relocating logo_bremen_calling.png and default_email_template to a novel folder in the library: resources. Adapted the dynamic path functions in the library. Created tests, which assert, when the files are missing. Relocating functions from stubs/email_template.py to the email_handling.py to avoid confusion.

src/server/BreCal/notifications/notifier.py

@@ -5,10 +5,9 @@ from BreCal.database.sql_queries import SQLQuery
 from BreCal.schemas import model
 from BreCal.brecal_utils.time_handling import difference_to_then
 
-from BreCal.services.email_handling import EmailHandler, create_shipcall_evaluation_notification, send_notification
+from BreCal.services.email_handling import EmailHandler, create_shipcall_evaluation_notification, send_notification, get_default_html_email
 from BreCal.database.enums import ParticipantwiseTimeDelta
 
-from BreCal.stubs.email_template import get_default_html_email
 eta_etd_type_dict = {
     model.ShipcallType.arrival : "Ankunft",
     model.ShipcallType.departure : "Abfahrt",
@@ -58,10 +57,6 @@ class Notifier():
         email_handler = EmailHandler(mail_server='w01d5503.kasserver.com', mail_port=465, mail_address="max.metz@scope-sorting.com")
         pwd = b'gAAAAABmqJlkXbtJTL1tFiyQNHhF_Y7sgtVI0xEx07ybwbX70Ro1Vp73CLDq49eFSYG-1SswIDQ2JBSORYlWaR-Vh2kIwPHy_lX8SxkySrRvBRzkyZP5x0I='
 
-        try:
-            # login in advance, so the email handler uses a shared connection. It disconnects only once at the end of the call.
-            email_handler.login(interactive=False, pwd=pwd)
-
         # get candidates: find all eligible shipcalls, where the evaluation state is yellow or red & the notifications are not yet sent
         eligible_shipcalls = Notifier.get_eligible_shipcalls()
 
@@ -69,19 +64,33 @@ class Notifier():
         # a time_diff_threshold is used to block those notifications, which are still fairly novel
         eligible_notifications = Notifier.get_eligible_notifications(eligible_shipcalls, time_diff_threshold)
 
+        if len(eligible_notifications) > 0: # only perform a login when there are eligible notifications
+            try:
+                # login in advance, so the email handler uses a shared connection. It disconnects only once at the end of the call.
+                email_handler.login(interactive=False, pwd=pwd)
+
                 for notification in eligible_notifications:
+                    eligible_users = Notifier.get_eligible_users(notification)
+
+                    # create an Email and send it to each eligible_user. 
+                    # #TODO: this method must be a distributor. It should send emails for those, who want emails, and provide placeholders for other types of notifications
+                    Notifier.create_and_send_email_notification(email_handler, pwd, eligible_users, notification, update_database=update_database, debug=debug)
+            finally:
+                email_handler.close()
+        return
+    
+    @staticmethod
+    def get_eligible_users(notification):
         # get all users, which are attached to the shipcall (uses the History dataset)
         users = Notifier.get_users_via_history(notification.shipcall_id)
 
         # filter: only consider the users, which have subscribed to the notification type
-                users = [user for user in users if Notifier.check_user_is_subscribed_to_notification_type(user,notification_type=notification.type)]
+        eligible_users = [user for user in users if Notifier.check_user_is_subscribed_to_notification_type(user,notification_type=notification.type)]
 
-                # obtain the mail address of each respective user
-                Notifier.create_and_send_email_notification(email_handler, pwd, users, notification, update_database=update_database, debug=debug)
-        finally:
-            email_handler.close()
-
-        return
+        # filter: consider only those users, where an Email is set
+        # #TODO: this is Email-specific and should not be a filter for other notifications
+        eligible_users = [user for user in eligible_users if user.user_email is not None]
+        return eligible_users
 
     @staticmethod
     def create(shipcall_id, old_state, new_state, user, update_database:bool=False)->typing.Optional[model.Notification]:
@@ -372,6 +381,12 @@ class Notifier():
 
     @staticmethod
     def create_and_send_email_notification(email_handler:EmailHandler, pwd:bytes, users:list[model.User], notification:model.Notification, update_database:bool=True, debug:bool=False):
+        """
+        # #TODO_rename: when there is more than one type of notification, this should be renamed. This method refers to a validation-state notification
+
+        this 'naive' method creates a message and simply sends it to all users in a list of users. 
+        Afterwards, the database will be updated, so the shipcall no longer requires a notification. 
+        """
         email_tgts = [user.user_email for user in users if user.user_email is not None]
 
         ship_name, evaluation_message, eta_etd, eta_etd_type = Notifier.prepare_notification_body(notification)
@@ -385,6 +400,8 @@ class Notifier():
         # send the messages via smtlib's SSL functions
         send_notification(email_handler, email_tgts, msg_multipart, pwd, debug=debug)
 
+        # #TODO_refactor: when there are multiple notification types, it makes sense to decouple updating the database
+        # from this method. Hence, an update would be done after *all* notifications are sent
         if update_database:
             Notifier.shipcall_put_update_evaluation_notifications_sent_flag(notification)
         return
@@ -412,6 +429,3 @@ class Notifier():
             raise NotImplementedError(notification_type)
 
