Move the notification service into the services directory

src/services/notifications.py

@@ -0,0 +1,89 @@
+import abc
+from typing import Any
+
+from src.services.email import EmailService
+
+from dataclasses import dataclass, field
+
+URL = str
+
+
+@dataclass
+class NotificationAction:
+    # A unique identifier for the action
+    action: str
+    # The title to show with the action
+    title: str
+    # Where to navigate to when clicked.
+    navigate: URL | None = None
+
+
+@dataclass
+class Notification:
+    """
+    Details to show in a notification
+
+    Much of the data here is intended to match the arguments to the [showNotification](https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorkerRegistration/showNotification)
+    Web API, but this content is ideally displayable in other contexts (for example in Email or RSS)
+    """
+
+    # The main title content to show
+    title: str
+    # The content of the notification
+    content: str
+
+    # The UNIX timestamp in milliseconds since the epoch associated with this notification
+    timestamp: int
+    # A list of actions included with this notification
+    actions: list[NotificationAction] = field(default_factory=list)
+    # The location of an icon to show as the icon for this notification
+    icon: URL | None = None
+
+    # The location of an image associated with this notification
+    image: URL | None = None
+
+
+class NotificationSender(abc.ABC):
+    """A service that sends notifications to the user"""
+
+    def __init__(self, name: str):
+        self._name = name
+
+    @property
+    def name(self):
+        return self._name
+
+    @abc.abstractmethod
+    def notify(self, user: Any, notification: Notification):
+        """Send a notification"""
+        pass
+
+
+class NotificationService:
+    def __init__(self):
+        self._senders = []
+
+    def register_sender(self, sender: NotificationSender):
+        self._senders.append(sender)
+
+    def notify_user(self, user: Any, notification: Notification):
+        for s in self._senders:
+            if s.name in user.notification_methods:
+                s.notify(user, notification)
+
+
+class EmailNotifier(NotificationSender):
+    def __init__(self, email_service: EmailService):
+        super().__init__('email')
+        self._email_service = email_service
+
+    def notify(self, user: Any, notification: Notification):
+        # TODO: Convert notification and user information into an EmailDTO for the email service
+        pass
+
+
+def get_notification_service(email_service: EmailService):
+    service = NotificationService()
+    service.register_sender(EmailNotifier(email_service))
+
+    return service