Refactor Toon serializer: robust navigation/type metadata

- Introduce AcNavigationPropertyInfo for unified, cached relationship metadata per property (primary key, navigation type, FK, other key, inverse, target type)
- Refactor relationship detection to use AcNavigationPropertyInfo, replacing ad-hoc logic and old RelationshipMetadata
- Add AcSerializerCommon.GetCSharpTypeName for consistent, C#-style type name formatting (handles primitives, generics, nullables, enums, collections)
- Use topological sort for @types output to ensure dependency order
- Improve enum handling: avoid redundant constraints, use new type name formatter for underlying types
- Output navigation, foreign-key, other-key, and inverse-property metadata consistently in meta section
- Enhance convention-based detection for inverse properties and "other key", including unidirectional/polymorphic support
- Add comprehensive test for navigation metadata completeness and demo test entities
- Add "source-code-language: C#" to meta section
- Misc: code cleanup, remove unused cache, improve property filtering

.claude/settings.local.json

@@ -26,7 +26,8 @@
       "Bash(cmd /c \"dir /B /O-D H:\\Applications\\Aycode\\Source\\AyCode.Core\\Test_Benchmark_Results\\Benchmark\\*.log 2>nul | head -3\")",
       "Bash(cmd /c \"dir /B /O-D H:\\Applications\\Aycode\\Source\\AyCode.Core\\Test_Benchmark_Results\\Benchmark\\*.log 2>nul | head -1\")",
       "Bash(timeout 30 dotnet run:*)",
-      "Bash(dotnet exec vstest:*)"
+      "Bash(dotnet exec vstest:*)",
+      "Bash(dotnet new:*)"
     ]
   }
 }

AyCode.Core/Serializers/AcSerializerCommon.cs

@@ -1006,4 +1006,102 @@ public static class AcSerializerCommon
     }
 
     #endregion
+
+    #region Type Name Formatting
+
+    /// <summary>
+    /// Gets the C# display name for a type (e.g., "int", "List&lt;string&gt;", "Dictionary&lt;int, string&gt;").
+    /// Handles primitives, nullables, generics, enums, collections, and dictionaries.
+    /// Thread-safe with circular reference protection.
+    /// </summary>
+    /// <param name="type">The type to get the name for.</param>
+    /// <param name="useShortNames">If true, uses C# keywords (int, string). If false, uses full names (Int32, String).</param>
+    /// <returns>C# display name of the type.</returns>
+    public static string GetCSharpTypeName(Type type, bool useShortNames = true)
+    {
+        // Handle nullable types
+        var underlying = Nullable.GetUnderlyingType(type);
+        if (underlying != null)
+        {
+            return GetCSharpTypeName(underlying, useShortNames) + "?";
+        }
+
+        // Handle arrays
+        if (type.IsArray)
+        {
+            var elementType = type.GetElementType()!;
+            return GetCSharpTypeName(elementType, useShortNames) + "[]";
+        }
+
+        // IMPORTANT: Check for enum BEFORE primitive type check!
+        // Enum TypeCode returns the underlying type's code (e.g., Int32),
+        // which would incorrectly return "int" instead of the enum name.
+        if (type.IsEnum)
+        {
+            return type.Name;
+        }
+
+        // Handle primitive types with C# keywords
+        if (useShortNames)
+        {
+            var typeCode = Type.GetTypeCode(type);
+            var primitiveName = typeCode switch
+            {
+                TypeCode.Boolean => "bool",
+                TypeCode.Byte => "byte",
+                TypeCode.SByte => "sbyte",
+                TypeCode.Char => "char",
+                TypeCode.Int16 => "short",
+                TypeCode.UInt16 => "ushort",
+                TypeCode.Int32 => "int",
+                TypeCode.UInt32 => "uint",
+                TypeCode.Int64 => "long",
+                TypeCode.UInt64 => "ulong",
+                TypeCode.Single => "float",
+                TypeCode.Double => "double",
+                TypeCode.Decimal => "decimal",
+                TypeCode.String => "string",
+                _ => null
+            };
+            if (primitiveName != null) return primitiveName;
+        }
+
+        // Handle common BCL types
+        if (type == typeof(object)) return "object";
+        if (type == typeof(void)) return "void";
+
+        // Handle generic types
+        if (type.IsGenericType)
+        {
+            var genericDef = type.GetGenericTypeDefinition();
+            var args = type.GetGenericArguments();
+
+            // Special handling for common generic types
+            if (genericDef == typeof(List<>))
+                return $"List<{GetCSharpTypeName(args[0], useShortNames)}>";
+            if (genericDef == typeof(Dictionary<,>))
+                return $"Dictionary<{GetCSharpTypeName(args[0], useShortNames)}, {GetCSharpTypeName(args[1], useShortNames)}>";
+            if (genericDef == typeof(IEnumerable<>))
+                return $"IEnumerable<{GetCSharpTypeName(args[0], useShortNames)}>";
+            if (genericDef == typeof(ICollection<>))
+                return $"ICollection<{GetCSharpTypeName(args[0], useShortNames)}>";
+            if (genericDef == typeof(IList<>))
+                return $"IList<{GetCSharpTypeName(args[0], useShortNames)}>";
+
+            // Generic type with name mangling (e.g., SomeType`2)
+            var baseName = type.Name;
+            var backtickIndex = baseName.IndexOf('`');
+            if (backtickIndex > 0)
+            {
+                baseName = baseName.Substring(0, backtickIndex);
+            }
+            var argNames = string.Join(", ", args.Select(a => GetCSharpTypeName(a, useShortNames)));
+            return $"{baseName}<{argNames}>";
+        }
+
+        // Simple type name (class, struct, enum, etc.)
+        return type.Name;
+    }
+
+    #endregion
 }

