api: dc_accounts_set_push_device_token and dc_get_push_state APIs

deltachat-ffi/deltachat.h

@@ -686,6 +686,24 @@ int             dc_get_connectivity          (dc_context_t* context);
 char*           dc_get_connectivity_html     (dc_context_t* context);
 
 
+#define DC_PUSH_NOT_CONNECTED 0
+#define DC_PUSH_HEARTBEAT     1
+#define DC_PUSH_CONNECTED     2
+
+/**
+ * Get the current push notification state.
+ * One of:
+ * - DC_PUSH_NOT_CONNECTED
+ * - DC_PUSH_HEARTBEAT
+ * - DC_PUSH_CONNECTED
+ *
+ * @memberof dc_context_t
+ * @param context The context object.
+ * @return Push notification state.
+ */
+int              dc_get_push_state           (dc_context_t* context);
+
+
 /**
  * Standalone version of dc_accounts_all_work_done().
  * Only used by the python tests.
@@ -3165,6 +3183,16 @@ void           dc_accounts_maybe_network_lost    (dc_accounts_t* accounts);
  */
 int            dc_accounts_background_fetch    (dc_accounts_t* accounts, uint64_t timeout);
 
+
+/**
+ * Sets device token for Apple Push Notification service.
+ * Returns immediately.
+ *
+ * @memberof dc_accounts_t
+ * @param token Hexadecimal device token
+ */
+void           dc_accounts_set_push_device_token (dc_accounts_t* accounts, const char *token);
+
 /**
  * Create the event emitter that is used to receive events.
  *

deltachat-ffi/src/lib.rs

@@ -384,7 +384,7 @@ pub unsafe extern "C" fn dc_get_connectivity(context: *const dc_context_t) -> li
         return 0;
     }
     let ctx = &*context;
-    block_on(async move { ctx.get_connectivity().await as u32 as libc::c_int })
+    block_on(ctx.get_connectivity()) as u32 as libc::c_int
 }
 
 #[no_mangle]
@@ -407,6 +407,16 @@ pub unsafe extern "C" fn dc_get_connectivity_html(
     })
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn dc_get_push_state(context: *const dc_context_t) -> libc::c_int {
+    if context.is_null() {
+        eprintln!("ignoring careless call to dc_get_push_state()");
+        return 0;
+    }
+    let ctx = &*context;
+    block_on(ctx.push_state()) as libc::c_int
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn dc_all_work_done(context: *mut dc_context_t) -> libc::c_int {
     if context.is_null() {
@@ -4919,6 +4929,29 @@ pub unsafe extern "C" fn dc_accounts_background_fetch(
     1
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn dc_accounts_set_push_device_token(
+    accounts: *mut dc_accounts_t,
+    token: *const libc::c_char,
+) {
+    if accounts.is_null() {
+        eprintln!("ignoring careless call to dc_accounts_set_push_device_token()");
+        return;
+    }
+
+    let accounts = &*accounts;
+    let token = to_string_lossy(token);
+
+    block_on(async move {
+        let mut accounts = accounts.write().await;
+        if let Err(err) = accounts.set_push_device_token(&token).await {
+            accounts.emit_event(EventType::Error(format!(
+                "Failed to set notify token: {err:#}."
+            )));
+        }
+    })
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn dc_accounts_get_event_emitter(
     accounts: *mut dc_accounts_t,

src/accounts.rs

@@ -19,6 +19,7 @@ use tokio::time::{sleep, Duration};
 
 use crate::context::{Context, ContextBuilder};
 use crate::events::{Event, EventEmitter, EventType, Events};
+use crate::push::PushSubscriber;
 use crate::stock_str::StockStrings;
 
