Format text based on group size via separator

6 files changed, 262 insertions, 197 deletions

diff --git a/ios/MullvadVPN.xcodeproj/project.pbxproj b/ios/MullvadVPN.xcodeproj/project.pbxproj
index 85f36e1a15..73a534a971 100644
--- a/ios/MullvadVPN.xcodeproj/project.pbxproj
+++ b/ios/MullvadVPN.xcodeproj/project.pbxproj
@@ -84,8 +84,7 @@
 		58293FB125124117005D0BB5 /* CustomTextField.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58293FB025124117005D0BB5 /* CustomTextField.swift */; };
 		58293FB3251241B4005D0BB5 /* CustomTextView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58293FB2251241B3005D0BB5 /* CustomTextView.swift */; };
 		582A8A3A28BCE19B00D0F9FB /* FixedWidthIntegerArithmeticsTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 582A8A3928BCE19B00D0F9FB /* FixedWidthIntegerArithmeticsTests.swift */; };
-		582AE3102440A6CA00E6733A /* AccountTokenInput.swift in Sources */ = {isa = PBXBuildFile; fileRef = 582AE30F2440A6CA00E6733A /* AccountTokenInput.swift */; };
-		582AE3122440CA0D00E6733A /* AccountTokenInputTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 582AE3112440CA0D00E6733A /* AccountTokenInputTests.swift */; };
+		582AE3102440A6CA00E6733A /* InputTextFormatter.swift in Sources */ = {isa = PBXBuildFile; fileRef = 582AE30F2440A6CA00E6733A /* InputTextFormatter.swift */; };
 		582BB1AF229566420055B6EF /* SettingsCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = 582BB1AE229566420055B6EF /* SettingsCell.swift */; };
 		582BB1B1229569620055B6EF /* UINavigationBar+Appearance.swift in Sources */ = {isa = PBXBuildFile; fileRef = 582BB1B0229569620055B6EF /* UINavigationBar+Appearance.swift */; };
 		5835B7CC233B76CB0096D79F /* TunnelManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5835B7CB233B76CB0096D79F /* TunnelManager.swift */; };
@@ -240,7 +239,7 @@
 		58B26E282943527300D5980C /* SystemNotificationProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58B26E272943527300D5980C /* SystemNotificationProvider.swift */; };
 		58B26E2A2943545A00D5980C /* NotificationManagerDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58B26E292943545A00D5980C /* NotificationManagerDelegate.swift */; };
 		58B43C1925F77DB60002C8C3 /* TunnelControlView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58B43C1825F77DB60002C8C3 /* TunnelControlView.swift */; };
-		58B8644529C7971B005E107C /* AccountTokenInput.swift in Sources */ = {isa = PBXBuildFile; fileRef = 582AE30F2440A6CA00E6733A /* AccountTokenInput.swift */; };
+		58B8644529C7971B005E107C /* InputTextFormatter.swift in Sources */ = {isa = PBXBuildFile; fileRef = 582AE30F2440A6CA00E6733A /* InputTextFormatter.swift */; };
 		58B8644629C7972F005E107C /* CustomDateComponentsFormatting.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5896AE83246D5889005B36CB /* CustomDateComponentsFormatting.swift */; };
 		58B93A1326C3F13600A55733 /* TunnelState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58B93A1226C3F13600A55733 /* TunnelState.swift */; };
 		58B993B12608A34500BA7811 /* LoginContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58B993B02608A34500BA7811 /* LoginContentView.swift */; };
@@ -403,6 +402,7 @@
 		E158B360285381C60002F069 /* String+AccountFormatting.swift in Sources */ = {isa = PBXBuildFile; fileRef = E158B35F285381C60002F069 /* String+AccountFormatting.swift */; };
 		E1FD0DF528AA7CE400299DB4 /* StatusActivityView.swift in Sources */ = {isa = PBXBuildFile; fileRef = E1FD0DF428AA7CE400299DB4 /* StatusActivityView.swift */; };
 		F03580252A13842C00E5DAFD /* IncreasedHitButton.swift in Sources */ = {isa = PBXBuildFile; fileRef = F03580242A13842C00E5DAFD /* IncreasedHitButton.swift */; };
+		F07BF2582A26112D00042943 /* InputTextFormatterTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = F07BF2572A26112D00042943 /* InputTextFormatterTests.swift */; };
 		F07CFF2029F2720E008C0343 /* RegisteredDeviceInAppNotificationProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = F07CFF1F29F2720E008C0343 /* RegisteredDeviceInAppNotificationProvider.swift */; };
