Separate classes to file

Training/train.swift

@@ -156,6 +156,12 @@ final class ClassifierCreator {
         }
         let changedMainImages = changedImageList.filter { $0.image == 0 }.map { $0.cap }
         let classes = imageCounts.keys.sorted()
+        
+        // Delete any image folders not present as caps
+        guard deleteUnnecessaryImageFolders(caps: classes) else {
+            return nil
+        }
+        
         return (classes, missingImageList.count + changedImageList.count, changedMainImages)
     }
     
@@ -176,6 +182,33 @@ final class ClassifierCreator {
         }
     }
     
+    private func deleteUnnecessaryImageFolders(caps: [Int]) -> Bool {
+        let validNames = caps.map { String(format: "%04d", $0) }
+        let folders: [String]
+        do {
+            folders = try FileManager.default.contentsOfDirectory(atPath: imageDirectory.path)
+        } catch {
+            print("[ERROR] Failed to get list of image folders: \(error)")
+            return false
+        }
+        for folder in folders {
+            if validNames.contains(folder) {
+                continue
+            }
+            
+            // Not a valid cap folder
+            let url = imageDirectory.appendingPathComponent(folder)
+            do {
+                try FileManager.default.removeItem(at: url)
+                print("[ERROR] Removed unused image folder '\(folder)'")
+            } catch {
+                print("[ERROR] Failed to delete unused image folder \(folder): \(error)")
+                return false
+            }
+        }
+        return true
+    }
+    
     private func imageUrl(base: URL, cap: Int, image: Int) -> URL {
         base.appendingPathComponent(String(format: "%04d/%04d-%02d.jpg", cap, cap, image))
     }
@@ -329,7 +362,7 @@ final class ClassifierCreator {
         let dateString = df.string(from: lastUpdate)
         return await post(
             url: server.appendingPathComponent("classes/\(dateString)"),
-            body: classes.map(String.init).joined(separator: "\n").data(using: .utf8)!)
+            body: classes.map(String.init).joined(separator: ",").data(using: .utf8)!)
     }
     
     // MARK: Step 7: Create thumbnails