 /// Account manager, that can handle multiple accounts in a single place.
@@ -37,6 +38,9 @@ pub struct Accounts {
     /// This way changing a translation for one context automatically
     /// changes it for all other contexts.
     pub(crate) stockstrings: StockStrings,
+
+    /// Push notification subscriber shared between accounts.
+    push_subscriber: PushSubscriber,
 }
 
 impl Accounts {
@@ -73,8 +77,9 @@ impl Accounts {
             .context("failed to load accounts config")?;
         let events = Events::new();
         let stockstrings = StockStrings::new();
+        let push_subscriber = PushSubscriber::new();
         let accounts = config
-            .load_accounts(&events, &stockstrings, &dir)
+            .load_accounts(&events, &stockstrings, push_subscriber.clone(), &dir)
             .await
             .context("failed to load accounts")?;
 
@@ -84,6 +89,7 @@ impl Accounts {
             accounts,
             events,
             stockstrings,
+            push_subscriber,
         })
     }
 
@@ -124,6 +130,7 @@ impl Accounts {
             .with_id(account_config.id)
             .with_events(self.events.clone())
             .with_stock_strings(self.stockstrings.clone())
+            .with_push_subscriber(self.push_subscriber.clone())
             .build()
             .await?;
         // Try to open without a passphrase,
@@ -144,6 +151,7 @@ impl Accounts {
             .with_id(account_config.id)
             .with_events(self.events.clone())
             .with_stock_strings(self.stockstrings.clone())
+            .with_push_subscriber(self.push_subscriber.clone())
             .build()
             .await?;
         self.accounts.insert(account_config.id, ctx);
@@ -340,6 +348,12 @@ impl Accounts {
     pub fn get_event_emitter(&self) -> EventEmitter {
         self.events.get_emitter()
     }
+
+    /// Sets notification token for Apple Push Notification service.
+    pub async fn set_push_device_token(&mut self, token: &str) -> Result<()> {
+        self.push_subscriber.set_device_token(token).await;
+        Ok(())
+    }
 }
 
 /// Configuration file name.
@@ -525,6 +539,7 @@ impl Config {
         &self,
         events: &Events,
         stockstrings: &StockStrings,
+        push_subscriber: PushSubscriber,
         dir: &Path,
     ) -> Result<BTreeMap<u32, Context>> {
         let mut accounts = BTreeMap::new();
@@ -535,6 +550,7 @@ impl Config {
                 .with_id(account_config.id)
                 .with_events(events.clone())
                 .with_stock_strings(stockstrings.clone())
+                .with_push_subscriber(push_subscriber.clone())
                 .build()
                 .await
                 .with_context(|| format!("failed to create context from file {:?}", &dbfile))?;

src/context.rs

@@ -30,6 +30,7 @@ use crate::login_param::LoginParam;
 use crate::message::{self, Message, MessageState, MsgId, Viewtype};
 use crate::param::{Param, Params};
 use crate::peerstate::Peerstate;
+use crate::push::PushSubscriber;
 use crate::quota::QuotaInfo;
 use crate::scheduler::{convert_folder_meaning, SchedulerState};
 use crate::sql::Sql;
@@ -86,6 +87,8 @@ pub struct ContextBuilder {
     events: Events,
     stock_strings: StockStrings,
     password: Option<String>,
+
+    push_subscriber: Option<PushSubscriber>,
 }
 
 impl ContextBuilder {
@@ -101,6 +104,7 @@ impl ContextBuilder {
             events: Events::new(),
             stock_strings: StockStrings::new(),
             password: None,
+            push_subscriber: None,
         }
     }
 
@@ -155,10 +159,23 @@ impl ContextBuilder {
         self
     }
 
+    /// Sets push subscriber.
+    pub(crate) fn with_push_subscriber(mut self, push_subscriber: PushSubscriber) -> Self {
+        self.push_subscriber = Some(push_subscriber);
+        self
+    }
+
     /// Builds the [`Context`] without opening it.
     pub async fn build(self) -> Result<Context> {
-        let context =
+        let push_subscriber = self.push_subscriber.unwrap_or_default();
-            Context::new_closed(&self.dbfile, self.id, self.events, self.stock_strings).await?;
+        let context = Context::new_closed(
+            &self.dbfile,
+            self.id,
+            self.events,
+            self.stock_strings,
+            push_subscriber,
+        )
+        .await?;
         Ok(context)
     }
 
