Backend: refactored and unified fetching offers from db based on diff…

…erent filters (#30)

backend/api/flask_app.py

@@ -14,7 +14,7 @@ def aircraft_models():
 
 @app.route('/api/offers')
 def offers():
-    return jsonify(db.get_offers_dict(aircraft_type=request.args.get('aircraft_type'),
+    return jsonify(db.get_offers(aircraft_type=request.args.get('aircraft_type'),
                                       offset=int(request.args.get('offset') or '0'),
                                       limit=int(request.args.get('limit') or '30')))
 
@@ -28,7 +28,7 @@ def model_information(manufacturer, model):
         abort(404)
     manufacturer_info = manufacturers[manufacturer]
     del (manufacturer_info["models"])  # remove models info
-    manufacturer_info["offers"] = db.get_offers_for_model(manufacturer, model)
+    manufacturer_info["offers"] = db.get_offers(manufacturer=manufacturer, model=model)
     return jsonify(manufacturer_info)
 
 if __name__ == '__main__':

backend/db.py

@@ -124,35 +124,26 @@ def convert_prices(offers, session):
     return offers
 
 
-def get_offers_for_model(manufacturer, model):
+def get_offers(offset: int = 0, limit: int = 30, aircraft_type=None, manufacturer=None, model=None):
     session = Session()
     try:
-        offers = session.query(AircraftOffer)
-        offers = offers.filter(AircraftOffer.manufacturer == manufacturer)
-        offers = offers.filter(AircraftOffer.model == model)
-        offers = offers.order_by(AircraftOffer.date.asc())
-        offers = offers.all()
-
-        ret = [offer.as_dict() for offer in offers]
-        ret = convert_prices(ret, session)
-        return ret
-    finally:
-        session.close()
-
+        offers = (session.query(AircraftOffer)
+                  .order_by(AircraftOffer.date.desc()))
 
-def get_offers_dict(limit: int = 30, offset: int = 0, aircraft_type=None):
-    session = Session()
-    try:
-        offers = session.query(AircraftOffer).order_by(AircraftOffer.date.desc())
         if aircraft_type is not None:
             offers = offers.filter(AircraftOffer.aircraft_type == aircraft_type)
         else:
             offers = offers.filter(AircraftOffer.aircraft_type is not None)
 
-        offers = offers.limit(min(limit, 100))
+        if manufacturer is not None:
+            offers = offers.filter(AircraftOffer.manufacturer == manufacturer)
+
+        if model is not None:
+            offers = offers.filter(AircraftOffer.model == model)
+
+        offers = offers.offset(offset or 0)
+        offers = offers.limit(min(limit, 300))
 
-        if offset is not None:
-            offers = offers.offset(offset)
         offers = offers.all()
 
         ret = [offer.as_dict() for offer in offers]

backend/tests/test_db.py

@@ -18,10 +18,36 @@ def test_should_store_and_fetch_offer(self):
         db.store_offer(sample_offer)
 
         # then
-        all_gliders_in_db = db.get_offers_dict(aircraft_type="glider")
+        all_gliders_in_db = db.get_offers()
         self.assertEqual(len(all_gliders_in_db), 1)
         self.assertEqual(all_gliders_in_db[0]["title"], "Glider A")
 
+    def test_should_filter_offers_by_aircraft_type(self):
+        # given
+        sample_offer = buildOfferWithUrl("https://offers.com/1")
+        db.store_offer(sample_offer)
+
+        # when
+        gliders_only = db.get_offers(aircraft_type="glider")
+        airplanes_only = db.get_offers(aircraft_type="airplane")
+
+        # then
+        self.assertEqual(len(gliders_only), 1)
+        self.assertEqual(len(airplanes_only), 0)
+
+    def test_should_filter_offers_by_manufacturer_and_model(self):
+        # given
+        sample_offer = buildOfferWithUrl("https://offers.com/1")
+        db.store_offer(sample_offer)
+
+        # when
+        mini_nimbuses = db.get_offers(manufacturer="Schempp-Hirth", model="Mini-Nimbus")
+        asg29s = db.get_offers(manufacturer="Alexander Schleicher", model="ASG 29 E")
+
+        # then
+        self.assertEqual(len(mini_nimbuses), 1)
+        self.assertEqual(len(asg29s), 0)
+
     def test_should_check_url_exists(self):
         # given offer exists in db
         db.store_offer(buildOfferWithUrl("https://offers.com/1"))
@@ -45,7 +71,9 @@ def buildOfferWithUrl(url):
         offer_url=url,
         spider="segelflug_de_kleinanzeigen",
         detail_text="does not matter to much",
-        aircraft_type="glider"
+        aircraft_type="glider",
+        manufacturer="Schempp-Hirth",
+        model="Mini-Nimbus"
     )
 
 

backend/tests/test_pipelines.py

@@ -131,7 +131,7 @@ def test_should_store_offer(self):
         self.storage.process_item(sample_raw_offer, None)
 
         # then
-        all_gliders_in_db = db.get_offers_dict(aircraft_type="glider")
+        all_gliders_in_db = db.get_offers(aircraft_type="glider")
         self.assertEqual(len(all_gliders_in_db), 1)
         self.assertEqual(all_gliders_in_db[0]["title"], "Glider A")
         self.assertTrue(db.offer_url_exists("https://offers.com/1"))