AyCode.Core/Serializers/Toons/AcNavigationPropertyInfo.cs

@@ -0,0 +1,71 @@
+using System;
+
+namespace AyCode.Core.Serializers.Toons;
+
+/// <summary>
+/// Cached navigation property metadata for efficient relationship information access.
+/// Contains all relationship details detected once during type metadata construction.
+/// </summary>
+public sealed class AcNavigationPropertyInfo
+{
+    /// <summary>
+    /// Whether this property is a primary key.
+    /// </summary>
+    public bool IsPrimaryKey { get; }
+
+    /// <summary>
+    /// Type of navigation relationship (ManyToOne, OneToMany, etc.).
+    /// Null if this is not a navigation property.
+    /// </summary>
+    public ToonRelationType? NavigationType { get; }
+
+    /// <summary>
+    /// Foreign key property name on the current side.
+    /// For ManyToOne/OneToOne: the FK property in this entity (e.g., "CustomerId").
+    /// For OneToMany: null (FK is on the other side, see OtherKey).
+    /// </summary>
+    public string? ForeignKey { get; }
+
+    /// <summary>
+    /// Foreign key property name on the other side of the relationship.
+    /// For OneToMany: the FK property in the related entity (e.g., "OrderId" in OrderItem).
+    /// For ManyToOne: null (FK is on this side, see ForeignKey).
+    /// This corresponds to Linq2Db's "OtherKey" concept.
+    /// </summary>
+    public string? OtherKey { get; }
+
+    /// <summary>
+    /// Navigation property name on the other side of the relationship.
+    /// For OneToMany: the navigation property in the related entity pointing back (e.g., "Order" in OrderItem).
+    /// For ManyToOne: the collection property in the related entity (e.g., "OrderItems" in Order).
+    /// </summary>
+    public string? InverseProperty { get; }
+
+    /// <summary>
+    /// Target entity type for navigation properties.
+    /// For collections (OneToMany), this is the element type.
+    /// For single references (ManyToOne), this is the property type.
+    /// </summary>
+    public Type? TargetType { get; }
+
+    public AcNavigationPropertyInfo(
+        bool isPrimaryKey = false,
+        ToonRelationType? navigationType = null,
+        string? foreignKey = null,
+        string? otherKey = null,
+        string? inverseProperty = null,
+        Type? targetType = null)
+    {
+        IsPrimaryKey = isPrimaryKey;
+        NavigationType = navigationType;
+        ForeignKey = foreignKey;
+        OtherKey = otherKey;
+        InverseProperty = inverseProperty;
+        TargetType = targetType;
+    }
+
+    /// <summary>
+    /// Empty navigation info (not a navigation property, not a primary key).
+    /// </summary>
+    public static readonly AcNavigationPropertyInfo Empty = new();
+}

AyCode.Core/Serializers/Toons/AcToonSerializer.AttributeExtraction.cs

@@ -14,8 +14,8 @@ public static partial class AcToonSerializer
     {
         var constraints = new List<string>();
 
-        var underlyingType = Nullable.GetUnderlyingType(type);
-        var isNullable = underlyingType != null || !type.IsValueType;
+        var nullableUnderlying = Nullable.GetUnderlyingType(type);
+        var isNullable = nullableUnderlying != null || !type.IsValueType;
 
         // Nullable/Required: NE írjuk ki automatikusan, mert redundáns (a típusból látszik)
         // Csak explicit [Required] attribute esetén írjuk ki (azt az ExtractDataAnnotationConstraints kezeli)
@@ -23,7 +23,17 @@ public static partial class AcToonSerializer
         // Numeric/Boolean: NE írjuk ki, mert redundáns (a típusból látszik)
         // Range-eket megtartjuk, mert azok hasznos extra információk
 
-        var baseType = underlyingType ?? type;
+        var baseType = nullableUnderlying ?? type;
+
+        // Enum property: NE írjunk automatic constraint-et!
+        // A típusból (pl. "TaxDisplayType: TaxDisplayType") már minden információ látszik.
+        // Az underlying type már az enum definíciójában megtalálható a @types szekcióban.
+        // Csak akkor kell constraint, ha explicit attribute-al van megjelölve.
+        if (baseType.IsEnum)
+        {
+            return string.Empty;
+        }
+
         var typeCode = Type.GetTypeCode(baseType);
         switch (typeCode)
         {
@@ -45,8 +55,6 @@ public static partial class AcToonSerializer
             // Int32, Int64, UInt64, Float, Double, Decimal, Boolean: nincs constraint (redundáns lenne)
         }
 
-        // Enum values: NE írjuk ki a constraint-ben, mert már a type metadata-ban benne van
-
         return constraints.Count > 0 ? string.Join(", ", constraints) : string.Empty;
     }
 

AyCode.Core/Serializers/Toons/AcToonSerializer.DataSection.cs

@@ -326,30 +326,12 @@ public static partial class AcToonSerializer
     }
 
     /// <summary>
-    /// Get type display name for a type (used in array hints).
+    /// Get C# type display name for a type (used in array hints).
+    /// Uses shared AcSerializerCommon.GetCSharpTypeName for consistency.
     /// </summary>
     private static string GetTypeDisplayName(Type type)
     {
-        var typeCode = Type.GetTypeCode(type);
-        return typeCode switch
-        {
-            TypeCode.Int32 => "int32",
-            TypeCode.Int64 => "int64",
-            TypeCode.Double => "float64",
-            TypeCode.Single => "float32",
-            TypeCode.Decimal => "decimal",
-            TypeCode.Boolean => "bool",
-            TypeCode.String => "string",
-            TypeCode.DateTime => "datetime",
-            TypeCode.Byte => "byte",
-            TypeCode.Int16 => "int16",
-            TypeCode.UInt16 => "uint16",
-            TypeCode.UInt32 => "uint32",
-            TypeCode.UInt64 => "uint64",
-            TypeCode.SByte => "sbyte",
-            TypeCode.Char => "char",
-            _ => type.Name.ToLowerInvariant()
-        };
+        return AcSerializerCommon.GetCSharpTypeName(type, useShortNames: true);
     }
 
     /// <summary>

AyCode.Core/Serializers/Toons/AcToonSerializer.MetaSection.cs

@@ -59,6 +59,7 @@ public static partial class AcToonSerializer
         context.CurrentIndentLevel++;
         context.WriteProperty("version", $"\"{FormatVersion}\"");
         context.WriteProperty("format", "\"toon\"");
+        context.WriteProperty("source-code-language", "\"C#\"");
 
