Implement subscribe function in Notification service.

src/service/notification.rs

@@ -12,4 +12,45 @@ use bambangshop_receiver::{compose_error_response, Result, APP_CONFIG, REQWEST_C
 
 pub struct NotificationService;
 
-impl NotificationService {}
+impl NotificationService {
+    #[tokio::main]
+    async fn subscribe_request(product_type: String) -> Result<SubscriberRequest> {
+        let product_type_upper: String = product_type.to_uppercase();
+        let product_type_str: &str = product_type_upper.as_str();
+        let notification_receiver_url: String =
+            format!("{}/receive", APP_CONFIG.get_instance_name().to_string());
+        let payload: SubscriberRequest = SubscriberRequest {
+            name: APP_CONFIG.get_instance_name().to_string(),
+            url: notification_receiver_url,
+        };
+
+        let request_url: String = format!(
+            "{}/notification/subscribe/{}",
+            APP_CONFIG.get_publisher_root_url(),
+            product_type_str
+        );
+        let request = REQWEST_CLIENT
+            .post(request_url.clone())
+            .header("Content-Type", "application/json")
+            .header("Accept", "application/json")
+            .body(to_string(&payload).unwrap())
+            .send()
+            .await;
+        log::warn_!("Sent subscribe request to: {}", request_url);
+
+        return match request {
+            Ok(f) => match f.json::<SubscriberRequest>().await {
+                Ok(x) => Ok(x),
+                Err(y) => Err(compose_error_response(Status::NotAcceptable, y.to_string())),
+            },
+            Err(e) => Err(compose_error_response(Status::NotFound, e.to_string())),
+        };
+    }
+
+    pub fn subscribe(product_type: &str) -> Result<SubscriberRequest> {
+        let product_type_clone = String::from(product_type);
+        return thread::spawn(move || Self::subscribe_request(product_type_clone))
+            .join()
+            .unwrap();
+    }
+}