feat: dc_accounts_set_push_device_token and dc_get_push_state APIs

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
+        }
+    }
+}