feat: ntfy notifications for imported, needs-decision, broken (#96)

crates/arr-daemon/src/notify.rs

@@ -0,0 +1,105 @@
+//! ntfy delivery for the three DESIGN.md §9.5 events: imported (to a title's
+//! owners), needs-a-decision and broken (both to the operator alone). See
+//! `attention.rs` and `broken.rs` for what decides *when* to send.
+
+use std::time::Duration;
+
+use reqwest::Client;
+
+const REQUEST_TIMEOUT: Duration = Duration::from_secs(10);
+
+#[derive(Debug, thiserror::Error)]
+pub enum NotifyError {
+    #[error("request: {0}")]
+    Request(#[from] reqwest::Error),
+    #[error("ntfy returned {0}")]
+    Status(reqwest::StatusCode),
+}
+
+/// A client for posting to one ntfy server, many topics.
+#[derive(Debug, Clone)]
+pub struct Notifier {
+    client: Client,
+    base_url: String,
+}
+
+impl Notifier {
+    pub fn new(base_url: impl Into<String>) -> Result<Self, NotifyError> {
+        let client = Client::builder().timeout(REQUEST_TIMEOUT).build()?;
+        Ok(Self {
+            client,
+            base_url: base_url.into(),
+        })
+    }
+
+    /// Post a plain-text message to one topic. The title is the message's
+    /// first line rather than ntfy's `Title` header — that header must be
+    /// ASCII, and titles here are TMDB titles in whatever language they were
+    /// released.
+    pub async fn send(&self, topic: &str, title: &str, body: &str) -> Result<(), NotifyError> {
+        let url = format!("{}/{topic}", self.base_url.trim_end_matches('/'));
+        let response = self
+            .client
+            .post(url)
+            .body(format!("{title}\n{body}"))
+            .send()
+            .await?;
+        if !response.status().is_success() {
+            return Err(NotifyError::Status(response.status()));
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+#[allow(clippy::unwrap_used)]
+mod tests {
+    use wiremock::matchers::{body_string, method, path};
+    use wiremock::{Mock, MockServer, ResponseTemplate};
+
+    use super::*;
+
+    #[tokio::test]
+    async fn send_posts_title_and_body_to_the_topic() {
+        let server = MockServer::start().await;
+        Mock::given(method("POST"))
+            .and(path("/owner-topic"))
+            .and(body_string("Dune: Part Two (2024)\nimported"))
+            .respond_with(ResponseTemplate::new(200))
+            .mount(&server)
+            .await;
+
+        let notifier = Notifier::new(server.uri()).unwrap();
+
+        notifier
+            .send("owner-topic", "Dune: Part Two (2024)", "imported")
+            .await
+            .unwrap();
+    }
+
+    #[tokio::test]
+    async fn a_non_success_status_is_an_error() {
+        let server = MockServer::start().await;
+        Mock::given(method("POST"))
+            .respond_with(ResponseTemplate::new(500))
+            .mount(&server)
+            .await;
+
+        let notifier = Notifier::new(server.uri()).unwrap();
+
+        assert!(matches!(
+            notifier.send("topic", "title", "body").await,
+            Err(NotifyError::Status(_))
+        ));
+    }
+
+    #[tokio::test]
+    async fn an_unreachable_server_is_an_error_the_caller_can_swallow() {
+        let notifier = Notifier::new("http://127.0.0.1:1").unwrap();
+
+        assert!(matches!(
+            notifier.send("topic", "title", "body").await,
+            Err(NotifyError::Request(_))
+        ));
+    }
+}