         // Write type list
         context.WriteIndent();
@@ -82,9 +83,12 @@ public static partial class AcToonSerializer
             .Where(t => !t.Name.StartsWith("List`", StringComparison.Ordinal) && !t.Name.StartsWith("ICollection`", StringComparison.Ordinal) && !t.Name.StartsWith("IEnumerable`", StringComparison.Ordinal) && !t.Name.StartsWith("Dictionary`", StringComparison.Ordinal))
             .ToList();
 
+        // DAG topological sort: dependencies first
+        var sortedTypes = TopologicalSortTypes(filteredTypes);
+
         context.Write("[");
         var first = true;
-        foreach (var t in filteredTypes)
+        foreach (var t in sortedTypes)
         {
             if (!first) context.Write(", ");
             context.Write($"\"{t.Name}\"");
@@ -101,11 +105,11 @@ public static partial class AcToonSerializer
             context.WriteLine();
         }
 
-        // @types section with descriptions
+        // @types section with descriptions (same sorted order)
         context.WriteLine("@types {");
         context.CurrentIndentLevel++;
 
-        foreach (var t in filteredTypes)
+        foreach (var t in sortedTypes)
         {
             WriteTypeDefinition(t, context);
         }
@@ -195,14 +199,13 @@ public static partial class AcToonSerializer
 
     /// <summary>
     /// Megkeresi a property-hez tartozó enum típust, ha az egy enum backing field.
-    /// Visszaadja az enum típust, ha van, különben null.
+    /// Visszaadja az enum típust CSAK akkor, ha:
+    /// 1. Van megfelelő nevű enum property (naming convention)
+    /// 2. Az enum property NotMapped/NotColumn/JsonIgnore attribútummal van ellátva
+    /// 3. A backing field típusa megegyezik az enum underlying type-jával (int/int?, byte/byte?, stb.)
     /// </summary>
     private static Type? FindEnumTypeForBackingField(PropertyInfo backingFieldProperty, Type declaringType)
     {
-        // Csak int/int? típusú property-k lehetnek backing field-ek
-        if (backingFieldProperty.PropertyType != typeof(int) && backingFieldProperty.PropertyType != typeof(int?))
-            return null;
-
         // Ha a property neve "...Id"-re végződik, keressük meg az enum property-t
         if (!backingFieldProperty.Name.EndsWith("Id", StringComparison.Ordinal))
             return null;
@@ -212,10 +215,36 @@ public static partial class AcToonSerializer
 
         var enumProperty = allProperties.FirstOrDefault(p =>
             p.Name == enumPropertyName &&
-            p.PropertyType.IsEnum);
+            (p.PropertyType.IsEnum || (Nullable.GetUnderlyingType(p.PropertyType)?.IsEnum ?? false)));
 
-        // Ha van enum property, visszaadjuk a típusát (függetlenül a NotMapped attribútumtól)
-        return enumProperty?.PropertyType;
+        if (enumProperty == null) return null;
+
+        // Ellenőrizzük, hogy NotMapped/NotColumn/JsonIgnore van-e rajta
+        var isNotMapped = enumProperty.GetCustomAttributes(inherit: true).Any(attr =>
+        {
+            var attrName = attr.GetType().Name;
+            return attrName == "NotMappedAttribute" ||
+                   attrName == "NotColumnAttribute" ||
+                   attrName == "JsonIgnoreAttribute";
+        });
+
+        // Csak akkor backing field, ha az enum property NotMapped!
+        if (!isNotMapped) return null;
+
+        // Ellenőrizzük, hogy a backing field típusa megegyezik-e az enum underlying type-jával
+        var enumType = Nullable.GetUnderlyingType(enumProperty.PropertyType) ?? enumProperty.PropertyType;
+        var enumUnderlyingType = Enum.GetUnderlyingType(enumType);
+
+        // A backing field lehet nullable vagy non-nullable is
+        var backingUnderlyingType = Nullable.GetUnderlyingType(backingFieldProperty.PropertyType)
+                                    ?? backingFieldProperty.PropertyType;
+
+        // Az underlying type-oknak meg kell egyezniük
+        if (backingUnderlyingType != enumUnderlyingType)
+            return null;
+
+        // Visszaadjuk az enum típust (nullable nélkül)
+        return enumType;
     }
 
     /// <summary>
@@ -272,8 +301,8 @@ public static partial class AcToonSerializer
             var constraints = GetFinalPropertyConstraints(prop, type);
             var examples = GetFinalPropertyExamples(prop);
 
-            // Detect relationship metadata
-            var relationshipMetadata = DetectRelationshipMetadata(prop.PropertyInfo, prop.CustomDescription);
+            // Use cached navigation metadata from property accessor
+            var nav = prop.Navigation;
 
             var typeHint = prop.TypeDisplayName;
 
@@ -294,26 +323,31 @@ public static partial class AcToonSerializer
                 if (!string.IsNullOrEmpty(examples))
                     context.WriteIndentedLine($"examples: \"{examples}\"");
 
-                // Add relationship metadata
-                if (relationshipMetadata.IsPrimaryKey)
+                // Add relationship metadata from cached navigation info
+                if (nav.IsPrimaryKey)
                     context.WriteIndentedLine($"primary-key: true");
-                if (!string.IsNullOrEmpty(relationshipMetadata.ForeignKeyNavigationProperty))
-                    context.WriteIndentedLine($"foreign-key: \"{relationshipMetadata.ForeignKeyNavigationProperty}\"");
-                if (relationshipMetadata.NavigationType.HasValue)
+
+                // Only write foreign-key for navigation properties, not for FK properties themselves
+                if (!string.IsNullOrEmpty(nav.ForeignKey) && nav.NavigationType.HasValue)
+                    context.WriteIndentedLine($"foreign-key: \"{nav.ForeignKey}\"");
+
+                if (!string.IsNullOrEmpty(nav.OtherKey))
+                    context.WriteIndentedLine($"other-key: \"{nav.OtherKey}\"");
+                if (nav.NavigationType.HasValue)
                 {
-                    var navType = relationshipMetadata.NavigationType.Value.ToString();
+                    var navType = nav.NavigationType.Value.ToString();
                     var navTypeFormatted = string.Concat(navType.Select((c, i) => i > 0 && char.IsUpper(c) ? "-" + char.ToLower(c) : char.ToLower(c).ToString()));
                     context.WriteIndentedLine($"navigation: \"{navTypeFormatted}\"");
                 }
-                if (!string.IsNullOrEmpty(relationshipMetadata.InverseProperty))
-                    context.WriteIndentedLine($"inverse-property: \"{relationshipMetadata.InverseProperty}\"");
+                if (!string.IsNullOrEmpty(nav.InverseProperty))
+                    context.WriteIndentedLine($"inverse-property: \"{nav.InverseProperty}\"");
 
                 context.CurrentIndentLevel--;
             }
             else
             {
                 // Simple format
-                var relationshipHint = GetRelationshipHint(relationshipMetadata);
+                var relationshipHint = GetRelationshipHint(nav);
 
