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Remove Dexcom Share follower management #96

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Merged
ps2 merged 3 commits into from
Oct 26, 2026
Merged

Remove Dexcom Share follower management #96

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2895d18
Remove Dexcom Share follower management
dnzxy Oct 17, 2026
da3477d
Recover from a refused Share recovery step
dnzxy Oct 23, 2026
a61492e
Merge next-dev into share-upload-only-next-dev
ps2 Oct 26, 2026
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4 changes: 0 additions & 4 deletions G7SensorKit.xcodeproj/project.pbxproj
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,6 @@
FE87266E3AE98CA87D903665 /* G7PCert.swift in Sources */ = {isa = PBXBuildFile; fileRef = 324F8C967DDB24EB158A1A45 /* G7PCert.swift */; };
2BC9F3807D05FB72B54407C6 /* G7Authenticator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 899E19256E3224A54FA35AD8 /* G7Authenticator.swift */; };
FADE00000000000000000330 /* Locked.swift in Sources */ = {isa = PBXBuildFile; fileRef = C17F513B291EB13D00555EB5 /* Locked.swift */; };
07C6427E5068FF4C00B4ACE7 /* G7ShareFollowersView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5BD28E35C047C73E1EC8AE73 /* G7ShareFollowersView.swift */; };
0BE316E9E980C04C39842D94 /* G7SensorModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2A301AE5854C83E5BD9C6539 /* G7SensorModel.swift */; };
0C557E84497DE72C92503098 /* G7AlertsFromLoopView.swift in Sources */ = {isa = PBXBuildFile; fileRef = F2A62D050A4DCCED5F4A51F9 /* G7AlertsFromLoopView.swift */; };
0F2F5FD6CB203E12707A95F0 /* G7SensorPackageTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 43AE2890ABEAE0FB78B276F1 /* G7SensorPackageTests.swift */; };
Expand Down Expand Up @@ -237,7 +236,6 @@
4A3F076AE2157B22DE43B91A /* G7PreviousSensorView.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = G7PreviousSensorView.swift; sourceTree = "<group>"; };
4CAA6FF14E0E9C16A25FD3B6 /* G7SessionMode.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = G7SessionMode.swift; sourceTree = "<group>"; };
588CB2A449236A6A47F4579B /* G7SessionModeMigrationTests.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = G7SessionModeMigrationTests.swift; sourceTree = "<group>"; };
5BD28E35C047C73E1EC8AE73 /* G7ShareFollowersView.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = G7ShareFollowersView.swift; sourceTree = "<group>"; };
6180916611D0990A46355025 /* G7PeripheralManager+Handshake.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = "G7PeripheralManager+Handshake.swift"; sourceTree = "<group>"; };
63E50F6710E2494A0E14A6D8 /* G7JPAKE.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = G7JPAKE.swift; sourceTree = "<group>"; };
64134474341A32F8DFDA266F /* G7P256Tests.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = G7P256Tests.swift; sourceTree = "<group>"; };
Expand Down Expand Up @@ -416,7 +414,6 @@
A83C615FDD5582DDDBD42526 /* Share */ = {
isa = PBXGroup;
children = (
5BD28E35C047C73E1EC8AE73 /* G7ShareFollowersView.swift */,
01B1A199C4CD5420A75C58E4 /* G7ShareSignInView.swift */,
);
name = Share;
Expand Down Expand Up @@ -1066,7 +1063,6 @@
0C557E84497DE72C92503098 /* G7AlertsFromLoopView.swift in Sources */,
EF41639FF51B727324A04A49 /* G7NotificationPermissionsView.swift in Sources */,
86DE2F2A3F8F5B73AFED5E75 /* G7CalibrationFlowView.swift in Sources */,
07C6427E5068FF4C00B4ACE7 /* G7ShareFollowersView.swift in Sources */,
33D21C38F39F73BCDFCFC0C5 /* G7ShareSignInView.swift in Sources */,
);
runOnlyForDeploymentPostprocessing = 0;
Expand Down
11 changes: 0 additions & 11 deletions G7SensorKit/G7CGMManager/G7CGMManager.swift
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Expand Up @@ -928,17 +928,6 @@ extension G7CGMManager: G7SensorDelegate {
)
}

/// A client for the signed-in account, for managing followers.
public var shareClient: G7ShareClient? {
G7ShareCredentialStore().load().map { credentials in
let client = G7ShareClient(credentials: credentials)
client.logHandler = { [weak self] message in
self?.logDeviceCommunication("Dexcom Share: " + message, type: .connection)
}
return client
}
}