 		F0C2AEFD2A0BB5CC00986207 /* NotificationProviderIdentifier.swift in Sources */ = {isa = PBXBuildFile; fileRef = F0C2AEFC2A0BB5CC00986207 /* NotificationProviderIdentifier.swift */; };
 /* End PBXBuildFile section */
@@ -847,8 +847,7 @@
 		58293FB025124117005D0BB5 /* CustomTextField.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CustomTextField.swift; sourceTree = "<group>"; };
 		58293FB2251241B3005D0BB5 /* CustomTextView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CustomTextView.swift; sourceTree = "<group>"; };
 		582A8A3928BCE19B00D0F9FB /* FixedWidthIntegerArithmeticsTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FixedWidthIntegerArithmeticsTests.swift; sourceTree = "<group>"; };
-		582AE30F2440A6CA00E6733A /* AccountTokenInput.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AccountTokenInput.swift; sourceTree = "<group>"; };
-		582AE3112440CA0D00E6733A /* AccountTokenInputTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AccountTokenInputTests.swift; sourceTree = "<group>"; };
+		582AE30F2440A6CA00E6733A /* InputTextFormatter.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = InputTextFormatter.swift; sourceTree = "<group>"; };
 		582BB1AE229566420055B6EF /* SettingsCell.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SettingsCell.swift; sourceTree = "<group>"; };
 		582BB1B0229569620055B6EF /* UINavigationBar+Appearance.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UINavigationBar+Appearance.swift"; sourceTree = "<group>"; };
 		582FFA82290A84E700895745 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist; path = Info.plist; sourceTree = "<group>"; };
@@ -1115,6 +1114,7 @@
 		E158B35F285381C60002F069 /* String+AccountFormatting.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "String+AccountFormatting.swift"; sourceTree = "<group>"; };
 		E1FD0DF428AA7CE400299DB4 /* StatusActivityView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusActivityView.swift; sourceTree = "<group>"; };
 		F03580242A13842C00E5DAFD /* IncreasedHitButton.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IncreasedHitButton.swift; sourceTree = "<group>"; };
+		F07BF2572A26112D00042943 /* InputTextFormatterTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = InputTextFormatterTests.swift; sourceTree = "<group>"; };
 		F07CFF1F29F2720E008C0343 /* RegisteredDeviceInAppNotificationProvider.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RegisteredDeviceInAppNotificationProvider.swift; sourceTree = "<group>"; };
 		F0C2AEFC2A0BB5CC00986207 /* NotificationProviderIdentifier.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NotificationProviderIdentifier.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
@@ -1426,19 +1426,19 @@
 		583FE01629C196E8006E85F9 /* View controllers */ = {
 			isa = PBXGroup;
 			children = (
-				583FE02529C1AD0E006E85F9 /* Launch */,
-				583FE02229C1AC68006E85F9 /* TermsOfService */,
-				583FE02129C1A0F4006E85F9 /* Login */,
 				583FE02029C1A0B1006E85F9 /* Account */,
-				583FE01E29C197D5006E85F9 /* Tunnel */,
+				5878F4FA29CDA2D4003D4BE2 /* ChangeLog */,
 				583FE01D29C197C1006E85F9 /* DeviceList */,
-				583FE01C29C19793006E85F9 /* RevokedDevice */,
+				583FE02529C1AD0E006E85F9 /* Launch */,
+				583FE02129C1A0F4006E85F9 /* Login */,
 				583FE01B29C19786006E85F9 /* OutOfTime */,
-				5878F4FA29CDA2D4003D4BE2 /* ChangeLog */,
 				583FE01A29C19777006E85F9 /* Preferences */,
 				583FE01929C19760006E85F9 /* ProblemReport */,
-				583FE01829C19709006E85F9 /* Settings */,
+				583FE01C29C19793006E85F9 /* RevokedDevice */,
 				583FE01729C196F3006E85F9 /* SelectLocation */,
+				583FE01829C19709006E85F9 /* Settings */,
+				583FE02229C1AC68006E85F9 /* TermsOfService */,
+				583FE01E29C197D5006E85F9 /* Tunnel */,
 			);
 			path = "View controllers";
 			sourceTree = "<group>";
@@ -1577,12 +1577,11 @@
 		583FE02129C1A0F4006E85F9 /* Login */ = {
 			isa = PBXGroup;
 			children = (
-				58B993B02608A34500BA7811 /* LoginContentView.swift */,
-				58CE5E65224146200008646E /* LoginViewController.swift */,
