Add versions/latestrelease and /latest api endpoints

backend/src/main/java/io/papermc/hangar/controller/api/v1/VersionsController.java

@@ -22,7 +22,6 @@ import io.papermc.hangar.security.annotations.ratelimit.RateLimit;
 import io.papermc.hangar.security.annotations.unlocked.Unlocked;
 import io.papermc.hangar.security.annotations.visibility.VisibilityRequired;
 import io.papermc.hangar.service.api.VersionsApiService;
-import io.papermc.hangar.service.internal.file.FileService;
 import io.papermc.hangar.service.internal.versions.DownloadService;
 import jakarta.servlet.http.HttpServletResponse;
 import java.time.OffsetDateTime;
@@ -45,13 +44,11 @@ public class VersionsController implements IVersionsController {
 
     private final DownloadService downloadService;
     private final VersionsApiService versionsApiService;
-    private final FileService fileService;
 
     @Autowired
-    public VersionsController(final DownloadService downloadService, final VersionsApiService versionsApiService, final FileService fileService) {
+    public VersionsController(final DownloadService downloadService, final VersionsApiService versionsApiService) {
         this.downloadService = downloadService;
         this.versionsApiService = versionsApiService;
-        this.fileService = fileService;
     }
 
     @Unlocked
@@ -75,6 +72,18 @@ public class VersionsController implements IVersionsController {
         return this.versionsApiService.getVersions(author, slug, pagination);
     }
 
+    @Override
+    @VisibilityRequired(type = VisibilityRequired.Type.PROJECT, args = "{#author, #slug}")
+    public String getLatestReleaseVersion(final String author, final String slug) {
+        return this.versionsApiService.latestVersion(author, slug);
+    }
+
+    @Override
+    @VisibilityRequired(type = VisibilityRequired.Type.PROJECT, args = "{#author, #slug}")
+    public String getLatestVersion(final String author, final String slug, final @NotNull String channel) {
+        return this.versionsApiService.latestVersion(author, slug, channel);
+    }
+
     @Override
     public Map<String, VersionStats> getVersionStats(final String author, final String slug, final String versionString, final @NotNull OffsetDateTime fromDate, final @NotNull OffsetDateTime toDate) {
         return this.versionsApiService.getVersionStats(author, slug, versionString, fromDate, toDate);

backend/src/main/java/io/papermc/hangar/controller/api/v1/interfaces/IVersionsController.java

@@ -86,6 +86,39 @@ public interface IVersionsController {
                                          @Parameter(description = "The slug of the project to return versions for") @PathVariable String slug,
                                          @Parameter(description = "Pagination information") @NotNull RequestPagination pagination);
 
+    @Operation(
+        summary = "Returns the latest release version of a project",
+        operationId = "latestReleaseVersion",
+        description = "Returns the latest version of a project. Requires the `view_public_info` permission in the project or owning organizations.",
+        security = @SecurityRequirement(name = "HangarAuth", scopes = "view_public_info"),
+        tags = "Versions"
+    )
+    @ApiResponses({
+        @ApiResponse(responseCode = "200", description = "Ok"),
+        @ApiResponse(responseCode = "401", description = "Api session missing, invalid or expired"),
+        @ApiResponse(responseCode = "403", description = "Not enough permissions to use this endpoint")
+    })
+    @GetMapping("/projects/{author}/{slug}/latestrelease")
+    String getLatestReleaseVersion(@Parameter(description = "The author of the project to return the latest version for") @PathVariable String author,
+                                         @Parameter(description = "The slug of the project to return the latest version for") @PathVariable String slug);
+
+    @Operation(
+        summary = "Returns the latest version of a project for a specific channel",
+        operationId = "latestVersion",
+        description = "Returns the latest version of a project. Requires the `view_public_info` permission in the project or owning organization.",
+        security = @SecurityRequirement(name = "HangarAuth", scopes = "view_public_info"),
+        tags = "Versions"
+    )
+    @ApiResponses({
+        @ApiResponse(responseCode = "200", description = "Ok"),
+        @ApiResponse(responseCode = "401", description = "Api session missing, invalid or expired"),
+        @ApiResponse(responseCode = "403", description = "Not enough permissions to use this endpoint")
+    })
+    @GetMapping("/projects/{author}/{slug}/latest")
+    String getLatestVersion(@Parameter(description = "The author of the project to return the latest version for") @PathVariable String author,
+                            @Parameter(description = "The slug of the project to return the latest version for") @PathVariable String slug,
+                            @Parameter(description = "The channel to return the latest version for", required = true) @NotNull String channel);
+
     @Operation(
         summary = "Returns the stats for a version",
         operationId = "showVersionStats",

