From 39138446ea003e3297ac537910813880668f9fa6 Mon Sep 17 00:00:00 2001
From: Ellpeck <me@ellpeck.de>
Date: Sun, 7 Nov 2021 00:23:48 +0100
Subject: [PATCH] added some more utility to JsonTypeSafeWrapper and revert
 SetData changes

---
 .../Json/JsonTypeSafeGenericDataHolder.cs     |  8 +++---
 MLEM.Data/Json/JsonTypeSafeWrapper.cs         | 25 ++++++++++++++++++-
 MLEM/Misc/GenericDataHolder.cs                |  7 +++---
 3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/MLEM.Data/Json/JsonTypeSafeGenericDataHolder.cs b/MLEM.Data/Json/JsonTypeSafeGenericDataHolder.cs
index bfb98b5..d5d88e2 100644
--- a/MLEM.Data/Json/JsonTypeSafeGenericDataHolder.cs
+++ b/MLEM.Data/Json/JsonTypeSafeGenericDataHolder.cs
@@ -16,21 +16,21 @@ namespace MLEM.Data.Json {
         private Dictionary<string, JsonTypeSafeWrapper> data;
 
         /// <inheritdoc />
-        public void SetData<T>(string key, T data) {
-            if (EqualityComparer<T>.Default.Equals(data, default)) {
+        public void SetData(string key, object data) {
+            if (data == default) {
                 if (this.data != null)
                     this.data.Remove(key);
             } else {
                 if (this.data == null)
                     this.data = new Dictionary<string, JsonTypeSafeWrapper>();
-                this.data[key] = new JsonTypeSafeWrapper<T>(data);
+                this.data[key] = JsonTypeSafeWrapper.Of(data);
             }
         }
 
         /// <inheritdoc />
         public T GetData<T>(string key) {
             if (this.data != null && this.data.TryGetValue(key, out var val))
-                return (T) val.Value;
+                return val.GetValue<T>();
             return default;
         }
 
diff --git a/MLEM.Data/Json/JsonTypeSafeWrapper.cs b/MLEM.Data/Json/JsonTypeSafeWrapper.cs
index f6191ec..968e269 100644
--- a/MLEM.Data/Json/JsonTypeSafeWrapper.cs
+++ b/MLEM.Data/Json/JsonTypeSafeWrapper.cs
@@ -8,7 +8,7 @@ namespace MLEM.Data.Json {
     /// A json type-safe wrapper can be used to wrap any objects of any type before submitting them to a non-specifically typed <see cref="List{T}"/> or <see cref="Dictionary{T,T}"/> that will be serialized using a <see cref="JsonSerializer"/> in cases where <see cref="JsonSerializer.TypeNameHandling"/> is not set to <see cref="TypeNameHandling.None"/>.
     /// If any object is not wrapped in this manner, and it has a custom <see cref="JsonConverter"/>, the value deserialized from it might not have the same type as the originally serialized object. This behavior can be observed, for example, when serializing a <see cref="List{T}"/> of <see cref="object"/> entries, one of which is a <see cref="TimeSpan"/>: The <see cref="TimeSpan"/> will be serialized as a <see cref="string"/> and, upon deserialization, will remain a <see cref="string"/>.
     /// In general, wrapping objects in this manner is only useful in rare cases, where custom data of an unexpected or unknown type is stored.
-    /// See <see cref="JsonTypeSafeGenericDataHolder"/> for an example of how this class and <see cref="JsonTypeSafeWrapper{T}"/> can be used, and see this stackoverflow answer for more information on the problem that this class solves: https://stackoverflow.com/a/38798114.
+    /// See <see cref="JsonTypeSafeGenericDataHolder"/> for an example of how this class can be used, and see this stackoverflow answer for more information on the problem that this class solves: https://stackoverflow.com/a/38798114.
     /// </summary>
     public abstract class JsonTypeSafeWrapper {
 
@@ -17,6 +17,28 @@ namespace MLEM.Data.Json {
         /// </summary>
         public abstract object Value { get; }
 
+        /// <summary>
+        /// Returns the current <see cref="Value"/> of this <see cref="JsonTypeSafeWrapper"/>, typecast to the given type <typeparamref name="T"/>.
+        /// If this <see cref="Value"/>'s type is incompatible with the given type, the type's default value is returned instead.
+        /// </summary>
+        /// <typeparam name="T">The type of value to return</typeparam>
+        /// <returns>The <see cref="Value"/>, castt to the given type if compatible, otherwise default</returns>
+        public T GetValue<T>() {
+            return this.Value is T t ? t : default;
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="JsonTypeSafeWrapper{T}"/> from the given value.
+        /// The type parameter of the returned wrapper will be equal to the <see cref="Type"/> of the <paramref name="value"/> passed.
+        /// If a <see cref="JsonTypeSafeWrapper{T}"/> for a specific type, known at comepile type, should be created, you can use <see cref="JsonTypeSafeWrapper{T}(T)"/>.
+        /// </summary>
+        /// <param name="value">The value to wrap</param>
+        /// <returns>A <see cref="JsonTypeSafeWrapper{T}"/> with a type matching the type of <paramref name="value"/></returns>
+        public static JsonTypeSafeWrapper Of(object value) {
+            var type = typeof(JsonTypeSafeWrapper<>).MakeGenericType(value.GetType());
+            return (JsonTypeSafeWrapper) Activator.CreateInstance(type, value);
+        }
+
     }
 
     /// <inheritdoc />
@@ -30,6 +52,7 @@ namespace MLEM.Data.Json {
 
         /// <summary>
         /// Creates a new json type-safe wrapper instance that wraps the given <paramref name="value"/>.
+        /// If the type of the value is unknown at compile time, <see cref="JsonTypeSafeWrapper.Of"/> can be used instead.
         /// </summary>
         /// <param name="value">The value to wrap</param>
         public JsonTypeSafeWrapper(T value) {
diff --git a/MLEM/Misc/GenericDataHolder.cs b/MLEM/Misc/GenericDataHolder.cs
index 120d3d9..224eace 100644
--- a/MLEM/Misc/GenericDataHolder.cs
+++ b/MLEM/Misc/GenericDataHolder.cs
@@ -11,8 +11,8 @@ namespace MLEM.Misc {
         private Dictionary<string, object> data;
 
         /// <inheritdoc />
-        public void SetData<T>(string key, T data) {
-            if (EqualityComparer<T>.Default.Equals(data, default)) {
+        public void SetData(string key, object data) {
+            if (data == default) {
                 if (this.data != null)
                     this.data.Remove(key);
             } else {
@@ -49,8 +49,7 @@ namespace MLEM.Misc {
         /// </summary>
         /// <param name="key">The key to store the data by</param>
         /// <param name="data">The data to store in the object</param>
-        /// <typeparam name="T">The type of the data to store</typeparam>
-        void SetData<T>(string key, T data);
+        void SetData(string key, object data);
 
         /// <summary>
         /// Returns a piece of generic data of the given type on this object.