.AddStyleClass(ButtonOpenBoth);
                continue;
            }

            var position = i switch
            {
                0 => 0,
                _ when i == visibleTabs.Count - 1 => 2,
                _ => 1,
            };
            button.AddStyleClass(GetDirection(TabLocation, position));
        }
    }
}

// For nice think of NeoTabContrainer
public sealed class TabIdPool
{
    private readonly Queue<TabId> _freeIds = new();
    private int _nextId = 1;

    public TabId Take()
    {
        if (_freeIds.Count > 0)
        {
            return _freeIds.Dequeue();
        }

        return new TabId(_nextId++);
    }

    public void Free(TabId id)
    {
        if (!_freeIds.Contains(id))
        {
            _freeIds.Enqueue(id);
        }
    }
}

public record struct TabId(int Id):
    IEquatable<int>,
    IComparable<TabId>,
    IAsType<int>
{
    public static implicit operator TabId(int id) => new TabId(id);
    public static implicit operator int(TabId id) => id.Id;
    public bool Equals(int other) => Id == other;
    public int CompareTo(TabId other) => Id.CompareTo(other.Id);
    public int AsType() => Id;
};