using System.ComponentModel;
using System.Diagnostics;

namespace Pf2eViewer.EntityTreeViewer;

public sealed partial class EntityTreeViewerControl : UserControl
{
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
    [Category("Entity Render")]
    [Description("The height of each item in the tree view.")]
    public int ItemHeight
    {
        get => _itemHeight;
        set
        {
            _itemHeight = value;
            UpdateView();
        }
    }
    private int _itemHeight = 20;

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public EntityView? EntityView
    {
        get => _entityView;
        set
        {
            _entityView = value;
            UpdateData();
        }
    }
    private EntityView? _entityView;

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
    [Category("Entity Render")]
    [Description("The size of tab.")]
    public int DepthSize
    {
        get => _depthSize;
        set
        {
            _depthSize = value;
            UpdateView();
        }
    }
    private int _depthSize = 20;

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
    [Category("Entity Render")]
    [Description("The size of plus/minus button.")]
    public int ButtonSize
    {
        get => _buttonSize;
        set
        {
            _buttonSize = value;
            UpdateView();
        }
    }
    private int _buttonSize = 20;

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public int NameWidth { get; private set; } = 200;

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
    [Category("Entity Render")]
    [Description("Color on item hover.")]
    public Color HoverColor
    {
        get => _hoverColor;
        set
        {
            _hoverColor = value;
            UpdateView();
        }
    }
    private Color _hoverColor = SystemColors.ControlDark;

    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public int ContentWidth => Width - SystemInformation.VerticalScrollBarWidth - 2;

    private readonly List<StructureField> _rows = [];

    private List<EntityTreeViewerControlRow> _viewerRows = [];

    private bool _rendering;

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public Bitmap ContentImage { get; set; }

    public EntityTreeViewerControl()
    {
        InitializeComponent();
        ContentImage = new(ContentWidth, Height);
        DoubleBuffered = true;
        VerticalScroll.Visible = true;
        HorizontalScroll.Visible = false;

        ContentPanel.MouseWheel += ContentPanel_MouseWheel;
    }

    public void UpdateData()
    {
        if (EntityView?.Entity is null)
        {
            return;
        }

        _rows.Clear();
        ContentPanel.Controls.Clear();

        StructureBuilder builder = new();

        _rows.Add(builder.Create("Entity", EntityView.Entity));

        if (EntityView.SubEntity is not null)
        {
            string typeName = EntityView.SubEntity.GetType().Name;

            _rows.Add(builder.Create(typeName, EntityView.SubEntity));
        }

        _viewerRows = _rows
            .SelectMany(r => r.GetRows(row => new EntityTreeViewerControlRow(this, row)))
            .ToList();

        UpdateRenders();
    }

    public void UpdateRenders()
    {
        int maxNameWidth = -1;

        foreach (EntityTreeViewerControlRow row in _viewerRows)
        {
            int nameWidth = row.NameWidth + row.Item.Depth * DepthSize;
            maxNameWidth = Math.Max(maxNameWidth, nameWidth);
        }

        NameWidth = maxNameWidth + 3;

        // Debug.WriteLine($@"Height Inner {ContentWidth} / Outer {Width}");
        // Debug.WriteLine($@"Name {NameWidth} / Full {ContentWidth}");

        foreach (EntityTreeViewerControlRow row in _viewerRows)
        {
            row.UpdateCache();
        }

        UpdateView();
    }

    public void UpdateView()
    {
        _viewerRows.ForEach(row => row.UpdateButton());

        List<EntityTreeViewerControlRow> rows = _viewerRows.Where(r => r.Item.Visible).ToList();
        if (rows.Count == 0)
        {
            return;
        }

        BuildLadder(rows);

        _rendering = true;
        ContentImage = new(ContentWidth, rows.Count * ItemHeight);
        Graphics g = Graphics.FromImage(ContentImage);

        int viewRow = 0;
        foreach (EntityTreeViewerControlRow row in rows)
        {
            row.ViewIndex = viewRow++;
            row.Invalidate(g);
        }

        g.Save();

        ContentPanel.Image = ContentImage;
        ContentPanel.Width = ContentImage.Width;
        ContentPanel.Height = ContentImage.Height;

        _rendering = false;
    }

    private void BuildLadder(List<EntityTreeViewerControlRow> rows)
    {
        List<LadderType> lastLadder = [];

        for (int i = rows.Count - 1; i >= 0; i--)
        {
            EntityTreeViewerControlRow row = rows[i];
            List<LadderType> ladder;

            if (row.Depth == 0)
            {
                ladder = [];
            }
            else if (row.Depth < lastLadder.Count)
            {
                ladder =
                [
                    .. lastLadder[..(row.Depth - 1)],
                    lastLadder[row.Depth - 1] == LadderType.Empty
                        ? LadderType.Last
                        : LadderType.Through,
                ];
            }
            else if (row.Depth == lastLadder.Count)
            {
                ladder = lastLadder;
            }
            else
            {
                ladder =
                [
                    .. lastLadder,
                    .. Enumerable.Repeat(LadderType.Empty, row.Depth - lastLadder.Count - 1),
                    LadderType.Last,
                ];
            }

            row.Ladder = ladder;

            lastLadder = ladder
                .Select(l => (l == LadderType.Last) ? LadderType.Through : l)
                .ToList();
        }
    }

    // Events

    private void EntityTreeViewerControl_Resize(object sender, EventArgs e)
    {
        if (_rendering)
        {
            return;
        }

        ContentPanel.Width = Width;

        UpdateRenders();
    }

    private void ContentPanel_MouseWheel(object? sender, MouseEventArgs e)
    {
        /*
        int initValue = VerticalScroll.Value;
        int delta = -e.Delta / 120;

        VerticalScroll.Value = Math.Clamp(
            initValue + delta,
            VerticalScrollBar.Minimum,
            VerticalScrollBar.Maximum - VerticalScrollBar.LargeChange + 1
        );

        if (VerticalScrollBar.Value != initValue)
        {
            ContentPanel.Invalidate();
        }
        */
    }

    private void ContentPanel_MouseMove(object sender, MouseEventArgs e)
    {
        PointF p = new(e.X, e.Y);

        foreach (EntityTreeViewerControlRow row in _viewerRows)
        {
            bool contained = row.Target.Contains(p);

            if (contained != row.Hovered)
            {
                Rectangle r = new();
                row.RealTarget.Intersect(r);
                ContentPanel.Invalidate(r);
            }

            row.Hovered = contained;
        }
    }
}