refactor(app): split service into two parts

src/app/alert_service.rs

@@ -0,0 +1,88 @@
+use crate::app::ports::driven::{
+    ForFormattingMessage, ForMonitoringSystem, ForSendingNotification,
+};
+
+pub struct AlertService {
+    notifier: Box<dyn ForSendingNotification>,
+    monitor: Box<dyn ForMonitoringSystem>,
+    formatter: Box<dyn ForFormattingMessage>,
+}
+
+pub fn new(
+    notifier: Box<dyn ForSendingNotification>,
+    monitor: Box<dyn ForMonitoringSystem>,
+    formatter: Box<dyn ForFormattingMessage>,
+) -> AlertService {
+    AlertService {
+        notifier,
+        monitor,
+        formatter,
+    }
+}
+
+impl AlertService {
+    /// Check for threshold violations and send alerts
+    pub fn alert_on_threshold_violation(&self) -> Result<(), Box<dyn std::error::Error>> {
+        let violations = self.monitor.check_thresholds();
+        for violation in violations {
+            let message = self.formatter.format_violation(violation);
+            self.notifier.send_notification(&message)?;
+        }
+        
+        Ok(())
+    }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashMap;
+
+    use crate::app::ports::driven::{MockForFormattingMessage, MockForMonitoringSystem, MockForSendingNotification};
+
+    use super::*;
+
+    #[test]
+    fn test_alert_on_threshold_violation() {
+        let mut notifier = MockForSendingNotification::new();
+        let mut monitor = MockForMonitoringSystem::new();
+        let mut formatter = MockForFormattingMessage::new();
+
+        notifier.expect_send_notification().returning(|_| Ok(()));
+        monitor.expect_check_thresholds().returning(|| vec![]);
+        monitor.expect_get_metrics().returning(|| HashMap::new());
+        formatter.expect_format_violation().returning(|_| "".to_string());
+        formatter.expect_format_summary().returning(|_| "".to_string());
+
+        let service = new(
+            Box::new(notifier),
+            Box::new(monitor),
+            Box::new(formatter),
+        );
+
+        assert!(service.alert_on_threshold_violation().is_ok());
+    }
+
+    #[test]
+    fn test_alert_on_threshold_violation_handles_send_error() {
+        let mut notifier = MockForSendingNotification::new();
+        let mut monitor = MockForMonitoringSystem::new();
+        let mut formatter = MockForFormattingMessage::new();
+
+        monitor.expect_check_thresholds().returning(|| {
+            vec![Box::new(crate::app::ports::driven::MockForGettingViolationData::new())]
+        });
+        formatter.expect_format_violation().returning(|_| "Test violation".to_string());
+        
+        notifier.expect_send_notification()
+            .returning(|_| Err("Network error".into()));
+
+        let service = new(
+            Box::new(notifier),
+            Box::new(monitor),
+            Box::new(formatter),
+        );
+
+        assert!(service.alert_on_threshold_violation().is_err());
+    }
+}