                 // Only write description if there's explicit description OR relationship metadata
                 if (!string.IsNullOrEmpty(propDescription) || !string.IsNullOrEmpty(relationshipHint))
@@ -371,18 +405,7 @@ public static partial class AcToonSerializer
 
             // Underlying type
             var underlyingType = Enum.GetUnderlyingType(enumType);
-            var underlyingTypeName = Type.GetTypeCode(underlyingType) switch
-            {
-                TypeCode.Byte => "byte",
-                TypeCode.SByte => "sbyte",
-                TypeCode.Int16 => "int16",
-                TypeCode.UInt16 => "uint16",
-                TypeCode.Int32 => "int32",
-                TypeCode.UInt32 => "uint32",
-                TypeCode.Int64 => "int64",
-                TypeCode.UInt64 => "uint64",
-                _ => underlyingType.Name.ToLower()
-            };
+            var underlyingTypeName = AcSerializerCommon.GetCSharpTypeName(underlyingType, useShortNames: true);
             context.WriteIndentedLine($"underlying-type: \"{underlyingTypeName}\"");
 
             // Default value (first enum member)
@@ -871,19 +894,22 @@ public static partial class AcToonSerializer
     /// <summary>
     /// Get relationship hint string for simple format output.
     /// </summary>
-    private static string GetRelationshipHint(RelationshipMetadata metadata)
+    private static string GetRelationshipHint(AcNavigationPropertyInfo nav)
     {
         var hints = new List<string>();
 
-        if (metadata.IsPrimaryKey)
+        if (nav.IsPrimaryKey)
             hints.Add("primary-key");
 
-        if (!string.IsNullOrEmpty(metadata.ForeignKeyNavigationProperty))
-            hints.Add($"fk->{metadata.ForeignKeyNavigationProperty}");
+        if (!string.IsNullOrEmpty(nav.ForeignKey))
+            hints.Add($"fk->{nav.ForeignKey}");
 
-        if (metadata.NavigationType.HasValue)
+        if (!string.IsNullOrEmpty(nav.OtherKey))
+            hints.Add($"other-key:{nav.OtherKey}");
+
+        if (nav.NavigationType.HasValue)
         {
-            var navType = metadata.NavigationType.Value switch
+            var navType = nav.NavigationType.Value switch
             {
                 ToonRelationType.ManyToOne => "many-to-one",
                 ToonRelationType.OneToMany => "one-to-many",
@@ -895,9 +921,136 @@ public static partial class AcToonSerializer
                 hints.Add(navType);
         }
 
-        if (!string.IsNullOrEmpty(metadata.InverseProperty))
-            hints.Add($"inverse:{metadata.InverseProperty}");
+        if (!string.IsNullOrEmpty(nav.InverseProperty))
+            hints.Add($"inverse:{nav.InverseProperty}");
 
         return hints.Count > 0 ? string.Join(", ", hints) : string.Empty;
     }
+
+    /// <summary>
+    /// Topological sort for types: dependencies appear before dependents.
+    /// Handles circular references by ignoring back-edges.
+    /// </summary>
+    private static List<Type> TopologicalSortTypes(List<Type> types)
+    {
+        // Build dependency graph
+        var graph = new Dictionary<Type, HashSet<Type>>();
+        var inDegree = new Dictionary<Type, int>();
+
+        foreach (var type in types)
+        {
+            if (!graph.ContainsKey(type))
+            {
+                graph[type] = new HashSet<Type>();
+                inDegree[type] = 0;
+            }
+        }
+
+        // For each type, find its dependencies (types referenced in properties)
+        foreach (var type in types)
+        {
+            var dependencies = GetTypeDependencies(type, types);
+            foreach (var dependency in dependencies)
+            {
+                if (graph.ContainsKey(dependency) && dependency != type) // Ignore self-references
+                {
+                    // dependency → type edge (dependency must come before type)
+                    if (graph[dependency].Add(type))
+                    {
+                        inDegree[type]++;
+                    }
+                }
+            }
+        }
+
+        // Kahn's algorithm for topological sort
+        var queue = new Queue<Type>();
+        var result = new List<Type>();
+
+        // Start with types that have no dependencies (in-degree = 0)
+        foreach (var type in types)
+        {
+            if (inDegree[type] == 0)
+            {
+                queue.Enqueue(type);
+            }
+        }
+
+        while (queue.Count > 0)
+        {
+            var current = queue.Dequeue();
+            result.Add(current);
+
+            // For each type that depends on current
+            foreach (var dependent in graph[current])
+            {
+                inDegree[dependent]--;
+                if (inDegree[dependent] == 0)
+                {
+                    queue.Enqueue(dependent);
+                }
+            }
+        }
+
+        // If there are cycles, add remaining types in alphabetical order
+        if (result.Count < types.Count)
+        {
+            var remaining = types.Where(t => !result.Contains(t)).OrderBy(t => t.Name);
+            result.AddRange(remaining);
+        }
+
+        return result;
+    }
+
+    /// <summary>
+    /// Get all type dependencies for a given type (types referenced in properties).
+    /// </summary>
+    private static HashSet<Type> GetTypeDependencies(Type type, List<Type> availableTypes)
+    {
+        var dependencies = new HashSet<Type>();
+
+        if (type.IsEnum)
+        {
+            // Enums have no dependencies
+            return dependencies;
+        }
+
+        var metadata = GetTypeMetadata(type);
+
+        foreach (var prop in metadata.Properties)
+        {
+            var propType = Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType;
+
+            // Check if this property type is in our available types
+            if (availableTypes.Contains(propType) && propType != type)
+            {
+                dependencies.Add(propType);
+            }
+
+            // Check for collection element types
+            if (typeof(IEnumerable).IsAssignableFrom(propType) && propType != typeof(string))
+            {
+                var elementType = GetCollectionElementType(propType);
+                if (elementType != null && availableTypes.Contains(elementType) && elementType != type)
+                {
+                    dependencies.Add(elementType);
+                }
+            }
+
+            // Check for dictionary key/value types
+            if (IsDictionaryType(propType, out var keyType, out var valueType))
+            {
+                if (keyType != null && availableTypes.Contains(keyType) && keyType != type)
+                {
+                    dependencies.Add(keyType);
+                }
+                if (valueType != null && availableTypes.Contains(valueType) && valueType != type)
+                {
+                    dependencies.Add(valueType);
+                }
+            }
+        }
+
+        return dependencies;
+    }
 }

