Implement isNodeUsed() API

flow-model-generator/modules/flow-model-generator-core/src/main/java/io/ballerina/flowmodelgenerator/core/BasicNodeGenerator.java

@@ -0,0 +1,46 @@
+/*
+ *  Copyright (c) 2024, WSO2 LLC. (http://www.wso2.com)
+ *
+ *  WSO2 LLC. licenses this file to you under the Apache License,
+ *  Version 2.0 (the "License"); you may not use this file except
+ *  in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+
+package io.ballerina.flowmodelgenerator.core;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import io.ballerina.flowmodelgenerator.core.model.FlowNode;
+import io.ballerina.tools.text.LinePosition;
+import io.ballerina.tools.text.LineRange;
+
+/**
+ * Generates information for a node.
+ *
+ * @since 1.4.0
+ */
+public class BasicNodeGenerator {
+
+    private final Gson gson;
+    private final FlowNode nodeToCheckUsages;
+
+    public BasicNodeGenerator(JsonElement nodeToCheckUsages) {
+        this.gson = new Gson();
+        this.nodeToCheckUsages = new Gson().fromJson(nodeToCheckUsages, FlowNode.class);
+    }
+
+    public LinePosition getNodeStartLocation() {
+        LineRange lineRange = nodeToCheckUsages.codedata().lineRange();
+        return lineRange.startLine();
+    }
+}

flow-model-generator/modules/flow-model-generator-ls-extension/src/main/java/io/ballerina/flowmodelgenerator/extension/FlowModelGeneratorService.java

@@ -28,12 +28,14 @@
 import io.ballerina.flowmodelgenerator.core.DeleteNodeGenerator;
 import io.ballerina.flowmodelgenerator.core.ErrorHandlerGenerator;
 import io.ballerina.flowmodelgenerator.core.FunctionGenerator;
+import io.ballerina.flowmodelgenerator.core.BasicNodeGenerator;
 import io.ballerina.flowmodelgenerator.core.ModelGenerator;
 import io.ballerina.flowmodelgenerator.core.NodeTemplateGenerator;
 import io.ballerina.flowmodelgenerator.core.OpenApiServiceGenerator;
 import io.ballerina.flowmodelgenerator.core.SourceGenerator;
 import io.ballerina.flowmodelgenerator.core.SuggestedComponentService;
 import io.ballerina.flowmodelgenerator.core.SuggestedModelGenerator;
+import io.ballerina.flowmodelgenerator.extension.request.IsNodeUsedRequest;
 import io.ballerina.flowmodelgenerator.extension.request.CopilotContextRequest;
 import io.ballerina.flowmodelgenerator.extension.request.FilePathRequest;
 import io.ballerina.flowmodelgenerator.extension.request.FlowModelAvailableNodesRequest;
@@ -53,11 +55,13 @@
 import io.ballerina.flowmodelgenerator.extension.response.FlowModelNodeTemplateResponse;
 import io.ballerina.flowmodelgenerator.extension.response.FlowModelSourceGeneratorResponse;
 import io.ballerina.flowmodelgenerator.extension.response.FlowNodeDeleteResponse;
+import io.ballerina.flowmodelgenerator.extension.response.IsNodeUsedResponse;
 import io.ballerina.flowmodelgenerator.extension.response.OpenApiServiceGenerationResponse;
 import io.ballerina.projects.Document;
 import io.ballerina.projects.DocumentId;
 import io.ballerina.projects.Module;
 import io.ballerina.projects.Project;
+import io.ballerina.tools.diagnostics.Location;
 import io.ballerina.tools.text.LinePosition;
 import io.ballerina.tools.text.LineRange;
 import io.ballerina.tools.text.TextDocument;
@@ -435,6 +439,28 @@ public CompletableFuture<FlowModelSourceGeneratorResponse> addErrorHandler(FileP
         });
     }
 
+    @JsonRequest
+    public CompletableFuture<IsNodeUsedResponse> isNodeUsed(IsNodeUsedRequest request) {
+        return CompletableFuture.supplyAsync(() -> {
+           IsNodeUsedResponse response = new IsNodeUsedResponse();
+           try {
+               Path filePath = Path.of(request.filePath());
+               Optional<SemanticModel> semanticModel = this.workspaceManager.semanticModel(filePath);
+               Optional<Document> document = this.workspaceManager.document(filePath);
+               if (semanticModel.isEmpty() || document.isEmpty()) {
+                   response.setUsed(false);
+                   return response;
+               }
+               BasicNodeGenerator basicNodeGenerator = new BasicNodeGenerator(request.flowNode());
+               List<Location> references = semanticModel.get().references(document.get(), basicNodeGenerator.getNodeStartLocation());
+               response.setUsed(!references.isEmpty());
+           } catch (Throwable e) {
+               response.setError(e);
+           }
+           return response;
+        });
+    }
+
     private static String getRelativePath(Path projectPath, Path filePath) {
         if (projectPath == null || filePath == null) {
             return "";

flow-model-generator/modules/flow-model-generator-ls-extension/src/main/java/io/ballerina/flowmodelgenerator/extension/request/IsNodeUsedRequest.java

@@ -0,0 +1,32 @@
+/*
+ *  Copyright (c) 2024, WSO2 LLC. (http://www.wso2.com)
+ *
+ *  WSO2 LLC. licenses this file to you under the Apache License,
+ *  Version 2.0 (the "License"); you may not use this file except
+ *  in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+
+package io.ballerina.flowmodelgenerator.extension.request;
+
+import com.google.gson.JsonElement;
+
+/**
+ * Represents the request to check whether a particular node is used.
+ *
+ * @param filePath file path of the source file
+ * @param flowNode flow node
+ * @since 1.4.0
+ */
+public record IsNodeUsedRequest(String filePath, JsonElement flowNode) {
+
+}

flow-model-generator/modules/flow-model-generator-ls-extension/src/main/java/io/ballerina/flowmodelgenerator/extension/response/IsNodeUsedResponse.java

@@ -0,0 +1,37 @@
+/*
+ *  Copyright (c) 2024, WSO2 LLC. (http://www.wso2.com)
+ *
+ *  WSO2 LLC. licenses this file to you under the Apache License,
+ *  Version 2.0 (the "License"); you may not use this file except
+ *  in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+
+package io.ballerina.flowmodelgenerator.extension.response;
+
+/**
+ * Represents the response after checking a particular node is used.
+ *
+ * @since 1.4.0
+ */
+public class IsNodeUsedResponse extends AbstractFlowModelResponse {
+
+    boolean isUsed;
+
+    public boolean isUsed() {
+        return isUsed;
+    }
+
+    public void setUsed(boolean used) {
+        isUsed = used;
+    }
+}