Link secondary devices as primary device

presage-cli/src/main.rs

@@ -503,7 +503,9 @@ async fn run<C: Store + 'static>(subcommand: Cmd, config_store: C) -> anyhow::Re
                 async move {
                     match provisioning_link_rx.await {
                         Ok(url) => {
-                            qr2term::print_qr(url.to_string()).expect("failed to render qrcode")
+                            println!("Please scan in the QR code:");
+                            qr2term::print_qr(url.to_string()).expect("failed to render qrcode");
+                            println!("Alternatively, use the URL: {}", url);
                         }
                         Err(e) => log::error!("Error linking device: {e}"),
                     }

presage/src/errors.rs

@@ -66,6 +66,10 @@ pub enum Error<S: std::error::Error> {
     RequestingCodeForbidden(libsignal_service::push_service::RegistrationSessionMetadataResponse),
     #[error("Unverified registration session (i.e. wrong verification code)")]
     UnverifiedRegistrationSession,
+    #[error("Failed to link secondary device")]
+    ServiceLinkError(#[from] libsignal_service::LinkError),
+    #[error("An operation was requested that requires the registration to be primary, but it was only secondary")]
+    NotPrimaryDevice,
 }
 
 impl<S: StoreError> From<S> for Error<S> {

presage/src/lib.rs

@@ -7,6 +7,7 @@ mod store;
 pub use errors::Error;
 pub use manager::{
     Confirmation, Linking, Manager, ReceivingMode, Registered, Registration, RegistrationOptions,
+    RegistrationType,
 };
 pub use store::{ContentTimestamp, Store, StoreError, Thread};
 

presage/src/manager.rs

@@ -16,7 +16,7 @@ use rand::{
 use serde::{Deserialize, Serialize};
 use url::Url;
 
-use libsignal_service::push_service::{RegistrationMethod, VerificationTransport};
+use libsignal_service::push_service::{DeviceInfo, RegistrationMethod, VerificationTransport};
 use libsignal_service::{
     attachment_cipher::decrypt_in_place,
     cipher,
@@ -71,6 +71,12 @@ impl<Store, State: fmt::Debug> fmt::Debug for Manager<Store, State> {
     }
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum RegistrationType {
+    Primary,
+    Secondary,
+}
+
 #[derive(Clone, Serialize, Deserialize)]
 pub struct RegistrationOptions<'a> {
     pub signal_servers: SignalServers,
@@ -1320,6 +1326,53 @@ impl<C: Store> Manager<C, Registered> {
         }
     }
 
+    /// Returns how this client was registered, either as a primary or secondary device.
+    pub fn registration_type(&self) -> RegistrationType {
+        if self.state.device_name.is_some() {
+            RegistrationType::Secondary
+        } else {
+            RegistrationType::Primary
+        }
+    }
+
+    /// As a primary device, link a secondary device.
+    pub async fn link_secondary(&self, secondary: Url) -> Result<(), Error<C::Error>> {
+        // XXX: What happens if secondary device? Possible to use static typing to make this method call impossible in that case?
+        if self.registration_type() != RegistrationType::Primary {
+            return Err(Error::NotPrimaryDevice);
+        }
+
+        let credentials = self.credentials()?.ok_or(Error::NotYetRegisteredError)?;
+        let mut account_manager =
+            AccountManager::new(self.push_service()?, Some(self.state.profile_key));
+        let store = &self.config_store;
+
+        account_manager
+            .link_device(secondary, store, credentials)
+            .await?;
+        Ok(())
+    }
+
+    /// As a primary device, unlink a secondary device.
+    pub async fn unlink_secondary(&self, device_id: i64) -> Result<(), Error<C::Error>> {
+        // XXX: What happens if secondary device? Possible to use static typing to make this method call impossible in that case?
+        if self.registration_type() != RegistrationType::Primary {
+            return Err(Error::NotPrimaryDevice);
+        }
+        self.push_service()?.unlink_device(device_id).await?;
+        Ok(())
+    }
+
+    /// As a primary device, list all the devices.
+    // XXX: Also shows the current device?
+    pub async fn linked_devices(&self) -> Result<Vec<DeviceInfo>, Error<C::Error>> {
+        // XXX: What happens if secondary device? Possible to use static typing to make this method call impossible in that case?
+        if self.registration_type() != RegistrationType::Primary {
+            return Err(Error::NotPrimaryDevice);
+        }
+        Ok(self.push_service()?.devices().await?)
+    }
+
     #[deprecated = "use Manager::contact_by_id"]
     pub fn get_contacts(
         &self,