Allow multi-stage BPMN model to build on previous executions

codegen-service/llm-generation-bpmn/src/main/java/org/rj/modelgen/bpmn/component/BpmnComponentLibraryDetailLevelSerializer.java

@@ -15,6 +15,6 @@ public String serialize(BpmnComponentLibrary library) {
                 .orElseGet(List::of)
                 .stream()
                 .map(BpmnComponent::serializeDetailLevel)
-                .collect(Collectors.joining("\n"));
+                .collect(Collectors.joining("\n---\n"));
     }
 }

codegen-service/llm-generation-bpmn/src/main/java/org/rj/modelgen/bpmn/component/BpmnComponentLibraryHighLevelSerializer.java

@@ -15,6 +15,6 @@ public String serialize(BpmnComponentLibrary library) {
                 .orElseGet(List::of)
                 .stream()
                 .map(BpmnComponent::serializeHighLevel)
-                .collect(Collectors.joining("\n"));
+                .collect(Collectors.joining("\n---\n"));
     }
 }

codegen-service/llm-generation-bpmn/src/main/resources/content/models/multilevel/bpmn-multilevel-high-level-generation-prompt

@@ -17,9 +17,19 @@ Other requirements:
 * A node can only have ONE outbound connection, UNLESS it is an 'exclusiveGateway' node.  As a result, you should use exclusiveGateway nodes to handling branching. They should be placed after a result is calculated which you want to branch on
 * Your process should begin with a Start Event and end with one or more End Events
 
+<#if CURRENT_STATE??>
+You have previously generated the following model, which follows the schema above:
+```
+${CURRENT_STATE}
+```
+You should make the following updates to this model, and return the new full model as JSON (complying to the schema above):
+```
+${PROMPT}
+```
+<#else>
 The model which you should generate in JSON form (complying to the given schema) is as follows:
 ```
 ${PROMPT}
 ```
-
+</#if>
 Return ONLY the JSON process data, with no other explanation or commentary.

codegen-service/llm-generation-core/src/main/java/org/rj/modelgen/llm/models/generation/multilevel/MultiLevelGenerationModel.java

@@ -77,7 +77,7 @@ TComponentLibrary extends ComponentLibrary<?>> ModelData buildModelData(
         final var stateExecuteHighLevel = new PrepareAndSubmitMLRequestForLevel<>(highLevelSchema, contextProvider,
                 highLevelPhaseConfig.getModelSanitizer(), modelPromptGenerator, MultiLevelModelPromptType.GenerateHighLevel,
                 componentLibrary, highLevelPhaseConfig.getComponentLibrarySelector(), highLevelPhaseConfig.getComponentLibrarySerializer())
-                //.withOverriddenModelSuccessResponse(Util.loadStringResource("generation-examples/multiLevel/example1/2-response-high-level.json"))
+                .withOverriddenModelSuccessResponse(Util.loadStringResource("generation-examples/multiLevel/example1/2-response-high-level.json"))
                 .withOverriddenId("executeHighLevel");
 
         final var stateValidateHighLevel = new ValidateLlmIntermediateModelResponse(
@@ -87,7 +87,7 @@ TComponentLibrary extends ComponentLibrary<?>> ModelData buildModelData(
         final var stateExecuteDetailLevel = new PrepareAndSubmitMLRequestForLevel<>(detailLevelSchema, contextProvider,
                 detailLevelPhaseConfig.getModelSanitizer(), modelPromptGenerator, MultiLevelModelPromptType.GenerateDetailLevel,
                 componentLibrary, detailLevelPhaseConfig.getComponentLibrarySelector(), detailLevelPhaseConfig.getComponentLibrarySerializer())
-                //.withOverriddenModelSuccessResponse(Util.loadStringResource("generation-examples/multiLevel/example1/4-response-detail-level.json"))
+                .withOverriddenModelSuccessResponse(Util.loadStringResource("generation-examples/multiLevel/example1/4-response-detail-level.json"))
                 .withOverriddenId("executeDetailLevel");
         //final var stateReturnToHighLevelIfRequired = new { ... } // TODO
         final var stateValidateDetailLevel = new ValidateLlmIntermediateModelResponse(

codegen-service/llm-generation-core/src/main/java/org/rj/modelgen/llm/prompt/PromptSubstitution.java

@@ -1,6 +1,9 @@
 package org.rj.modelgen.llm.prompt;
 
 import org.apache.commons.lang3.StringUtils;
+import org.rj.modelgen.llm.util.Util;
+
+import java.util.Optional;
 
 public class PromptSubstitution {
     private final String existingString;
@@ -31,4 +34,17 @@ public String apply(String targetString) {
 
         return StringUtils.replace(targetString, existingString, newString);
     }
+
+    @Override
+    public String toString() {
+        return String.format("%s -> %s", componentToString(existingString), componentToString(newString));
+    }
+
+    private String componentToString(String comp) {
+        if (comp == null) {
+            return "<null>";
+        }
+
+        return String.format("\"%s\"", Util.displayStringWithMaxLength(comp, 50));
+    }
 }

codegen-service/llm-generation-core/src/main/java/org/rj/modelgen/llm/statemodel/states/common/PrepareModelGenerationRequest.java

@@ -63,7 +63,7 @@ protected List<PromptSubstitution> generatePromptSubstitutions(ModelSchema model
         substitutionData.put(StandardPromptPlaceholders.PROMPT.getValue(), request);
         substitutionData.put(StandardPromptPlaceholders.SCHEMA_CONTENT.getValue(), modelSchema.getSchemaContent());
         substitutionData.put(StandardPromptPlaceholders.CURRENT_STATE.getValue(), context.getLatestModelEntry()
-                .orElseGet(() -> ContextEntry.forModel("{}")).getContent());
+                .orElseGet(() -> ContextEntry.forModel(null)).getContent());
 
         // Allow subclasses to insert additional data.  Will overwrite exiting placeholders if they exist
         final var substitutions = substitutionData.entrySet().stream()

codegen-service/llm-generation-core/src/main/java/org/rj/modelgen/llm/util/Util.java

@@ -174,4 +174,12 @@ public static int estimateTokenSize(String string) {
 
         return StringUtils.countMatches(string, ' ') + 1;
     }
+
+    public static String displayStringWithMaxLength(String str, int maxLength) {
+        if (str.length() > maxLength) {
+            return str.substring(0, maxLength) + "...";
+        }
+
+        return str;
+    }
 }