Combine key scanning logic in one class

pass/Models/QRKeyScanner.swift

@@ -0,0 +1,73 @@
+//
+//  QRKeyScanner.swift
+//  pass
+//
+//  Created by Danny Moesch on 19.08.20.
+//  Copyright © 2020 Bob Sun. All rights reserved.
+//
+
+struct QRKeyScanner {
+    enum Result: Equatable {
+        case lookingForStart
+        case wrongKeyType(ScannableKeyType)
+        case completed
+        case scanned(Int)
+
+        var message: String {
+            switch self {
+            case .lookingForStart:
+                return "LookingForStartingFrame.".localize()
+            case let .wrongKeyType(keyType):
+                return "Scan\(keyType.visibility)Key.".localize()
+            case .completed:
+                return "Done".localize()
+            case let .scanned(count):
+                return "ScannedQrCodes(%d)".localize(count)
+            }
+        }
+
+        var unrolled: (accepted: Bool, message: String) {
+            if self == .completed {
+                return (true, message)
+            }
+            return (false, message)
+        }
+    }
+
+    private var segments = [String]()
+    private var previousResult = Result.lookingForStart
+
+    let keyType: ScannableKeyType
+
+    init(keyType: ScannableKeyType) {
+        self.keyType = keyType
+    }
+
+    var scannedKey: String {
+        segments.joined()
+    }
+
+    mutating func add(segment: String) -> Result {
+        // Skip duplicated segments.
+        guard segment != segments.last else {
+            return previousResult
+        }
+
+        // Check whether we have found the first block.
+        guard !segments.isEmpty || segment.contains(keyType.headerStart) else {
+            // Check whether we are scanning the wrong key type.
+            if let counterKeyType = keyType.counterType, segment.contains(counterKeyType.headerStart) {
+                previousResult = .wrongKeyType(counterKeyType)
+            }
+            return previousResult
+        }
+
+        // Update the list of scanned segments and return.
+        segments.append(segment)
+        if segment.starts(with: keyType.footerStart), segment.hasSuffix(keyType.footerEnd) {
+            return .completed
+        }
+        previousResult = .scanned(segments.count)
+        return previousResult
+    }
+}

pass/Models/ScannableKeyType.swift

@@ -0,0 +1,60 @@
+//
+//  ScannableKeyType.swift
+//  pass
+//
+//  Created by Danny Moesch on 19.08.20.
+//  Copyright © 2020 Bob Sun. All rights reserved.
+//
+
+enum ScannableKeyType {
+    case pgpPublic
+    case pgpPrivate
+    case sshPrivate
+
+    var visibility: String {
+        switch self {
+        case .pgpPublic:
+            return "Public"
+        case .pgpPrivate, .sshPrivate:
+            return "Private"
+        }
+    }
+
+    var headerStart: String {
+        switch self {
+        case .pgpPublic, .pgpPrivate:
+            return "-----BEGIN PGP \(visibility.uppercased()) KEY BLOCK-----"
+        case .sshPrivate:
+            return "-----BEGIN"
+        }
+    }
+
+    var footerStart: String {
+        switch self {
+        case .pgpPublic, .pgpPrivate:
+            return "-----END PGP \(visibility.uppercased())"
+        case .sshPrivate:
+            return "-----END"
+        }
+    }
+
+    var footerEnd: String {
+        switch self {
+        case .pgpPublic, .pgpPrivate:
+            return "KEY BLOCK-----"
+        case .sshPrivate:
+            return "KEY-----"
+        }
+    }
+
+    var counterType: Self? {
+        switch self {
+        case .pgpPublic:
+            return .pgpPrivate
+        case .pgpPrivate:
+            return .pgpPublic
+        case .sshPrivate:
+            return nil
+        }
+    }
+}

pass/Models/ScannedPGPKey.swift

@@ -1,52 +0,0 @@
-//
-//  ScannedPGPKey.swift
-//  pass
-//
-//  Created by Danny Moesch on 05.07.20.
-//  Copyright © 2020 Bob Sun. All rights reserved.
-//
-
-class ScannedPGPKey {
-    enum KeyType {
-        case publicKey, privateKey
-    }
-
-    var keyType = KeyType.publicKey
-    var segments = [String]()
-    var message = ""
-
-    func reset(keytype: KeyType) {
-        keyType = keytype
-        segments.removeAll()
-        message = "LookingForStartingFrame.".localize()
-    }
-
-    func addSegment(segment: String) -> (accept: Bool, message: String) {
-        let keyTypeStr = keyType == .publicKey ? "Public" : "Private"
-        let theOtherKeyTypeStr = keyType == .publicKey ? "Private" : "Public"
-
-        // Skip duplicated segments.
-        guard segment != segments.last else {
-            return (accept: false, message: message)
-        }
-
-        // Check whether we have found the first block.
-        guard !segments.isEmpty || segment.contains("-----BEGIN PGP \(keyTypeStr.uppercased()) KEY BLOCK-----") else {
-            // Check whether we are scanning the wrong key type.
-            if segment.contains("-----BEGIN PGP \(theOtherKeyTypeStr.uppercased()) KEY BLOCK-----") {
-                message = "Scan\(keyTypeStr)Key.".localize()
-            }
-            return (accept: false, message: message)
-        }
-
-        // Update the list of scanned segment and return.
-        segments.append(segment)
-        if segment.contains("-----END PGP \(keyTypeStr.uppercased()) KEY BLOCK-----") {
-            message = "Done".localize()
-            return (accept: true, message: message)
-        } else {
-            message = "ScannedQrCodes(%d)".localize(segments.count)
-            return (accept: false, message: message)
-        }
-    }
-}