feat: Add Variation configuration section type and MaxLength field (#869)

Co-authored-by: yuskithedeveloper <yuskianywhere@gmail.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Oleg Zhuk <zhukoo@gmail.com>

Author: 4 people

src/VirtoCommerce.CatalogModule.Core/Model/Configuration/ProductConfigurationSection.cs

@@ -16,6 +16,7 @@ public class ProductConfigurationSection : AuditableEntity, ICloneable, IHasName
     public string Type { get; set; }
     public bool AllowCustomText { get; set; }
     public bool AllowPredefinedOptions { get; set; }
+    public int? MaxLength { get; set; }
 
     [JsonIgnore]
     public ProductConfiguration Configuration { get; set; }

src/VirtoCommerce.CatalogModule.Core/ModuleConstants.cs

@@ -11,6 +11,7 @@ namespace VirtoCommerce.CatalogModule.Core
     public static class ModuleConstants
     {
         public const string ConfigurationSectionTypeProduct = "Product";
+        public const string ConfigurationSectionTypeVariation = "Variation";
         public const string ConfigurationSectionTypeText = "Text";
         public const string ConfigurationSectionTypeFile = "File";
         public const string ConfigurationSectionFilesScope = "product-configuration";

src/VirtoCommerce.CatalogModule.Core/Serialization/ProductJsonSerializer.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Globalization;
+using System.IO;
+using System.Text;
+using Newtonsoft.Json;
+using VirtoCommerce.Platform.Core.Common;
+
+namespace VirtoCommerce.CatalogModule.Core.Serialization;
+
+/// <summary>
+/// Provides JSON serialization and deserialization for catalog objects (products, categories, etc.)
+/// with settings optimized for compact storage (e.g. product snapshots in orders).
+/// </summary>
+public static class ProductJsonSerializer
+{
+    public static JsonSerializer ObjectSerializer { get; } = new()
+    {
+        DefaultValueHandling = DefaultValueHandling.Include,
+        NullValueHandling = NullValueHandling.Ignore,
+        Formatting = Formatting.None,
+        ReferenceLoopHandling = ReferenceLoopHandling.Ignore,
+        TypeNameHandling = TypeNameHandling.None,
+    };
+
+    public static string Serialize(object obj)
+    {
+        using var stringWriter = new StringWriter(new StringBuilder(256), CultureInfo.InvariantCulture);
+        using var jsonTextWriter = new JsonTextWriter(stringWriter);
+        jsonTextWriter.Formatting = ObjectSerializer.Formatting;
+        ObjectSerializer.Serialize(jsonTextWriter, obj, objectType: null);
+
+        return stringWriter.ToString();
+    }
+
+    public static T Deserialize<T>(string json)
+    {
+        return (T)Deserialize(json, typeof(T));
+    }
+
+    public static object Deserialize(string json, Type type)
+    {
+        using var stringReader = new StringReader(json);
+        using var jsonTextReader = new JsonTextReader(stringReader);
+        var result = ObjectSerializer.Deserialize(jsonTextReader, type);
+
+        return result;
+    }
+
+    /// <summary>
+    /// Deserializes JSON to the correct polymorphic type using <see cref="AbstractTypeFactory{T}"/>.
+    /// </summary>
+    public static T DeserializePolymorphic<T>(string json)
+        where T : class
+    {
+        var type = AbstractTypeFactory<T>.TryCreateInstance().GetType();
+        return Deserialize(json, type) as T;
+    }
+}