COVIDSafe code from version 2.0 (#37)

CovidSafe/Herald/Sensor/SensorArray.swift

@@ -0,0 +1,59 @@
+//
+//  SensorArray.swift
+//
+//  Copyright 2020 VMware, Inc.
+//  SPDX-License-Identifier: MIT
+//
+
+import Foundation
+import UIKit
+
+/// Sensor array for combining multiple detection and tracking methods.
+public class SensorArray : NSObject, Sensor {
+    private let logger = ConcreteSensorLogger(subsystem: "Sensor", category: "SensorArray")
+    private var sensorArray: [Sensor] = []
+    private var sensorDelegates: [SensorDelegate] = []
+    public let payloadData: PayloadData
+    public static let deviceDescription = "\(UIDevice.current.name) (iOS \(UIDevice.current.systemVersion))"
+
+    public init(_ payloadDataSupplier: PayloadDataSupplier) {
+        logger.debug("init")
+        // BLE sensor for detecting and tracking proximity
+        sensorArray.append(ConcreteBLESensor(payloadDataSupplier))
+        // Payload data at initiation time for identifying this device in the logs
+        payloadData = payloadDataSupplier.payload(PayloadTimestamp())
+        super.init()
+        
+        // Loggers
+        #if DEBUG
+            add(delegate: ContactLog(filename: "contacts.csv"))
+            add(delegate: StatisticsLog(filename: "statistics.csv", payloadData: payloadData))
+            add(delegate: DetectionLog(filename: "detection.csv", payloadData: payloadData))
+            _ = BatteryLog(filename: "battery.csv")
+        #endif
+        logger.info("DEVICE (payloadPrefix=\(payloadData.shortName),description=\(SensorArray.deviceDescription))")
+    }
+    
+    public func add(delegate: SensorDelegate) {
+        sensorDelegates.append(delegate)
+        sensorArray.forEach { $0.add(delegate: delegate) }
+    }
+    
+    public func start() {
+        logger.debug("start")
+        sensorArray.forEach { $0.start() }
+    }
+    
+    public func stop() {
+        logger.debug("stop")
+        sensorArray.forEach { $0.stop() }
+    }
+    
+    public func startAwakeSensor() {
+        // Location sensor is necessary for enabling background BLE advert detection
+        let awakeSensor = ConcreteAwakeSensor(rangeForBeacon: UUID(uuidString:  BLESensorConfiguration.serviceUUID.uuidString))
+        sensorDelegates.forEach { awakeSensor.add(delegate: $0) }
+        sensorArray.append(awakeSensor)
+        awakeSensor.start()
+    }
+}