AI Implementation feature(903): Admin Area Challenges: List, Import/Export and Add/Edit Modal 1.03 (#44)

backend/src/modules/admin/challenges.service.ts

@@ -446,24 +446,29 @@ export class AdminChallengesService {
     }
 
     const result: ImportResult = { imported: 0, skipped: [], warnings: [] };
+    let orphanedStoredFilenames: string[] = [];
     try {
       await this.dataSource.transaction(async (manager) => {
         const challengeRepo = manager.getRepository(ChallengeEntity);
         const fileRepo = manager.getRepository(ChallengeFileEntity);
+
+        // Full-replace: capture every existing challenge and its disk-bound
+        // files so we can unlink them after the wipe, then delete every row.
+        // ChallengeFileEntity and SolveEntity both cascade on challenge delete.
+        const existingChallenges = await challengeRepo.find();
+        const existingIds = existingChallenges.map((c) => c.id);
+        if (existingIds.length > 0) {
+          const existingFiles = await fileRepo.find({ where: { challengeId: In(existingIds) } });
+          orphanedStoredFilenames = existingFiles.map((f) => f.storedFilename);
+          await manager.delete(ChallengeEntity, { id: In(existingIds) });
+        }
+
         for (const ch of doc.challenges) {
           const cat = catMap.get(ch.categorySystemKey.toLowerCase());
           if (!cat) {
             result.skipped.push({ name: ch.name, reason: `Unknown category: ${ch.categorySystemKey}` });
             continue;
           }
-          // Upsert by case-insensitive name.
-          const existing = await challengeRepo
-            .createQueryBuilder('c')
-            .where('LOWER(c.name) = :n', { n: ch.name.toLowerCase() })
-            .getOne();
-          if (existing) {
-            await manager.delete(ChallengeEntity, { id: existing.id });
-          }
           const row = challengeRepo.create({
             id: uuid(),
             name: ch.name,
@@ -501,6 +506,11 @@ export class AdminChallengesService {
       throw err;
     }
 
+    // Best-effort unlink of files owned by wiped challenges (post-commit).
+    for (const storedFilename of orphanedStoredFilenames) {
+      this.fileService.removeFinal(storedFilename);
+    }
+
     // Commit each staged file by renaming to its final filename (the
     // ChallengeFile rows already reference those names).
     for (const list of stagedByName.values()) {