/// Verifies the credentials with the service, keeps them, and starts
/// uploading. Throws the service's refusal if they are wrong.
public func signInToShare(_ credentials: G7ShareCredentials) async throws {
Expand Down
155 changes: 6 additions & 149 deletions G7SensorKit/Share/G7ShareClient.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -39,21 +39,11 @@ public enum G7ShareError: Error, Equatable {
public static let receiverSerialMismatch = "MonitoredReceiverSerialNumberDoesNotMatch"
public static let monitoringSessionNotActive = "MonitoringSessionNotActive"
public static let duplicateEgvPosted = "DuplicateEgvPosted"
public static let contactNameTaken = "ContactNameAlreadyExists"

/// CreateSubscriptionInvitation's refusal while a new contact has not
/// reached it yet ("Failed to read Contact by id").
public var isContactNotFound: Bool {
serviceCode?.localizedCaseInsensitiveContains("ContactIdNotFound") == true
}

/// CreateContact's refusal when the account already has a contact of
/// that name ("The contact name already exists for this account").
public var isContactNameTaken: Bool {
guard case .service(let code, let message) = self else { return false }
return code.localizedCaseInsensitiveContains("ContactNameAlreadyExists")
|| code.localizedCaseInsensitiveContains("ContactAlreadyExists")
|| (message ?? "").localizedCaseInsensitiveContains("contact name already exists")
/// The account's monitored device is not this serial, e.g. after a
/// sensor change.
public var isReceiverRefused: Bool {
serviceCode == G7ShareError.receiverNotAssigned || serviceCode == G7ShareError.receiverSerialMismatch
}

/// Starting a monitoring session when one is already running is refused
Expand Down Expand Up @@ -139,41 +129,6 @@ public struct G7ShareReading: Equatable {
}
}

/// A follower, as the service lists it.
public struct G7ShareFollower: Equatable, Identifiable {
public let contactId: String
public let subscriptionId: String?
public let contactName: String
public let displayName: String?
public let state: String?
public let permissions: Int?

public var id: String { contactId }
}

/// The alert settings a follower starts with; the follower can change them
/// in the Follow app. Values are mg/dL and ISO 8601 durations.
public struct G7ShareFollowerAlerts: Equatable {
public var highEnabled = false
public var highThreshold = 200
public var lowEnabled = false
public var lowThreshold = 70
public var urgentLowEnabled = true
public var urgentLowThreshold = 55
public var noDataEnabled = false

public init() {}

var json: [String: Any] {
[
"HighAlert": ["MinValue": highThreshold, "MaxValue": 401, "AlarmDelay": "PT1H", "RealarmDelay": "PT2H", "AlertType": 1, "IsEnabled": highEnabled, "Sound": "High.wav"],
"LowAlert": ["MinValue": 39, "MaxValue": lowThreshold, "AlarmDelay": "PT30M", "RealarmDelay": "PT2H", "AlertType": 2, "IsEnabled": lowEnabled, "Sound": "Low.wav"],
"FixedLowAlert": ["MinValue": 39, "MaxValue": urgentLowThreshold, "AlarmDelay": "PT0M", "RealarmDelay": "PT30M", "AlertType": 3, "IsEnabled": urgentLowEnabled, "Sound": "UrgentLow.wav"],
"NoDataAlert": ["MinValue": 39, "MaxValue": 401, "AlarmDelay": "PT1H", "RealarmDelay": "PT0M", "AlertType": 4, "IsEnabled": noDataEnabled, "Sound": "NoData.wav"],
]
}
}

/// Talks to the Share service for one account. Signs in on demand and
/// keeps the session id; `sessionId` is nil until the first call.
public final class G7ShareClient {
Expand Down Expand Up @@ -231,23 +186,13 @@ public final class G7ShareClient {

// MARK: - Uploading

/// Whether the service has this serial as the account's monitored
/// device: "AssignedToYou", "NotAssigned", or assigned elsewhere.
public func receiverAssignment(serial: String) async throws -> String {
let sessionId = try await requireSession()
return try await post("Publisher/CheckMonitoredReceiverAssignmentStatus", query: ["sessionId": sessionId, "serialNumber": serial])
}

