1 files changed, 138 insertions, 0 deletions
diff --git a/src/push/app.rs b/src/push/app.rs
new file mode 100644
index 0000000..2d6e15c
--- /dev/null
+++ b/src/push/app.rs
@@ -0,0 +1,138 @@
+use sqlx::SqlitePool;
+use web_push::{
+    ContentEncoding, IsahcWebPushClient, PartialVapidSignatureBuilder, SubscriptionInfo,
+    WebPushClient, WebPushMessageBuilder,
+};
+
+use super::{Id, repo::Provider as _};
+
+use crate::{
+    db::NotFound as _,
+    user::{self, User},
+};
+
+pub struct Push<'a> {
+    db: &'a SqlitePool,
+    vapid_public_key: &'a str,
+    vapid_signer: &'a PartialVapidSignatureBuilder,
+}
+
+impl<'a> Push<'a> {
+    pub const fn new(
+        db: &'a SqlitePool,
+        vapid_public_key: &'a str,
+        vapid_signer: &'a PartialVapidSignatureBuilder,
+    ) -> Self {
+        Self {
+            db,
+            vapid_public_key,
+            vapid_signer,
+        }
+    }
+
+    pub fn public_key(&self) -> &str {
+        self.vapid_public_key
+    }
+
+    pub async fn register(
+        &self,
+        user: &User,
+        subscription: &SubscriptionInfo,
+    ) -> Result<Id, RegisterError> {
+        let mut tx = self.db.begin().await?;
+        let id = tx.subscriptions().create(user, subscription).await?;
+        tx.commit().await?;
+
+        Ok(id)
+    }
+
+    pub async fn echo(
+        &self,
+        user: &User,
+        subscription: &Id,
+        message: &str,
+    ) -> Result<(), EchoError> {
+        let mut tx = self.db.begin().await?;
+        let subscription = tx
+            .subscriptions()
+            .by_id(subscription)
+            .await
+            .not_found(|| EchoError::NotFound(subscription.clone()))?;
+        if subscription.user != user.id {
+            return Err(EchoError::NotSubscriber(subscription.id, user.id.clone()));
+        }
+
+        tx.commit().await?;
+
+        self.send(&subscription.info, message).await?;
+
+        Ok(())
+    }
+
+    async fn send(&self, subscription: &SubscriptionInfo, message: &str) -> Result<(), EchoError> {
+        let sig_builder = self
+            .vapid_signer
+            .clone()
+            .add_sub_info(subscription)
+            .build()?;
+
+        let payload = message.as_bytes();
+
+        let mut message_builder = WebPushMessageBuilder::new(subscription);
+        message_builder.set_payload(ContentEncoding::Aes128Gcm, payload);
+        message_builder.set_vapid_signature(sig_builder);
+        let message = message_builder.build()?;
+
+        let client = IsahcWebPushClient::new()?;
+        client.send(message).await?;
+
+        Ok(())
+    }
+
+    pub async fn unregister(&self, user: &User, subscription: &Id) -> Result<(), UnregisterError> {
+        let mut tx = self.db.begin().await?;
+        let subscription = tx
+            .subscriptions()
+            .by_id(subscription)
+            .await
+            .not_found(|| UnregisterError::NotFound(subscription.clone()))?;
+        if subscription.user != user.id {
+            return Err(UnregisterError::NotSubscriber(
+                subscription.id,
+                user.id.clone(),
+            ));
+        }
+        tx.subscriptions().delete(&subscription).await?;
+        tx.commit().await?;
+
+        Ok(())
+    }
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum RegisterError {
+    #[error(transparent)]
+    Database(#[from] sqlx::Error),
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum EchoError {
+    #[error("subscription {0} not found")]
+    NotFound(Id),
+    #[error("user {1} is not the subscriber for subscription {0}")]
+    NotSubscriber(Id, user::Id),
+    #[error(transparent)]
+    WebPush(#[from] web_push::WebPushError),
+    #[error(transparent)]
+    Database(#[from] sqlx::Error),
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum UnregisterError {
+    #[error("subscription {0} not found")]
+    NotFound(Id),
+    #[error("user {1} is not the subscriber for subscription {0}")]
+    NotSubscriber(Id, user::Id),
+    #[error(transparent)]
+    Database(#[from] sqlx::Error),
+}