Chim/feature/integrate noti optimiser (#307)

## Describe your changes
1. I add notification functionality inside `save` method in optimiser
class.

## Issue ticket number and link

[Jira](https://fireapp-emergiq-2024.atlassian.net/jira/software/projects/FIR/boards/2?selectedIssue=FIR-122)

controllers/v2/optimiser/api.py

@@ -1,22 +1,31 @@
+import logging
 from flask_restful import Resource, marshal_with, reqparse
+from repository.fcm_token_repository import FCMTokenRepository
 from .response_models import optimiser_response_model
 from repository.shift_repository import ShiftRepository
 from services.jwk import requires_auth, is_user_or_has_role
 from domain import UserType, session_scope
 from controllers.v2.v2_blueprint import v2_api
 from services.optimiser.optimiser import Optimiser
-import logging
+
 
 # Initialise parser for potential arguments in future extensions (if needed)
 parser = reqparse.RequestParser()
 parser.add_argument('debug', type=bool, required=False, help="Optional debug mode flag.")
 
 
 class OptimiserResource(Resource):
+
     optimiser_repository: ShiftRepository
+    fcm_token_repository: FCMTokenRepository
 
-    def __init__(self, optimiser_repository: ShiftRepository = ShiftRepository()):
+    def __init__(
+            self,
+            optimiser_repository: ShiftRepository = ShiftRepository(),
+            fcm_token_repository: FCMTokenRepository = FCMTokenRepository()
+    ):
         self.optimiser_repository = optimiser_repository
+        self.fcm_token_repository = fcm_token_repository
 
     @requires_auth
     @is_user_or_has_role(None, UserType.ROOT_ADMIN)
@@ -33,7 +42,13 @@ def post(self):
         try:
             with session_scope() as session:
                 # Initialise and run the optimiser
-                optimiser = Optimiser(session=session, repository=self.optimiser_repository, debug=debug)
+                optimiser = Optimiser(
+                    session=session,
+                    repository=self.optimiser_repository,
+                    debug=debug,
+                    fcm_token_repository=self.fcm_token_repository
+                )
+
                 result = optimiser.solve()
                 optimiser.save_result(result)
 

services/optimiser/optimiser.py

@@ -2,11 +2,12 @@
 import minizinc
 from sqlalchemy import orm
 from datetime import datetime
-
 from domain import ShiftRequestVolunteer, UnavailabilityTime
+from repository.fcm_token_repository import FCMTokenRepository
 from services.optimiser.calculator import Calculator
 from repository.shift_repository import ShiftRepository
 
+
 # Set up logging
 logging.basicConfig(level=logging.INFO)
 logger = logging.getLogger(__name__)
@@ -16,7 +17,13 @@ class Optimiser:
     # The calculator generates data structures for the optimiser to solve.
     calculator = None
 
-    def __init__(self, session: orm.session, repository: ShiftRepository, debug: bool):
+    def __init__(
+            self,
+            session: orm.session,
+            repository: ShiftRepository,
+            debug: bool,
+            fcm_token_repository: FCMTokenRepository = None,
+    ):
         """
         @param session: The SQLAlchemy session to use
         @param repository: The repository class for database operations.
@@ -25,6 +32,7 @@ def __init__(self, session: orm.session, repository: ShiftRepository, debug: boo
         self.calculator = Calculator(session)
         self.repository = repository
         self.debug = debug
+        self.fcm_token_repository = fcm_token_repository
 
     @staticmethod
     def generate_model_string():
@@ -204,6 +212,18 @@ def save_result(self, result) -> None:
                                 'shift_end': shift.endTime
                             })
 
+                            # Send notification
+                            try:
+                                title = "New shift assignment"
+                                body = "You have been assigned to a new shift"
+                                self.fcm_token_repository.notify_user(
+                                    user_id=user.id,
+                                    title=title,
+                                    body=body
+                                )
+                            except Exception as e:
+                                logger.error(f"Error sending notification to user {user.id}: {e}")
+
             # Update shifts to PENDING status
             for shift_id in shifts_to_update:
                 self.repository.update_shift_pending(shift_id)