AyCode.Core/Serializers/Toons/AcToonSerializer.RelationshipDetection.cs

@@ -7,89 +7,114 @@ namespace AyCode.Core.Serializers.Toons;
 public static partial class AcToonSerializer
 {
     /// <summary>
-    /// Relationship metadata for a property.
-    /// </summary>
-    private sealed class RelationshipMetadata
-    {
-        public bool IsPrimaryKey { get; set; }
-        public string? ForeignKeyNavigationProperty { get; set; }
-        public ToonRelationType? NavigationType { get; set; }
-        public string? InverseProperty { get; set; }
-    }
-
-    /// <summary>
-    /// Detects relationship metadata for a property with fallback chain.
+    /// Detects navigation property metadata for a property with fallback chain.
     /// Priority: ToonDescription -> EF Core/Linq2Db attributes -> Convention-based detection.
+    /// Returns cached AcNavigationPropertyInfo with all relationship details.
     /// </summary>
-    private static RelationshipMetadata DetectRelationshipMetadata(PropertyInfo property, ToonDescriptionAttribute? customDescription)
+    internal static AcNavigationPropertyInfo DetectNavigationMetadata(PropertyInfo property, ToonDescriptionAttribute? customDescription)
     {
-        var metadata = new RelationshipMetadata();
-
         // 1. IsPrimaryKey - Priority: ToonDescription -> EF Core [Key] -> Linq2Db [PrimaryKey] -> Convention
+        bool isPrimaryKey;
         if (customDescription?.IsPrimaryKey.HasValue == true)
         {
-            metadata.IsPrimaryKey = customDescription.IsPrimaryKey.Value;
+            isPrimaryKey = customDescription.IsPrimaryKey.Value;
         }
         else if (TryGetEFCoreKey(property) || TryGetLinq2DbPrimaryKey(property))
         {
-            metadata.IsPrimaryKey = true;
+            isPrimaryKey = true;
         }
         else
         {
-            metadata.IsPrimaryKey = IsConventionPrimaryKey(property);
+            isPrimaryKey = IsConventionPrimaryKey(property);
         }
 
-        // 2. ForeignKey - Priority: ToonDescription -> EF Core [ForeignKey] -> Linq2Db [Association] -> Convention
-        if (!string.IsNullOrEmpty(customDescription?.ForeignKey))
-        {
-            metadata.ForeignKeyNavigationProperty = customDescription.ForeignKey;
-        }
-        else
-        {
-            var efCoreFk = TryGetEFCoreForeignKey(property);
-            if (!string.IsNullOrEmpty(efCoreFk))
-            {
-                metadata.ForeignKeyNavigationProperty = efCoreFk;
-            }
-            else
-            {
-                metadata.ForeignKeyNavigationProperty = DetectConventionForeignKey(property);
-            }
-        }
-
-        // 3. Navigation - Priority: ToonDescription -> EF Core [InverseProperty] -> Linq2Db [Association] -> Convention
+        // 2. Navigation type detection (needed early for FK detection logic)
+        ToonRelationType? navigationType = null;
         if (customDescription?.Navigation.HasValue == true)
         {
-            metadata.NavigationType = customDescription.Navigation.Value;
+            navigationType = customDescription.Navigation.Value;
         }
         else
         {
             var linq2dbNav = TryGetLinq2DbNavigation(property);
             if (linq2dbNav.HasValue)
             {
-                metadata.NavigationType = linq2dbNav.Value;
+                navigationType = linq2dbNav.Value;
             }
             else
             {
-                metadata.NavigationType = DetectConventionNavigation(property);
+                navigationType = DetectConventionNavigation(property);
             }
         }
 
-        // 4. InverseProperty - Priority: ToonDescription -> EF Core [InverseProperty]
+        // 3. ForeignKey - Priority: ToonDescription -> EF Core [ForeignKey] -> Linq2Db [Association] -> Convention
+        string? foreignKey = null;
+        if (!string.IsNullOrEmpty(customDescription?.ForeignKey))
+        {
+            foreignKey = customDescription.ForeignKey;
+        }
+        else
+        {
+            var efCoreFk = TryGetEFCoreForeignKey(property);
+            if (!string.IsNullOrEmpty(efCoreFk))
+            {
+                foreignKey = efCoreFk;
+            }
+            else
+            {
+                // For FK properties (int/Guid/etc ending with Id)
+                foreignKey = DetectConventionForeignKey(property);
+
+                // For navigation properties (ManyToOne/OneToOne), find the FK property name
+                if (string.IsNullOrEmpty(foreignKey) &&
+                    (navigationType == ToonRelationType.ManyToOne || navigationType == ToonRelationType.OneToOne))
+                {
+                    foreignKey = DetectForeignKeyForNavigationProperty(property);
+                }
+            }
+        }
+
+        // 4. InverseProperty - Priority: ToonDescription -> EF Core [InverseProperty] -> Convention
+        string? inverseProperty = null;
         if (!string.IsNullOrEmpty(customDescription?.InverseProperty))
         {
-            metadata.InverseProperty = customDescription.InverseProperty;
+            inverseProperty = customDescription.InverseProperty;
         }
         else
         {
             var efCoreInverse = TryGetEFCoreInverseProperty(property);
             if (!string.IsNullOrEmpty(efCoreInverse))
             {
-                metadata.InverseProperty = efCoreInverse;
+                inverseProperty = efCoreInverse;
+            }
+            else
+            {
+                // Fallback: convention-based detection
+                inverseProperty = DetectConventionInverseProperty(property, navigationType);
             }
         }
 