backend/src/main/java/io/papermc/hangar/db/dao/v1/VersionsApiDAO.java

@@ -22,6 +22,7 @@ import org.jdbi.v3.sqlobject.config.ValueColumn;
 import org.jdbi.v3.sqlobject.customizer.Define;
 import org.jdbi.v3.sqlobject.statement.SqlQuery;
 import org.jdbi.v3.stringtemplate4.UseStringTemplateEngine;
+import org.jetbrains.annotations.Nullable;
 import org.springframework.stereotype.Repository;
 
 @Repository
@@ -66,7 +67,7 @@ public interface VersionsApiDAO {
                pv.id = :versionId
            ORDERED BY pv.created_at DESC
     """)
-    Map.Entry<Long, Version> getVersion(long versionId, @Define boolean canSeeHidden, @Define Long userId);
+    @Nullable Map.Entry<Long, Version> getVersion(long versionId, @Define boolean canSeeHidden, @Define Long userId);
 
     @KeyColumn("id")
     @RegisterColumnMapper(VersionStatsMapper.class)
@@ -105,7 +106,7 @@ public interface VersionsApiDAO {
                lower(p.slug) = lower(:slug) AND
                pv.version_string = :versionString
     """)
-    Map.Entry<Long, Version> getVersionWithVersionString(String author, String slug, String versionString, @Define boolean canSeeHidden, @Define Long userId);
+    @Nullable Map.Entry<Long, Version> getVersionWithVersionString(String author, String slug, String versionString, @Define boolean canSeeHidden, @Define Long userId);
 
     @KeyColumn("id")
     @RegisterColumnMapper(VersionStatsMapper.class)
@@ -213,4 +214,26 @@ public interface VersionsApiDAO {
         GROUP BY date;
             """)
     Map<String, VersionStats> getVersionStats(String author, String slug, String versionString, OffsetDateTime fromDate, OffsetDateTime toDate);
+
+    @SqlQuery("""
+        SELECT pv.version_string
+           FROM project_versions pv
+               JOIN project_channels pc ON pv.channel_id = pc.id
+               JOIN projects p ON pv.project_id = p.id
+               LEFT JOIN users u ON pv.author_id = u.id
+           WHERE
+               <if(!canSeeHidden)>
+                   (pv.visibility = 0
+                   <if(userId)>
+                       OR (<userId> IN (SELECT pm.user_id FROM project_members_all pm WHERE pm.id = p.id) AND pv.visibility != 4)
+                   <endif>)
+                   AND
+               <endif>
+               lower(p.owner_name) = lower(:author) AND
+               lower(p.slug) = lower(:slug) AND
+               pc.name = :channel
+           ORDER BY pv.created_at DESC
+           LIMIT 1
+    """)
+    @Nullable String getLatestVersion(String author, String slug, String channel, @Define boolean canSeeHidden, @Define Long userId);
 }

backend/src/main/java/io/papermc/hangar/service/api/VersionsApiService.java

@@ -24,6 +24,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.SortedSet;
+import org.jetbrains.annotations.Nullable;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.stereotype.Service;
@@ -173,4 +174,17 @@ public class VersionsApiService extends HangarComponent {
         }
         return this.versionsApiDAO.getVersionStats(author, slug, versionString, fromDate, toDate);
     }
+
+    public @Nullable String latestVersion(final String author, final String slug) {
+        return this.latestVersion(author, slug, this.config.channels.nameDefault());
+    }
+
+    public @Nullable String latestVersion(final String author, final String slug, final String channel) {
+        final boolean canSeeHidden = this.getGlobalPermissions().has(Permission.SeeHidden);
+        final String version = this.versionsApiDAO.getLatestVersion(author, slug, channel, canSeeHidden, this.getHangarUserId());
+        if (version == null) {
+            throw new HangarApiException(HttpStatus.NOT_FOUND, "No version found for " + author + "/" + slug + " on channel " + channel);
+        }
+        return version;
+    }
 }