EnvelopeGenerator/EnvelopeGenerator.API/Models/PsPdfKitAnnotation/AnnotationParams.cs

using EnvelopeGenerator.API.Models.PsPdfKitAnnotation;
using System.Text.Json.Serialization;

namespace EnvelopeGenerator.API.Models.PsPdfKitAnnotation;

public class AnnotationParams
{
    public AnnotationParams()
    {
        _AnnotationJSObjectInitor = new(CreateAnnotationJSObject);
    }

    public Background? Background { get; init; }

    #region Annotation
    [JsonIgnore]
    public Annotation? DefaultAnnotation { get; init; }

    private readonly List<Annotation> _annots = new List<Annotation>();

    public bool TryGet(string name, out Annotation annotation)
    {
#pragma warning disable CS8601 // Possible null reference assignment.
        annotation = _annots.FirstOrDefault(a => a.Name == name);
#pragma warning restore CS8601 // Possible null reference assignment.
        return annotation is not null;
    }

    public required IEnumerable<Annotation> Annotations
    {
        get => _annots;
        init
        {
            _annots = value.ToList();

            if (DefaultAnnotation is not null)
                foreach (var annot in _annots)
                    annot.Default = DefaultAnnotation;

            for (int i = 0; i < _annots.Count; i++)
            {
                #region set bound annotations
                // horizontal
                if (_annots[i].HorBoundAnnotName is string horBoundAnnotName)
                    if (TryGet(horBoundAnnotName, out var horBoundAnnot))
                        _annots[i].HorBoundAnnot = horBoundAnnot;
                    else
                        throw new InvalidOperationException($"{horBoundAnnotName} added as bound anotation. However, it is not defined.");

                // vertical
                if (_annots[i].VerBoundAnnotName is string verBoundAnnotName)
                    if (TryGet(verBoundAnnotName, out var verBoundAnnot))
                        _annots[i].VerBoundAnnot = verBoundAnnot;
                    else
                        throw new InvalidOperationException($"{verBoundAnnotName} added as bound anotation. However, it is not defined.");
                #endregion
            }
        }
    }
    #endregion

    #region AnnotationJSObject
    private Dictionary<string, IAnnotation> CreateAnnotationJSObject()
    {
        var dict = _annots.ToDictionary(a => a.Name.ToLower(), a => a as IAnnotation);

        if (Background is not null)
        {
            Background.Locate(_annots);
            dict.Add(Background.Name.ToLower(), Background);
        }            

        return dict;
    }

    private readonly Lazy<Dictionary<string, IAnnotation>> _AnnotationJSObjectInitor;

    public Dictionary<string, IAnnotation> AnnotationJSObject => _AnnotationJSObjectInitor.Value;
    #endregion
}