Remove classifier version from database

Caps/ContentView.swift

@@ -357,6 +357,7 @@ struct ContentView: View {
     private func downloadClassifier() {
         Task {
             await database.downloadClassifier()
+            await database.downloadClassifierClasses()
         }
     }
 

Caps/Data/Cap.swift

@@ -17,9 +17,6 @@ struct Cap {
     /// The index of the main image for the cap
     var mainImage: Int
 
-    /// The version of the first classifier capable of recognizing the cap
-    var classifierVersion: Int?
-
     var color: Color?
 
     /// The subpath to the main image on the server
@@ -44,13 +41,12 @@ struct Cap {
      - Parameter id: The unique id of the cap
      - Parameter name: The name associated with the cap
      */
-    init(id: Int, name: String, classifier: Int? = nil) {
+    init(id: Int, name: String) {
         self.id = id
         self.name = name
         self.cleanName = name.clean
         self.imageCount = 0
         self.mainImage = 0
-        self.classifierVersion = classifier
     }
 
     init(data: CapData) {
@@ -59,7 +55,6 @@ struct Cap {
         self.cleanName = data.name.clean
         self.imageCount = data.count
         self.mainImage = data.mainImage
-        self.classifierVersion = data.classifierVersion
     }
     
     var data: CapData {
@@ -67,7 +62,6 @@ struct Cap {
               name: name,
               count: imageCount,
               mainImage: mainImage,
-              classifierVersion: classifierVersion,
               color: color)
     }
 
@@ -76,30 +70,18 @@ struct Cap {
         self.cleanName = data.name.clean
         self.imageCount = data.count
         self.mainImage = data.mainImage
-        self.classifierVersion = data.classifierVersion
     }
 
     static func ==(lhs: Cap, rhs: CapData) -> Bool {
         lhs.id == rhs.id &&
         lhs.name == rhs.name &&
         lhs.imageCount == rhs.count &&
-        lhs.mainImage == rhs.mainImage &&
+        lhs.mainImage == rhs.mainImage
-        lhs.classifierVersion == rhs.classifierVersion
     }
 
     static func !=(lhs: Cap, rhs: CapData) -> Bool {
         !(lhs == rhs)
     }
-
-    func classifiable(by classifierVersion: Int?) -> Bool {
-        guard let version = classifierVersion else {
-            return false
-        }
-        guard let own = self.classifierVersion else {
-            return false
-        }
-        return version >= own
-    }
 }
 
 extension Cap {
@@ -130,7 +112,6 @@ extension Cap: Codable {
         case cleanName = "c"
         case imageCount = "i"
         case mainImage = "m"
-        case classifierVersion = "v"
         case color = "f"
     }
 }

Caps/Data/CapData.swift

@@ -10,8 +10,6 @@ struct CapData: Codable {
 
     var mainImage: Int
 
-    var classifierVersion: Int?
-
     var color: Cap.Color?
 
     enum CodingKeys: String, CodingKey {
@@ -19,7 +17,6 @@ struct CapData: Codable {
         case name = "n"
         case count = "c"
         case mainImage = "m"
-        case classifierVersion = "v"
         case color = "f"
     }
 }

Caps/Data/Database.swift

@@ -107,6 +107,35 @@ final class Database: ObservableObject {
     @Published
     var isUploading = false
     
+    @AppStorage("classifierClasses")
+    private var _classifierClassesString: String = ""
+    
+    private var _classifierClassesCache: Set<Int>?
+    
+    private var classifierClasses: Set<Int> {
+        get {
+            _classifierClassesCache ?? loadClassifierClasses()
+        }
+        set {
+            _classifierClassesCache = newValue
+            DispatchQueue.main.async {
+                self._classifierClassesString = newValue.map { "\($0)" }.joined(separator: ",")
+            }
+        }
+    }
+    
+    private func loadClassifierClasses() -> Set<Int> {
+        let elements: [Int] = _classifierClassesString.components(separatedBy: ",").compactMap {
+            guard let id = Int($0) else {
+                log("Failed to load classifier class from '\($0)'")
+                return nil
+            }
+            return id
+        }
+        _classifierClassesCache = Set(elements)
+        return _classifierClassesCache!
+    }
+
     init(server: URL, folder: URL = FileManager.default.documentDirectory) {
         self.serverUrl = server
         self.folderUrl = folder
@@ -152,6 +181,10 @@ final class Database: ObservableObject {
         serverUrl.appendingPathComponent("classifier.mlmodel")
     }
     
+    private var serverClassifierClassesUrl: URL {
+        serverUrl.appendingPathComponent("classifier.classes")
+    }
+
     private var serverClassifierVersionUrl: URL {
         serverUrl.appendingPathComponent("version")
     }
@@ -360,6 +393,48 @@ final class Database: ObservableObject {
         return true
     }
     
+    @discardableResult
+    func downloadClassifierClasses() async -> Bool {
+        log("Downloading classifier classes")
+        let data: Data
+        let response: URLResponse
+        do {
+            (data, response) = try await URLSession.shared.data(from: serverClassifierClassesUrl)
+        } catch {
+            log("Failed to download classifier classes: \(error)")
+            return false
+        }
+        guard (response as? HTTPURLResponse)?.statusCode == 200 else {
+            return false
+        }
+
+        guard let string = String(data: data, encoding: .utf8) else {
+            log("Classifier classes is invalid data (not a string)")
+            return false
+        }
+        let classes = string.components(separatedBy: ",")
+        
+        // Validate input
+        var isValid = true
+        let ids: [Int] = classes.compactMap { s in
+            guard let id = Int(s) else {
+                log("Invalid id '\(s)' in downloaded classes list")
+                isValid = false
+                return nil
+            }
+            if caps[id] == nil {
+                // Caps which are deleted may still be recognized
+                return nil
+            }
+            return id
+        }
+        guard isValid else {
+            return false
+        }
+        self.classifierClasses = Set(ids)
+        return true
+    }
+
     /**
      Indicate that the cap has pending operations, such as determining the color or a thumbnail
      */
@@ -374,7 +449,7 @@ final class Database: ObservableObject {
     // MARK: Adding new data
 
     func save(newCap name: String) -> Cap {
-        let cap = Cap(id: nextCapId, name: name, classifier: nil)
+        let cap = Cap(id: nextCapId, name: name)
         caps[cap.id] = cap
         DispatchQueue.main.async {
             self.changedCaps.insert(cap.id)
@@ -746,6 +821,10 @@ final class Database: ObservableObject {
         }
     }
     
+    func canClassify(cap id: Int) -> Bool {
+        classifierClasses.contains(id)
+    }
+
     private func getClassifier() -> Classifier? {
         if let classifier = classifier {
             return classifier
@@ -847,8 +926,7 @@ final class Database: ObservableObject {
     }
 
     var classifierClassCount: Int {
-        let version = classifierVersion
+        classifierClasses.count
-        return caps.values.filter { $0.classifiable(by: version) }.count
     }
 
     func imageCacheSize() async -> Int {
@@ -883,7 +961,7 @@ extension Database {
     static var largeMock: Database {
         let db = Database(server: URL(string: "https://christophhagen.de/caps")!)
         db.caps = (1..<500)
-            .map { Cap(id: $0, name: "Cap \($0)", classifier: nil)}
+            .map { Cap(id: $0, name: "Cap \($0)") }
             .reduce(into: [:]) { $0[$1.id] = $1 }
         db.image = UIImage(systemSymbol: .photo)
         return db