Publisher example: Add a setting for logging LocationHistoryData JSON

While testing a fix for #425, I wanted to have access to the location
history data in a log message.

This adds a switch in a new "Developer settings" section of the Settings
page, which when turned on will emit a JSON serialization of the
location history data when it’s received from the SDK. It’s turned off
by default, because it's only for my specific use case.

Examples/PublisherExampleSwiftUI/PublisherExampleSwiftUI/Model/ObservablePublisher.swift

@@ -1,9 +1,11 @@
 import Combine
 import AblyAssetTrackingPublisher
 import Foundation
+import Logging
 
 class ObservablePublisher: ObservableObject {
     private let publisher: AblyAssetTrackingPublisher.Publisher
+    private let logger: Logger?
     let configInfo: PublisherConfigInfo
     let locationHistoryDataHandler: LocationHistoryDataHandlerProtocol?
 
@@ -22,11 +24,12 @@ class ObservablePublisher: ObservableObject {
     @Published private(set) var lastError: ErrorInformation?
 
     // After initialising an ObservablePublisher instance, you need to manually set the publisher’s delegate to the created instance.
-    init(publisher: AblyAssetTrackingPublisher.Publisher, configInfo: PublisherConfigInfo, locationHistoryDataHandler: LocationHistoryDataHandlerProtocol? = nil) {
+    init(publisher: AblyAssetTrackingPublisher.Publisher, configInfo: PublisherConfigInfo, locationHistoryDataHandler: LocationHistoryDataHandlerProtocol? = nil, logger: Logger? = nil) {
         self.publisher = publisher
         self.configInfo = configInfo
         self.routingProfile = publisher.routingProfile
         self.locationHistoryDataHandler = locationHistoryDataHandler
+        self.logger = logger
     }
 
     func stop(completion: @escaping ResultHandler<Void>) {
@@ -89,6 +92,19 @@ extension ObservablePublisher: PublisherDelegate {
     }
 
     func publisher(sender: AblyAssetTrackingPublisher.Publisher, didFinishRecordingLocationHistoryData locationHistoryData: LocationHistoryData) {
+        if SettingsModel.shared.logLocationHistoryJSON {
+            do {
+                let jsonData = try JSONEncoder().encode(locationHistoryData)
+                if let jsonString = String(data: jsonData, encoding: .utf8) {
+                    logger?.log(level: .debug, "Received location history data: \(jsonString)")
+                } else {
+                    logger?.log(level: .error, "Failed to convert location history data to string")
+                }
+            } catch {
+                logger?.log(level: .error, "Failed to serialize location history data to JSON: \(error.localizedDescription)")
+            }
+        }
+
         locationHistoryDataHandler?.handleLocationHistoryData(locationHistoryData)
     }
 

Examples/PublisherExampleSwiftUI/PublisherExampleSwiftUI/Model/SettingsModel.swift

@@ -67,6 +67,15 @@ class SettingsModel {
         }
     }
 
+    var logLocationHistoryJSON: Bool {
+        get {
+            UserDefaults.standard.bool(forKey: "logLocationHistoryJSON")
+        }
+        set {
+            UserDefaults.standard.set(newValue, forKey: "logLocationHistoryJSON")
+        }
+    }
+
     var vehicleProfile: VehicleProfile {
         get {
             guard let profile: VehicleProfile = UserDefaults.standard.get("vehicleProfile") else {

Examples/PublisherExampleSwiftUI/PublisherExampleSwiftUI/View/Settings/SettingsView.swift

@@ -45,6 +45,15 @@ struct SettingsView: View {
             } header: {
                 Text("Other settings")
             }
+
+            Section {
+                Toggle(isOn: $viewModel.logLocationHistoryJSON) {
+                    Text("Log location history JSON")
+                    Text("Causes the app to emit a `debug` level log message when a `LocationHistoryData` is received from the Asset Tracking SDK. The log message will contain a JSON serialization of this history data.")
+                }
+            } header: {
+                Text("Developer settings")
+            }
         }
         .listStyle(.grouped)
         .navigationBarTitle("Settings")

Examples/PublisherExampleSwiftUI/PublisherExampleSwiftUI/ViewModel/CreatePublisherViewModel.swift

@@ -136,7 +136,7 @@ class CreatePublisherViewModel: ObservableObject {
 
         let configInfo = ObservablePublisher.PublisherConfigInfo(areRawLocationsEnabled: areRawLocationsEnabled, constantResolution: constantResolution)
 
-        let observablePublisher = ObservablePublisher(publisher: publisher, configInfo: configInfo, locationHistoryDataHandler: locationHistoryDataHandler)
+        let observablePublisher = ObservablePublisher(publisher: publisher, configInfo: configInfo, locationHistoryDataHandler: locationHistoryDataHandler, logger: logger)
         publisher.delegate = observablePublisher
 
         return observablePublisher

Examples/PublisherExampleSwiftUI/PublisherExampleSwiftUI/ViewModel/SettingsViewModel.swift

@@ -9,6 +9,12 @@ class SettingsViewModel: ObservableObject {
         }
     }
 
+    @Published var logLocationHistoryJSON: Bool = SettingsModel.shared.logLocationHistoryJSON {
+        didSet {
+            SettingsModel.shared.logLocationHistoryJSON = logLocationHistoryJSON
+        }
+    }
+
     @Published var defaultResolutionMinimumDisplacement: String  = "\(SettingsModel.shared.defaultResolution.minimumDisplacement)"
     @Published var defaultResolutionDesiredInterval: String  = "\(SettingsModel.shared.defaultResolution.desiredInterval)"