Sync settings between computers through the account

src-tauri/build.rs

@@ -46,6 +46,9 @@ fn main() {
         "cancel_sign_in",
         "sign_out",
         "delete_account",
+        "get_settings_sync",
+        "sync_settings_now",
+        "resolve_settings_sync",
     ]);
     let mut attributes = tauri_build::Attributes::new().app_manifest(app_manifest);
     if std::env::var("CARGO_CFG_TARGET_OS").as_deref() == Ok("windows") {

src-tauri/capabilities/main.json

@@ -45,6 +45,9 @@
     "allow-verify-sign-in-code",
     "allow-cancel-sign-in",
     "allow-sign-out",
-    "allow-delete-account"
+    "allow-delete-account",
+    "allow-get-settings-sync",
+    "allow-sync-settings-now",
+    "allow-resolve-settings-sync"
   ]
 }

src-tauri/permissions/autogenerated/get_settings_sync.toml

@@ -0,0 +1,11 @@
+# Automatically generated - DO NOT EDIT!
+
+[[permission]]
+identifier = "allow-get-settings-sync"
+description = "Enables the get_settings_sync command without any pre-configured scope."
+commands.allow = ["get_settings_sync"]
+
+[[permission]]
+identifier = "deny-get-settings-sync"
+description = "Denies the get_settings_sync command without any pre-configured scope."
+commands.deny = ["get_settings_sync"]

src-tauri/permissions/autogenerated/resolve_settings_sync.toml

@@ -0,0 +1,11 @@
+# Automatically generated - DO NOT EDIT!
+
+[[permission]]
+identifier = "allow-resolve-settings-sync"
+description = "Enables the resolve_settings_sync command without any pre-configured scope."
+commands.allow = ["resolve_settings_sync"]
+
+[[permission]]
+identifier = "deny-resolve-settings-sync"
+description = "Denies the resolve_settings_sync command without any pre-configured scope."
+commands.deny = ["resolve_settings_sync"]

src-tauri/permissions/autogenerated/sync_settings_now.toml

@@ -0,0 +1,11 @@
+# Automatically generated - DO NOT EDIT!
+
+[[permission]]
+identifier = "allow-sync-settings-now"
+description = "Enables the sync_settings_now command without any pre-configured scope."
+commands.allow = ["sync_settings_now"]
+
+[[permission]]
+identifier = "deny-sync-settings-now"
+description = "Denies the sync_settings_now command without any pre-configured scope."
+commands.deny = ["sync_settings_now"]

src-tauri/src/account.rs

@@ -189,8 +189,6 @@ pub struct AccountView {
 /// A usable access token for the signed-in user.
 #[derive(Clone)]
 pub struct Authorized {
-    // Read by the sync engine (#986).
-    #[allow(dead_code)]
     pub user_id: String,
     pub access_token: String,
 }
@@ -289,6 +287,14 @@ impl Account {
         let _ = self.store.delete();
     }
 
+    /// The project URL and publishable key, for the database requests made by
+    /// settings sync with an `Authorized` token.
+    pub fn endpoint(&self) -> Option<(String, String)> {
+        self.config
+            .as_ref()
+            .map(|config| (config.url.clone(), config.key.clone()))
+    }
+
     fn config(&self) -> Result<&Config, String> {
         self.config
             .as_ref()

src-tauri/src/lib.rs

@@ -37,6 +37,7 @@ mod scan_tile;
 mod scan_tree;
 mod scanning;
 mod scanning_runtime;
+mod settings_sync;
 mod state;
 mod storage;
 mod switch_gestures;
@@ -826,8 +827,20 @@ fn delete_switch_profile(
 }
 
 #[tauri::command]
-async fn get_account(account: State<'_, account::Account>) -> Result<account::AccountView, String> {
-    Ok(account.view().await)
+async fn get_account(
+    app: AppHandle,
+    account: State<'_, account::Account>,
+) -> Result<account::AccountView, String> {
+    let view = account.view().await;
+    // Opening the tab can find a session a locked keychain hid at startup.
+    if view.signed_in {
+        if let Some(sync) = sync_engine(&app) {
+            if sync.view().status == settings_sync::Status::Off {
+                sync.wake();
+            }
+        }
+    }
+    Ok(view)
 }
 
 #[tauri::command]
@@ -851,6 +864,11 @@ async fn verify_sign_in_code(
     let result = account.verify_code(&code).await;
     // Emitted on failure too: a rejected session signs out mid-action.
     account::emit(&app, &account.current_view().await);
+    if result.is_ok() {
+        if let Some(sync) = app.try_state::<std::sync::Arc<settings_sync::Engine>>() {
+            sync.wake();
+        }
+    }
     result
 }
 