-        return metadata;
+        // 5. OtherKey - Detect FK on the other side (for OneToMany)
+        string? otherKey = DetectOtherKey(property, navigationType, inverseProperty);
+
+        // 6. TargetType - Extract target entity type
+        Type? targetType = null;
+        if (navigationType == ToonRelationType.OneToMany || navigationType == ToonRelationType.ManyToMany)
+        {
+            targetType = GetCollectionElementType(property.PropertyType);
+        }
+        else if (navigationType == ToonRelationType.ManyToOne || navigationType == ToonRelationType.OneToOne)
+        {
+            targetType = property.PropertyType;
+        }
+
+        return new AcNavigationPropertyInfo(
+            isPrimaryKey: isPrimaryKey,
+            navigationType: navigationType,
+            foreignKey: foreignKey,
+            otherKey: otherKey,
+            inverseProperty: inverseProperty,
+            targetType: targetType);
     }
 
     /// <summary>
@@ -432,4 +457,186 @@ public static partial class AcToonSerializer
     }
 
     #endregion
-}
+
+    #region Convention-based Inverse Property Detection
+
+    /// <summary>
+    /// Convention: Detect inverse property by looking at the related type's properties.
+    /// For OneToMany: Look for ManyToOne property in element type that points back.
+    /// For ManyToOne: Look for OneToMany collection in related type that points back.
+    /// </summary>
+    private static string? DetectConventionInverseProperty(PropertyInfo property, ToonRelationType? navigationType)
+    {
+        if (!navigationType.HasValue)
+            return null;
+
+        var declaringType = property.DeclaringType;
+        if (declaringType == null)
+            return null;
+
+        if (navigationType == ToonRelationType.OneToMany)
+        {
+            // OneToMany: look for ManyToOne in element type that points back to declaring type
+            var elementType = GetCollectionElementType(property.PropertyType);
+            if (elementType == null)
+                return null;
+
+            var elementProperties = TypeMetadataBase.GetSerializableProperties(elementType);
+            for (int i = 0; i < elementProperties.Length; i++)
+            {
+                if (IsTypeMatch(elementProperties[i].PropertyType, declaringType))
+                    return elementProperties[i].Name;
+            }
+        }
+        else if (navigationType == ToonRelationType.ManyToOne)
+        {
+            // ManyToOne: look for OneToMany collection in related type that points back
+            var relatedProperties = TypeMetadataBase.GetSerializableProperties(property.PropertyType);
+            for (int i = 0; i < relatedProperties.Length; i++)
+            {
+                var relatedProp = relatedProperties[i];
+                if (typeof(IEnumerable).IsAssignableFrom(relatedProp.PropertyType) && 
+                    relatedProp.PropertyType != typeof(string) &&
+                    IsTypeMatch(GetCollectionElementType(relatedProp.PropertyType), declaringType))
+                {
+                    return relatedProp.Name;
+                }
+            }
+        }
+
+        return null;
+    }
+
+    /// <summary>
+    /// Check if two types match (handles different Type instances from different assemblies).
+    /// </summary>
+    private static bool IsTypeMatch(Type? type1, Type? type2)
+    {
+        if (type1 == null || type2 == null) return false;
+        return type1 == type2 || type2.IsAssignableFrom(type1) || type1.FullName == type2.FullName;
+    }
+
+    /// <summary>
+    /// Detect the foreign key property name on the other side of the relationship (OtherKey).
+    /// For OneToMany: Order.OrderItems → OrderItem has "OrderId" FK.
+    /// </summary>
+    private static string? DetectOtherKey(PropertyInfo property, ToonRelationType? navigationType, string? inverseProperty)
+    {
+        if (navigationType != ToonRelationType.OneToMany)
+            return null;
+
+        var elementType = GetCollectionElementType(property.PropertyType);
+        if (elementType == null)
+            return null;
+
+        // Use ReflectedType if available (the type we're reflecting on), otherwise DeclaringType
+        var declaringType = property.ReflectedType ?? property.DeclaringType;
+        if (declaringType == null)
+            return null;
+
+        var elementProperties = elementType.GetProperties(BindingFlags.Public | BindingFlags.Instance);
+
+        // Strategy 1: FK based on inverse property name
+        if (!string.IsNullOrEmpty(inverseProperty))
+        {
+            var fk = TryFindForeignKeyPropertyDirect(elementProperties, inverseProperty);
+            if (fk != null) return fk;
+        }
+
+        // Strategy 2: FK based on declaring type name (with Dto suffix handling)
+        var fkFromType = TryFindForeignKeyPropertyDirect(elementProperties, declaringType.Name);
+        if (fkFromType != null) return fkFromType;
+
+        // Strategy 3: FK based on element type name prefix
+        // OrderNote.OrderId → "Order" is prefix of "OrderNote", so look for "{prefix}Id"
+        var elementTypeName = elementType.Name;
+        for (int i = 0; i < elementProperties.Length; i++)
+        {
+            var prop = elementProperties[i];
+            if (!prop.Name.EndsWith("Id", StringComparison.Ordinal) || !prop.PropertyType.IsValueType)
+                continue;
+            
+            // Extract the prefix: "OrderId" → "Order"
+            var fkPrefix = prop.Name.Substring(0, prop.Name.Length - 2);
+            
+            // Check if element type name starts with this prefix: "OrderNote".StartsWith("Order")
+            if (elementTypeName.StartsWith(fkPrefix, StringComparison.Ordinal) && fkPrefix.Length > 0)
+            {
+                return prop.Name;
+            }
+        }
+
+        // Strategy 4: FK that has navigation property pointing back
+        for (int i = 0; i < elementProperties.Length; i++)
+        {
+            var prop = elementProperties[i];
+            if (!prop.Name.EndsWith("Id", StringComparison.Ordinal) || !prop.PropertyType.IsValueType)
+                continue;
+
+            var navName = prop.Name.Substring(0, prop.Name.Length - 2);
+            for (int j = 0; j < elementProperties.Length; j++)
+            {
+                if (elementProperties[j].Name == navName && IsTypeMatch(elementProperties[j].PropertyType, declaringType))
+                    return prop.Name;
+            }
+        }
+
+        return null;
+    }
+
+    /// <summary>
+    /// Detect FK property name for a navigation property.
+    /// Example: Customer navigation → CustomerId FK.
+    /// Also tries target type name: ShippingDocumentFile (type: Files) → FilesId FK.
+    /// </summary>
+    private static string? DetectForeignKeyForNavigationProperty(PropertyInfo property)
+    {
+        var declaringType = property.DeclaringType;
+        if (declaringType == null)
+            return null;
+
+        var allProperties = declaringType.GetProperties(BindingFlags.Public | BindingFlags.Instance);
+        
+        // Strategy 1: FK based on navigation property name (e.g., Customer → CustomerId)
+        var fk = TryFindForeignKeyPropertyDirect(allProperties, property.Name);
+        if (fk != null)
+            return fk;
+
+        // Strategy 2: FK based on target type name (e.g., ShippingDocumentFile: Files → FilesId)
+        var targetTypeName = property.PropertyType.Name;
+        fk = TryFindForeignKeyPropertyDirect(allProperties, targetTypeName);
+        if (fk != null)
+            return fk;
+
+        return null;
+    }
+
+    /// <summary>
+    /// Find FK property by name using direct PropertyInfo array (not filtered by GetSerializableProperties).
+    /// </summary>
+    private static string? TryFindForeignKeyPropertyDirect(PropertyInfo[] properties, string baseName)
+    {
+        // Try "{baseName}Id"
+        var fkName = baseName + "Id";
+        for (int i = 0; i < properties.Length; i++)
+        {
+            if (properties[i].Name == fkName && properties[i].PropertyType.IsValueType)
+                return fkName;
+        }
+
+        // Try without "Dto" suffix: "OrderDto" → "OrderId"
+        if (baseName.Length > 3 && baseName.EndsWith("Dto", StringComparison.Ordinal))
+        {
+            fkName = baseName.Substring(0, baseName.Length - 3) + "Id";
+            for (int i = 0; i < properties.Length; i++)
+            {
+                if (properties[i].Name == fkName && properties[i].PropertyType.IsValueType)
+                    return fkName;
+            }
+        }
+
+        return null;
+    }
+
+    #endregion
+}

