feat: implement dependency injection for file processing and refactor…

… upload endpoint (#35)

Introduce dependency injection for the file processing service, refactor
the upload endpoint to utilize this service, and clean up obsolete code
and import paths.

src/api/v1/endpoints/sensors.py

@@ -1,64 +1,35 @@
-import io
-import os
-import time
-import shutil
-from fastapi import APIRouter, HTTPException, Query, Request, status
+from fastapi import APIRouter, HTTPException, Query, Request, status, Depends
+from injector import Injector, inject
+from src.service.file_service import MAX_FILE_SIZE, FileService
 
 router = APIRouter()
 
-MAX_FILE_SIZE = 1024 * 1024  
-DIR = "saved_files"
-ALLOWED_EXTENSIONS = [".txt", ".json", ".csv"]
 
-async def process_up(content: str, extension: str):
-    print("Procesando evento 'up'")
-
-    timestamp = time.strftime("%Y-%m-%d-%H-%M-%S", time.localtime())
+def get_file_service(request: Request) -> FileService:
+    injector: Injector = request.app.state.injector
+    return injector.get(FileService)
 
-    filename = f"{timestamp}{extension}"
-    os.makedirs(DIR, exist_ok=True)
-    file_location = os.path.join(DIR, filename)
-
-
-    with open(file_location, "wb+") as f:
-        shutil.copyfileobj(content, f)
-
-    print(f"file saved: {file_location}")
-
-async def process_join(content: str):
-    pass
 
 @router.post("/uploadFile")
 async def create_upload_file(
     request: Request,
-    event: str = Query(..., description="Tipo de evento. Ejemplo: 'up' o 'join'")
+    event: str = Query(...,
+                       description="Tipo de evento. Ejemplo: 'up' o 'join'"),
+    file_service: FileService = Depends(get_file_service)
 ):
     body = await request.body()
-
-    if (len(body) > MAX_FILE_SIZE):
-        raise HTTPException(
-            detail="File too large",
-            status_code=403
-        )
-
-    content = io.BytesIO(body)
-
-    timestamp = time.strftime("%Y-%m-%d-%H-%M-%S", time.localtime())
-    extension = ".json"
-    filename = f"{timestamp}{extension}"
-    os.makedirs(DIR, exist_ok=True)
-    file_location = os.path.join(DIR, filename)
 
-    with open(file_location, "wb") as f:
-        f.write(content.getvalue())
+    if len(body) > MAX_FILE_SIZE:
+        raise HTTPException(detail="File too large", status_code=403)
 
-    content.seek(0)
+    extension = ".json"
 
     if event == "up":
-        await process_up(content, extension)
+        file_service.process_up(body, extension)
     elif event == "join":
-        await process_join(content)
+        file_service.process_join(body)
     else:
-        raise HTTPException(status_code=400, detail=f"Evento {event} no implementado")
+        raise HTTPException(
+            status_code=400, detail=f"Evento {event} no implementado")
 
     return status.HTTP_200_OK

src/core/db/connection.py

@@ -6,6 +6,7 @@
 load_dotenv()
 engine = create_engine(str(settings.SQLALCHEMY_DATABASE_URI))
 
+
 def get_session():
     with Session(engine) as session:
         yield session

src/core/di.py

@@ -0,0 +1,17 @@
+# src/core/di.py
+from injector import Module, provider, singleton
+from sqlmodel import Session
+from src.service.file_service import FileService
+from src.core.db.connection import engine
+
+
+class AppModule(Module):
+    @singleton
+    @provider
+    def provide_session(self) -> Session:
+        return Session(engine)
+
+    @singleton
+    @provider
+    def provide_file_service(self, session: Session) -> FileService:
+        return FileService(session)

src/main.py

@@ -1,6 +1,9 @@
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from src.api.v1.endpoints import sensors
+from injector import Injector
+from src.core.di import AppModule
+
 
 def create_app() -> FastAPI:
     app = FastAPI()
@@ -11,6 +14,10 @@ def create_app() -> FastAPI:
         allow_methods=["*"],
         allow_headers=["*"],
     )
+
+    injector = Injector([AppModule()])
+    app.state.injector = injector
+
     app.include_router(sensors.router)
     return app
 

src/service/file_service.py

@@ -0,0 +1,29 @@
+import os
+import time
+from sqlmodel import Session
+
+DIR = "saved_files"
+MAX_FILE_SIZE = 1024 * 1024
+ALLOWED_EXTENSIONS = [".txt", ".json", ".csv"]
+
+
+class FileService:
+    def __init__(self, session: Session):
+        self.session = session
+
+    def save_file(self, content: bytes, extension: str) -> str:
+        timestamp = time.strftime("%Y-%m-%d-%H-%M-%S", time.localtime())
+        filename = f"{timestamp}{extension}"
+        os.makedirs(DIR, exist_ok=True)
+        file_location = os.path.join(DIR, filename)
+
+        with open(file_location, "wb") as f:
+            f.write(content)
+
+        return file_location
+
+    def process_up(self, content: bytes, extension: str):
+        file_location = self.save_file(content, extension)
+
+    def process_join(self, content: bytes):
+        pass