@@ -872,6 +890,9 @@ async fn sign_out(
     let result = account.sign_out().await;
     // Emitted on failure too: a rejected session signs out mid-action.
     account::emit(&app, &account.current_view().await);
+    if let Some(sync) = app.try_state::<std::sync::Arc<settings_sync::Engine>>() {
+        sync.wake();
+    }
     result
 }
 
@@ -883,9 +904,39 @@ async fn delete_account(
     let result = account.delete_account().await;
     // Emitted on failure too: a rejected session signs out mid-action.
     account::emit(&app, &account.current_view().await);
+    if result.is_ok() {
+        if let Some(sync) = sync_engine(&app) {
+            sync.forget().await;
+        }
+    }
     result
 }
 
+fn sync_engine(app: &AppHandle) -> Option<std::sync::Arc<settings_sync::Engine>> {
+    app.try_state::<std::sync::Arc<settings_sync::Engine>>()
+        .map(|engine| engine.inner().clone())
+}
+
+#[tauri::command]
+fn get_settings_sync(app: AppHandle) -> settings_sync::SyncView {
+    sync_engine(&app).map_or_else(settings_sync::SyncView::unavailable, |engine| engine.view())
+}
+
+#[tauri::command]
+async fn sync_settings_now(app: AppHandle) -> Result<settings_sync::SyncView, String> {
+    let engine = sync_engine(&app).ok_or("Settings sync is unavailable in this build.")?;
+    Ok(engine.sync(None).await)
+}
+
+#[tauri::command]
+async fn resolve_settings_sync(
+    app: AppHandle,
+    choice: settings_sync::Choice,
+) -> Result<settings_sync::SyncView, String> {
+    let engine = sync_engine(&app).ok_or("Settings sync is unavailable in this build.")?;
+    Ok(engine.sync(Some(choice)).await)
+}
+
 fn publish_update(app: &AppHandle, model: &AppModel, update: UpdateView) -> AppState {
     model
         .shared
@@ -1588,6 +1639,7 @@ pub fn run() {
             switch_runtime::install(app.handle());
             remote_scan::install(app.handle());
             point_scan_runtime::install(app.handle());
+            settings_sync::install(app.handle());
             install_tray(app)?;
             if updater_is_configured(app.config().plugins.0.get("updater")) {
                 let model = app.state::<AppModel>();
@@ -1719,7 +1771,10 @@ pub fn run() {
             verify_sign_in_code,
             cancel_sign_in,
             sign_out,
-            delete_account
+            delete_account,
+            get_settings_sync,
+            sync_settings_now,
+            resolve_settings_sync
         ])
         .run(tauri::generate_context!())
         .expect("error while running Switchify PC");

src-tauri/src/portable_settings.rs

@@ -5,8 +5,6 @@
 //! registration never leave this install. Incoming documents are fully
 //! validated before anything is applied, and each section is applied through
 //! the same path as a local save so runtime state and overlays stay in step.
-// Wired up by the sync engine (#986).
-#![allow(dead_code)]
 
 use crate::{
     point_scan, remote_scan,
@@ -224,6 +222,7 @@ pub struct Plan {
 }
 
 impl Plan {
+    #[cfg(test)]
     pub fn is_empty(&self) -> bool {
         *self == Self::default()
     }
@@ -268,8 +267,9 @@ pub fn plan(local: &Local, incoming: Document) -> Result<Plan, String> {
 
 /// Replaces the custom profiles with the incoming set, keeping built-ins.
 /// A changed profile gets a version above both copies so connected phones
-/// notice the new bindings. Returns `None` when nothing would change.
-fn merge_profiles(
+/// notice the new bindings; an unchanged one keeps the higher of the two.
+/// Returns `None` when nothing would change.
+pub(crate) fn merge_profiles(
     local: &[SwitchProfile],
     mut incoming: Vec<SwitchProfile>,
 ) -> Result<Option<Vec<SwitchProfile>>, String> {
@@ -299,8 +299,11 @@ fn merge_profiles(
             .iter()
             .find(|candidate| candidate.id == profile.id && !candidate.built_in)
         {
+            // Same content: never lower the version, so computers that synced
+            // the same profile converge on one version instead of trading
+            // their own back and forth.
             profile.version = if same_profile(existing, &profile) {
-                existing.version
+                existing.version.max(profile.version)
             } else {
                 profile.version.max(existing.version.saturating_add(1))
             };