AyCode.Core/Serializers/Toons/AcToonSerializer.ToonTypeMetadata.cs

@@ -10,8 +10,9 @@ public static partial class AcToonSerializer
 {
     /// <summary>
     /// Cached metadata for a type including properties, type name, and descriptions.
+    /// Uses TypeMetadataBase infrastructure for shared caching across all serializers.
     /// </summary>
-    private sealed class ToonTypeMetadata
+    private sealed class ToonTypeMetadata : TypeMetadataBase<ToonTypeMetadata>
     {
         public string TypeName { get; }
         public string ShortTypeName { get; }
@@ -21,7 +22,7 @@ public static partial class AcToonSerializer
         public Type? ElementType { get; }
         public ToonDescriptionAttribute? CustomDescription { get; }
 
-        public ToonTypeMetadata(Type type)
+        public ToonTypeMetadata(Type type) : base(type)
         {
             TypeName = type.FullName ?? type.Name;
             ShortTypeName = type.Name;
@@ -29,7 +30,7 @@ public static partial class AcToonSerializer
             // Get custom attribute if present
             CustomDescription = type.GetCustomAttribute<ToonDescriptionAttribute>();
 
-            // Check if collection or dictionary (matches AcBinarySerializer logic)
+            // Check if collection or dictionary (use shared JsonUtilities methods)
             IsDictionary = IsDictionaryType(type, out _, out _);
             if (!IsDictionary)
             {
@@ -41,14 +42,11 @@ public static partial class AcToonSerializer
                 }
             }
 
-            // Build property accessors
+            // Build property accessors using shared GetSerializableProperties from base
             if (!IsCollection && !IsDictionary && !IsPrimitiveOrStringFast(type))
             {
-                var props = type.GetProperties(BindingFlags.Public | BindingFlags.Instance)
-                    .Where(p => p.CanRead &&
-                               p.GetIndexParameters().Length == 0 &&
-                               !HasJsonIgnoreAttribute(p))
-                    .Select(p => new ToonPropertyAccessor(p))
+                var props = GetSerializableProperties(type, requiresRead: true, requiresWrite: false)
+                    .Select(p => new ToonPropertyAccessor(p, type))
                     .ToArray();
 
                 Properties = props;
@@ -61,56 +59,31 @@ public static partial class AcToonSerializer
     }
 
     /// <summary>
-    /// Property accessor with compiled getter for performance.
+    /// Property accessor with compiled getter and cached navigation metadata.
+    /// Extends PropertyAccessorBase for shared functionality and adds Toon-specific metadata.
     /// </summary>
-    private sealed class ToonPropertyAccessor
+    private sealed class ToonPropertyAccessor : PropertyAccessorBase
     {
-        public string Name { get; }
-        public Type PropertyType { get; }
         public PropertyInfo PropertyInfo { get; }
-        public TypeCode PropertyTypeCode { get; }
         public string TypeDisplayName { get; }
-        public bool IsNullable { get; }
-
-        // Custom attribute metadata
         public ToonDescriptionAttribute? CustomDescription { get; }
+        public AcNavigationPropertyInfo Navigation { get; }
 
-        private readonly Func<object, object?> _getter;
-
-        public ToonPropertyAccessor(PropertyInfo prop)
+        public ToonPropertyAccessor(PropertyInfo prop, Type declaringType)
+            : base(prop, declaringType)
         {
-            Name = prop.Name;
-            PropertyType = prop.PropertyType;
             PropertyInfo = prop;
 
-            var underlyingType = Nullable.GetUnderlyingType(PropertyType);
-            IsNullable = underlyingType != null;
-
-            var actualType = underlyingType ?? PropertyType;
-            PropertyTypeCode = Type.GetTypeCode(actualType);
-
             // Build type display name for meta section
             TypeDisplayName = BuildTypeDisplayName(PropertyType);
 
