From f761990225fd98160b52ef90f88b769c0f6b0dc6 Mon Sep 17 00:00:00 2001
From: Rory& <root@rory.gay>
Date: Mon, 15 Jul 2024 13:52:47 +0200
Subject: Working json canonicalisation

---
 LibMatrix/Extensions/CanonicalJsonSerializer.cs | 91 +++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 LibMatrix/Extensions/CanonicalJsonSerializer.cs

(limited to 'LibMatrix/Extensions/CanonicalJsonSerializer.cs')

diff --git a/LibMatrix/Extensions/CanonicalJsonSerializer.cs b/LibMatrix/Extensions/CanonicalJsonSerializer.cs
new file mode 100644
index 0000000..a6fbcf4
--- /dev/null
+++ b/LibMatrix/Extensions/CanonicalJsonSerializer.cs
@@ -0,0 +1,91 @@
+using System.Collections.Frozen;
+using System.Reflection;
+using System.Security.Cryptography;
+using System.Text.Encodings.Web;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using System.Text.Json.Serialization;
+using System.Text.Json.Serialization.Metadata;
+using System.Text.Unicode;
+using ArcaneLibs.Extensions;
+
+namespace LibMatrix.Extensions;
+
+public static class CanonicalJsonSerializer {
+    // TODO: Alphabetise dictionaries
+    private static JsonSerializerOptions _options => new() {
+        WriteIndented = false,
+        Encoder = UnicodeJsonEncoder.Singleton,
+    };
+
+    private static readonly FrozenSet<PropertyInfo> JsonSerializerOptionsProperties = typeof(JsonSerializerOptions)
+        .GetProperties(BindingFlags.Public | BindingFlags.Instance)
+        .Where(x => x.SetMethod != null && x.GetMethod != null)
+        .ToFrozenSet();
+
+    private static JsonSerializerOptions MergeOptions(JsonSerializerOptions? inputOptions) {
+        var newOptions = _options;
+        if (inputOptions == null)
+            return newOptions;
+        
+        foreach (var property in JsonSerializerOptionsProperties) {
+            if(property.Name == nameof(JsonSerializerOptions.Encoder))
+                continue;
+            if (property.Name == nameof(JsonSerializerOptions.WriteIndented))
+                continue;
+                
+            var value = property.GetValue(inputOptions);
+            // if (value == null)
+                // continue;
+            property.SetValue(newOptions, value);
+        }
+
+        return newOptions;
+    }
+
+#region STJ API
+
+    public static String Serialize<TValue>(TValue value, JsonSerializerOptions? options = null) {
+        var newOptions = MergeOptions(options);
+
+        return System.Text.Json.JsonSerializer.SerializeToNode(value, options) // We want to allow passing custom converters for eg. double/float -> string here...
+            .SortProperties()!
+            .CanonicalizeNumbers()!
+            .ToJsonString(newOptions);
+        
+            
+        // System.Text.Json.JsonSerializer.SerializeToNode(System.Text.Json.JsonSerializer.Deserialize<dynamic>("{\n    \"a\": -0,\n    \"b\": 1e10\n}")).ToJsonString();
+        
+    }
+
+    public static String Serialize(object value, Type inputType, JsonSerializerOptions? options = null) => JsonSerializer.Serialize(value, inputType, _options);
+    // public static String Serialize<TValue>(TValue value, JsonTypeInfo<TValue> jsonTypeInfo) => JsonSerializer.Serialize(value, jsonTypeInfo, _options);
+    // public static String Serialize(Object value, JsonTypeInfo jsonTypeInfo) 
+
+#endregion
+
+    private static partial class JsonExtensions {
+        public static Action<JsonTypeInfo> AlphabetizeProperties(Type type) {
+            return typeInfo => {
+                if (typeInfo.Kind != JsonTypeInfoKind.Object || !type.IsAssignableFrom(typeInfo.Type))
+                    return;
+                AlphabetizeProperties()(typeInfo);
+            };
+        }
+
+        public static Action<JsonTypeInfo> AlphabetizeProperties() {
+            return static typeInfo => {
+                if (typeInfo.Kind == JsonTypeInfoKind.Dictionary) { }
+
+                if (typeInfo.Kind != JsonTypeInfoKind.Object)
+                    return;
+                var properties = typeInfo.Properties.OrderBy(p => p.Name, StringComparer.Ordinal).ToList();
+                typeInfo.Properties.Clear();
+                for (int i = 0; i < properties.Count; i++) {
+                    properties[i].Order = i;
+                    typeInfo.Properties.Add(properties[i]);
+                }
+            };
+        }
+    }
+}
\ No newline at end of file
-- 
cgit 1.4.1