Iss #13 - Add current modern release return for legacy release endpoint

Resolves #13 (closed)

src/main/java/org/eclipsefoundation/downloads/resources/DownloadsResource.java

@@ -15,6 +15,9 @@ package org.eclipsefoundation.downloads.resources;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
+import java.util.function.Predicate;
+import java.util.function.Supplier;
+import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
 import javax.inject.Inject;
@@ -25,6 +28,7 @@ import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
 import javax.ws.rs.QueryParam;
+import javax.ws.rs.ServerErrorException;
 import javax.ws.rs.WebApplicationException;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.MultivaluedMap;
@@ -41,6 +45,7 @@ import org.eclipsefoundation.downloads.dto.DownloadFileIndex;
 import org.eclipsefoundation.downloads.models.ReleaseVersionPackages;
 import org.eclipsefoundation.downloads.models.ReleaseVersionPackages.ReleaseTrackerPackages;
 import org.eclipsefoundation.downloads.models.TrackedReleases.Release;
+import org.eclipsefoundation.downloads.models.TrackedReleases.ReleaseVersion;
 import org.eclipsefoundation.downloads.namespaces.DownloadsUrlParameterNames;
 import org.eclipsefoundation.downloads.services.ReleaseTrackerService;
 import org.eclipsefoundation.persistence.dao.impl.DefaultHibernateDao;
@@ -55,6 +60,10 @@ import org.slf4j.LoggerFactory;
 public class DownloadsResource {
     private static final Logger LOGGER = LoggerFactory.getLogger(DownloadsResource.class);
 
+    private static final Pattern MODERN_RELEASE_PATTERN = Pattern.compile("^\\d");
+
+    private static final String RELEASE_TYPE_ERROR_MESSAGE_FORMAT = "Invalid release type: %s";
+
     @Inject
     DefaultHibernateDao dao;
     @Inject
@@ -108,7 +117,7 @@ public class DownloadsResource {
             @QueryParam(DownloadsUrlParameterNames.RELEASE_VERSION_VALUE) String releaseVersion) {
 
         if (!isValidType(releaseType)) {
-            throw new BadRequestException(String.format("Invalid release type: %s", releaseType));
+            throw new BadRequestException(String.format(RELEASE_TYPE_ERROR_MESSAGE_FORMAT, releaseType));
         }
 
         // use existing calls and route according to what query params are provided
@@ -116,9 +125,11 @@ public class DownloadsResource {
             return releaseVersion(releaseType, releaseName, releaseVersion);
         } else if (StringUtils.isNotBlank(releaseName)) {
             return release(releaseType, releaseName);
+        } else if (StringUtils.isNotBlank(releaseVersion)) {
+            throw new BadRequestException("Cannot retrieve a release solely by version name");
+        } else {
+            return getLatestReleaseVersionPackages(releaseType);
         }
-
-        throw new BadRequestException("At least the release_name query parameter is required to use this endpoint");
     }
 
     @GET
@@ -133,7 +144,7 @@ public class DownloadsResource {
             @PathParam("releaseName") String releaseName) {
 
         if (!isValidType(releaseType)) {
-            throw new BadRequestException(String.format("Invalid release type: %s", releaseType));
+            throw new BadRequestException(String.format(RELEASE_TYPE_ERROR_MESSAGE_FORMAT, releaseType));
         }
 
         // check that the release name is valid
@@ -172,7 +183,7 @@ public class DownloadsResource {
     public Response releaseVersion(@PathParam("releaseType") String releaseType,
             @PathParam("releaseName") String releaseName, @PathParam("releaseVersion") String releaseVersion) {
         if (!isValidType(releaseType)) {
-            throw new BadRequestException(String.format("Invalid release type: %s", releaseType));
+            throw new BadRequestException(String.format(RELEASE_TYPE_ERROR_MESSAGE_FORMAT, releaseType));
         }
 
         // check that the release name is valid
@@ -207,12 +218,45 @@ public class DownloadsResource {
                 .build();
     }
 
+    /**
+     * Iterates over the current active releases to find the most recent one, and then converts it to the release
+     * packages output.
+     * 
+     * @param releaseType the release type for the current request
+     * @return response containing the most recent release packages
+     */
+    private Response getLatestReleaseVersionPackages(String releaseType) {
+        // set up the reused predicates
+        Predicate<ReleaseVersion> isLatestReleaseVersion = rv -> rv.getIsCurrent()
+                && "release".equalsIgnoreCase(rv.getType());
+        Supplier<ServerErrorException> errorForMissingCurrentRelease = () -> new ServerErrorException(
+                "Could not find any active modern releases", 500);
+        // get the latest modern release
+        Release latestRelease = releaseTrackerService
+                .getActiveReleases()
+                .stream()
+                .filter(release -> release.getVersions().stream().anyMatch(isLatestReleaseVersion)
+                        && MODERN_RELEASE_PATTERN.matcher(release.getName()).find())
+                .sorted((r1, r2) -> r2.getName().compareTo(r1.getName()))
+                .findFirst()
+                .orElseThrow(errorForMissingCurrentRelease);
+        // convert the data to the release version output
+        return releaseVersion(releaseType, latestRelease.getName(),
+                latestRelease
+                        .getVersions()
+                        .stream()
+                        .filter(isLatestReleaseVersion)
+                        .findFirst()
+                        .orElseThrow(errorForMissingCurrentRelease)
+                        .getName());
+    }
+
     /**
      * @param type the type of the release
      * @return True if valid, false if not
      */
     private boolean isValidType(String type) {
-        return (!type.equals("epp") && !type.equals("eclipse_packages")) ? false : true;
+        return "epp".equalsIgnoreCase(type) || "eclipse_packages".equalsIgnoreCase(type);
     }
 
     /**