From f39a140527af768cbd34b2c44081237dee58c12b Mon Sep 17 00:00:00 2001
From: Samuele Maci <macisamuele@gmail.com>
Date: Wed, 20 Mar 2019 12:36:18 +0100
Subject: [PATCH 1/2] Add supporrt for composed models and reference models

---
 .../java/com/yelp/codegen/SharedCodegen.kt    | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/plugin/src/main/java/com/yelp/codegen/SharedCodegen.kt b/plugin/src/main/java/com/yelp/codegen/SharedCodegen.kt
index 838b04c2..2e008cef 100644
--- a/plugin/src/main/java/com/yelp/codegen/SharedCodegen.kt
+++ b/plugin/src/main/java/com/yelp/codegen/SharedCodegen.kt
@@ -10,9 +10,11 @@ import io.swagger.codegen.CodegenType
 import io.swagger.codegen.DefaultCodegen
 import io.swagger.codegen.SupportingFile
 import io.swagger.models.ArrayModel
+import io.swagger.models.ComposedModel
 import io.swagger.models.Model
 import io.swagger.models.ModelImpl
 import io.swagger.models.Operation
+import io.swagger.models.RefModel
 import io.swagger.models.Swagger
 import io.swagger.models.properties.ArrayProperty
 import io.swagger.models.properties.MapProperty
@@ -164,14 +166,65 @@ abstract class SharedCodegen : DefaultCodegen(), CodegenConfig {
         }
     }
 
+    /**
+     * Given a model determine what is the underlying data type ensuring.
+     * The method takes care of:
+     *  * references to references
+     *  * composed models where only one of the allOf items is responsible for type definition
+     */
+    private fun getModelDataType(model: Model?): String? {
+        return when (model) {
+            is ModelImpl -> {
+                if (model.type == null) {
+                    if (false == model.properties?.isEmpty() || model.additionalProperties != null) {
+                        "object"
+                    } else {
+                        null
+                    }
+                } else {
+                    model.type
+                }
+            }
+            is RefModel -> toModelName(model.simpleRef)
+            is ComposedModel -> {
+                val allOfModelDefinitions = model.allOf.mapNotNull { allOfItem ->
+                    when (allOfItem) {
+                        is Model, is RefModel -> getModelDataType(allOfItem)
+                        else -> null
+                    }
+                }
+                if (allOfModelDefinitions.size == 1) {
+                    allOfModelDefinitions[0]
+                } else {
+                    null
+                }
+            }
+            else -> null
+        }
+    }
+
     override fun fromModel(name: String, model: Model, allDefinitions: MutableMap<String, Model>?): CodegenModel {
         propagateXNullable(model, allDefinitions)
         val codegenModel = super.fromModel(name, model, allDefinitions)
 
+        // Deal with composed models (models with allOf) that are meant to override descriptions and
+        // with references to references
+        if (model is ComposedModel || model is RefModel) {
+            val modelDataType = getModelDataType(model)
+            if (modelDataType != null) {
+                codegenModel.isAlias = true
+                codegenModel.dataType = modelDataType
+                // This workaround is done to prevent regeneration of enums that would not be used anyway as
+                // the current codegenModel is a pure type alias
+                codegenModel.hasEnums = false
+            }
+        }
+
         // Top level array Models should generate a typealias.
         if (codegenModel.isArrayModel) {
             codegenModel.isAlias = true
         }
+
         // If model is an Alias will generate a typealias. We need to check if the type is aliasing
         // to any 'x-nullable' annotated model.
         if (codegenModel.isAlias) {

From 8f37a16fcf3dd113131f5b3ad0c85dd07a4154d1 Mon Sep 17 00:00:00 2001
From: Nicola Corti <corti.nico@gmail.com>
Date: Wed, 15 May 2019 14:27:33 +0200
Subject: [PATCH 2/2] Inverting logic for null checks on getModelDataType

---
 .../main/java/com/yelp/codegen/SharedCodegen.kt    | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/plugin/src/main/java/com/yelp/codegen/SharedCodegen.kt b/plugin/src/main/java/com/yelp/codegen/SharedCodegen.kt
index 2e008cef..fab481fe 100644
--- a/plugin/src/main/java/com/yelp/codegen/SharedCodegen.kt
+++ b/plugin/src/main/java/com/yelp/codegen/SharedCodegen.kt
@@ -175,14 +175,15 @@ abstract class SharedCodegen : DefaultCodegen(), CodegenConfig {
     private fun getModelDataType(model: Model?): String? {
         return when (model) {
             is ModelImpl -> {
-                if (model.type == null) {
-                    if (false == model.properties?.isEmpty() || model.additionalProperties != null) {
+                if (model.type != null) {
+                    model.type
+                } else {
+                    if (false == model.properties?.isEmpty() ||
+                            model.additionalProperties != null) {
                         "object"
                     } else {
                         null
                     }
-                } else {
-                    model.type
                 }
             }
             is RefModel -> toModelName(model.simpleRef)
@@ -210,10 +211,9 @@ abstract class SharedCodegen : DefaultCodegen(), CodegenConfig {
         // Deal with composed models (models with allOf) that are meant to override descriptions and
         // with references to references
         if (model is ComposedModel || model is RefModel) {
-            val modelDataType = getModelDataType(model)
-            if (modelDataType != null) {
+            getModelDataType(model)?.let {
                 codegenModel.isAlias = true
-                codegenModel.dataType = modelDataType
+                codegenModel.dataType = it
                 // This workaround is done to prevent regeneration of enums that would not be used anyway as
                 // the current codegenModel is a pure type alias
                 codegenModel.hasEnums = false