using System.Collections.Generic;
using Pf2eViewer.EntityTreeViewer;
namespace Pf2eViewer.EntityTreeViewer;

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

    private EntityView? _entityView;

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

        ContentPanel.AutoScroll = false;
        ContentPanel.HorizontalScroll.Maximum = 0;
        ContentPanel.HorizontalScroll.Visible = false;
        ContentPanel.AutoScroll = true;
    }

    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<Control>());
        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.NameWidth + row.Item.Depth * DepthSize;
            maxNameWidth = Math.Max(maxNameWidth, nameWidth);
        }

        NameWidth = maxNameWidth;

        BuildLadder(rows);

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

    private void BuildLadder(List<EntityTreeViewerRow> rows)
        List<LadderType> lastLadder = [];
        ContentPanel.VerticalScroll.Visible = true;

        for (int i = rows.Count - 1; i >= 0; i--)
        {
            EntityTreeViewerRow 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 ContentPanel_Resize(object sender, EventArgs e)
    {
        UpdateView();
    }
}