matrix: skip room invite when the user is already invited or joined

hive-c0re/src/matrix.rs

@@ -1353,9 +1353,41 @@ async fn invite_to_room(
     invite_user_id(client, admin_token, room_id, &user_id).await
 }
 
+/// Fetch a user's current membership in a room via the admin token, or
+/// `None` if there is no membership event (never invited) or the lookup
+/// fails. Returns the raw membership string (`invite`, `join`, `leave`, …).
+async fn room_membership(
+    client: &reqwest::Client,
+    admin_token: &str,
+    encoded_room_id: &str,
+    user_id: &str,
+) -> Option<String> {
+    // `:` must be percent-encoded in both the room-id and user-id path
+    // segments; `@` and `!` are permitted path characters per RFC 3986.
+    let encoded_user = user_id.replace(':', "%3A");
+    let url = format!(
+        "{MATRIX_HTTP}/_matrix/client/v3/rooms/{encoded_room_id}/state/m.room.member/{encoded_user}"
+    );
+    let resp = client
+        .get(&url)
+        .bearer_auth(admin_token)
+        .send()
+        .await
+        .ok()?;
+    if !resp.status().is_success() {
+        // 404 = no membership event yet; anything else we treat as "unknown"
+        // and let the caller fall through to the invite attempt.
+        return None;
+    }
+    let body = resp.json::<serde_json::Value>().await.ok()?;
+    body["membership"].as_str().map(ToOwned::to_owned)
+}
+
 /// Invite a fully-qualified Matrix user id (`@user:server`) to `room_id`
-/// using the admin token. Idempotent: a 403 `M_FORBIDDEN` / `M_BAD_STATE`
-/// (already a member or pending invite) is treated as success.
+/// using the admin token. Idempotent: a user who is already a member or
+/// already has a pending invite is left untouched (no fresh invite is sent,
+/// so they are not re-notified), and a 403 `M_FORBIDDEN` / `M_BAD_STATE`
+/// from a racing invite is still treated as success.
 async fn invite_user_id(
     client: &reqwest::Client,
     admin_token: &str,
@@ -1365,6 +1397,17 @@ async fn invite_user_id(
     // `:` must be percent-encoded in the room-id path segment; `!` is
     // permitted in URL path characters per RFC 3986.
     let encoded_room_id = room_id.replace(':', "%3A");
+
+    // Skip the invite entirely when the user is already invited or joined.
+    // Re-POSTing an invite to a pending member re-sends the invite event,
+    // which re-notifies the agent on every provisioning sweep.
+    if let Some(membership) = room_membership(client, admin_token, &encoded_room_id, user_id).await
+        && matches!(membership.as_str(), "invite" | "join")
+    {
+        tracing::debug!(%user_id, %room_id, %membership, "matrix: invite skipped (already a member/invited)");
+        return Ok(());
+    }
+
     let url = format!("{MATRIX_HTTP}/_matrix/client/v3/rooms/{encoded_room_id}/invite");
     let resp = client
         .post(&url)