namespace Pf2eViewer.EntityTreeViewer;

public sealed partial class EntityTreeViewerControl : UserControl
{
    private int _itemHeight = 20;

    private EntityView? _entityView = null;

    private int _depthSize = 20;

    public int ItemHeight
    {
        get => _itemHeight;
        set
        {
            _itemHeight = value;
            UpdateView();
        }
    }

    public EntityView? EntityView
    {
        get => _entityView;
        set
        {
            _entityView = value;
            UpdateData();
        }
    }

    public int DepthSize
    {
        get => _depthSize;
        set
        {
            _depthSize = value;
            UpdateView();
        }
    }

    public int NameWidth { get; private set; } = 200;

    private readonly List<StructureField> _rows = [];

    private List<EntityTreeViewerRow> _viewerRows = [];

    public DarkModeCS? DarkMode;

    public EntityTreeViewerControl()
    {
        InitializeComponent();
        DoubleBuffered = true;

        ContentPanel.AutoScroll = false;
        ContentPanel.VerticalScroll.Enabled = true;
        ContentPanel.VerticalScroll.Visible = true;

        ContentPanel.MouseWheel += ContentPanel_MouseWheel;
    }

    private int _visibleRows;

    public int ScrollPosition
    {
        get => ContentPanel.VerticalScroll.Value / ItemHeight;
        set
        {
            VScrollProperties scrollBar = ContentPanel.VerticalScroll;
            int oldValue = scrollBar.Value / ItemHeight;
            int visibleItems = scrollBar.LargeChange / ItemHeight;

            int scrollValue = Math.Min(Math.Max(value, 0), _visibleRows - visibleItems);

            if (oldValue != scrollValue)
            {
                ContentPanel.VerticalScroll.Value = scrollValue * ItemHeight;
                UpdateScroll();
            }
        }
    }

    public void UpdateData()
    {
        ContentPanel.Controls.Clear();

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

        _rows.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));
        }

        UpdateRows();
        UpdateView();
    }

    public void UpdateRows()
    {
        _viewerRows = _rows.SelectMany(r => r.GetTextRows(this)).ToList();

        ContentPanel.Controls.Clear();

        ContentPanel.Controls.AddRange(_viewerRows.ToArray());

        UpdateView();
    }

    public void UpdateView()
    {
        foreach (EntityTreeViewerRow row in _viewerRows)
        {
            row.Visible = row.Item.Visible;
        }

        List<EntityTreeViewerRow> rows = _viewerRows.Where(r => r.Item.Visible).ToList();

        int maxNameWidth = -1;
        int viewRow = 0;

        foreach (EntityTreeViewerRow row in rows)
        {
            row.ViewIndex = viewRow++;
            int nameWidth = row.GetNameWidth() + row.Item.Depth * DepthSize;
            maxNameWidth = Math.Max(maxNameWidth, nameWidth);
        }

        NameWidth = maxNameWidth;

        foreach (EntityTreeViewerRow row in rows)
        {
            row.Refresh();
        }

        UpdateScroll();
    }

    public void UpdateScroll()
    {
        List<EntityTreeViewerRow> rows = _viewerRows.Where(r => r.Item.Visible).ToList();
        _visibleRows = rows.Count;

        ContentPanel.VerticalScroll.Enabled = true;
        ContentPanel.VerticalScroll.Visible = true;

        ContentPanel.VerticalScroll.SmallChange = ItemHeight;
        ContentPanel.VerticalScroll.LargeChange = ContentPanel.Height;
        ContentPanel.VerticalScroll.Minimum = 0;
        ContentPanel.VerticalScroll.Maximum = _visibleRows * ItemHeight;

        // ContentPanel.VerticalScroll.Value = VerticalScrollBar.Value * ItemHeight;
        /*
        ContentPanel.Top = -VerticalScrollBar.Value * ItemHeight;
        ContentPanel.Invalidate();
        */
    }

    // Events

    private void VerticalScrollBar_Scroll(object sender, ScrollEventArgs e)
    {
        UpdateScroll();
    }

    private void ContentPanel_MouseWheel(object? sender, MouseEventArgs e)
    {
        Focus();
        // ScrollPosition -= e.Delta / 120;
    }

    private void ContentPanel_Resize(object sender, EventArgs e)
    {
        UpdateView();
    }
}