Add reviewer singleton

Prompt for rating after N events.

Passepartout.xcodeproj/project.pbxproj

@@ -40,6 +40,7 @@
 		0E5E5DE521511C5F00E318A3 /* GracefulVPN.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0E5E5DE421511C5F00E318A3 /* GracefulVPN.swift */; };
 		0E6BE13A20CFB76800A6DD36 /* ApplicationError.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0E6BE13920CFB76800A6DD36 /* ApplicationError.swift */; };
 		0E6BE13F20CFBAB300A6DD36 /* DebugLogViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0E6BE13E20CFBAB300A6DD36 /* DebugLogViewController.swift */; };
+		0E78179F21BE852200950C58 /* Reviewer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0E78179E21BE852200950C58 /* Reviewer.swift */; };
 		0E79D13F21919EC900BB5FB2 /* PlaceholderConnectionProfile.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0E79D13E21919EC900BB5FB2 /* PlaceholderConnectionProfile.swift */; };
 		0E79D14121919F5600BB5FB2 /* ProfileKey.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0E79D14021919F5600BB5FB2 /* ProfileKey.swift */; };
 		0E89DFC5213DF7AE00741BA1 /* Preferences.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0E89DFC4213DF7AE00741BA1 /* Preferences.swift */; };
@@ -162,6 +163,7 @@
 		0E5E5DE421511C5F00E318A3 /* GracefulVPN.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GracefulVPN.swift; sourceTree = "<group>"; };
 		0E6BE13920CFB76800A6DD36 /* ApplicationError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ApplicationError.swift; sourceTree = "<group>"; };
 		0E6BE13E20CFBAB300A6DD36 /* DebugLogViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DebugLogViewController.swift; sourceTree = "<group>"; };
+		0E78179E21BE852200950C58 /* Reviewer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Reviewer.swift; sourceTree = "<group>"; };
 		0E79D13E21919EC900BB5FB2 /* PlaceholderConnectionProfile.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PlaceholderConnectionProfile.swift; sourceTree = "<group>"; };
 		0E79D14021919F5600BB5FB2 /* ProfileKey.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ProfileKey.swift; sourceTree = "<group>"; };
 		0E89DFC4213DF7AE00741BA1 /* Preferences.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Preferences.swift; sourceTree = "<group>"; };
@@ -468,6 +470,7 @@
 				0E39BCF2214DA9310035E9DE /* AppConstants.swift */,
 				0E6BE13920CFB76800A6DD36 /* ApplicationError.swift */,
 				0EDE8DED20C93E4C004C739C /* GroupConstants.swift */,
+				0E78179E21BE852200950C58 /* Reviewer.swift */,
 				0E05C5E320D1993C006EE732 /* SwiftGen+Strings.swift */,
 				0E4FD7ED20D539A0002221FF /* Utils.swift */,
 			);
@@ -808,6 +811,7 @@
 			files = (
 				0E5E5DDF215119AF00E318A3 /* VPNStatus.swift in Sources */,
 				0ECEE44E20E1122200A6BB43 /* TableModel.swift in Sources */,
+				0E78179F21BE852200950C58 /* Reviewer.swift in Sources */,
 				0ED38AD9213F33150004D387 /* WizardHostViewController.swift in Sources */,
 				0EE3BBB2215ED3A900F30952 /* AboutViewController.swift in Sources */,
 				0EBE3A79213C4E5500BFA2F5 /* OrganizerViewController.swift in Sources */,

Passepartout/Sources/Reviewer.swift

@@ -0,0 +1,75 @@
+//
+//  Reviewer.swift
+//  Passepartout
+//
+//  Created by Davide De Rosa on 12/10/18.
+//  Copyright (c) 2018 Davide De Rosa. All rights reserved.
+//
+//  https://github.com/passepartoutvpn
+//
+//  This file is part of Passepartout.
+//
+//  Passepartout is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  Passepartout is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with Passepartout.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+import StoreKit
+import SwiftyBeaver
+
+private let log = SwiftyBeaver.self
+
+class Reviewer {
+    private struct Keys {
+        static let eventCount = "ReviewerEventCount"
+    
+        static let lastVersion = "ReviewerLastVersion"
+    }
+    
+    static let shared = Reviewer()
+    
+    private let defaults: UserDefaults
+    
+    var eventCountBeforeRating = 3
+    
+    private init() {
+        defaults = .standard
+    }
+    
+    func reportEvent() {
+        let currentVersion = GroupConstants.App.buildNumber
+        let lastVersion = defaults.integer(forKey: Keys.lastVersion)
+        if lastVersion > 0 {
+            log.debug("App last reviewed for version \(lastVersion)")
+        } else {
+            log.debug("App was never reviewed")
+        }
+        guard currentVersion != lastVersion else {
+            log.debug("App already reviewed for version \(currentVersion)")
+            return
+        }
+
+        var count = defaults.integer(forKey: Keys.eventCount)
+        count += 1
+        defaults.set(count, forKey: Keys.eventCount)
+        log.debug("Event reported for version \(currentVersion) (count: \(count), prompt: \(eventCountBeforeRating))")
+        
+        guard count >= eventCountBeforeRating else {
+            return
+        }
+        log.debug("Prompting for review...")
+
+        SKStoreReviewController.requestReview()
+        defaults.removeObject(forKey: Keys.eventCount)
+        defaults.set(currentVersion, forKey: Keys.lastVersion)
+    }
+}