From d62bdfc637634b6d878e1745b8e4c34889e848a7 Mon Sep 17 00:00:00 2001
From: Zoe Roux <zoe.roux@zoriya.dev>
Date: Fri, 22 Mar 2024 23:04:07 +0100
Subject: [PATCH] Add loadable fields handling on system.text.json serializer

---
 back/src/Kyoo.Core/CoreModule.cs              |  5 +++-
 .../Helper/Serializers/WithKindResolver.cs    | 23 +++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/back/src/Kyoo.Core/CoreModule.cs b/back/src/Kyoo.Core/CoreModule.cs
index 73b97dd9..6a0c36f3 100644
--- a/back/src/Kyoo.Core/CoreModule.cs
+++ b/back/src/Kyoo.Core/CoreModule.cs
@@ -95,8 +95,11 @@ namespace Kyoo.Core
 				})
 				.AddJsonOptions(x =>
 				{
+					x.JsonSerializerOptions.TypeInfoResolver = new WithKindResolver()
+					{
+						Modifiers = { WithKindResolver.HandleLoadableFields }
+					};
 					x.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());
-					x.JsonSerializerOptions.TypeInfoResolver = new WithKindResolver();
 					x.JsonSerializerOptions.PropertyNamingPolicy = JsonNamingPolicy.CamelCase;
 				})
 				.AddDataAnnotations()
diff --git a/back/src/Kyoo.Core/Views/Helper/Serializers/WithKindResolver.cs b/back/src/Kyoo.Core/Views/Helper/Serializers/WithKindResolver.cs
index 7c120aae..cfc65c26 100644
--- a/back/src/Kyoo.Core/Views/Helper/Serializers/WithKindResolver.cs
+++ b/back/src/Kyoo.Core/Views/Helper/Serializers/WithKindResolver.cs
@@ -18,10 +18,13 @@
 
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Text.Json;
 using System.Text.Json.Serialization.Metadata;
 using Kyoo.Abstractions.Models;
+using Kyoo.Abstractions.Models.Attributes;
+using Microsoft.AspNetCore.Http;
 using static System.Text.Json.JsonNamingPolicy;
 
 namespace Kyoo.Core.Api;
@@ -53,4 +56,24 @@ public class WithKindResolver : DefaultJsonTypeInfoResolver
 
 		return jsonTypeInfo;
 	}
+
+	private static readonly IHttpContextAccessor _accessor = new HttpContextAccessor();
+
+	public static void HandleLoadableFields(JsonTypeInfo info)
+	{
+		foreach (JsonPropertyInfo prop in info.Properties)
+		{
+			object[] attributes =
+				prop.AttributeProvider?.GetCustomAttributes(typeof(LoadableRelationAttribute), true)
+				?? Array.Empty<object>();
+			if (attributes.FirstOrDefault() is not LoadableRelationAttribute relation)
+				continue;
+			prop.ShouldSerialize = (_, _) =>
+			{
+				if (_accessor?.HttpContext?.Items["fields"] is not ICollection<string> fields)
+					return false;
+				return fields.Contains(prop.Name, StringComparer.InvariantCultureIgnoreCase);
+			};
+		}
+	}
 }