/// Makes this serial the account's monitored device, replacing whatever
/// was registered before.
public func assignReceiver(serial: String) async throws {
let sessionId = try await requireSession()
try await postExpectingNothing("Publisher/ReplacePublisherAccountMonitoredReceiver", query: ["sessionId": sessionId, "serialNumber": serial])
}

public func isRemoteMonitoringSessionActive() async throws -> Bool {
let sessionId = try await requireSession()
return try await post("Publisher/IsRemoteMonitoringSessionActive", query: ["sessionId": sessionId])
}

public func startRemoteMonitoringSession(serial: String) async throws {
let sessionId = try await requireSession()
try await postExpectingNothing("Publisher/StartRemoteMonitoringSession", query: ["sessionId": sessionId, "serialNumber": serial])
Expand All @@ -264,94 +209,6 @@ public final class G7ShareClient {
["SN": serial, "Egvs": readings.map(\.json), "TA": -5]
}

// MARK: - Followers

public func listFollowers() async throws -> [G7ShareFollower] {
let sessionId = try await requireSession()
let entries: [[String: Any]] = try await post("Publisher/ListPublisherAccountSubscriptions", query: ["sessionId": sessionId])
return entries.compactMap { entry in
guard let contactId = entry["ContactId"] as? String else { return nil }
return G7ShareFollower(
contactId: contactId,
subscriptionId: entry["SubscriptionId"] as? String,
contactName: entry["ContactName"] as? String ?? "",
displayName: entry["DisplayName"] as? String,
state: (entry["State"] as? String) ?? (entry["State"] as? Int).map(String.init),
permissions: entry["Permissions"] as? Int
)
}
}

/// Invites someone to follow: a contact is created for them and an
/// invitation attached to it, which the service emails. Returns the
/// contact id, which is also what removes them.
public func inviteFollower(name: String, email: String, displayName: String, alerts: G7ShareFollowerAlerts = G7ShareFollowerAlerts()) async throws -> String {
let sessionId = try await requireSession()
let contactId: String
var createdContact = false
do {
contactId = try await post("Publisher/CreateContact", query: ["sessionId": sessionId, "contactName": name, "emailAddress": email])
createdContact = true
} catch let error as G7ShareError where error.isContactNameTaken {
// A contact of that name is already on the account, e.g. from an
// invitation that did not complete. Reuse it.
guard let existing = try await existingContactId(named: name, sessionId: sessionId) else {
throw G7ShareError.service(code: G7ShareError.contactNameTaken, message: LocalizedString("A contact with this name was left on the account by an earlier invitation that did not complete, and it cannot be reused. Invite them under a slightly different name.", comment: "Share error: contact name taken by an orphaned contact"))
}
logHandler?("Reusing existing contact \(existing) for \(name)")
contactId = existing
}

let invitation: [String: Any] = [
"AlertSettings": alerts.json,
"Permissions": 1,
"DisplayName": displayName,
]
// A contact that was just created takes the invitation side of the
// service a while to see (DeleteContact knows it at once; observed
// 2 s not always being enough), so keep trying with a growing wait.
// If it never appears, take the contact back out so the name is free
// for another attempt.
var attempt = 0
while true {
do {
try await createInvitation(contactId: contactId, sessionId: sessionId, body: invitation)
return contactId
} catch let error as G7ShareError where error.isContactNotFound && attempt < G7ShareClient.invitationRetryDelays.count {
let delay = G7ShareClient.invitationRetryDelays[attempt]
attempt += 1
logHandler?("Contact not visible to the invitation yet; retrying in \(Int(delay)) s")
try? await Task.sleep(nanoseconds: UInt64(delay * 1_000_000_000))
} catch {
if createdContact {
logHandler?("Invitation failed; removing the contact just created")
try? await removeFollower(contactId: contactId)
}
throw error
}
}
}

/// The id of an existing contact, by name, among the followers. A
/// contact with no subscription cannot be found: `ReadContactByName`
/// belongs to the newer request generation and wants a signed request
/// ("String parameter 'signedRequest' cannot be null"), signed with a
/// key the Dexcom app holds.
private func existingContactId(named name: String, sessionId: String) async throws -> String? {
try await listFollowers().first(where: { $0.contactName.caseInsensitiveCompare(name) == .orderedSame })?.contactId
}

static let invitationRetryDelays: [TimeInterval] = [2, 4, 8]

private func createInvitation(contactId: String, sessionId: String, body: [String: Any]) async throws {
let _: String = try await post("Publisher/CreateSubscriptionInvitation", query: ["sessionId": sessionId, "contactId": contactId], body: body)
}

public func removeFollower(contactId: String) async throws {
let sessionId = try await requireSession()
try await postExpectingNothing("Publisher/DeleteContact", query: ["sessionId": sessionId, "contactId": contactId])
}

// MARK: - Transport

private func request(_ path: String, query: [String: String], body: [String: Any]?) throws -> URLRequest {
Expand Down
101 changes: 65 additions & 36 deletions G7SensorKit/Share/G7ShareUploader.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -23,20 +23,22 @@ public struct G7ShareUploadStatus: Equatable {
}
}

