fix ระบบแจ้ง Error #2497

Services/ImportBackgroundService.cs

@@ -566,9 +566,48 @@ public class ImportBackgroundService : BackgroundService
 
         if (rec_import.ScoreImport != null && rec_import.ScoreImport.Scores != null)
         {
+            // Store old ScoreImport ID and MinIO document ID for cleanup
+            var oldScoreImportId = rec_import.ScoreImport.Id;
+            var oldDocId = rec_import.ScoreImport.ImportFile?.Id;
+
+            // Delete old scores first
             await _context.BulkDeleteAsync(rec_import.ScoreImport.Scores.ToList());
+
+            // Delete the old ScoreImport entity to prevent duplicate FK constraint
+            await _context.BulkDeleteAsync(new List<ScoreImport> { rec_import.ScoreImport });
+
+            // TODO: Implement retention policy for old MinIO documents
+            // For now, keep old files to allow recovery and avoid immediate deletion
+            // if (oldDocId.HasValue && oldDocId.Value != Guid.Empty)
+            // {
+            //     try { await _minioService.DeleteFileAsync(oldDocId.Value); } catch { }
+            // }
+
+            // Clear ChangeTracker after bulk operations
+            _context.ChangeTracker.Clear();
         }
 
+        // Reload to get fresh entity state after clearing
+        rec_import = await _context.RecruitImports.AsQueryable()
+                                .Include(x => x.ImportHostories)
+                                .FirstOrDefaultAsync(x => x.Id == job.RecruitImportId)
+            ?? throw new Exception("RecruitImport not found after reload");
+
+        // get doc from minio
+        var doc = await _minioService.UploadFileAsync(new DummyFormFile(job.ImportFile));
+        var docId = doc.Id; // Store the ID before clearing tracker
+
+        // Detach document entity to prevent duplicate INSERT on next SaveChangesAsync
+        _context.Entry(doc).State = EntityState.Detached;
+        _context.ChangeTracker.Clear();
+
+        // Reload RecruitImport after clearing tracker to get fresh entity
+        rec_import = await _context.RecruitImports.AsQueryable()
+                                .Include(x => x.ImportHostories)
+                                .FirstOrDefaultAsync(x => x.Id == job.RecruitImportId)
+            ?? throw new Exception("RecruitImport not found after MinIO upload");
+
+        // Add import history
         rec_import.ImportHostories.Add(new RecruitImportHistory
         {
             Description = "นำเข้าข้อมูลผลคะแนนสอบ",
@@ -580,12 +619,14 @@ public class ImportBackgroundService : BackgroundService
             LastUpdateFullName = job.FullName ?? "System Administrator",
         });
 
-        // get doc from minio
+        // Load Document entity fresh from database to avoid tracking conflicts
-        var doc = await _minioService.UploadFileAsync(new DummyFormFile(job.ImportFile));
+        var freshDoc = await _context.Documents.FindAsync(docId)
+         ?? throw new Exception("Failed to retrieve uploaded document. Please contact support.");
+
         var imported = new ScoreImport
         {
             Year = rec_import.Year,
-            ImportFile = doc,
+            ImportFile = freshDoc,
             CreatedAt = DateTime.Now,
             CreatedUserId = job.UserId ?? "",
             CreatedFullName = job.FullName ?? "System Administrator",
@@ -595,6 +636,9 @@ public class ImportBackgroundService : BackgroundService
             Scores = new List<RecruitScore>()
         };
 
+        // Add ScoreImport to context explicitly to ensure EF Core knows to INSERT it
+        _context.Add(imported);
+
         // Save ScoreImport parent first to get its Id
         rec_import.ScoreImport = imported;
         await _context.SaveChangesAsync();