feat(push): relay notifications as encrypted web push (#2906)

fluxer_push/src/job.rs

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use serde::Deserialize;
+use thiserror::Error;
+
+pub const SUBJECT_MESSAGE: &str = "push.job.message";
+pub const SUBJECT_CLEAR: &str = "push.job.clear";
+pub const QUEUE_GROUP: &str = "fluxer-push";
+
+const SUPPORTED_VERSION: u8 = 1;
+const DIRECT_MESSAGE_GUILD_ID: &str = "0";
+
+#[derive(Clone, Debug, Deserialize, Eq, PartialEq)]
+pub struct MessageJob {
+    pub v: u8,
+    pub config_version: u64,
+    pub guild_id: String,
+    pub channel_id: String,
+    pub message_id: String,
+    pub notification: NotificationFields,
+    pub user_ids: Vec<String>,
+}
+
+#[derive(Clone, Debug, Deserialize, Eq, PartialEq)]
+pub struct NotificationFields {
+    pub title: String,
+    pub body: String,
+    pub icon: String,
+    pub badge: String,
+    pub tag: String,
+    pub notification_tag: String,
+    pub url: String,
+    #[serde(default)]
+    pub image_url: Option<String>,
+}
+
+#[derive(Clone, Debug, Deserialize, Eq, PartialEq)]
+pub struct ClearJob {
+    pub v: u8,
+    pub config_version: u64,
+    pub user_id: String,
+    pub channel_id: String,
+    pub message_id: String,
+}
+
+#[derive(Debug, Error)]
+pub enum JobError {
+    #[error("push job version {0} is not supported")]
+    UnsupportedVersion(u8),
+    #[error("push job is not a valid job document: {0}")]
+    Decode(#[from] serde_json::Error),
+}
+
+impl MessageJob {
+    pub fn is_direct_message(&self) -> bool {
+        self.guild_id == DIRECT_MESSAGE_GUILD_ID
+    }
+}
+
+pub fn decode_message(bytes: &[u8]) -> Result<MessageJob, JobError> {
+    let job: MessageJob = serde_json::from_slice(bytes)?;
+    supported(job.v)?;
+    Ok(job)
+}
+
+pub fn decode_clear(bytes: &[u8]) -> Result<ClearJob, JobError> {
+    let job: ClearJob = serde_json::from_slice(bytes)?;
+    supported(job.v)?;
+    Ok(job)
+}
+
+fn supported(version: u8) -> Result<(), JobError> {
+    if version == SUPPORTED_VERSION {
+        return Ok(());
+    }
+    Err(JobError::UnsupportedVersion(version))
+}