@@ -263,6 +280,13 @@ pub struct InnerContext {
     /// Standard RwLock instead of [`tokio::sync::RwLock`] is used
     /// because the lock is used from synchronous [`Context::emit_event`].
     pub(crate) debug_logging: std::sync::RwLock<Option<DebugLogging>>,
+
+    /// Push subscriber to store device token
+    /// and register for heartbeat notifications.
+    pub(crate) push_subscriber: PushSubscriber,
+
+    /// True if account has subscribed to push notifications via IMAP.
+    pub(crate) push_subscribed: AtomicBool,
 }
 
 /// The state of ongoing process.
@@ -308,7 +332,8 @@ impl Context {
         events: Events,
         stock_strings: StockStrings,
     ) -> Result<Context> {
-        let context = Self::new_closed(dbfile, id, events, stock_strings).await?;
+        let context =
+            Self::new_closed(dbfile, id, events, stock_strings, Default::default()).await?;
 
         // Open the database if is not encrypted.
         if context.check_passphrase("".to_string()).await? {
@@ -323,6 +348,7 @@ impl Context {
         id: u32,
         events: Events,
         stockstrings: StockStrings,
+        push_subscriber: PushSubscriber,
     ) -> Result<Context> {
         let mut blob_fname = OsString::new();
         blob_fname.push(dbfile.file_name().unwrap_or_default());
@@ -331,7 +357,14 @@ impl Context {
         if !blobdir.exists() {
             tokio::fs::create_dir_all(&blobdir).await?;
         }
-        let context = Context::with_blobdir(dbfile.into(), blobdir, id, events, stockstrings)?;
+        let context = Context::with_blobdir(
+            dbfile.into(),
+            blobdir,
+            id,
+            events,
+            stockstrings,
+            push_subscriber,
+        )?;
         Ok(context)
     }
 
@@ -374,6 +407,7 @@ impl Context {
         id: u32,
         events: Events,
         stockstrings: StockStrings,
+        push_subscriber: PushSubscriber,
     ) -> Result<Context> {
         ensure!(
             blobdir.is_dir(),
@@ -408,6 +442,8 @@ impl Context {
             last_full_folder_scan: Mutex::new(None),
             last_error: std::sync::RwLock::new("".to_string()),
             debug_logging: std::sync::RwLock::new(None),
+            push_subscriber,
+            push_subscribed: AtomicBool::new(false),
         };
 
         let ctx = Context {
@@ -1509,7 +1545,14 @@ mod tests {
         let tmp = tempfile::tempdir().unwrap();
         let dbfile = tmp.path().join("db.sqlite");
         let blobdir = PathBuf::new();
-        let res = Context::with_blobdir(dbfile, blobdir, 1, Events::new(), StockStrings::new());
+        let res = Context::with_blobdir(
+            dbfile,
+            blobdir,
+            1,
+            Events::new(),
+            StockStrings::new(),
+            Default::default(),
+        );
         assert!(res.is_err());
     }
 
@@ -1518,7 +1561,14 @@ mod tests {
         let tmp = tempfile::tempdir().unwrap();
         let dbfile = tmp.path().join("db.sqlite");
         let blobdir = tmp.path().join("blobs");
-        let res = Context::with_blobdir(dbfile, blobdir, 1, Events::new(), StockStrings::new());
+        let res = Context::with_blobdir(
+            dbfile,
+            blobdir,
+            1,
+            Events::new(),
+            StockStrings::new(),
+            Default::default(),
+        );
         assert!(res.is_err());
     }
 
@@ -1741,16 +1791,18 @@ mod tests {
         let dir = tempdir()?;
         let dbfile = dir.path().join("db.sqlite");
 
-        let id = 1;
+        let context = ContextBuilder::new(dbfile.clone())
-        let context = Context::new_closed(&dbfile, id, Events::new(), StockStrings::new())
+            .with_id(1)
+            .build()
             .await
             .context("failed to create context")?;
         assert_eq!(context.open("foo".to_string()).await?, true);
         assert_eq!(context.is_open().await, true);
         drop(context);
 