-				58CAF9FF2983FF0200BE19F7 /* LoginInteractor.swift */,
-				582AE30F2440A6CA00E6733A /* AccountTokenInput.swift */,
 				58C3A4B122456F1A00340BDB /* AccountInputGroupView.swift */,
 				58CCA01D2242787B004F3011 /* AccountTextField.swift */,
+				58B993B02608A34500BA7811 /* LoginContentView.swift */,
+				58CAF9FF2983FF0200BE19F7 /* LoginInteractor.swift */,
+				58CE5E65224146200008646E /* LoginViewController.swift */,
 			);
 			path = Login;
 			sourceTree = "<group>";
@@ -1662,6 +1661,7 @@
 				5896AE83246D5889005B36CB /* CustomDateComponentsFormatting.swift */,
 				58138E60294871C600684F0C /* DeviceDataThrottling.swift */,
 				7A7AD28C29DC677800480EF1 /* FirstTimeLaunch.swift */,
+				582AE30F2440A6CA00E6733A /* InputTextFormatter.swift */,
 				58CC40EE24A601900019D96E /* ObserverList.swift */,
 				5872D6E7286304DE00DB5F4E /* TermsOfService.swift */,
 			);
@@ -1854,11 +1854,11 @@
 		58B0A2A1238EE67E00BC001D /* MullvadVPNTests */ = {
 			isa = PBXGroup;
 			children = (
-				582AE3112440CA0D00E6733A /* AccountTokenInputTests.swift */,
 				5896AE85246D6AD8005B36CB /* CustomDateComponentsFormattingTests.swift */,
 				58915D622A25F8400066445B /* DeviceCheckOperationTests.swift */,
 				582A8A3928BCE19B00D0F9FB /* FixedWidthIntegerArithmeticsTests.swift */,
 				58B0A2A4238EE67E00BC001D /* Info.plist */,
+				F07BF2572A26112D00042943 /* InputTextFormatterTests.swift */,
 				584B26F3237434D00073B10E /* RelaySelectorTests.swift */,
 				5807E2C1243203D000F5FF30 /* StringTests.swift */,
 				58165EBD2A262CBB00688EAD /* WgKeyRotationTests.swift */,
@@ -2838,12 +2838,12 @@
 			buildActionMask = 2147483647;
 			files = (
 				58915D6A2A26031B0066445B /* DNSSettings.swift in Sources */,
-				58B8644529C7971B005E107C /* AccountTokenInput.swift in Sources */,
+				58B8644529C7971B005E107C /* InputTextFormatter.swift in Sources */,
 				58915D692A2601FB0066445B /* WgKeyRotation.swift in Sources */,
-				582AE3122440CA0D00E6733A /* AccountTokenInputTests.swift in Sources */,
 				580810E62A30E13D00B74552 /* DeviceStateAccessorProtocol.swift in Sources */,
 				58915D642A25F8B30066445B /* DeviceCheckOperation.swift in Sources */,
 				58915D652A25F9E20066445B /* TunnelSettingsV2.swift in Sources */,
+				58B8644529C7971B005E107C /* InputTextFormatter.swift in Sources */,
 				582A8A3A28BCE19B00D0F9FB /* FixedWidthIntegerArithmeticsTests.swift in Sources */,
 				58915D632A25F8400066445B /* DeviceCheckOperationTests.swift in Sources */,
 				5896AE86246D6AD8005B36CB /* CustomDateComponentsFormattingTests.swift in Sources */,
@@ -2852,6 +2852,7 @@
 				58165EBE2A262CBB00688EAD /* WgKeyRotationTests.swift in Sources */,
 				5807E2C3243203E700F5FF30 /* String+Split.swift in Sources */,
 				580810E92A30E17300B74552 /* DeviceCheckRemoteServiceProtocol.swift in Sources */,
+				F07BF2582A26112D00042943 /* InputTextFormatterTests.swift in Sources */,
 				58B0A2A8238EE68200BC001D /* RelaySelectorTests.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -2933,7 +2934,7 @@
 				58138E61294871C600684F0C /* DeviceDataThrottling.swift in Sources */,
 				5878A279290954790096FC88 /* TunnelViewControllerInteractor.swift in Sources */,
 				7A818F1F29F0305800C7F0F4 /* RootConfiguration.swift in Sources */,
-				582AE3102440A6CA00E6733A /* AccountTokenInput.swift in Sources */,
+				582AE3102440A6CA00E6733A /* InputTextFormatter.swift in Sources */,
 				5820EDAB288FF0D2006BF4E4 /* DeviceRowView.swift in Sources */,
 				5846227726E22A7C0035F7C2 /* StorePaymentManagerDelegate.swift in Sources */,
 				58EF581125D69DB400AEBA94 /* StatusImageView.swift in Sources */,
diff --git a/ios/MullvadVPN/View controllers/Login/AccountTokenInput.swift b/ios/MullvadVPN/Classes/InputTextFormatter.swift
index 1fef51a479..89e1df7607 100644
--- a/ios/MullvadVPN/View controllers/Login/AccountTokenInput.swift
+++ b/ios/MullvadVPN/Classes/InputTextFormatter.swift
@@ -1,5 +1,5 @@
 //
-//  AccountTokenInput.swift
+//  InputTextFormatter.swift
 //  MullvadVPN
 //
 //  Created by pronebird on 08/04/2020.
@@ -11,15 +11,33 @@ import UIKit
 
