using System.Drawing;

namespace System.Windows.Forms
{
    public static class TextRenderer
    {
        private static Graphics measureGraphics = Graphics.FromImage(new Bitmap(1, 1));

        private static StringFormat GetStringFormat(TextFormatFlags flags)
        {
            var format = new StringFormat(StringFormat.GenericTypographic);

            var rtl = false;
            if ((flags & TextFormatFlags.RightToLeft) != 0)
            {
                format.FormatFlags |= StringFormatFlags.DirectionRightToLeft;
                rtl = true;
            }

            if ((flags & TextFormatFlags.HorizontalCenter) != 0)
                format.Alignment = StringAlignment.Center;
            if ((flags & TextFormatFlags.Right) != 0)
                format.Alignment = rtl ? StringAlignment.Near : StringAlignment.Far;

            if ((flags & TextFormatFlags.VerticalCenter) != 0)
                format.LineAlignment = StringAlignment.Center;
            if ((flags & TextFormatFlags.Bottom) != 0)
                format.LineAlignment = StringAlignment.Far;

            if ((flags & TextFormatFlags.EndEllipsis) != 0)
            {
                format.Trimming = StringTrimming.EllipsisCharacter;
                format.FormatFlags |= StringFormatFlags.NoWrap;
            }
            else
                format.Trimming = StringTrimming.Character;

            format.HotkeyPrefix = Drawing.Text.HotkeyPrefix.Hide;
            format.FormatFlags &= ~StringFormatFlags.LineLimit;

            return format;
        }

        private static void Transform(Graphics g, TextFormatFlags flags)
        {
            var offset = new PointF(g.Transform.OffsetX, g.Transform.OffsetY);
            g.ResetTransform();
            if ((flags & TextFormatFlags.PreserveGraphicsTranslateTransform) != 0)
                g.TranslateTransform(offset.X, offset.Y);
        }

        public static void DrawText(Graphics g, string text, Font font, System.Drawing.Point pos, Color foreColor, TextFormatFlags flags)
        {
            using (StringFormat format = GetStringFormat(flags))
            using (SolidBrush brush = new SolidBrush(foreColor))
            {
                var state = g.Save();
                Transform(g, flags);
                if ((flags & TextFormatFlags.RightToLeft) != 0)
                {
                    pos.X += MeasureText(text, font).Width - 4;
                }

                g.DrawString(text, font, brush, pos.X + 2, pos.Y, format);
                g.Restore(state);
            }
        }

        public static void DrawText(Graphics g, string text, Font font, System.Drawing.Point pos, Color foreColor) => DrawText(g, text, font, pos, foreColor, TextFormatFlags.Default);

        public static void DrawText(Graphics g, string text, Font font, Rectangle rect, Color foreColor, TextFormatFlags flags)
        {
            using (StringFormat format = GetStringFormat(flags))
            using (SolidBrush brush = new SolidBrush(foreColor))
            {
                var state = g.Save();
                Transform(g, flags);
                g.DrawString(text, font, brush, new Rectangle(rect.X + 2, rect.Y, rect.Width - 4, rect.Height), format);
                g.Restore(state);
            }
        }

        public static void DrawText(Graphics g, string text, Font font, Rectangle rect, Color foreColor) => DrawText(g, text, font, rect, foreColor, TextFormatFlags.Default);
        public static void DrawText(Graphics g, string text, Font font, Rectangle rect, Color foreColor, Color backColor, TextFormatFlags flags) => DrawText(g, text, font, rect, foreColor, flags);

        public static System.Drawing.Size MeasureText(string text, Font font) => MeasureString(text, font).ToSize();

        public static System.Drawing.Size MeasureText(string text, Font font, Drawing.Size size) => MeasureString(text, font, size.Width, StringFormat.GenericTypographic).ToSize();

        public static SizeF MeasureString(string text, Font font) => measureGraphics.MeasureString(text, font);

        public static SizeF MeasureString(string text, Font font, int maxWidth, StringFormat format) => measureGraphics.MeasureString(text, font, maxWidth, format);
    }

    [Flags]
    public enum TextFormatFlags
    {
        Bottom = 0x8,
        EndEllipsis = 0x8000,
        ExpandTabs = 0x40,
        ExternalLeading = 0x200,
        Default = 0x0,
        HidePrefix = 0x100000,
        HorizontalCenter = 0x1,
        Internal = 0x1000,
        Left = 0x0,
        ModifyString = 0x10000,
        NoClipping = 0x100,
        NoPrefix = 0x800,
        NoFullWidthCharacterBreak = 0x80000,
        PathEllipsis = 0x4000,
        PrefixOnly = 0x200000,
        Right = 0x2,
        RightToLeft = 0x20000,
        SingleLine = 0x20,
        TextBoxControl = 0x2000,
        Top = 0x0,
        VerticalCenter = 0x4,
        WordBreak = 0x10,
        WordEllipsis = 0x40000,
        PreserveGraphicsClipping = 0x1000000,
        PreserveGraphicsTranslateTransform = 0x2000000,
        GlyphOverhangPadding = 0x0,
        NoPadding = 0x10000000,
        LeftAndRightPadding = 0x20000000
    }

}