added back the schedule generation

Author: amgreer99

merlin-framework-processor/src/main/java/gov/nasa/jpl/aerie/merlin/processor/generator/MissionModelGenerator.java

@@ -261,6 +261,7 @@ private static CodeBlock generateMissionModelInstantiation(final MissionModelRec
   /** Generate `GeneratedSchedulerModel` class. */
   public JavaFile generateSchedulerModel(final MissionModelRecord missionModel) {
     final var typeName = missionModel.getSchedulerModelName();
+    final var durationValueMapperCodeBlock = generateDurationMapperBlock(missionModel);
 
     final var typeSpec =
         TypeSpec
@@ -303,6 +304,32 @@ public JavaFile generateSchedulerModel(final MissionModelRecord missionModel) {
                             .orElse(CodeBlock.builder()).build())
                     .addStatement("return result")
                     .build())
+            .addMethod(MethodSpec
+                           .methodBuilder("serializeDuration")
+                           .addModifiers(Modifier.PUBLIC)
+                           .addAnnotation(Override.class)
+                           .returns(SerializedValue.class)
+                           .addParameter(
+                               TypeName.get(Duration.class),
+                               "duration",
+                               Modifier.FINAL)
+                           .addStatement(
+                               "return $L.serializeValue(duration)", durationValueMapperCodeBlock.get()
+                           )
+                           .build())
+            .addMethod(MethodSpec
+                           .methodBuilder("deserializeDuration")
+                           .addModifiers(Modifier.PUBLIC)
+                           .addAnnotation(Override.class)
+                           .addParameter(
+                               TypeName.get(SerializedValue.class),
+                               "serializedDuration",
+                               Modifier.FINAL)
+                           .addStatement(
+                               "return $L.deserializeValue(serializedDuration).getSuccessOrThrow()", durationValueMapperCodeBlock.get()
+                           )
+                           .returns(Duration.class)
+                           .build())
             .build();
 
     return JavaFile
@@ -886,7 +913,19 @@ private static MethodSpec makeSerializeReturnValueMethod(final ActivityTypeRecor
                          "return this." + COMPUTED_ATTRIBUTES_VALUE_MAPPER_FIELD_NAME + ".serializeValue(returnValue)")
                      .build();
   }
-
+  private Optional<CodeBlock> generateDurationMapperBlock(final MissionModelRecord missionModel){
+    final var resolver = new Resolver(this.typeUtils, this.elementUtils, missionModel.typeRules());
+    final var mapperBlock = resolver.instantiateNullableMapperFor(
+        elementUtils.getTypeElement(Duration.class.getName()).asType());
+    if (mapperBlock.isPresent()) {
+      return mapperBlock;
+    } else {
+      messager.printMessage(
+          Diagnostic.Kind.ERROR,
+          "Failed to generate value mapper for Duration");
+      return Optional.empty();
+    }
+  }
   private Optional<Map<String, CodeBlock>> generateParameterMapperBlocks(final MissionModelRecord missionModel, final InputTypeRecord inputType)
   {
     final var resolver = new Resolver(this.typeUtils, this.elementUtils, missionModel.typeRules());