Add newly refactored /classes/{class} endpoint

service/src/main/java/gov/nasa/pds/api/registry/controllers/ProductsController.java

@@ -2,12 +2,9 @@
 
 import java.lang.reflect.InvocationTargetException;
 import java.io.IOException;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.HashMap;
-import java.util.Objects;
+import java.util.*;
 
+import gov.nasa.pds.api.base.ClassesApi;
 import gov.nasa.pds.api.registry.model.exceptions.*;
 import gov.nasa.pds.api.registry.model.identifiers.PdsLid;
 import gov.nasa.pds.api.registry.model.identifiers.PdsLidVid;
@@ -22,8 +19,10 @@
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.HttpStatusCode;
 import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Controller;
+import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.context.request.RequestContextHolder;
 import org.springframework.web.context.request.ServletRequestAttributes;
 import gov.nasa.pds.api.base.ProductsApi;
@@ -40,7 +39,16 @@
 
 
 @Controller
-public class ProductsController implements ProductsApi {
+// TODO: Refactor common controller code out of ProductsController and split the additional API implementations out into
+//  corresponding controllers
+public class ProductsController implements ProductsApi, ClassesApi {
+
+  @Override
+  // TODO: Remove this when the common controller code is refactored out - it is only necessary because additional
+  // interfaces have been implemented as a stopgap
+  public Optional<NativeWebRequest> getRequest() {
+    return ProductsApi.super.getRequest();
+  }
 
   private static final Logger log = LoggerFactory.getLogger(ProductsController.class);
 
@@ -600,4 +608,36 @@ public ResponseEntity<Object> productMemberOfOf(
     }
   }
 
+  @Override
+  // TODO: Relocate this to ClassesController once common controller code has been extracted/refactored
+  public ResponseEntity<Object> classList(String propertyClass, List<String> fields, List<String> keywords, Integer limit, String q, List<String> sort, List<String> searchAfter) throws Exception {
+    PdsProductClasses pdsProductClass;
+    try {
+       pdsProductClass = PdsProductClasses.fromSwaggerName(propertyClass);
+    } catch (IllegalArgumentException err) {
+      throw new BadRequestException(err.getMessage());
+    }
+
+    SearchRequest searchRequest = new RegistrySearchRequestBuilder(this.connectionContext)
+            .matchProductClass(pdsProductClass)
+            .constrainByQueryString(q)
+            .addKeywordsParam(keywords)
+            .fieldsFromStrings(fields)
+            .paginate(limit, sort, searchAfter)
+            .onlyLatest()
+            .build();
+
+    SearchResponse<HashMap> searchResponse =
+            this.openSearchClient.search(searchRequest, HashMap.class);
+
+    RawMultipleProductResponse products = new RawMultipleProductResponse(searchResponse);
+
+    return formatMultipleProducts(products, fields);
+  }
+
+  @Override
+  // TODO: Relocate this to ClassesController once common controller code has been extracted/refactored
+  public ResponseEntity<List<String>> classes() throws Exception {
+    return new ResponseEntity<>(Arrays.stream(PdsProductClasses.values()).map(PdsProductClasses::getSwaggerName).toList(), HttpStatusCode.valueOf(200));
+  }
 }

service/src/main/java/gov/nasa/pds/api/registry/model/identifiers/PdsProductClasses.java

@@ -1,5 +1,8 @@
 package gov.nasa.pds.api.registry.model.identifiers;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * An enumeration of the valid product_class values from the PDS4 Data Dictionary
  * <a href="https://pds.nasa.gov/datastandards/documents/dd/v1/PDS4_PDS_DD_1M00.html#N-1195656387">...</a>
@@ -52,12 +55,52 @@ public String getValue() {
     }
 
     /**
-     * @return The database property/field these string values appear in. Provided for convenience.
+     * @return the database property/field these string values appear in. Provided for convenience.
      */
     public static String getPropertyName() {
         return "product_class";
     }
 
+    public static List<String> getValidSwaggerNames() {
+        return Arrays.stream(PdsProductClasses.values()).map(PdsProductClasses::getSwaggerName).toList();
+    }
+
+    /**
+     * @return the shorthand name used for convenience in API routes, ex. "Product_Bundle" -> "bundle"
+     */
+    public String getSwaggerName() {
+        List<String> chunks = Arrays.asList(this.value.split("_"));
+
+        if (chunks.size() < 2 || !chunks.get(0).equals("Product")) {
+            throw new IllegalArgumentException("Could not generate swagger name for PDSProductClasses value '" + this.value + "'");
+        }
+
+        List<String> relevantChunks = chunks.subList(1, chunks.size());
+
+        return String.join("-", relevantChunks).toLowerCase();
+    }
+
+    /**
+     * @return the PdsProductClass which is equivalent to a given swagger-formatted product class name
+     */
+    public static PdsProductClasses fromSwaggerName(String swaggerName) {
+        List<PdsProductClasses> matches = Arrays.stream(PdsProductClasses.values())
+                .filter(value -> value.getSwaggerName().equals(swaggerName))
+                .toList();
+
+        if (matches.isEmpty()) {
+            throw new IllegalArgumentException("No PdsProductClass matches swagger name '" + swaggerName + "'"
+                    + "'. Valid names are: " + String.join(", ", getValidSwaggerNames()));
+        }
+
+        if (matches.size() > 1) {
+//            This should never be possible and indicates an error in the enum value definitions
+            throw new IllegalArgumentException("Multiple PdsProductClass matches swagger name '" + swaggerName + "'");
+        }
+
+        return matches.get(0);
+    }
+
     public Boolean isBundle() {
         return this == Product_Bundle;
     }

service/src/main/java/gov/nasa/pds/api/registry/search/RegistrySearchRequestBuilder.java

@@ -169,6 +169,10 @@ public RegistrySearchRequestBuilder matchLid(PdsProductIdentifier identifier) {
     return this.matchField("lid", identifier.getLid());
   }
 
+  public RegistrySearchRequestBuilder matchProductClass(PdsProductClasses productClass) {
+    return this.matchField(PdsProductClasses.getPropertyName(), productClass.getValue());
+  }
+
   public RegistrySearchRequestBuilder matchMembersOfBundle(PdsLidVid identifier) {
     return this.matchField("ops:Provenance/ops:parent_bundle_identifier", identifier);
   }

service/src/test/java/gov/nasa/pds/api/registry/model/PdsProductClassesTest.java

@@ -0,0 +1,16 @@
+package gov.nasa.pds.api.registry.model;
+
+import gov.nasa.pds.api.registry.model.identifiers.PdsProductClasses;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class PdsProductClassesTest {
+  @Test
+  public void testSwaggerConversions() {
+    for (PdsProductClasses canonicalClass : PdsProductClasses.values()) {
+      String swaggerName = canonicalClass.getSwaggerName();
+      PdsProductClasses parsedClass = PdsProductClasses.fromSwaggerName(swaggerName);
+      Assert.assertEquals(canonicalClass, parsedClass);
+    }
+  }
+}