 /// A class describing the account token input and caret management.
 /// Suitable to be used with `UITextField`.
-class AccountTokenInput: NSObject {
-    /// The group separator character
-    static let groupSeparator: Character = " "
+class InputTextFormatter: NSObject, UITextFieldDelegate, UITextPasteDelegate {
+    enum AllowedInput {
+        case numeric, alphanumeric(isUpperCase: Bool)
+    }
+
+    struct Configuration {
+        /// Allowed characters.
+        var allowedInput: AllowedInput
+
+        /// Separator between groups of characters.
+        var groupSeparator: Character
 
-    /// The character size of each group of digits
-    static let groupSize = 4
+        /// The size of each group of characters .
+        var groupSize: UInt8
 
-    /// Parsed account token string
-    private(set) var parsedString = ""
+        /// Maximum number of groups of characters allowed.
+        var maxGroups: UInt
+    }
+
+    var configuration: Configuration {
+        didSet {
+            replace(with: string)
+        }
+    }
+
+    /// Parsed string
+    private(set) var string = ""
 
     /// Formatted string
     private(set) var formattedString = ""
@@ -27,7 +45,8 @@ class AccountTokenInput: NSObject {
     // Computed caret position
     private(set) var caretPosition = 0
 
-    init(string: String = "") {
+    init(string: String = "", configuration: Configuration) {
+        self.configuration = configuration
         super.init()
 
         replace(with: string)
@@ -45,13 +64,8 @@ class AccountTokenInput: NSObject {
     }
 
     /// Replace characters in range maintaining the caret position
-    ///
-    /// - Parameter range: a range within a string to replace
-    /// - Parameter replacementString: a string to replace the characters in the given range
-    /// - Parameter emptySelection: a hint to indicate if the text field selection is empty.
-    ///                             This is normally the default state unless a text range is
-    ///                             selected.
-    ///
+    /// Note: `emptySelection` hints that text field selection is empty. This is normally
+    /// the default state unless a text range is selected.
     func replaceCharacters(
         in range: Range<String.Index>,
         replacementString: String,
@@ -61,10 +75,12 @@ class AccountTokenInput: NSObject {
 
         // Since removing separator alone makes no sense, this computation extends the string range
         // to include the digit preceding a separator.
-        if replacementString.isEmpty, emptySelection, !formattedString.isEmpty {
+        if replacementString.isEmpty, emptySelection,
+           !formattedString.isEmpty
+        {
             let precedingDigitIndex = formattedString
                 .prefix(through: stringRange.lowerBound)
-                .lastIndex { Self.isDigit($0) } ?? formattedString.startIndex
+                .lastIndex { isAllowed($0) } ?? formattedString.startIndex
 
             stringRange = precedingDigitIndex ..< stringRange.upperBound
         }
@@ -96,7 +112,7 @@ class AccountTokenInput: NSObject {
 
         for (index, element) in newString.enumerated() {
             // Skip disallowed characters
-            if !Self.isDigit(element) {
+            if !isAllowed(element) {
                 // Adjust the caret position for characters removed before the insertion location
                 if originalCaretPosition > index {
                     newCaretPosition -= 1
@@ -104,9 +120,24 @@ class AccountTokenInput: NSObject {
                 continue
             }
 
