Move SQL out of API and into separate modules

Create modules for each Table in our SQL database. This cleans up the handler
bodies at the expense of introducing more files and indirection.

src/App.hs

@@ -10,7 +10,6 @@ import Control.Monad.IO.Class (liftIO)
 import Data.Function ((&))
 import Data.String.Conversions (cs)
 import Data.Text (Text)
-import Database.SQLite.Simple
 import Network.Wai.Handler.Warp as Warp
 import Servant
 import API
@@ -18,6 +17,8 @@ import API
 import qualified Crypto.KDF.BCrypt as BC
 import qualified Data.Text.Encoding as TE
 import qualified Types as T
+import qualified Accounts as Accounts
+import qualified Trips as Trips
 --------------------------------------------------------------------------------
 
 server :: FilePath -> Server API
@@ -39,44 +40,35 @@ server dbFile = createAccountH
 
     -- TODO(wpcarro): Handle failed CONSTRAINTs instead of sending 500s
     createAccount :: T.CreateAccountRequest -> IO NoContent
-    createAccount request = withConnection dbFile $ \conn -> do
-      hashed <- T.hashPassword (T.createAccountRequestPassword request)
-      execute conn "INSERT INTO Accounts (username,password,email,role) VALUES (?,?,?,?)"
-        ( T.createAccountRequestUsername request
-        , hashed
-        , T.createAccountRequestEmail request
-        , T.createAccountRequestRole request
-        )
+    createAccount request = do
+      Accounts.create dbFile
+        (T.createAccountRequestUsername request)
+        (T.createAccountRequestPassword request)
+        (T.createAccountRequestEmail request)
+        (T.createAccountRequestRole request)
       pure NoContent
 
     deleteAccount :: Text -> IO NoContent
-    deleteAccount username = withConnection dbFile $ \conn -> do
-      execute conn "DELETE FROM Accounts WHERE username = ?"
-        (Only (T.Username username))
+    deleteAccount username = do
+      Accounts.delete dbFile (T.Username username)
       pure NoContent
 
     listAccounts :: IO [T.User]
-    listAccounts = withConnection dbFile $ \conn -> do
-      accounts <- query_ conn "SELECT * FROM Accounts"
-      pure $ T.userFromAccount <$> accounts
+    listAccounts = Accounts.list dbFile
 
     createTrip :: T.Trip -> IO NoContent
-    createTrip trip = withConnection dbFile $ \conn -> do
-      execute conn "INSERT INTO Trips (username,destination,startDate,endDate,comment) VALUES (?,?,?,?,?)"
-        (trip & T.tripFields)
+    createTrip trip = do
+      Trips.create dbFile trip
       pure NoContent
 
     listTrips :: IO [T.Trip]
-    listTrips = withConnection dbFile $ \conn ->
-      query_ conn "SELECT * FROM Trips"
+    listTrips = Trips.list dbFile
 
     -- TODO(wpcarro): Validate incoming data like startDate.
     deleteTrip :: T.TripPK -> IO NoContent
-    deleteTrip tripPK =
-      withConnection dbFile $ \conn -> do
-        execute conn "DELETE FROM Trips WHERE username = ? AND destination = ? and startDate = ?"
-          (tripPK & T.tripPKFields)
-        pure NoContent
+    deleteTrip tripPK = do
+      Trips.delete dbFile tripPK
+      pure NoContent
 
     -- TODO(wpcarro): Create and store a session token
     login :: T.AccountCredentials -> IO (Maybe T.Session)