test: Adding integration tests for spanner retriever service (#364)

The tests takes following inputs from environments: 
1. DB_PROJECT
2. DB_INSTANCE
3. DB_NAME
4. SERVICE_ACCOUNT_KEY_FILE_PATH

---------

Co-authored-by: Yuan <45984206+Yuan325@users.noreply.github.com>

retrieval_service/datastore/providers/spanner_gsql.py

@@ -333,7 +333,14 @@ async def initialize_data(
 
         # Insert data into 'flights' table using batch operation
         values = [
-            tuple(getattr(flight, field) for field in self.FLIGHTS_COLUMNS)
+            tuple(
+                (
+                    str(getattr(flight, field))
+                    if isinstance(getattr(flight, field), datetime.datetime)
+                    else getattr(flight, field)
+                )
+                for field in self.FLIGHTS_COLUMNS
+            )
             for flight in flights
         ]
 
@@ -520,7 +527,7 @@ async def get_airport_by_iata(self, iata: str) -> Optional[models.Airport]:
         with self.__database.snapshot() as snapshot:
             # Execute SQL query to fetch airport by ID
             result = snapshot.execute_sql(
-                sql="SELECT * FROM airports WHERE iata LIKE @iata",
+                sql="SELECT * FROM airports WHERE LOWER(iata) LIKE LOWER(@iata)",
                 params={"iata": iata},
                 param_types={"iata": param_types.STRING},
             )
@@ -560,10 +567,9 @@ async def search_airports(
             # Construct SQL query based on provided parameters
             query = """
                 SELECT * FROM airports
-                  WHERE (@country IS NULL OR country LIKE @country)
-                  AND (@city IS NULL OR city LIKE @city)
-                  AND (@name IS NULL OR name LIKE '%' || @name || '%')
-                  LIMIT 10
+                  WHERE (@country IS NULL OR LOWER(country) LIKE LOWER(@country))
+                  AND (@city IS NULL OR LOWER(city) LIKE LOWER(@city))
+                  AND (@name IS NULL OR LOWER(name) LIKE '%' || LOWER(@name) || '%')
                 """
 
             # Execute SQL query with parameters
@@ -649,7 +655,7 @@ async def amenities_search(
                        COSINE_DISTANCE(embedding, @query_embedding) AS similarity
                     FROM amenities
                 ) AS sorted_amenities
-                WHERE (2 - similarity) > @similarity_threshold
+                WHERE (1 - similarity) > @similarity_threshold
                 ORDER BY similarity
                 LIMIT @top_k
             """
@@ -671,7 +677,7 @@ async def amenities_search(
 
         # Convert query result to model instance using model_validate method
         amenities = [
-            {key: value for key, value in zip(self.AMENITIES_COLUMNS, a)}
+            {key: value for key, value in zip(self.AMENITIES_COLUMNS[1:], a)}
             for a in results
         ]
 
@@ -773,8 +779,8 @@ async def search_flights_by_airports(
             # Spread SQL query for readability
             query = """
                 SELECT * FROM flights
-                WHERE (@departure_airport IS NULL OR departure_airport LIKE @departure_airport)
-                AND (@arrival_airport IS NULL OR arrival_airport LIKE @arrival_airport)
+                WHERE (@departure_airport IS NULL OR LOWER(departure_airport) LIKE LOWER(@departure_airport))
+                AND (@arrival_airport IS NULL OR LOWER(arrival_airport) LIKE LOWER(@arrival_airport))
                 AND cast(departure_time as TIMESTAMP) >= CAST(@datetime AS TIMESTAMP)
                 AND cast(departure_time as TIMESTAMP) < TIMESTAMP_ADD(CAST(@datetime AS TIMESTAMP), INTERVAL 1 DAY)
                 LIMIT 10
@@ -786,7 +792,7 @@ async def search_flights_by_airports(
                 params={
                     "departure_airport": departure_airport,
                     "arrival_airport": arrival_airport,
-                    "datetime": datetime.datetime.strptime(date, "%Y-%m-%d"),
+                    "datetime": date,
                 },
                 param_types={
                     "departure_airport": param_types.STRING,
@@ -819,10 +825,10 @@ async def validate_ticket(
             results = snapshot.execute_sql(
                 sql="""
                     SELECT * FROM flights
-                    WHERE airline LIKE @airline
-                    AND flight_number LIKE @flight_number
-                    AND departure_airport LIKE @departure_airport
-                    AND arrival_airport LIKE @arrival_airport
+                    WHERE LOWER(airline) LIKE LOWER(@airline)
+                    AND LOWER(flight_number) LIKE LOWER(@flight_number)
+                    AND LOWER(departure_airport) LIKE LOWER(@departure_airport)
+                    AND LOWER(arrival_airport) LIKE LOWER(@arrival_airport)
                     AND departure_time = @departure_time
                     AND arrival_time = @arrival_time
                 """,
@@ -831,8 +837,8 @@ async def validate_ticket(
                     "flight_number": flight_number,
                     "departure_airport": departure_airport,
                     "arrival_airport": arrival_airport,
-                    "departure_time": departure_time.strftime("%Y-%m-%dT%H:%M:%S.%fZ"),
-                    "arrival_time": arrival_time.strftime("%Y-%m-%dT%H:%M:%S.%fZ"),
+                    "departure_time": departure_time.strftime("%Y-%m-%d %H:%M:%S"),
+                    "arrival_time": arrival_time.strftime("%Y-%m-%d %H:%M:%S"),
                 },
                 param_types={
                     "airline": param_types.STRING,
@@ -878,10 +884,10 @@ async def insert_ticket(
             arrival_time (str): The arrival time of the flight.
         """
         departure_time_datetime = datetime.datetime.strptime(
-            departure_time, "%Y-%m-%dT%H:%M:%S.%fZ"
+            departure_time, "%Y-%m-%d %H:%M:%S"
         )
         arrival_time_datetime = datetime.datetime.strptime(
-            arrival_time, "%Y-%m-%dT%H:%M:%S.%fZ"
+            arrival_time, "%Y-%m-%d %H:%M:%S"
         )
 
         if not await self.validate_ticket(
@@ -991,8 +997,8 @@ async def policies_search(
                     SELECT content,  COSINE_DISTANCE(embedding, @query_embedding) AS similarity
                     FROM policies 
                 ) AS sorted_policies
-                WHERE (2 - similarity) > @similarity_threshold
-                ORDER BY similarity DESC
+                WHERE (1 - similarity) > @similarity_threshold
+                ORDER BY similarity
                 LIMIT @top_k
             """