using System.Diagnostics.CodeAnalysis;
using FontAwesome.Sharp;

namespace Pf2eViewer.EntityTreeViewer;

internal sealed partial class EntityTreeViewerRow : UserControl
{
    public readonly EntityTreeViewerControl ParentControl;

    public readonly StructureField Item;

    public int ViewIndex = 0;

    public Bitmap IconCache
    {
        get
        {
            if (_iconCache == null)
            {
                UpdateCache();
            }
            return _iconCache!;
        }
        set => _iconCache = value;
    }
    private Bitmap? _iconCache;

    public List<LadderType> Ladder
    {
        get => _ladder;
        set
        {
            _ladder = value;
            _iconCache = null;
        }
    }
    private List<LadderType> _ladder = [];

    public override Font Font
    {
        get => ParentControl.Font;
        set => ParentControl.Font = value;
    }
    public override Color ForeColor
    {
        get => ParentControl.ForeColor;
        set => ParentControl.ForeColor = value;
    }
    public override Color BackColor
    {
        get => ParentControl.BackColor;
        set => ParentControl.BackColor = value;
    }
    public int ItemHeight
    {
        get => ParentControl.ItemHeight;
        set => ParentControl.ItemHeight = value;
    }
    public int DepthSize
    {
        get => ParentControl.ItemHeight;
        set => ParentControl.ItemHeight = value;
    }

    // Value functions

    public bool HasButton => Item.FieldType == StructureFieldType.Complex;
    public int Depth => Item.Depth;
    public int NameWidth => TextRenderer.MeasureText(NameLabel.Text, Font).Width + DepthSize;

    public EntityTreeViewerRow(EntityTreeViewerControl parent, StructureField item)
    {
        ParentControl = parent;

        Item = item;

        InitializeComponent();
        ApplyItem();
        Refresh();
    }

    private void ApplyItem()
    {
        TypeLabel.Font = new(Font.FontFamily, Font.Size - 2, FontStyle.Italic);

        NameLabel.Text = Item.Name;
        TypeLabel.Text = Item.GetTypeString();
        if (TypeLabel.Text != "")
        {
            TypeLabel.Text = $@"({TypeLabel.Text})";
        }

        ValueLabel.Text = Item.GetValueString();
        TypeLabel.ForeColor = ValueLabel.ForeColor = GetValueColor();

        if (Item.FieldType == StructureFieldType.Complex)
        {
            ValueLabel.Font = new(Font, FontStyle.Italic);
        }

        UpdateCache();
        Refresh();
    }

    public new void Refresh()
    {
        base.Refresh();

        Left = 0;
        Top = ViewIndex * ParentControl.ItemHeight;
        Width = ParentControl.ContentPanel.Width - Left - SystemInformation.VerticalScrollBarWidth;
        Height = ParentControl.ItemHeight;

        // Name Panel
        NamePanel.Left = 0;
        NamePanel.Width = ParentControl.NameWidth - NamePanel.Left;

        IconPictureBox.Width = IconCache.Width;
        IconPictureBox.Image = IconCache;

        NameLabel.Left = IconPictureBox.Width;
        NameLabel.Width = NamePanel.Width - NameLabel.Left;

        // Value Panel
        ValuePanel.Left = NamePanel.Left + NamePanel.Width;
        ValuePanel.Width = Width - ValuePanel.Left;

        Size typeSize = TextRenderer.MeasureText(TypeLabel.Text, TypeLabel.Font);
        TypeLabel.Width = typeSize.Width + 3;
    }

    private Color BlendColor(Color color, double rate = 0.5)
    {
        return BlendColor(ForeColor, color, rate);
    }

    private Color BlendColor(Color color1, Color color2, double rate)
    {
        return Color.FromArgb(
            Mix(color1.A, color2.A),
            Mix(color1.R, color2.R),
            Mix(color1.G, color2.G),
            Mix(color1.B, color2.B)
        );

        int Mix(int a, int b) => Convert.ToInt32(Math.Round(a * rate + b * (1 - rate)));
    }

    public Color GetValueColor()
    {
        return Item switch
        {
            StructureFieldPrimitive primitive => Type.GetTypeCode(primitive.Type) switch
            {
                TypeCode.Boolean => BlendColor(Color.DarkGoldenrod),
                TypeCode.Int32 => BlendColor(Color.Blue),
                TypeCode.Double => BlendColor(Color.Aqua),
                TypeCode.String => BlendColor(Color.Green),
                _ => ForeColor,
            },
            StructureFieldEnum => BlendColor(Color.Red),
            _ => ForeColor,
        };
    }

    // Events

    private void IconPictureBox_Click(object sender, EventArgs e)
    {
        if (Item.GetType() != typeof(StructureFieldComplex))
        {
            return;
        }

        StructureFieldComplex complex = (StructureFieldComplex)Item;

        complex.Collapsed = !complex.Collapsed;
        ParentControl.UpdateView();
    }

    private Bitmap? GetIconImage()
    {
        if (Item.GetType() != typeof(StructureFieldComplex))
        {
            return null;
        }

        StructureFieldComplex complex = (StructureFieldComplex)Item;

        int size = Convert.ToInt32(Math.Round(DepthSize * 0.6));

        return complex.Collapsed
            ? IconChar.PlusSquare.ToBitmap(IconFont.Auto, size, ForeColor)
            : IconChar.MinusSquare.ToBitmap(IconFont.Auto, size, ForeColor);
    }

    private void UpdateCache()
    {
        int n = Depth;
        int h = ItemHeight;
        int w = DepthSize;

        _iconCache = new(w * (n + 1), h);

        if (_ladder.Count < Depth)
        {
            return;
        }

        Graphics g = Graphics.FromImage(_iconCache);

        Pen pen = new(Color.FromArgb(127, ForeColor.R, ForeColor.G, ForeColor.B), 1);
        pen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;

        float cy = 0.5f * h;

        for (int i = 0; i < n; i++)
        {
            float cx = (i + 1.5f) * w;

            switch (_ladder[i])
            {
                case LadderType.Last:
                    g.DrawLine(pen, cx, 0, cx, cy);
                    break;
                case LadderType.Through:
                    g.DrawLine(pen, cx, 0, cx, h);
                    break;
                case LadderType.Empty:
                default:
                    break;
            }

            if (i == n - 1)
            {
                g.DrawLine(pen, cx, cy, (i + 2) * w, cy);
            }
        }

        Bitmap? icon = GetIconImage();

        if (icon is not null)
        {
            float cx = (n + 0.5f) * w;

            g.FillRectangle(
                new SolidBrush(BackColor),
                cx - 0.5f * icon.Width - 1,
                cy - 0.5f * icon.Height - 1,
                icon.Width + 2,
                icon.Height + 2
            );

            g.DrawImage(icon, new PointF(cx - 0.5f * icon.Width, cy - 0.5f * icon.Height));
        }

        g.Save();
    }
}