COVIDSafe code from version 1.4 (#3)

CovidSafe/EncounterV2Mapping.swift

@@ -0,0 +1,102 @@
+//
+//  EncounterV2Mapping.swift
+//  CovidSafe
+//
+//  Copyright © 2020 Australian Government. All rights reserved.
+//
+
+import CoreData
+
+struct MigrationRemoteBlob: Encodable {
+    enum CodingKeys: String, CodingKey {
+        case msg
+        case modelC
+        case modelP
+        case rssi
+        case txPower
+    }
+    var msg: String?
+    var modelC: String?
+    var modelP: String?
+    var rssi: NSNumber?
+    var txPower: NSNumber?
+    
+    func encode(to encoder: Encoder) throws {
+        
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        if let msg = msg {
+            try container.encode(msg, forKey: .msg)
+        }
+        
+        if let modelC = modelC, modelC != BluetraceConfig.DummyModel{
+            try container.encode(modelC, forKey: .modelC)
+        }
+        if let modelP = modelP, modelP != BluetraceConfig.DummyModel {
+            try container.encode(modelP, forKey: .modelP)
+        }
+        if let rssi = rssi, rssi.intValue != BluetraceConfig.DummyRSSI {
+            try container.encode(rssi.doubleValue, forKey: .rssi)
+        }
+        if let txPower = txPower, txPower.intValue != BluetraceConfig.DummyTxPower {
+            try container.encode(txPower.doubleValue, forKey: .txPower)
+        }
+    }
+    
+}
+
+
+class EncounterV2Mapping: NSEntityMigrationPolicy {
+    var localEmptyBlob: String = ""
+    override func begin(_ mapping: NSEntityMapping, with manager: NSMigrationManager) throws {
+        try super.begin(mapping, with: manager)
+        let emptyLocal = try JSONEncoder().encode(MigrationRemoteBlob())
+        localEmptyBlob = try Crypto.encrypt(dataToEncrypt: emptyLocal)
+    }
+    override func createDestinationInstances(forSource sInstance: NSManagedObject, in mapping: NSEntityMapping, manager: NSMigrationManager) throws {
+        
+        if (sInstance.entity.name == "Encounter") {
+            guard let version = sInstance.primitiveValue(forKey: "v") as? Int64 else {
+                return
+            }
+            let encounterV2 = NSEntityDescription.insertNewObject(forEntityName: "Encounter", into: manager.destinationContext)
+            let msg = sInstance.primitiveValue(forKey: "msg") as? String
+            let modelC = sInstance.primitiveValue(forKey: "modelC") as? String
+            let modelP = sInstance.primitiveValue(forKey: "modelP") as? String
+            let rssi = sInstance.primitiveValue(forKey: "rssi") as? NSNumber
+            let txPower = sInstance.primitiveValue(forKey: "txPower") as? NSNumber
+            let org = sInstance.primitiveValue(forKey: "org") as? String
+            let timestamp = sInstance.primitiveValue(forKey: "timestamp") as? Date
+            
+            
+            encounterV2.setPrimitiveValue(org, forKey: "org")
+            encounterV2.setPrimitiveValue(BluetraceConfig.ProtocolVersion, forKey: "v")
+            encounterV2.setPrimitiveValue(timestamp, forKey: "timestamp")
+            do {
+                try autoreleasepool {
+                    if version == 1 {
+                        //convert a regular old v1 entry
+                        encounterV2.setPrimitiveValue(localEmptyBlob, forKey: "localBlob")
+                        let remoteBlob = MigrationRemoteBlob(msg: msg, modelC: modelC, modelP: modelP, rssi: rssi, txPower: txPower)
+                        
+                        let blobJson = try JSONEncoder().encode(remoteBlob)
+                        let remoteBlobEncrypted = try Crypto.encrypt(dataToEncrypt: blobJson)
+                        encounterV2.setPrimitiveValue(remoteBlobEncrypted, forKey: "remoteBlob")
+                        manager.associate(sourceInstance: sInstance, withDestinationInstance: encounterV2, for: mapping)
+                        
+                    } else if version == 2 {
+                        //convert an entry that was recieved from an already updated app (the msg will already be encrypted)
+                        let localMigrationBlob = MigrationRemoteBlob(msg: nil, modelC: modelC, modelP: modelP, rssi: rssi, txPower: txPower)
+                        let jsonLocal = try JSONEncoder().encode(localMigrationBlob)
+                        let localBlob = try Crypto.encrypt(dataToEncrypt: jsonLocal)
+                        encounterV2.setPrimitiveValue(localBlob, forKey: "localBlob")
+                        encounterV2.setPrimitiveValue(msg, forKey: "remoteBlob")
+                        manager.associate(sourceInstance: sInstance, withDestinationInstance: encounterV2, for: mapping)
+                    }
+                }
+            } catch {
+                throw(error)
+            }
+            // we're dropping all the debug messages save to the db during the migration as they're unnessecary
+        }
+    }
+}