Migrate Copilot Libraries API & Add Keyword Search

.gitignore

@@ -46,3 +46,4 @@ build/
 
 # macOS metadata files
 .DS_Store
+.claude

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

@@ -0,0 +1,133 @@
+/*
+ *  Copyright (c) 2025, 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 java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+/**
+ * Utility class for loading custom instructions from resource files.
+ * Instructions are organized by package in the resources/copilot/instructions directory.
+ *
+ * <p>Directory structure:
+ * <pre>
+ * resources/copilot/instructions/
+ *   └── {org}/
+ *       └── {module}/
+ *           ├── library.md      → Library.instructions
+ *           ├── service.md      → GenericService.instructions
+ *           └── test.md         → Service.testGenerationInstruction
+ * </pre>
+ *
+ * @since 1.0.1
+ */
+public final class InstructionLoader {
+
+    private static final String INSTRUCTIONS_BASE_PATH = "/copilot/instructions";
+    private static final String LIBRARY_INSTRUCTION_FILE = "library.md";
+    private static final String SERVICE_INSTRUCTION_FILE = "service.md";
+    private static final String TEST_INSTRUCTION_FILE = "test.md";
+
+    private InstructionLoader() {
+        // Utility class, prevent instantiation
+    }
+
+    /**
+     * Loads the library instruction for a given package.
+     *
+     * @param packageName the full package name (e.g., "ballerina/http")
+     * @return Optional containing the instruction content, or empty if not found
+     */
+    public static Optional<String> loadLibraryInstruction(String packageName) {
+        return loadInstruction(packageName, LIBRARY_INSTRUCTION_FILE);
+    }
+
+    /**
+     * Loads the service instruction for a given package.
+     *
+     * @param packageName the full package name (e.g., "ballerina/http")
+     * @return Optional containing the instruction content, or empty if not found
+     */
+    public static Optional<String> loadServiceInstruction(String packageName) {
+        return loadInstruction(packageName, SERVICE_INSTRUCTION_FILE);
+    }
+
+    /**
+     * Loads the test generation instruction for a given package.
+     *
+     * @param packageName the full package name (e.g., "ballerina/http")
+     * @return Optional containing the instruction content, or empty if not found
+     */
+    public static Optional<String> loadTestInstruction(String packageName) {
+        return loadInstruction(packageName, TEST_INSTRUCTION_FILE);
+    }
+
+    /**
+     * Loads an instruction file from the resources.
+     *
+     * @param packageName the full package name (e.g., "ballerina/http")
+     * @param fileName    the instruction file name (e.g., "library.md")
+     * @return Optional containing the instruction content, or empty if not found
+     */
+    private static Optional<String> loadInstruction(String packageName, String fileName) {
+        String resourcePath = buildResourcePath(packageName, fileName);
+        try (InputStream inputStream = InstructionLoader.class.getResourceAsStream(resourcePath)) {
+            if (inputStream == null) {
+                return Optional.empty();
+            }
+            try (BufferedReader reader = new BufferedReader(
+                    new InputStreamReader(inputStream, StandardCharsets.UTF_8))) {
+                String content = reader.lines().collect(Collectors.joining("\n"));
+                return content.isEmpty() ? Optional.empty() : Optional.of(content);
+            }
+        } catch (IOException e) {
+            return Optional.empty();
+        }
+    }
+
+    /**
+     * Builds the resource path for an instruction file.
+     *
+     * @param packageName the full package name (e.g., "ballerina/http")
+     * @param fileName    the instruction file name
+     * @return the full resource path
+     */
+    private static String buildResourcePath(String packageName, String fileName) {
+        // Package name format: "org/module" (e.g., "ballerina/http")
+        // Resource path: /copilot/instructions/org/module/filename.md
+        return INSTRUCTIONS_BASE_PATH + "/" + packageName + "/" + fileName;
+    }
+
+    /**
+     * Checks if any instruction exists for a given package.
+     *
+     * @param packageName the full package name
+     * @return true if at least one instruction file exists
+     */
+    public static boolean hasAnyInstruction(String packageName) {
+        return loadLibraryInstruction(packageName).isPresent() ||
+                loadServiceInstruction(packageName).isPresent() ||
+                loadTestInstruction(packageName).isPresent();
+    }
+}