Refactor of caching & data storage part 9 #118

providers/alert/alert_provider.py

@@ -0,0 +1,45 @@
+from datetime import datetime
+
+import pytz
+
+from core.data_store import DATA_STORE
+
+
+class AlertProvider:
+    """Generic alert provider class. Subclasses of this query the individual APIs for alerts."""
+
+    def __init__(self, name, provider_config):
+        """Constructor"""
+
+        self.name = name
+        self.enabled = provider_config["enabled"]
+        self.last_update_time = datetime.min.replace(tzinfo=pytz.UTC)
+        self.status = "Not Started" if self.enabled else "Disabled"
+        self._alerts = DATA_STORE.alerts
+
+    def start(self):
+        """Start the provider. This should return immediately after spawning threads to access the remote resources"""
+
+        raise NotImplementedError("Subclasses must implement this method")
+
+    def _submit_batch(self, alerts):
+        """Submit a batch of alerts retrieved from the provider. There is no timestamp checking like there is for spots,
+        because alerts could be created at any point for any time in the future. Rely on hashcode-based id matching
+        to deal with duplicates."""
+
+        # Sort the batch so that earliest ones go in first. This helps keep the ordering correct when alerts are fired
+        # off to SSE listeners.
+        alerts = sorted(alerts, key=lambda a: (a.start_time if a and a.start_time else 0))
+        for alert in alerts:
+            # Fill in any blanks and add to the list
+            alert.infer_missing()
+            self._add_alert(alert)
+
+    def _add_alert(self, alert):
+        if not alert.expired():
+            self._alerts.set(alert.id, alert)
+
+    def stop(self):
+        """Stop any threads and prepare for application shutdown"""
+
+        raise NotImplementedError("Subclasses must implement this method")