publishing supported log types if c8y bridge is up

Signed-off-by: initard <solo@softwareag.com>

2 files changed, 37 insertions, 0 deletions

diff --git a/crates/core/c8y_api/src/lib.rs b/crates/core/c8y_api/src/lib.rs
index 7eb6352c..64cd7a32 100644
--- a/crates/core/c8y_api/src/lib.rs
+++ b/crates/core/c8y_api/src/lib.rs
@@ -1,2 +1,3 @@
 pub mod http_proxy;
 pub mod json_c8y;
+pub mod utils;
diff --git a/crates/core/c8y_api/src/utils.rs b/crates/core/c8y_api/src/utils.rs
new file mode 100644
index 00000000..89ce4b18
--- /dev/null
+++ b/crates/core/c8y_api/src/utils.rs
@@ -0,0 +1,36 @@
+pub mod bridge {
+
+    use mqtt_channel::Message;
+
+    pub const C8Y_BRIDGE_HEALTH_TOPIC: &str = "tedge/health/mosquitto-c8y-bridge";
+    const C8Y_BRIDGE_UP_PAYLOAD: &str = "1";
+
+    pub fn is_c8y_bridge_up(message: &Message) -> bool {
+        match message.payload_str() {
+            Ok(payload) => {
+                message.topic.name == C8Y_BRIDGE_HEALTH_TOPIC && payload == C8Y_BRIDGE_UP_PAYLOAD
+            }
+            Err(_err) => false,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use mqtt_channel::{Message, Topic};
+    use test_case::test_case;
+
+    use crate::utils::bridge::{is_c8y_bridge_up, C8Y_BRIDGE_HEALTH_TOPIC};
+
+    #[test_case(C8Y_BRIDGE_HEALTH_TOPIC, "1", true)]
+    #[test_case(C8Y_BRIDGE_HEALTH_TOPIC, "0", false)]
+    #[test_case("tedge/not/health/topic", "1", false)]
+    #[test_case("tedge/not/health/topic", "0", false)]
+    fn test_bridge_is_up(topic: &str, payload: &str, expected: bool) {
+        let topic = Topic::new(topic).unwrap();
+        let message = Message::new(&topic, payload);
+
+        let actual = is_c8y_bridge_up(&message);
+        assert_eq!(actual, expected);
+    }
+}