Things were working, suddenly regressed

SVSim.EmulatedEntrypoint/Extensions/FormatExtensions.cs

@@ -0,0 +1,88 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using SVSim.Database.Enums;
+
+namespace SVSim.EmulatedEntrypoint.Extensions;
+
+/// <summary>
+/// Bridges the server's internal <see cref="Format"/> enum (a verbatim copy of the client's
+/// Wizard.Format) and the wire <c>deck_format</c> integer the client speaks. The two are not
+/// interchangeable: the wire value is what flows over the network and what the client's
+/// LoadDetail._userRank dictionary is keyed by AFTER routing through Data.ParseApiFormat;
+/// the internal value is what the server uses for switches, dictionary keys, and database
+/// columns.
+///
+/// Mapping mirrors the client's <c>Wizard.Data.FormatConvertApi</c>
+/// (Shadowverse_Code/Assembly-CSharp/Wizard/Data.cs:580); the inverse mirrors
+/// <c>Data.ParseApiFormat</c> (Data.cs:635). See
+/// docs/api-spec/common/types.ts.md for the table and rationale.
+/// </summary>
+public static class FormatExtensions
+{
+    /// <summary>Internal <see cref="Format"/> &#x2192; wire <c>deck_format</c> integer.</summary>
+    public static int ToApi(this Format format) => format switch
+    {
+        Format.Rotation    => 1,
+        Format.Unlimited   => 2,
+        Format.Max         => 1, // client sentinel; aliases onto Rotation, same as FormatConvertApi.
+        Format.PreRotation => 3,
+        Format.Sealed      => 20,
+        Format.MyRotation  => 5,
+        Format.TwoPick     => 10,
+        Format.Hof         => 31,
+        Format.Windfall    => 33,
+        Format.Avatar      => 39,
+        Format.All         => 0,
+        Format.Crossover   => 4,
+        _ => throw new ArgumentOutOfRangeException(nameof(format), format,
+            $"No wire deck_format mapping for {format} ({(int)format}). " +
+            "Update FormatExtensions.ToApi and Data.cs:580 if a new format was added.")
+    };
+
+    /// <summary>Wire <c>deck_format</c> integer &#x2192; internal <see cref="Format"/>.</summary>
+    public static Format FromApi(int apiValue) => apiValue switch
+    {
+        0  => Format.All,         // Client emits 0 only for "all formats" meta-queries.
+        1  => Format.Rotation,
+        2  => Format.Unlimited,
+        3  => Format.PreRotation,
+        4  => Format.Crossover,
+        5  => Format.MyRotation,
+        10 => Format.TwoPick,
+        20 => Format.Sealed,
+        31 => Format.Hof,
+        33 => Format.Windfall,
+        39 => Format.Avatar,
+        _ => throw new ArgumentOutOfRangeException(nameof(apiValue), apiValue,
+            $"Unknown wire deck_format {apiValue}. The client's ParseApiFormat would warn and " +
+            "fall back to Format.Max; we throw so the calling controller surfaces the bad input.")
+    };
+}
+
+/// <summary>
+/// System.Text.Json converter that emits / accepts <see cref="Format"/> as the wire
+/// <c>deck_format</c> integer rather than the underlying enum value. Wired up in Program.cs
+/// via AddJsonOptions; applies to every response DTO property typed <see cref="Format"/>.
+///
+/// IMPORTANT: this only runs on the System.Text.Json serialization path (response writer +
+/// model binder). MessagePack-CSharp deserialization of request DTOs does NOT honor STJ
+/// converters &#x2014; keep request DTO format fields typed as <c>int</c> and call
+/// <see cref="FormatExtensions.FromApi"/> in the controller.
+/// </summary>
+public sealed class FormatJsonConverter : JsonConverter<Format>
+{
+    public override Format Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        if (reader.TokenType != JsonTokenType.Number || !reader.TryGetInt32(out int wire))
+        {
+            throw new JsonException(
+                $"Expected deck_format as a JSON number, got {reader.TokenType}.");
+        }
+        return FormatExtensions.FromApi(wire);
+    }
+
+    public override void Write(Utf8JsonWriter writer, Format value, JsonSerializerOptions options)
+    {
+        writer.WriteNumberValue(value.ToApi());
+    }
+}