using System.IO;
using System.Text;
using System.Xml;

namespace AIPractice.Shared.Labels
{
    public class LabelAssociation
    {
        /// <summary>
        /// Gets the left label.
        /// </summary>
        public ImageLabel Left { get; }

        /// <summary>
        /// Gets the right label.
        /// </summary>
        public ImageLabel Right { get; }

        public LabelAssociation(ImageLabel left, ImageLabel right)
        {
            Left = left;
            Right = right;
        }

        public static LabelAssociation FromXml(string xmlContent)
        {
            ImageLabel left = null;
            ImageLabel right = null;
            using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(xmlContent)))
            {
                using (XmlReader r = XmlReader.Create(ms))
                {
                    r.Read();
                    while (r.NodeType == XmlNodeType.Element &&
                           (r.Name == nameof(DescriptionLabel) ||
                            r.Name == nameof(ConclusionLabel)) || r.Read())
                    {
                        if (r.NodeType == XmlNodeType.EndElement && r.Name == nameof(LabelAssociation))
                        {
                            break;
                        }

                        if (r.Name == nameof(DescriptionLabel) && left == null)
                        {
                            left = DescriptionLabel.FromXml(r.ReadOuterXml());
                        }
                        if (r.Name == nameof(DescriptionLabel) && left != null && right == null)
                        {
                            right = DescriptionLabel.FromXml(r.ReadOuterXml());
                        }
                        if (r.Name == nameof(ConclusionLabel) && left == null)
                        {
                            left = ConclusionLabel.FromXml(r.ReadOuterXml());
                        }
                        if (r.Name == nameof(ConclusionLabel) && left != null && right == null)
                        {
                            right = ConclusionLabel.FromXml(r.ReadOuterXml());
                        }
                    }

                    return new LabelAssociation(left, right);
                }
            }
        }

        public string ToXml()
        {
            var sb = new StringBuilder();
            sb.Append($"<{nameof(LabelAssociation)}>");
            sb.Append(Left.ToXml());
            sb.Append(Right.ToXml());
            sb.Append($"</{nameof(LabelAssociation)}>");
            return sb.ToString();
        }
    }
}