Feature/celery notifications

backend/.env.example

@@ -144,6 +144,8 @@ CELERY_BROKER_URL=redis://localhost:6379/1
 
 CELERY_RESULT_BACKEND=redis://localhost:6379/2
 
+CELERY_TASK_ALWAYS_EAGER=false
+
 # ----------------------------------------------------------
 # WebSocket
 # ----------------------------------------------------------

backend/app/core/celery_app.py

@@ -0,0 +1,24 @@
+from __future__ import annotations
+
+from celery import Celery
+
+from app.core.config import settings
+
+celery_app = Celery(
+    "devlink",
+    broker=settings.CELERY_BROKER_URL,
+    backend=settings.CELERY_RESULT_BACKEND,
+    include=["app.tasks.notification_tasks"],
+)
+
+celery_app.conf.update(
+    task_serializer="json",
+    result_serializer="json",
+    accept_content=["json"],
+    timezone="UTC",
+    enable_utc=True,
+    task_track_started=True,
+    task_time_limit=60,
+    task_soft_time_limit=45,
+    task_always_eager=settings.CELERY_TASK_ALWAYS_EAGER,
+)

backend/app/core/config.py

@@ -135,6 +135,8 @@ class Settings(BaseSettings):
     CELERY_BROKER_URL: str = "redis://localhost:6379/1"
     CELERY_RESULT_BACKEND: str = "redis://localhost:6379/2"
 
+    CELERY_TASK_ALWAYS_EAGER: bool = False
+
     # ==========================================================
     # WebSocket
     # ==========================================================

backend/app/routers/applications.py

@@ -14,6 +14,9 @@
     ApplicationUpdate,
 )
 from app.services.application_service import ApplicationService
+from app.models.notification import NotificationType
+from app.models.project import Project
+from app.services.notification_service import NotificationService
 
 router = APIRouter(
     prefix="/applications",
@@ -32,14 +35,33 @@ def create_application(
     current_user: User = Depends(get_current_user),
 ):
 
-    return ApplicationService.create_application(
+    created = ApplicationService.create_application(
         db=db,
         applicant_id=current_user.id,
         project_id=application.project_id,
         flare_id=application.flare_id,
         application=application,
     )
 
+    try:
+        project = db.get(Project, created.project_id)
+        if project is not None:
+            NotificationService.enqueue(
+                db,
+                recipient_id=project.owner_id,
+                sender_id=current_user.id,
+                type=NotificationType.APPLICATION,
+                title="New application",
+                message=f"{current_user.username} applied to your project.",
+                project_id=created.project_id,
+                application_id=created.id,
+                action_url=f"/applications/{created.id}",
+            )
+    except Exception:
+        db.rollback()
+
+    return created
+
 
 @router.get(
     "/{application_id}",
@@ -129,6 +151,7 @@ def update_application(
 def accept_application(
     application_id: uuid.UUID,
     db: Session = Depends(get_db),
+    current_user: User = Depends(get_current_user),
 ):
 
     db_application = ApplicationService.get_application(
@@ -142,11 +165,28 @@ def accept_application(
             detail="Application not found",
         )
 
-    return ApplicationService.accept_application(
+    accepted = ApplicationService.accept_application(
         db,
         db_application,
     )
 
+    try:
+        NotificationService.enqueue(
+            db,
+            recipient_id=db_application.applicant_id,
+            sender_id=current_user.id,
+            type=NotificationType.APPLICATION_ACCEPTED,
+            title="Application accepted",
+            message="Your application was accepted. 🎉",
+            project_id=db_application.project_id,
+            application_id=db_application.id,
+            action_url=f"/applications/{db_application.id}",
+        )
+    except Exception:
+        db.rollback()
+
+    return accepted
+
 
 @router.patch(
     "/{application_id}/reject",
@@ -155,6 +195,7 @@ def accept_application(
 def reject_application(
     application_id: uuid.UUID,
     db: Session = Depends(get_db),
+    current_user: User = Depends(get_current_user),
 ):
 
     db_application = ApplicationService.get_application(
@@ -168,11 +209,28 @@ def reject_application(
             detail="Application not found",
         )
 
-    return ApplicationService.reject_application(
+    rejected = ApplicationService.reject_application(
         db,
         db_application,
     )
 
