From 0976631bcd7ee29e45d1cdbd7a6875cbe4359117 Mon Sep 17 00:00:00 2001
From: Andrzej Zabost <5508894+azabost@users.noreply.github.com>
Date: Thu, 29 Jun 2023 02:13:59 +0200
Subject: [PATCH] WIP: Try supporting arrays by using ArrayTypeAdapter

---
 .../codified/gson/CodifiedEnumTypeAdapter.kt  | 34 +++++++++++++++++--
 .../codified/gson/GsonTest.kt                 | 14 ++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/enums-gson/src/main/kotlin/pl/brightinventions/codified/gson/CodifiedEnumTypeAdapter.kt b/enums-gson/src/main/kotlin/pl/brightinventions/codified/gson/CodifiedEnumTypeAdapter.kt
index b74ec03..cf9e286 100644
--- a/enums-gson/src/main/kotlin/pl/brightinventions/codified/gson/CodifiedEnumTypeAdapter.kt
+++ b/enums-gson/src/main/kotlin/pl/brightinventions/codified/gson/CodifiedEnumTypeAdapter.kt
@@ -3,12 +3,15 @@ package pl.brightinventions.codified.gson
 import com.google.gson.Gson
 import com.google.gson.TypeAdapter
 import com.google.gson.TypeAdapterFactory
+import com.google.gson.internal.`$Gson$Types`
+import com.google.gson.internal.bind.ArrayTypeAdapter
 import com.google.gson.reflect.TypeToken
 import com.google.gson.stream.JsonReader
 import com.google.gson.stream.JsonWriter
 import pl.brightinventions.codified.Codified
 import pl.brightinventions.codified.enums.CodifiedEnum
 import pl.brightinventions.codified.enums.CodifiedEnumDecoder
+import java.lang.reflect.GenericArrayType
 import java.lang.reflect.ParameterizedType
 
 class CodifiedEnumTypeAdapter<T, C : Any>(
@@ -21,16 +24,43 @@ class CodifiedEnumTypeAdapter<T, C : Any>(
 
     class Factory : TypeAdapterFactory {
         override fun <T : Any> create(gson: Gson, typeToken: TypeToken<T>?): TypeAdapter<T>? {
-            if (typeToken?.rawType != CodifiedEnum::class.java) {
+            if (typeToken == null) {
                 return null
             }
 
+            if (typeToken.rawType == CodifiedEnum::class.java) {
+                return createCodifiedEnumTypeAdapter(typeToken, gson)
+            }
+
+            val type = typeToken.type
+            if (!(type is GenericArrayType || type is Class<*> && type.isArray)) {
+                return null
+            }
+
+            val componentType = `$Gson$Types`.getArrayComponentType(type)
+
+            //if (componentRawType == CodifiedEnum::class.java) ?
+            //val adapter: TypeAdapter<*> = createCodifiedEnumTypeAdapter(TypeToken.get(componentType), gson)// as TypeAdapter<T>
+
+            @Suppress("UNCHECKED_CAST")
+            val arrayAdapter: TypeAdapter<T> = ArrayTypeAdapter(
+                gson,
+                gson.getAdapter(TypeToken.get(componentType)),
+                `$Gson$Types`.getRawType(componentType) // TODO won't compile
+            ) as TypeAdapter<T>
+
+            return arrayAdapter
+        }
+
+        private fun <T : Any> createCodifiedEnumTypeAdapter(
+            typeToken: TypeToken<T>,
+            gson: Gson
+        ): TypeAdapter<T> {
             val parameterizedType = typeToken.type as ParameterizedType
             val enumType = parameterizedType.actualTypeArguments[0]
             val enumTypeToken = TypeToken.get(enumType)
             val codeType = parameterizedType.actualTypeArguments[1]
             val codeAdapter = gson.getAdapter(TypeToken.get(codeType))
-
             @Suppress("UNCHECKED_CAST")
             return CodifiedEnumTypeAdapter(enumTypeToken, codeAdapter) as TypeAdapter<T>
         }
diff --git a/enums-gson/src/test/kotlin/pl/brightinventions/codified/gson/GsonTest.kt b/enums-gson/src/test/kotlin/pl/brightinventions/codified/gson/GsonTest.kt
index 5507cb4..ed0e751 100644
--- a/enums-gson/src/test/kotlin/pl/brightinventions/codified/gson/GsonTest.kt
+++ b/enums-gson/src/test/kotlin/pl/brightinventions/codified/gson/GsonTest.kt
@@ -52,6 +52,20 @@ class GsonTest {
         wrapper.intEnum.code().shouldEqual(123)
     }
 
+    @Test
+    fun `known and unknown enums should be serialized`() {
+        val enums = listOf<CodifiedEnum<StringEnum, String>>(
+            CodifiedEnum.Known(StringEnum.BAR),
+            CodifiedEnum.Unknown("hello"),
+            CodifiedEnum.Known(StringEnum.FOO),
+            CodifiedEnum.Unknown("world"),
+        )
+
+        val string = gson.toJson(enums)
+
+        string.shouldEqual("")
+    }
+
     @Test
     fun `known and unknown enums in a wrapper should be serialized`() {
         val enums = listOf<CodifiedEnum<StringEnum, String>>(