Fix TimestampTag being sadge (#2468)

* Im so sad

* Im so sad v2

* oopsie uwu

src/Discord.Net.Core/Entities/Messages/TimestampTag.cs

@@ -5,58 +5,87 @@ namespace Discord
     /// <summary>
     ///     Represents a class used to make timestamps in messages. see <see href="https://discord.com/developers/docs/reference#message-formatting-timestamp-styles"/>.
     /// </summary>
-    public class TimestampTag
+    public readonly struct TimestampTag
     {
         /// <summary>
-        ///     Gets or sets the style of the timestamp tag.
+        ///     Gets the time for this timestamp tag.
         /// </summary>
-        public TimestampTagStyles Style { get; set; } = TimestampTagStyles.ShortDateTime;
+        public DateTimeOffset Time { get; }
 
         /// <summary>
-        ///     Gets or sets the time for this timestamp tag.
+        ///     Gets the style of this tag. <see langword="null"/> if none was provided.
         /// </summary>
-        public DateTimeOffset Time { get; set; }
+        public TimestampTagStyles? Style { get; }
+
+        /// <summary>
+        ///     Creates a new <see cref="TimestampTag"/> from the provided time.
+        /// </summary>
+        /// <param name="time">The time for this timestamp tag.</param>
+        /// <param name="style">The style for this timestamp tag.</param>
+        public TimestampTag(DateTimeOffset time, TimestampTagStyles? style = null)
+        {
+            Time = time;
+            Style = style;
+        }
 
         /// <summary>
         ///     Converts the current timestamp tag to the string representation supported by discord.
         ///     <para>
         ///         If the <see cref="Time"/> is null then the default 0 will be used.
         ///     </para>
         /// </summary>
+        /// <remarks>
+        ///     Will use the provided <see cref="Style"/> if provided. If this value is null, it will default to <see cref="TimestampTagStyles.ShortDateTime"/>.
+        /// </remarks>
         /// <returns>A string that is compatible in a discord message, ex: <code>&lt;t:1625944201:f&gt;</code></returns>
         public override string ToString()
-        {
-            return $"<t:{Time.ToUnixTimeSeconds()}:{(char)Style}>";
-        }
+            => ToString(Style ?? TimestampTagStyles.ShortDateTime);
+
+        /// <summary>
+        ///     Converts the current timestamp tag to the string representation supported by discord.
+        ///     <para>
+        ///         If the <see cref="Time"/> is null then the default 0 will be used.
+        ///     </para>
+        /// </summary>
+        /// <param name="style">The formatting style for this tag.</param>
+        /// <returns>A string that is compatible in a discord message, ex: <code>&lt;t:1625944201:f&gt;</code></returns>
+        public string ToString(TimestampTagStyles style)
+            => $"<t:{Time.ToUnixTimeSeconds()}:{(char)style}>";
 
         /// <summary>
         ///     Creates a new timestamp tag with the specified <see cref="DateTime"/> object.
         /// </summary>
         /// <param name="time">The time of this timestamp tag.</param>
         /// <param name="style">The style for this timestamp tag.</param>
         /// <returns>The newly create timestamp tag.</returns>
-        public static TimestampTag FromDateTime(DateTime time, TimestampTagStyles style = TimestampTagStyles.ShortDateTime)
-        {
-            return new TimestampTag
-            {
-                Style = style,
-                Time = time
-            };
-        }
+        public static TimestampTag FromDateTime(DateTime time, TimestampTagStyles? style = null)
+            => new(time, style);
 
         /// <summary>
         ///     Creates a new timestamp tag with the specified <see cref="DateTimeOffset"/> object.
         /// </summary>
         /// <param name="time">The time of this timestamp tag.</param>
         /// <param name="style">The style for this timestamp tag.</param>
         /// <returns>The newly create timestamp tag.</returns>
-        public static TimestampTag FromDateTimeOffset(DateTimeOffset time, TimestampTagStyles style = TimestampTagStyles.ShortDateTime)
-        {
-            return new TimestampTag
-            {
-                Style = style,
-                Time  = time
-            };
-        }
+        public static TimestampTag FromDateTimeOffset(DateTimeOffset time, TimestampTagStyles? style = null)
+            => new(time, style);
+
+        /// <summary>
+        ///     Immediately formats the provided time and style into a timestamp string.
+        /// </summary>
+        /// <param name="time">The time of this timestamp tag.</param>
+        /// <param name="style">The style for this timestamp tag.</param>
+        /// <returns>The newly create timestamp string.</returns>
+        public static string FormatFromDateTime(DateTime time, TimestampTagStyles style)
+            => FormatFromDateTimeOffset(time, style);
+
+        /// <summary>
+        ///     Immediately formats the provided time and style into a timestamp string.
+        /// </summary>
+        /// <param name="time">The time of this timestamp tag.</param>
+        /// <param name="style">The style for this timestamp tag.</param>
+        /// <returns>The newly create timestamp string.</returns>
+        public static string FormatFromDateTimeOffset(DateTimeOffset time, TimestampTagStyles style)
+            => $"<t:{time.ToUnixTimeSeconds()}:{(char)style}>";
     }
-}
+}