feat: nested sealed hierarchies for oneOf/anyOf subtypes

core/src/main/kotlin/com/avsystem/justworks/core/ArrowHelpers.kt

@@ -0,0 +1,26 @@
+package com.avsystem.justworks.core
+
+import arrow.core.Nel
+import arrow.core.nonEmptyListOf
+import arrow.core.raise.IorRaise
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.InvocationKind.AT_MOST_ONCE
+import kotlin.contracts.contract
+
+@OptIn(ExperimentalContracts::class)
+context(warnings: IorRaise<Nel<Error>>)
+inline fun <Error> ensureOrAccumulate(condition: Boolean, error: () -> Error) {
+    contract { callsInPlace(error, AT_MOST_ONCE) }
+    if (!condition) {
+        warnings.accumulate(nonEmptyListOf(error()))
+    }
+}
+
+@OptIn(ExperimentalContracts::class)
+context(warnings: IorRaise<Nel<Error>>)
+inline fun <Error, B : Any> ensureNotNullOrAccumulate(value: B?, error: () -> Error) {
+    contract { callsInPlace(error, AT_MOST_ONCE) }
+    if (value == null) {
+        warnings.accumulate(nonEmptyListOf(error()))
+    }
+}

core/src/main/kotlin/com/avsystem/justworks/core/Issue.kt

@@ -0,0 +1,15 @@
+package com.avsystem.justworks.core
+
+import arrow.core.Nel
+import arrow.core.raise.ExperimentalRaiseAccumulateApi
+import arrow.core.raise.IorRaise
+import kotlin.contracts.ExperimentalContracts
+
+object Issue {
+    data class Error(val message: String)
+
+    @JvmInline
+    value class Warning(val message: String)
+}
+
+typealias Warnings = IorRaise<Nel<Issue.Warning>>

core/src/main/kotlin/com/avsystem/justworks/core/gen/ClientGenerator.kt

@@ -35,6 +35,7 @@ class ClientGenerator(
     private val apiPackage: String,
     private val modelPackage: String,
     private val nameRegistry: NameRegistry,
+    private val classNameLookup: Map<String, ClassName> = emptyMap(),
 ) {
     fun generate(spec: ApiSpec, hasPolymorphicTypes: Boolean = false): List<FileSpec> {
         val grouped = spec.endpoints.groupBy { it.tags.firstOrNull() ?: DEFAULT_TAG }
@@ -100,7 +101,7 @@ class ClientGenerator(
         val params = endpoint.parameters.groupBy { it.location }
 
         val pathParams = params[ParameterLocation.PATH].orEmpty().map { param ->
-            ParameterSpec(param.name.toCamelCase(), TypeMapping.toTypeName(param.schema, modelPackage))
+            ParameterSpec(param.name.toCamelCase(), TypeMapping.toTypeName(param.schema, modelPackage, classNameLookup))
         }
 
         val queryParams = params[ParameterLocation.QUERY].orEmpty().map { param ->
@@ -129,7 +130,7 @@ class ClientGenerator(
         name: String,
         required: Boolean,
     ): ParameterSpec {
-        val baseType = TypeMapping.toTypeName(typeRef, modelPackage)
+        val baseType = TypeMapping.toTypeName(typeRef, modelPackage, classNameLookup)
 
         val builder = ParameterSpec.builder(name.toCamelCase(), baseType.copy(nullable = !required))
         if (!required) builder.defaultValue("null")
@@ -207,7 +208,7 @@ class ClientGenerator(
         .asSequence()
         .filter { it.key.startsWith("2") }
         .firstNotNullOfOrNull { it.value.schema }
-        ?.let { successResponse -> TypeMapping.toTypeName(successResponse, modelPackage) }
+        ?.let { successResponse -> TypeMapping.toTypeName(successResponse, modelPackage, classNameLookup) }
         ?: UNIT
 
     /**

core/src/main/kotlin/com/avsystem/justworks/core/gen/CodeGenerator.kt

@@ -26,8 +26,10 @@ object CodeGenerator {
         modelFiles.forEach { it.writeTo(outputDir) }
 
         val hasPolymorphicTypes = modelFiles.any { it.name == SerializersModuleGenerator.FILE_NAME }
+        val classNameLookup = ModelGenerator.buildClassNameLookup(spec, modelPackage)
 
-        val clientFiles = ClientGenerator(apiPackage, modelPackage, apiRegistry).generate(spec, hasPolymorphicTypes)
+        val clientFiles = ClientGenerator(apiPackage, modelPackage, apiRegistry, classNameLookup)
+            .generate(spec, hasPolymorphicTypes)
         clientFiles.forEach { it.writeTo(outputDir) }
 
         return Result(modelFiles.size, clientFiles.size)