Refactor code structure for improved readability and maintainability; optimize performance in key functions.

src/AirGap/__Libraries/StellaOps.AirGap.Bundle/Serialization/BundleManifestSerializer.cs

@@ -0,0 +1,47 @@
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Encodings.Web;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using StellaOps.AirGap.Bundle.Models;
+using StellaOps.Canonical.Json;
+
+namespace StellaOps.AirGap.Bundle.Serialization;
+
+/// <summary>
+/// Canonical serialization for bundle manifests.
+/// </summary>
+public static class BundleManifestSerializer
+{
+    private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web)
+    {
+        WriteIndented = false,
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
+    };
+
+    public static string Serialize(BundleManifest manifest)
+    {
+        var jsonBytes = JsonSerializer.SerializeToUtf8Bytes(manifest, JsonOptions);
+        var canonicalBytes = CanonJson.CanonicalizeParsedJson(jsonBytes);
+        return Encoding.UTF8.GetString(canonicalBytes);
+    }
+
+    public static BundleManifest Deserialize(string json)
+    {
+        return JsonSerializer.Deserialize<BundleManifest>(json, JsonOptions)
+            ?? throw new InvalidOperationException("Failed to deserialize bundle manifest");
+    }
+
+    public static string ComputeDigest(BundleManifest manifest)
+    {
+        var withoutDigest = manifest with { BundleDigest = null };
+        var json = Serialize(withoutDigest);
+        var hash = SHA256.HashData(Encoding.UTF8.GetBytes(json));
+        return Convert.ToHexString(hash).ToLowerInvariant();
+    }
+
+    public static BundleManifest WithDigest(BundleManifest manifest)
+        => manifest with { BundleDigest = ComputeDigest(manifest) };
+}