+            // Apply cap on number of groups of characters that can be entered.
+            if configuration.maxGroups > 0 {
+                let numGroups = reparsedString.count / Int(configuration.groupSize)
+
+                if numGroups >= configuration.maxGroups {
+                    if originalCaretPosition > index {
+                        newCaretPosition = reformattedString.count
+                    }
+                    break
+                }
+            }
+
             // Add separator between the groups of digits
-            if numDigits > 0, numDigits % Self.groupSize == 0 {
-                reformattedString.append(Self.groupSeparator)
+            if numDigits > 0,
+               configuration.groupSize > 0,
+               numDigits % Int(configuration.groupSize) == 0
+            {
+                reformattedString.append(configuration.groupSeparator)
 
                 if originalCaretPosition > index {
                     // Adjust the caret position to account for separators added before the
@@ -120,22 +151,15 @@ class AccountTokenInput: NSObject {
             numDigits += 1
         }
 
+        if case AllowedInput.alphanumeric(true) = configuration.allowedInput {
+            reformattedString = reformattedString.uppercased()
+        }
+
         caretPosition = newCaretPosition
         formattedString = reformattedString
-        parsedString = reparsedString
+        string = reparsedString
     }
 
-    private class func isDigit(_ character: Character) -> Bool {
-        switch character {
-        case "0" ... "9":
-            return true
-        default:
-            return false
-        }
-    }
-}
-
-extension AccountTokenInput: UITextFieldDelegate, UITextPasteDelegate {
     /// Update the text and caret position in the given text field
     func updateTextField(_ textField: UITextField) {
         updateTextField(textField, notifyDelegate: false)
@@ -197,7 +221,7 @@ extension AccountTokenInput: UITextFieldDelegate, UITextPasteDelegate {
 
     // MARK: - Private
 
-    /// A caret position as utf-16 offset compatible for use with `NSString` and `UITextField`
+    /// A caret position as utf-16 offset compatible for use with `NSString` and `UITextField`.
     private var caretPositionUtf16: Int {
         let startIndex = formattedString.startIndex
         let endIndex = formattedString.index(startIndex, offsetBy: caretPosition)
@@ -205,7 +229,7 @@ extension AccountTokenInput: UITextFieldDelegate, UITextPasteDelegate {
         return formattedString.utf16.distance(from: startIndex, to: endIndex)
     }
 
-    /// Convert the computed caret position to an empty `UITextRange` within the given text field
+    /// Convert the computed caret position to an empty `UITextRange` within the given text field.
     private func caretTextRange(in textField: UITextField) -> UITextRange? {
         guard let position = textField.position(
             from: textField.beginningOfDocument,
@@ -216,7 +240,7 @@ extension AccountTokenInput: UITextFieldDelegate, UITextPasteDelegate {
     }
 
     /// A helper to update the text and caret in the given text field, and optionally post
-    /// `UITextField.textDidChange` notification
+    /// `UITextField.textDidChange` notification.
     private func updateTextField(_ textField: UITextField, notifyDelegate: Bool) {
         textField.text = formattedString
         textField.selectedTextRange = caretTextRange(in: textField)
@@ -226,11 +250,20 @@ extension AccountTokenInput: UITextFieldDelegate, UITextPasteDelegate {
         }
     }
 
-    /// Post `UITextField.textDidChange` notification
+    /// Posts `UITextField.textDidChange` notification.
     private class func notifyTextDidChange(in textField: UITextField) {
         NotificationCenter.default.post(
             name: UITextField.textDidChangeNotification,
             object: textField
         )
     }
+
+    private func isAllowed(_ character: Character) -> Bool {
+        switch configuration.allowedInput {
+        case .numeric:
+            return character.isASCII && character.isNumber
+        case .alphanumeric:
+            return character.isASCII && character.isLetter
+        }
+    }
 }
diff --git a/ios/MullvadVPN/View controllers/Login/AccountInputGroupView.swift b/ios/MullvadVPN/View controllers/Login/AccountInputGroupView.swift
index 4ea71c6b9c..ec298656ca 100644
--- a/ios/MullvadVPN/View controllers/Login/AccountInputGroupView.swift
+++ b/ios/MullvadVPN/View controllers/Login/AccountInputGroupView.swift
@@ -9,9 +9,10 @@
 import UIKit
 
