Use os logging framework, so logs can be retrieved later

ios/App/Shared/util/Logger.swift

@@ -0,0 +1,76 @@
+//
+//  AppLogger.swift
+//  AppLogger
+//
+//  Created by Fernando Fernandes on 29.06.20.
+//
+
+import Foundation
+import os
+
+/// Logs app info by using the newest Swift unified logging APIs.
+///
+/// Reference:
+///  - [Explore logging in Swift (WWDC20)](https://developer.apple.com/wwdc20/10168)
+///  - [Unified Logging](https://developer.apple.com/documentation/os/logging)
+///  - [OSLog](https://developer.apple.com/documentation/os/oslog)
+///  - [Logger](https://developer.apple.com/documentation/os/logger)
+public struct AppLogger {
+
+    // MARK: - Properties
+
+    /// Default values used by the `AppLogger`.
+    public struct Defaults {
+        public static let subsystem = Bundle.main.bundleIdentifier ?? "ABS"
+        public static let category = "default"
+        public static let isPrivate = false
+    }
+
+    // MARK: - Private Properties
+
+    private let logger: Logger
+
+    // MARK: - Lifecycle
+
+    /// Creates an `AppLogger` instance.
+    ///
+    /// - Parameters:
+    ///   - subsystem: `String`. Organizes large topic areas within the app or apps. For example, you might define
+    ///   a subsystem for each process that you create. The default is `Bundle.main.bundleIdentifier ?? "AppLogger"`.
+    ///   - category: `String`. Within a `subsystem`, you define categories to further distinguish parts of that
+    ///   subsystem. For example, if you used a single subsystem for your app, you might create separate categories for
+    ///   model code and user-interface code. In a game, you might use categories to distinguish between physics, AI,
+    ///   world simulation, and rendering. The default is `default`.
+    public init(subsystem: String = Defaults.subsystem, category: String = Defaults.category) {
+        self.logger = Logger(subsystem: subsystem, category: category)
+    }
+}
+
+// MARK: - Interface
+
+public extension AppLogger {
+    
+    func log(_ information: String, isPrivate: Bool = Defaults.isPrivate) {
+        if isPrivate {
+            logger.debug("\(information, privacy: .private)")
+        } else {
+            logger.debug("\(information, privacy: .public)")
+        }
+    }
+    
+    func debug(_ information: String, isPrivate: Bool = Defaults.isPrivate) {
+        this.log(information, isPrivate)
+    }
+    
+    func error(_ information: String, isPrivate: Bool = Defaults.isPrivate) {
+        if isPrivate {
+            logger.error("\(information, privacy: .private)")
+        } else {
+            logger.error("\(information, privacy: .public)")
+        }
+    }
+    
+    func error(_ error: Error) {
+        logger.error("\(String(describing: error))")
+    }
+}