+    try:
+        NotificationService.enqueue(
+            db,
+            recipient_id=db_application.applicant_id,
+            sender_id=current_user.id,
+            type=NotificationType.APPLICATION_REJECTED,
+            title="Application rejected",
+            message="Your application was not accepted this time.",
+            project_id=db_application.project_id,
+            application_id=db_application.id,
+            action_url=f"/applications/{db_application.id}",
+        )
+    except Exception:
+        db.rollback()
+
+    return rejected
+
 
 @router.patch(
     "/{application_id}/withdraw",

backend/app/routers/followers.py

@@ -10,6 +10,8 @@
 from app.models.user import User
 from app.schemas.follower import FollowerResponse
 from app.services.follower_service import FollowerService
+from app.models.notification import NotificationType
+from app.services.notification_service import NotificationService
 
 router = APIRouter(
     prefix="/followers",
@@ -46,12 +48,27 @@ def follow_user(
             detail="Already following this user",
         )
 
-    return FollowerService.follow_user(
+    follow = FollowerService.follow_user(
         db,
         current_user.id,
         user_id,
     )
 
+    try:
+        NotificationService.enqueue(
+            db,
+            recipient_id=user_id,
+            sender_id=current_user.id,
+            type=NotificationType.FOLLOW,
+            title="New follower",
+            message=f"{current_user.username} started following you.",
+            action_url=f"/users/{current_user.id}",
+        )
+    except Exception:
+        db.rollback()
+
+    return follow
+
 
 @router.delete(
     "/{user_id}",

backend/app/routers/messages.py

@@ -14,6 +14,11 @@
     MessageUpdate,
 )
 from app.services.message_service import MessageService
+from sqlalchemy import select
+
+from app.models.conversation_member import ConversationMember
+from app.models.notification import NotificationType
+from app.services.notification_service import NotificationService
 
 router = APIRouter(
     prefix="/messages",
@@ -32,13 +37,38 @@ def send_message(
     current_user: User = Depends(get_current_user),
 ):
 
-    return MessageService.send_message(
+    sent = MessageService.send_message(
         db=db,
         conversation_id=message.conversation_id,
         sender_id=current_user.id,
         message=message,
     )
 
+    try:
+        recipient_ids = db.scalars(
+            select(ConversationMember.user_id).where(
+                ConversationMember.conversation_id == message.conversation_id,
+                ConversationMember.user_id != current_user.id,
+            )
+        ).all()
+
+        for recipient_id in recipient_ids:
+            NotificationService.enqueue(
+                db,
+                recipient_id=recipient_id,
+                sender_id=current_user.id,
+                type=NotificationType.MESSAGE,
+                title="New message",
+                message=f"{current_user.username} sent you a message.",
+                conversation_id=message.conversation_id,
+                message_id=sent.id,
+                action_url=f"/conversations/{message.conversation_id}",
+            )
+    except Exception:
+        db.rollback()
+
+    return sent
+
 
 @router.get(
     "/{message_id}",

backend/app/schemas/notification.py

@@ -0,0 +1,69 @@
+from __future__ import annotations
+
+import uuid
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, ConfigDict
+
+from app.models.notification import NotificationType
+
+
+# ==========================================================
+# Base
+# ==========================================================
+
+
+class NotificationBase(BaseModel):
+    type: NotificationType
+    title: str
+    message: str
+
+    action_url: Optional[str] = None
+    image_url: Optional[str] = None
+
+    project_id: Optional[uuid.UUID] = None
+    conversation_id: Optional[uuid.UUID] = None
+    message_id: Optional[uuid.UUID] = None
+    application_id: Optional[uuid.UUID] = None
+
+
+# ==========================================================
+# Create  (the existing test endpoint reads notification.recipient_id)
+# ==========================================================
+
+
+class NotificationCreate(NotificationBase):
+    recipient_id: uuid.UUID
+
+
+# ==========================================================
+# Update
+# ==========================================================
+
+
+class NotificationUpdate(BaseModel):
+    is_read: Optional[bool] = None
+    title: Optional[str] = None
+    message: Optional[str] = None
+    action_url: Optional[str] = None
+    image_url: Optional[str] = None
+
+
+# ==========================================================
+# Response
+# ==========================================================
+
+
+class NotificationResponse(NotificationBase):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: uuid.UUID
+    recipient_id: uuid.UUID
+    sender_id: Optional[uuid.UUID] = None
+
+    is_read: bool
+    read_at: Optional[datetime] = None
+
+    created_at: datetime
+    updated_at: datetime