ReFuel.Gltf/ReFuel.Gltf/GltfImage.cs

using System;
using System.IO;
using System.Text.Json;
using ReFuel.Gltf.IO;

namespace ReFuel.Gltf
{
    public class GltfImage : GltfIdObject
    {
        private GltfSmartId<GltfBufferView> _bufferView;
        public override GltfObjectKind Kind => GltfObjectKind.Image;

        public string? Name { get; set; }
        public Uri? Uri { get; set; }
        public string? MediaType { get; set; }

        public GltfBufferView? BufferView
        {
            get => _bufferView.IsSet ? _bufferView.Value : null;
            set
            {
                if (value is null)
                {
                    _bufferView.Reset();
                }
                else
                {
                    _bufferView.Value = value;
                }
            }
        }

        internal GltfImage(GltfDocument document) : base(document)
        {
            _bufferView = new GltfSmartId<GltfBufferView>(document.BufferViews);
        }

        public Stream Open(string? pwd = null, IGltfStreamProvider? provider = null)
        {
            if (Uri == null)
            {
                throw new Exception("Only images with a URI property are to be opened.");
            }

            if (Uri.IsAbsoluteUri)
            {
                switch (Uri.Scheme)
                {
                    case "file":
                        if (provider != null)
                        {
                            return provider.OpenFile(pwd, Uri) ?? throw new FileNotFoundException(Uri.ToString());
                        }
                        else
                        {
                            string path = Path.Combine(pwd ?? string.Empty, Uri.LocalPath);
                            return File.OpenRead(path);
                        }
                    case "data":
                        return DataUriStream.FromUri(Uri.OriginalString);
                }
            }

            // otherwise

            if (provider != null)
                return provider.OpenFile(pwd, Uri) ?? throw new FileNotFoundException(Uri.ToString());
            else
                return File.OpenRead(Path.Combine(pwd ?? string.Empty, Uri.LocalPath));

            // throw new Exception("Unrecognized URI scheme.");
        }

        internal override void Deserialize(JsonElement element)
        {
            if (element.ValueKind != JsonValueKind.Object)
                throw new Exception("Expected a JSON object for glTF image node.");

            foreach (JsonProperty property in element.EnumerateObject())
            {
                switch (property.Name)
                {
                case "uri":
                    Uri = new Uri(property.Value.GetString() ?? throw new Exception("Expected a string."), UriKind.RelativeOrAbsolute);
                    break;
                case "mimeType":
                    MediaType = property.Value.GetString() ?? throw new Exception("Expected a string.");
                    break;
                case "bufferView":
                    _bufferView.Id = property.Value.GetInt32();
                    break;
                case "name":
                    Name = property.Value.GetString();
                    break;
                }
            }

            DeserializeCommon(element);
        }

        internal override void Serialize(Utf8JsonWriter writer)
        {
            throw new NotImplementedException();
        }
    }
}