[Feature] add findToursByIds() to CompetitionFacade (#563)

Author: antonpampukha

src/main/java/com/itasocialacademy/oitassist/competition/api/CompetitionFacade.java

@@ -59,4 +59,15 @@ public interface CompetitionFacade {
      * @return the competition tree, or empty if no competition with this ID exists
      */
     Optional<CompetitionTreeDetail> findCompetitionTreeByCompetitionId(Long competitionId);
+
+    /**
+     * Retrieves tours by their IDs.
+     *
+     * @param tourIds Tour IDs, must not be {@code null} (an empty list yields an
+     *                empty result)
+     * @return the tours found for the given IDs, in unspecified order; IDs with no
+     *         matching tour are silently omitted, so the result may be smaller than
+     *         {@code tourIds}
+     */
+    List<TourDetail> findToursByIds(List<Long> tourIds);
 }

src/main/java/com/itasocialacademy/oitassist/competition/service/CompetitionFacadeImpl.java

@@ -78,6 +78,18 @@ public Optional<CompetitionTreeDetail> findCompetitionTreeByCompetitionId(Long c
             .map(this::buildTreeDetail);
     }
 
+    @Override
+    @Transactional(readOnly = true)
+    public List<TourDetail> findToursByIds(List<Long> tourIds) {
+        Objects.requireNonNull(tourIds, "tourIds must not be null");
+        if (tourIds.isEmpty()) {
+            return List.of();
+        }
+        return tourRepository.findAllById(tourIds).stream()
+            .map(tourMapper::toTourDetail)
+            .toList();
+    }
+
     private CompetitionTreeDetail buildTreeDetail(Competition competitionEntity) {
         CompetitionDetail competitionDetail = competitionMapper.toCompetitionDetail(competitionEntity);