-        let id = 2;
+        let context = ContextBuilder::new(dbfile)
-        let context = Context::new(&dbfile, id, Events::new(), StockStrings::new())
+            .with_id(2)
+            .build()
             .await
             .context("failed to create context")?;
         assert_eq!(context.is_open().await, false);
@@ -1766,8 +1818,9 @@ mod tests {
         let dir = tempdir()?;
         let dbfile = dir.path().join("db.sqlite");
 
-        let id = 1;
+        let context = ContextBuilder::new(dbfile)
-        let context = Context::new_closed(&dbfile, id, Events::new(), StockStrings::new())
+            .with_id(1)
+            .build()
             .await
             .context("failed to create context")?;
         assert_eq!(context.open("foo".to_string()).await?, true);

src/imap.rs

@@ -8,6 +8,7 @@ use std::{
     collections::{BTreeMap, BTreeSet, HashMap},
     iter::Peekable,
     mem::take,
+    sync::atomic::Ordering,
     time::Duration,
 };
 
@@ -1445,6 +1446,37 @@ impl Session {
         *lock = Some(ServerMetadata { comment, admin });
         Ok(())
     }
+
+    /// Stores device token into /private/devicetoken IMAP METADATA of the Inbox.
+    pub(crate) async fn register_token(&mut self, context: &Context) -> Result<()> {
+        if context.push_subscribed.load(Ordering::Relaxed) {
+            return Ok(());
+        }
+
+        let Some(device_token) = context.push_subscriber.device_token().await else {
+            return Ok(());
+        };
+
+        if self.can_metadata() && self.can_push() {
+            let folder = context
+                .get_config(Config::ConfiguredInboxFolder)
+                .await?
+                .context("INBOX is not configured")?;
+
+            self.run_command_and_check_ok(format!(
+                "SETMETADATA \"{folder}\" (/private/devicetoken \"{device_token}\")"
+            ))
+            .await
+            .context("SETMETADATA command failed")?;
+            context.push_subscribed.store(true, Ordering::Relaxed);
+        } else if !context.push_subscriber.heartbeat_subscribed().await {
+            let context = context.clone();
+            // Subscribe for heartbeat notifications.
+            tokio::spawn(async move { context.push_subscriber.subscribe().await });
+        }
+
+        Ok(())
+    }
 }
 
 impl Session {

src/imap/capabilities.rs

@@ -25,6 +25,13 @@ pub(crate) struct Capabilities {
     /// <https://tools.ietf.org/html/rfc5464>
     pub can_metadata: bool,
 
+    /// True if the server supports XDELTAPUSH capability.
+    /// This capability means setting /private/devicetoken IMAP METADATA
+    /// on the INBOX results in new mail notifications
+    /// via notifications.delta.chat service.
+    /// This is supported by <https://github.com/deltachat/chatmail>
+    pub can_push: bool,
+
     /// Server ID if the server supports ID capability.
     pub server_id: Option<HashMap<String, String>>,
 }

src/imap/client.rs

@@ -60,6 +60,7 @@ async fn determine_capabilities(
         can_check_quota: caps.has_str("QUOTA"),
         can_condstore: caps.has_str("CONDSTORE"),
         can_metadata: caps.has_str("METADATA"),
+        can_push: caps.has_str("XDELTAPUSH"),
         server_id,
     };
     Ok(capabilities)

src/imap/session.rs

@@ -90,6 +90,10 @@ impl Session {
         self.capabilities.can_metadata
     }
 
+    pub fn can_push(&self) -> bool {
+        self.capabilities.can_push
+    }
+
     /// Returns the names of all folders on the IMAP server.
     pub async fn list_folders(&mut self) -> Result<Vec<async_imap::types::Name>> {
         let list = self.list(Some(""), Some("*")).await?.try_collect().await?;

src/lib.rs

@@ -98,6 +98,7 @@ mod color;
 pub mod html;
 pub mod net;
 pub mod plaintext;
+mod push;
 pub mod summary;
 
 mod debug_logging;