 private let animationDuration: TimeInterval = 0.25
-private let minimumAccountTokenLength = 10
 
 final class AccountInputGroupView: UIView {
+    private let minimumAccountTokenLength = 10
+
     enum Style {
         case normal, error, authenticating
     }
diff --git a/ios/MullvadVPN/View controllers/Login/AccountTextField.swift b/ios/MullvadVPN/View controllers/Login/AccountTextField.swift
index 74c6c1c45e..cf3412ab6c 100644
--- a/ios/MullvadVPN/View controllers/Login/AccountTextField.swift
+++ b/ios/MullvadVPN/View controllers/Login/AccountTextField.swift
@@ -9,7 +9,12 @@
 import UIKit
 
 class AccountTextField: CustomTextField, UITextFieldDelegate {
-    private let input = AccountTokenInput()
+    private let inputFormatter = InputTextFormatter(configuration: InputTextFormatter.Configuration(
+        allowedInput: .numeric,
+        groupSeparator: " ",
+        groupSize: 4,
+        maxGroups: 4
+    ))
 
     var onReturnKey: ((AccountTextField) -> Bool)?
 
@@ -20,7 +25,7 @@ class AccountTextField: CustomTextField, UITextFieldDelegate {
         cornerRadius = 0
 
         delegate = self
-        pasteDelegate = input
+        pasteDelegate = inputFormatter
 
         NotificationCenter.default.addObserver(
             self,
@@ -36,16 +41,16 @@ class AccountTextField: CustomTextField, UITextFieldDelegate {
 
     var autoformattingText: String {
         set {
-            input.replace(with: newValue)
-            input.updateTextField(self)
+            inputFormatter.replace(with: newValue)
+            inputFormatter.updateTextField(self)
         }
         get {
-            input.formattedString
+            inputFormatter.formattedString
         }
     }
 
     var parsedToken: String {
-        return input.parsedString
+        return inputFormatter.string
     }
 
