Add classifier update routes

Sources/App/CapServer.swift

@@ -12,12 +12,34 @@ final class CapServer {
     
     private let classifierVersionFile: URL
     
+    private let classifierFile: URL
+    
     private let fm = FileManager.default
     
     // MARK: Caps
 
     private var writers: Set<String>
     
+    var classifierVersion: Int {
+        get {
+            do {
+                let content = try String(contentsOf: classifierVersionFile)
+                return Int(content) ?? 0
+            } catch {
+                log("Failed to read classifier version file: \(error)")
+                return 0
+            }
+        }
+        set {
+            do {
+                try "\(newValue)".data(using: .utf8)!
+                    .write(to: classifierVersionFile)
+            } catch {
+                log("Failed to save classifier version: \(error)")
+            }
+        }
+    }
+
     /**
      The time to wait for changes to be written to disk.
 
@@ -44,6 +66,7 @@ final class CapServer {
         self.imageFolder = folder.appendingPathComponent("images")
         self.dbFile = folder.appendingPathComponent("caps.json")
         self.classifierVersionFile = folder.appendingPathComponent("classifier.version")
+        self.classifierFile = folder.appendingPathComponent("classifier.mlmodel")
         self.writers = Set(writers)
         
         var isDirectory: ObjCBool = false
@@ -216,25 +239,11 @@ final class CapServer {
         log("Updated cap \(existingCap.id)")
     }
     
-    func updateClassifierCaps(from url: URL) {
-        guard fm.fileExists(atPath: url.path) else {
-            return
-        }
-        let content: String
-        do {
-            content = try String(contentsOf: url)
-        } catch {
-            log("Failed to read classifier training result file: \(error)")
-            return
-        }
-        guard let version = readClassifierVersionFromDisk() else {
-            return
-        }
-        
+    func updateTrainedClasses(content: String) {
         let trainedCaps = content
             .components(separatedBy: "\n")
             .compactMap(Int.init)
-        
+        let version = classifierVersion
         for cap in trainedCaps {
             if caps[cap]?.classifierVersion == nil {
                 caps[cap]?.classifierVersion = version
@@ -242,13 +251,13 @@ final class CapServer {
         }
     }
     
-    private func readClassifierVersionFromDisk() -> Int? {
+    func save(classifier: Data, version: Int) throws {
         do {
-            let content = try String(contentsOf: classifierVersionFile)
-            return Int(content)
+            try classifier.write(to: classifierFile)
         } catch {
-            log("Failed to read classifier version file: \(error)")
-            return nil
+            log("Failed to write classifier: \(error)")
+            throw Abort(.internalServerError)
         }
+        classifierVersion = version
     }
 }

Sources/App/routes.swift

@@ -14,6 +14,10 @@ private func authorize(_ request: Request) throws {
 
 func routes(_ app: Application) throws {
     
+    app.getCatching("version") { _ in
+        return "\(server.classifierVersion)"
+    }
+
     // Add or change a cap
     app.postCatching("cap") { request in
         try authorize(request)
@@ -40,10 +44,36 @@ func routes(_ app: Application) throws {
         try server.save(image: data, for: cap)
     }
     
-    // Update the classifier versions from file on disk
-    app.getCatching("refresh") { _ in
-        let url = URL(fileURLWithPath: app.directory.resourcesDirectory)
-            .appendingPathComponent("classifier.trained")
-        server.updateClassifierCaps(from: url)
+    // Update the classifier
+    app.postCatching("classifier", ":version") { request in
+        try authorize(request)
+        guard let version = request.parameters.get("version", as: Int.self) else {
+            log("Invalid parameter for version")
+            throw Abort(.badRequest)
+        }
+        guard version > server.classifierVersion else {
+            throw Abort(.alreadyReported)
+        }
+        guard let buffer = request.body.data else {
+            log("Missing body data: \(request.body.description)")
+            throw CapError.invalidBody
+        }
+        let data = Data(buffer: buffer)
+        try server.save(image: data, for: version)
+    }
+    
+    // Update the trained classes
+    app.postCatching("classes") { request in
+        try authorize(request)
+        guard let buffer = request.body.data else {
+            log("Missing body data: \(request.body.description)")
+            throw CapError.invalidBody
+        }
+        let data = Data(buffer: buffer)
+        guard let content = String(data: data, encoding: .utf8) else {
+            log("Invalid string body: \(request.body.description)")
+            throw CapError.invalidBody
+        }
+        server.updateTrainedClasses(content: content)
     }
 }