From fc715724ce53fb29586743e74c3937fe80d8e1a1 Mon Sep 17 00:00:00 2001
From: Timur Nizametdinov <nizametdinov@crxmarkets.com>
Date: Mon, 27 May 2024 12:03:21 +0200
Subject: [PATCH] JsonEnumDefaultValue support

---
 .../module/jackson/JacksonModule.java         |  2 ++
 .../jackson/JsonEnumDefaultValueResolver.java | 20 +++++++++++++++++++
 .../module/jackson/IntegrationTest.java       |  7 +++++++
 .../jackson/integration-test-result.json      |  5 +++++
 4 files changed, 34 insertions(+)
 create mode 100644 jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonEnumDefaultValueResolver.java

diff --git a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JacksonModule.java b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JacksonModule.java
index 1d887605..0fa6df67 100644
--- a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JacksonModule.java
+++ b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JacksonModule.java
@@ -114,6 +114,8 @@ public void applyToConfigBuilder(SchemaGeneratorConfigBuilder builder) {
 
         applySubtypeResolverToConfigBuilder(generalConfigPart, fieldConfigPart, methodConfigPart);
 
+        fieldConfigPart.withDefaultResolver(JsonEnumDefaultValueResolver::apply);
+
         generalConfigPart.withCustomDefinitionProvider(new JsonUnwrappedDefinitionProvider());
     }
 
diff --git a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonEnumDefaultValueResolver.java b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonEnumDefaultValueResolver.java
new file mode 100644
index 00000000..96c32e8c
--- /dev/null
+++ b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonEnumDefaultValueResolver.java
@@ -0,0 +1,20 @@
+package com.github.victools.jsonschema.module.jackson;
+
+import com.fasterxml.jackson.annotation.JsonEnumDefaultValue;
+import com.github.victools.jsonschema.generator.TypeScope;
+import java.lang.reflect.Field;
+import java.util.Arrays;
+
+public class JsonEnumDefaultValueResolver {
+
+    public static String apply(TypeScope typeScope) {
+        if (typeScope.getType().getErasedType().isEnum()) {
+            return Arrays.stream(typeScope.getType().getErasedType().getDeclaredFields())
+                    .filter(enumValue -> enumValue.isAnnotationPresent(JsonEnumDefaultValue.class))
+                    .findFirst()
+                    .map(Field::getName)
+                    .orElse(null);
+        }
+        return null;
+    }
+}
diff --git a/jsonschema-module-jackson/src/test/java/com/github/victools/jsonschema/module/jackson/IntegrationTest.java b/jsonschema-module-jackson/src/test/java/com/github/victools/jsonschema/module/jackson/IntegrationTest.java
index 061a5312..e560d923 100644
--- a/jsonschema-module-jackson/src/test/java/com/github/victools/jsonschema/module/jackson/IntegrationTest.java
+++ b/jsonschema-module-jackson/src/test/java/com/github/victools/jsonschema/module/jackson/IntegrationTest.java
@@ -17,6 +17,7 @@
 package com.github.victools.jsonschema.module.jackson;
 
 import com.fasterxml.jackson.annotation.JsonClassDescription;
+import com.fasterxml.jackson.annotation.JsonEnumDefaultValue;
 import com.fasterxml.jackson.annotation.JsonIdentityInfo;
 import com.fasterxml.jackson.annotation.JsonIdentityReference;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -95,6 +96,8 @@ static class TestClass {
 
         public TestEnumWithJsonPropertyAnnotations enumValueWithJsonPropertyAnnotations;
 
+        public TestEnumWithJsonEnumDefaultAnnotations enumValueWithJsonEnumDefaultValueAnnotation;
+
         public BaseType interfaceWithDeclaredSubtypes;
 
         @JsonUnwrapped
@@ -131,6 +134,10 @@ enum TestEnumWithJsonPropertyAnnotations {
         @JsonProperty Y
     }
 
+    enum TestEnumWithJsonEnumDefaultAnnotations {
+        A, @JsonEnumDefaultValue B, C
+    }
+
     @JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")
     static class TestTypeWithObjectId {
         IdType id;
diff --git a/jsonschema-module-jackson/src/test/resources/com/github/victools/jsonschema/module/jackson/integration-test-result.json b/jsonschema-module-jackson/src/test/resources/com/github/victools/jsonschema/module/jackson/integration-test-result.json
index 8e48e311..ce5c1ed1 100644
--- a/jsonschema-module-jackson/src/test/resources/com/github/victools/jsonschema/module/jackson/integration-test-result.json
+++ b/jsonschema-module-jackson/src/test/resources/com/github/victools/jsonschema/module/jackson/integration-test-result.json
@@ -54,6 +54,11 @@
             "type": "string",
             "enum": ["entry1", "entry2", "entry3"]
         },
+      "enumValueWithJsonEnumDefaultValueAnnotation": {
+            "type": "string",
+            "enum": ["A", "B", "C"],
+             "default": "B"
+        },
         "fieldWithDescription": {
             "type": "string",
             "description": "field description"