             // Get custom attribute if present
             CustomDescription = prop.GetCustomAttribute<ToonDescriptionAttribute>();
 
-            // Compile getter for fast access
-            _getter = CreateCompiledGetter(prop.DeclaringType!, prop);
+            // Detect and cache navigation metadata once
+            Navigation = DetectNavigationMetadata(prop, CustomDescription);
         }
 
-        private static Func<object, object?> CreateCompiledGetter(Type declaringType, PropertyInfo prop)
-        {
-            var objParam = Expression.Parameter(typeof(object), "obj");
-            var castExpr = Expression.Convert(objParam, declaringType);
-            var propAccess = Expression.Property(castExpr, prop);
-            var boxed = Expression.Convert(propAccess, typeof(object));
-            return Expression.Lambda<Func<object, object?>>(boxed, objParam).Compile();
-        }
-
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public object? GetValue(object obj) => _getter(obj);
-
         /// <summary>
         /// Checks if value is default/null without boxing value types.
         /// </summary>
@@ -142,97 +115,13 @@ public static partial class AcToonSerializer
             return false;
         }
 
-        // Thread-local visited set to prevent circular reference stack overflow
-        [ThreadStatic]
-        private static HashSet<Type>? t_visitedTypes;
-
         /// <summary>
-        /// Build human-readable type name for meta section.
-        /// Uses thread-local visited set to prevent stack overflow on circular references.
+        /// Build human-readable C# type name for meta section.
+        /// Uses shared AcSerializerCommon.GetCSharpTypeName for consistency.
         /// </summary>
         private static string BuildTypeDisplayName(Type type)
         {
-            var underlying = Nullable.GetUnderlyingType(type);
-            var isNullable = underlying != null;
-            var actualType = underlying ?? type;
-
-            var baseName = Type.GetTypeCode(actualType) switch
-            {
-                TypeCode.Int32 => "int32",
-                TypeCode.Int64 => "int64",
-                TypeCode.Double => "float64",
-                TypeCode.Decimal => "decimal",
-                TypeCode.Single => "float32",
-                TypeCode.Boolean => "bool",
-                TypeCode.String => "string",
-                TypeCode.DateTime => "datetime",
-                TypeCode.Byte => "byte",
-                TypeCode.Int16 => "int16",
-                TypeCode.UInt16 => "uint16",
-                TypeCode.UInt32 => "uint32",
-                TypeCode.UInt64 => "uint64",
-                TypeCode.SByte => "sbyte",
-                TypeCode.Char => "char",
-                _ => GetComplexTypeName(actualType)
-            };
-
-            return isNullable ? baseName + "?" : baseName;
-        }
-
-        /// <summary>
-        /// Get complex type name WITH circular reference protection using thread-local visited set.
-        /// </summary>
-        private static string GetComplexTypeName(Type type)
-        {
-            // Initialize thread-local visited set if needed
-            t_visitedTypes ??= new HashSet<Type>();
-
-            // Check for circular reference - if already visiting, return simple name
-            if (!t_visitedTypes.Add(type))
-            {
-                return type.Name; // Break circular reference
-            }
-
-            try
-            {
-                if (ReferenceEquals(type, GuidType)) return "guid";
-                if (ReferenceEquals(type, DateTimeOffsetType)) return "datetimeoffset";
-                if (ReferenceEquals(type, TimeSpanType)) return "timespan";
-                if (type.IsEnum) return "enum";
-
-                // For collections: recursively build element type name (safe with visited tracking)
-                if (typeof(IEnumerable).IsAssignableFrom(type) && !ReferenceEquals(type, StringType))
-                {
-                    var elementType = GetCollectionElementType(type);
-                    if (elementType != null && elementType != typeof(object))
-                    {
-                        var elementTypeName = BuildTypeDisplayName(elementType);
-                        return $"{elementTypeName}[]";
-                    }
-                }
-
-                // For dictionaries: recursively build key/value type names (safe with visited tracking)
-                if (IsDictionaryType(type, out var keyType, out var valueType))
-                {
-                    var keyTypeName = keyType != null ? BuildTypeDisplayName(keyType) : "object";
-                    var valueTypeName = valueType != null ? BuildTypeDisplayName(valueType) : "object";
-                    return $"dict<{keyTypeName}, {valueTypeName}>";
-                }
-
-                // Simple type name for complex objects
-                return type.Name;
-            }
-            finally
-            {
-                // Remove from visited set when done (allows reuse in different branches)
-                t_visitedTypes.Remove(type);
-
-                // Clear the set if empty to avoid memory leaks
-                if (t_visitedTypes.Count == 0)
-                {
-                    t_visitedTypes = null;
-                }
-            }
+            return AcSerializerCommon.GetCSharpTypeName(type, useShortNames: true);
         }
     }
 }

AyCode.Core/Serializers/Toons/AcToonSerializer.cs

@@ -1,5 +1,4 @@
 using System.Collections;
-using System.Collections.Concurrent;
 using System.Globalization;
 using System.Runtime.CompilerServices;
 using System.Text;
@@ -18,8 +17,6 @@ namespace AyCode.Core.Serializers.Toons;
 /// </summary>
 public static partial class AcToonSerializer
 {
-    private static readonly ConcurrentDictionary<Type, ToonTypeMetadata> TypeMetadataCache = new();
-
     /// <summary>
     /// Format version for Toon serialization.
     /// Incremented when breaking changes are made to format.
@@ -323,9 +320,13 @@ public static partial class AcToonSerializer
 
     #region Type Metadata
 
+    /// <summary>
+    /// Gets or creates ToonTypeMetadata using TypeMetadataBase infrastructure.
+    /// This uses the shared GlobalMetadataCache and ThreadLocal cache for optimal performance.
+    /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static ToonTypeMetadata GetTypeMetadata(Type type)
-        => TypeMetadataCache.GetOrAdd(type, static t => new ToonTypeMetadata(t));
+        => ToonTypeMetadata.GetOrCreateMetadata(type, static t => new ToonTypeMetadata(t));
 
     #endregion
 }