 
-"""# build the list of evaluation times ('now', as isoformat)"""
-#evaluation_times = [datetime.datetime.now().isoformat() for _i in range(len(evaluation_states_new))]
-

src/server/BreCal/services/email_handling.py

@@ -237,6 +237,48 @@ import typing
 from email.mime.application import MIMEApplication
 import mimetypes
 
+import os
+
+def find_warning_notification_email_template()->str:
+    """
+    dynamically finds the 'default_email_template.txt' file within the module. 
+    """
+    # __file__ is BreCal/stubs/email_template.py
+    # parent of email_template.py is stubs
+    # parent of stubs is BreCal
+    brecal_root_folder = os.path.dirname(os.path.dirname(__file__)) # .../BreCal
+    resource_root_folder = os.path.join(brecal_root_folder, "resources") # .../BreCal/resources
+    html_filepath = os.path.join(resource_root_folder,"warning_notification_email_template.txt") # .../BreCal/resources/warning_notification_email_template.txt
+    assert os.path.exists(html_filepath), f"could not find default email template file at path: {html_filepath}"
+    return html_filepath
+
+def get_default_html_email()->str:
+    """
+    dynamically finds the 'default_email_template.txt' file within the module. It opens the file and returns the content.
+
+    __file__ returns to the file, where this function is stored (e.g., within BreCal.stubs.email_template)
+    using the dirname refers to the directory, where __file__ is stored.
+    finally, the 'default_email_template.txt' is stored within that folder
+    """
+    html_filepath = find_warning_notification_email_template()
+    with open(html_filepath,"r", encoding="utf-8") as file: # encoding = "utf-8" allows for German Umlaute
+        content = file.read()
+    return content
+
+def find_bremen_calling_logo():
+    """
+    find the path towards the logo file (located at 'brecal\src\BreCalClient\Resources\logo_bremen_calling.png')
+    """
+    # __file__ is services/email_handling.py
+    # parent of __file__ is services
+    # parent of services is BreCal
+    src_root_folder = os.path.dirname(os.path.dirname(__file__)) # .../BreCal
+    resource_root_folder = os.path.join(src_root_folder, "resources")
+
+    path = os.path.join(resource_root_folder, "logo_bremen_calling.png")
+    assert os.path.exists(path), f"cannot find logo of bremen calling at path: {os.path.abspath(path)}"
+    return path
+
 def add_bremen_calling_logo(msg_multipart):
     """
     The image is not attached automatically when it is embedded to the content. To circumvent this,
@@ -244,12 +286,7 @@ def add_bremen_calling_logo(msg_multipart):
 
     The content body refers to 'LogoBremenCalling', which the 'Content-ID' of the logo is assigned as.
     """
-    # find the path towards the logo file (located at 'brecal\src\BreCalClient\Resources\logo_bremen_calling.png')
-    src_root_folder = os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(__file__))))
-    resource_root_folder = os.path.join(src_root_folder, "BreCalClient", "Resources")
-
-    path = os.path.join(resource_root_folder, "logo_bremen_calling.png")
-    assert os.path.exists(path), f"cannot find logo of bremen calling at path: {os.path.abspath(path)}"
+    path = find_bremen_calling_logo()
 
     with open(path, 'rb') as file:
         attachment = MIMEApplication(file.read(), _subtype=mimetypes.MimeTypes().guess_type(path), Name="bremen_calling.png")

src/server/BreCal/stubs/email_template.py

@@ -1,15 +0,0 @@
-import os
-
-def get_default_html_email():
-    """
-    dynamically finds the 'default_email_template.txt' file within the module. It opens the file and returns the content.
-
-    __file__ returns to the file, where this function is stored (e.g., within BreCal.stubs.email_template)
-    using the dirname refers to the directory, where __file__ is stored.
-    finally, the 'default_email_template.txt' is stored within that folder
-    """
-    html_filepath = os.path.join(os.path.dirname(__file__),"default_email_template.txt")
-    assert os.path.exists(html_filepath), f"could not find default email template file at path: {html_filepath}"
-    with open(html_filepath,"r", encoding="utf-8") as file: # encoding = "utf-8" allows for German Umlaute
-        content = file.read()
-    return content

src/server/tests/resources/test_find_defaults.py

@@ -0,0 +1,14 @@
+import pytest
+import os
+
+def test_find_bremen_calling_logo():
+    from BreCal.services.email_handling import find_bremen_calling_logo
+    path = find_bremen_calling_logo()
+    assert os.path.exists(path), f"cannot find the bremen calling logo file, which is needed for notifications (e.g., Email). Searched at path: \n\t{path}"
+    return
+
+def test_find_warning_notification_email_template():
+    from BreCal.services.email_handling import find_warning_notification_email_template
+    path = find_warning_notification_email_template()
+    assert os.path.exists(path), f"cannot find the required email template, which is needed for warning notifications. Searched at path: \n\t{path}"
+    return