     var enableReturnKey = true {
@@ -70,7 +75,7 @@ class AccountTextField: CustomTextField, UITextFieldDelegate {
         shouldChangeCharactersIn range: NSRange,
         replacementString string: String
     ) -> Bool {
-        return input.textField(
+        return inputFormatter.textField(
             textField,
             shouldChangeCharactersIn: range,
             replacementString: string
diff --git a/ios/MullvadVPNTests/AccountTokenInputTests.swift b/ios/MullvadVPNTests/AccountTokenInputTests.swift
deleted file mode 100644
index 82a09e1285..0000000000
--- a/ios/MullvadVPNTests/AccountTokenInputTests.swift
+++ /dev/null
@@ -1,132 +0,0 @@
-//
-//  AccountTokenInputTests.swift
-//  MullvadVPNTests
-//
-//  Created by pronebird on 10/04/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import XCTest
-
-private let kSampleToken = "12345678"
-
-class AccountTokenInputTests: XCTestCase {
-    func testInitialValue() {
-        let input = AccountTokenInput(string: kSampleToken)
-
-        XCTAssertEqual(input.formattedString, "1234 5678")
-        XCTAssertEqual(input.caretPosition, 9)
-    }
-
-    func testReplacingValue() {
-        let input = AccountTokenInput()
-        input.replace(with: "00000000")
-
-        XCTAssertEqual(input.formattedString, "0000 0000")
-        XCTAssertEqual(input.caretPosition, 9)
-    }
-
-    func testRemovingSeparator() {
-        let input = AccountTokenInput(string: kSampleToken)
-
-        input.replaceCharacters(
-            in: input.formattedString.range(withOffset: 4, length: 1),
-            replacementString: "",
-            emptySelection: true
-        )
-
-        XCTAssertEqual(input.formattedString, "1235 678")
-        XCTAssertEqual(input.caretPosition, 3)
-    }
-
-    func testRemovingSeparatorRange() {
-        let input = AccountTokenInput(string: kSampleToken)
-
-        input.replaceCharacters(
-            in: input.formattedString.range(withOffset: 4, length: 1),
-            replacementString: "",
-            emptySelection: false
-        )
-
-        XCTAssertEqual(input.formattedString, "1234 5678")
-        XCTAssertEqual(input.caretPosition, 4)
-    }
-
-    func testRemovingRange() {
-        let input = AccountTokenInput(string: kSampleToken)
-
-        input.replaceCharacters(
-            in: input.formattedString.range(withOffset: 7, length: 2),
-            replacementString: "",
-            emptySelection: false
-        )
-
-        XCTAssertEqual(input.formattedString, "1234 56")
-        XCTAssertEqual(input.caretPosition, 7)
-    }
-
-    func testInserting() {
-        let input = AccountTokenInput(string: kSampleToken)
-
-        input.replaceCharacters(
-            in: input.formattedString.range(withOffset: 5, length: 0),
-            replacementString: "0000",
-            emptySelection: true
-        )
-
-        XCTAssertEqual(input.formattedString, "1234 0000 5678")
-        XCTAssertEqual(input.caretPosition, 9)
-    }
-
-    func testReplacingRange() {
-        let input = AccountTokenInput(string: kSampleToken)
-
-        input.replaceCharacters(
-            in: input.formattedString.range(withOffset: 5, length: 4),
-            replacementString: "0000",
-            emptySelection: false
-        )
-
-        XCTAssertEqual(input.formattedString, "1234 0000")
-        XCTAssertEqual(input.caretPosition, 9)
-    }
-
-    func testInvalidCharactersReplacesTextFieldTextWithFormattedString() {
-        let input = AccountTokenInput(string: kSampleToken)
-        let invalidRange = NSRange(location: kSampleToken.count + 1, length: 0)
-        let textField = UITextField()
-
-        _ = input.textField(textField, shouldChangeCharactersIn: invalidRange, replacementString: "´")
-
-        XCTAssertEqual(textField.text, input.formattedString)
-    }
-
-    func testDeleteCharacterOutsideOfTokenBoundaryDoesNotDeleteAnything() {
-        let input = AccountTokenInput(string: kSampleToken)
-        let invalidRange = NSRange(location: kSampleToken.count + 1, length: 1)
-        let textField = UITextField()
-
-        _ = input.textField(textField, shouldChangeCharactersIn: invalidRange, replacementString: "")
-
-        XCTAssertEqual(textField.text, input.formattedString)
-    }
-
-    func testDeleteLastCharacter() {
-        let input = AccountTokenInput(string: kSampleToken)
-        let lastCharacterRange = NSRange(location: kSampleToken.count, length: 1)
-        let textField = UITextField()
-
-        _ = input.textField(textField, shouldChangeCharactersIn: lastCharacterRange, replacementString: "")
-
-        XCTAssertEqual(textField.text, "1234 567")
-    }
-}
-
-private extension String {
-    func range(withOffset offset: Int, length: Int) -> Range<String.Index> {
-        let start = index(startIndex, offsetBy: offset)
-        let end = index(start, offsetBy: length)
-
-        return start ..< end
-    }
-}
diff --git a/ios/MullvadVPNTests/InputTextFormatterTests.swift b/ios/MullvadVPNTests/InputTextFormatterTests.swift
new file mode 100644
index 0000000000..5ff8d0daef
--- /dev/null
+++ b/ios/MullvadVPNTests/InputTextFormatterTests.swift
@@ -0,0 +1,157 @@
+//
+//  InputTextFormatterTests.swift
+//  MullvadVPNTests
+//