src/push.rs

@@ -0,0 +1,115 @@
+use std::sync::atomic::Ordering;
+use std::sync::Arc;
+
+use anyhow::Result;
+use tokio::sync::RwLock;
+
+use crate::context::Context;
+use crate::net::http;
+
+/// Manages subscription to Apple Push Notification services.
+///
+/// This structure is created by account manager and is shared between accounts.
+/// To enable notifications, application should request the device token as described in
+/// <https://developer.apple.com/documentation/usernotifications/registering-your-app-with-apns>
+/// and give it to the account manager, which will forward the token in this structure.
+///
+/// Each account (context) can then retrieve device token
+/// from this structure and give it to the email server.
+/// If email server does not support push notifications,
+/// account can call `subscribe` method
+/// to register device token with the heartbeat
+/// notification provider server as a fallback.
+#[derive(Debug, Clone, Default)]
+pub struct PushSubscriber {
+    inner: Arc<RwLock<PushSubscriberState>>,
+}
+
+impl PushSubscriber {
+    /// Creates new push notification subscriber.
+    pub(crate) fn new() -> Self {
+        Default::default()
+    }
+
+    /// Sets device token for Apple Push Notification service.
+    pub(crate) async fn set_device_token(&mut self, token: &str) {
+        self.inner.write().await.device_token = Some(token.to_string());
+    }
+
+    /// Retrieves device token.
+    ///
+    /// Token may be not available if application is not running on Apple platform,
+    /// failed to register for remote notifications or is in the process of registering.
+    ///
+    /// IMAP loop should periodically check if device token is available
+    /// and send the token to the email server if it supports push notifications.
+    pub(crate) async fn device_token(&self) -> Option<String> {
+        self.inner.read().await.device_token.clone()
+    }
+
+    /// Subscribes for heartbeat notifications with previously set device token.
+    pub(crate) async fn subscribe(&self) -> Result<()> {
+        let mut state = self.inner.write().await;
+
+        if state.heartbeat_subscribed {
+            return Ok(());
+        }
+
+        let Some(ref token) = state.device_token else {
+            return Ok(());
+        };
+
+        let socks5_config = None;
+        let response = http::get_client(socks5_config)?
+            .post("https://notifications.delta.chat/register")
+            .body(format!("{{\"token\":\"{token}\"}}"))
+            .send()
+            .await?;
+
+        let response_status = response.status();
+        if response_status.is_success() {
+            state.heartbeat_subscribed = true;
+        }
+        Ok(())
+    }
+
+    pub(crate) async fn heartbeat_subscribed(&self) -> bool {
+        self.inner.read().await.heartbeat_subscribed
+    }
+}
+
+#[derive(Debug, Default)]
+pub(crate) struct PushSubscriberState {
+    /// Device token.
+    device_token: Option<String>,
+
+    /// If subscribed to heartbeat push notifications.
+    heartbeat_subscribed: bool,
+}
+
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, FromPrimitive, ToPrimitive)]
+#[repr(i8)]
+pub enum NotifyState {
+    /// Not subscribed to push notifications.
+    #[default]
+    NotConnected = 0,
+
+    /// Subscribed to heartbeat push notifications.
+    Heartbeat = 1,
+
+    /// Subscribed to push notifications for new messages.
+    Connected = 2,
+}
+
+impl Context {
+    /// Returns push notification subscriber state.
+    pub async fn push_state(&self) -> NotifyState {
+        if self.push_subscribed.load(Ordering::Relaxed) {
+            NotifyState::Connected
+        } else if self.push_subscriber.heartbeat_subscribed().await {
+            NotifyState::Heartbeat
+        } else {
+            NotifyState::NotConnected
+        }
+    }
+}

src/scheduler.rs

@@ -525,6 +525,10 @@ async fn inbox_fetch_idle(ctx: &Context, imap: &mut Imap, mut session: Session)
         .fetch_metadata(ctx)
         .await
         .context("Failed to fetch metadata")?;
+    session
+        .register_token(ctx)
+        .await
+        .context("Failed to register push token")?;
 
     let session = fetch_idle(ctx, imap, session, FolderMeaning::Inbox).await?;
     Ok(session)