gui-cs.Terminal.Gui/Terminal.Gui/Configuration/AttributeJsonConverter.cs

using System;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace Terminal.Gui; 

/// <summary>
/// Json converter fro the <see cref="Attribute"/> class.
/// </summary>
class AttributeJsonConverter : JsonConverter<Attribute> {
	static AttributeJsonConverter _instance;

	/// <summary>
	/// 
	/// </summary>
	public static AttributeJsonConverter Instance {
		get {
			if (_instance == null) {
				_instance = new AttributeJsonConverter ();
			}

			return _instance;
		}
	}

	public override Attribute Read (ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
	{
		if (reader.TokenType != JsonTokenType.StartObject) {
			throw new JsonException ($"Unexpected StartObject token when parsing Attribute: {reader.TokenType}.");
		}

		var attribute = new Attribute ();
		Color? foreground = null;
		Color? background = null;
		while (reader.Read ()) {
			if (reader.TokenType == JsonTokenType.EndObject) {
				if (foreground == null || background == null) {
					throw new JsonException ("Both Foreground and Background colors must be provided.");
				}
				return new Attribute (foreground.Value, background.Value);
			}

			if (reader.TokenType != JsonTokenType.PropertyName) {
				throw new JsonException ($"Unexpected token when parsing Attribute: {reader.TokenType}.");
			}

			var propertyName = reader.GetString ();
			reader.Read ();
			var color = $"\"{reader.GetString ()}\"";

			switch (propertyName?.ToLower ()) {
			case "foreground":
				foreground = JsonSerializer.Deserialize<Color> (color, options);
				break;
			case "background":
				background = JsonSerializer.Deserialize<Color> (color, options);
				break;
			//case "bright":
			//case "bold":
			//	attribute.Bright = reader.GetBoolean ();
			//	break;
			//case "dim":
			//	attribute.Dim = reader.GetBoolean ();
			//	break;
			//case "underline":
			//	attribute.Underline = reader.GetBoolean ();
			//	break;
			//case "blink":
			//	attribute.Blink = reader.GetBoolean ();
			//	break;
			//case "reverse":
			//	attribute.Reverse = reader.GetBoolean ();
			//	break;
			//case "hidden":
			//	attribute.Hidden = reader.GetBoolean ();
			//	break;
			//case "strike-through":
			//	attribute.StrikeThrough = reader.GetBoolean ();
			//	break;				
			default:
				throw new JsonException ($"Unknown Attribute property {propertyName}.");
			}
		}
		throw new JsonException ();
	}

	public override void Write (Utf8JsonWriter writer, Attribute value, JsonSerializerOptions options)
	{
		writer.WriteStartObject ();
		writer.WritePropertyName (nameof (Attribute.Foreground));
		ColorJsonConverter.Instance.Write (writer, value.Foreground, options);
		writer.WritePropertyName (nameof (Attribute.Background));
		ColorJsonConverter.Instance.Write (writer, value.Background, options);

		writer.WriteEndObject ();
	}
}