+//  Created by pronebird on 10/04/2020.
+//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
+//
+
+import XCTest
+
+class InputTextFormatterTests: XCTestCase {
+    private let accountNumber = "12345678"
+    private var inputTextFormatter: InputTextFormatter!
+
+    private let configuration = InputTextFormatter.Configuration(
+        allowedInput: .numeric,
+        groupSeparator: " ",
+        groupSize: 4,
+        maxGroups: 4
+    )
+
+    override func setUp() {
+        inputTextFormatter = InputTextFormatter(
+            string: accountNumber,
+            configuration: configuration
+        )
+    }
+
+    override func tearDown() {
+        inputTextFormatter = nil
+    }
+
+    func testInitialValue() {
+        XCTAssertEqual(inputTextFormatter.formattedString, "1234 5678")
+        XCTAssertEqual(inputTextFormatter.caretPosition, 9)
+    }
+
+    func testReplacingValue() {
+        inputTextFormatter.replace(with: "00000000")
+
+        XCTAssertEqual(inputTextFormatter.formattedString, "0000 0000")
+        XCTAssertEqual(inputTextFormatter.caretPosition, 9)
+    }
+
+    func testRemovingSeparator() {
+        guard let range = inputTextFormatter.formattedString.range(withOffset: 4, length: 1) else {
+            return XCTAssertNil("Out of range", file: #file, line: #line)
+        }
+
+        inputTextFormatter.replaceCharacters(
+            in: range,
+            replacementString: "",
+            emptySelection: true
+        )
+
+        XCTAssertEqual(inputTextFormatter.formattedString, "1235 678")
+        XCTAssertEqual(inputTextFormatter.caretPosition, 3)
+    }
+
+    func testRemovingSeparatorRange() {
+        guard let range = inputTextFormatter.formattedString.range(withOffset: 4, length: 1) else {
+            return XCTAssertNil("Out of range", file: #file, line: #line)
+        }
+
+        inputTextFormatter.replaceCharacters(
+            in: range,
+            replacementString: "",
+            emptySelection: false
+        )
+
+        XCTAssertEqual(inputTextFormatter.formattedString, "1234 5678")
+        XCTAssertEqual(inputTextFormatter.caretPosition, 4)
+    }
+
+    func testRemovingRange() {
+        guard let range = inputTextFormatter.formattedString.range(withOffset: 7, length: 2) else {
+            return XCTAssertNil("Out of range", file: #file, line: #line)
+        }
+
+        inputTextFormatter.replaceCharacters(
+            in: range,
+            replacementString: "",
+            emptySelection: false
+        )
+
+        XCTAssertEqual(inputTextFormatter.formattedString, "1234 56")
+        XCTAssertEqual(inputTextFormatter.caretPosition, 7)
+    }
+
+    func testInserting() {
+        guard let range = inputTextFormatter.formattedString.range(withOffset: 5, length: 0) else {
+            return XCTAssertNil("Out of range", file: #file, line: #line)
+        }
+
+        inputTextFormatter.replaceCharacters(
+            in: range,
+            replacementString: "0000",
+            emptySelection: true
+        )
+
+        XCTAssertEqual(inputTextFormatter.formattedString, "1234 0000 5678")
+        XCTAssertEqual(inputTextFormatter.caretPosition, 9)
+    }
+
+    func testReplacingRange() {
+        guard let range = inputTextFormatter.formattedString.range(withOffset: 5, length: 4) else {
+            return XCTAssertNil("Out of range", file: #file, line: #line)
+        }
+
+        inputTextFormatter.replaceCharacters(
+            in: range,
+            replacementString: "0000",
+            emptySelection: false
+        )
+
+        XCTAssertEqual(inputTextFormatter.formattedString, "1234 0000")
+        XCTAssertEqual(inputTextFormatter.caretPosition, 9)
+    }
+
+    func testInvalidCharactersReplacesTextFieldTextWithFormattedString() {
+        let invalidRange = NSRange(location: accountNumber.count + 1, length: 0)
+        let textField = UITextField()
+
+        _ = inputTextFormatter.textField(textField, shouldChangeCharactersIn: invalidRange, replacementString: "´")
+
+        XCTAssertEqual(textField.text, inputTextFormatter.formattedString)
+    }
+
+    func testDeleteCharacterOutsideOfTokenBoundaryDoesNotDeleteAnything() {
+        let invalidRange = NSRange(location: accountNumber.count + 1, length: 1)
+        let textField = UITextField()
+
+        _ = inputTextFormatter.textField(textField, shouldChangeCharactersIn: invalidRange, replacementString: "")
+
+        XCTAssertEqual(textField.text, inputTextFormatter.formattedString)
+    }
+
+    func testDeleteLastCharacter() {
+        let lastCharacterRange = NSRange(location: accountNumber.count, length: 1)
+        let textField = UITextField()
+
+        _ = inputTextFormatter.textField(textField, shouldChangeCharactersIn: lastCharacterRange, replacementString: "")
+
+        XCTAssertEqual(textField.text, "1234 567")
+    }
+}
+
+private extension String {
+    func range(withOffset offset: Int, length: Int) -> Range<String.Index>? {
+        guard let start = index(startIndex, offsetBy: offset, limitedBy: endIndex),
+              let end = index(start, offsetBy: length, limitedBy: endIndex)
+        else {
+            return nil
+        }
+        return start ..< end
+    }
+}