/// Sends readings to Dexcom Share as they arrive. The service wants a
/// signed-in session with the sensor registered as the account's device and
/// a monitoring session started; all of that is done lazily and redone when
/// the service says it has lapsed. Readings that could not be sent wait for
/// the next attempt, up to a day's worth.
/// Sends readings to Dexcom Share as they arrive. It posts first and only
/// signs in, starts a monitoring session or registers the sensor as the
/// account's device when the service refuses for that reason. Readings
/// that could not be sent wait for the next attempt, up to a day's worth.
final class G7ShareUploader {
private let log = OSLog(category: "G7ShareUploader")
private let queue = DispatchQueue(label: "org.loopkit.G7SensorKit.share")

private let client: G7ShareClient
private var pending: [G7ShareReading] = []
private var uploadedThrough: Date?
private var receiverReady = false
private var monitoringReady = false
/// The serial last registered as the account's device, so a refusal for
/// it is not answered by registering it again. Kept until relaunch or a
/// new sign-in: if the Dexcom app takes the account's device back, we
/// let it rather than taking turns with it.
private var assignedSerial: String?
private var task: Task<Void, Never>?
private(set) var status = G7ShareUploadStatus()

Expand Down Expand Up @@ -115,47 +117,74 @@ final class G7ShareUploader {
}
}

private enum Recovery {
case signIn
case startMonitoring
case assignReceiver
}

/// Posts, answering each refusal with its recovery, including a refusal of
/// a recovery itself (a monitoring session refused because the sensor is
/// not registered yet). Each recovery runs once per attempt, except that a
/// new registration may need a new monitoring session.
private func upload(_ batch: [G7ShareReading], serial: String) async -> Result<Void, Error> {
do {
try await uploadOnce(batch, serial: serial)
return .success(())
} catch let error as G7ShareError where error.isSessionExpired || error.serviceCode == G7ShareError.monitoringSessionNotActive {
// A lapsed session or monitoring window: start over once.
client.forgetSession()
receiverReady = false
monitoringReady = false
var attempted: Set<Recovery> = []
var next: Recovery?
while true {
do {
try await uploadOnce(batch, serial: serial)
if let recovery = next {
next = nil
try await perform(recovery, serial: serial)
if recovery == .assignReceiver {
attempted.remove(.startMonitoring)
}
continue
}
try await post(batch, serial: serial)
return .success(())
} catch let error as G7ShareError {
guard let recovery = recovery(for: error, serial: serial), attempted.insert(recovery).inserted else {
return .failure(error)
}
next = recovery
} catch {
return .failure(error)
}
} catch {
return .failure(error)
}
}

private func uploadOnce(_ batch: [G7ShareReading], serial: String) async throws {
if !receiverReady {
let assignment = try await client.receiverAssignment(serial: serial)
if assignment != "AssignedToYou" {
onLog?("Registering sensor \(serial) as the Dexcom Share device (was \(assignment))")
try await client.assignReceiver(serial: serial)
}
receiverReady = true
private func recovery(for error: G7ShareError, serial: String) -> Recovery? {
if error.isSessionExpired {
return .signIn
}
if !monitoringReady {
if try await client.isRemoteMonitoringSessionActive() {
onLog?("Dexcom Share monitoring session is already active")
} else {
do {
try await client.startRemoteMonitoringSession(serial: serial)
} catch let error as G7ShareError where error.isMonitoringSessionAlreadyActive {
// Started by someone else in the meantime; fine.
}
if error.serviceCode == G7ShareError.monitoringSessionNotActive {
return .startMonitoring
}
if error.isReceiverRefused, assignedSerial != serial {
return .assignReceiver
}
return nil
}

private func perform(_ recovery: Recovery, serial: String) async throws {
switch recovery {
case .signIn:
client.forgetSession()
try await client.signIn()
case .startMonitoring:
do {
try await client.startRemoteMonitoringSession(serial: serial)
} catch let error as G7ShareError where error.isMonitoringSessionAlreadyActive {
// Started by someone else in the meantime; fine.
}
monitoringReady = true
case .assignReceiver:
onLog?("Registering sensor \(serial) as the Dexcom Share device")
try await client.assignReceiver(serial: serial)
assignedSerial = serial
}
}

private func post(_ batch: [G7ShareReading], serial: String) async throws {
do {
try await client.postReadings(batch, serial: serial)
} catch let error as G7ShareError where error.serviceCode == G7ShareError.duplicateEgvPosted {
Expand Down
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