[haskell] abstracted away common database access patterns

haskell/src/SpaceTraders/APIClient/Contracts.hs

@@ -0,0 +1,30 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module SpaceTraders.APIClient.Contracts
+  ( myContracts
+  ) where
+
+import Network.HTTP.Simple
+
+import SpaceTraders
+import SpaceTraders.APIClient.Client
+import SpaceTraders.APIClient.Pagination
+import SpaceTraders.Database.Contracts
+import SpaceTraders.Model.Contract(Contract)
+
+myContracts :: SpaceTradersT (APIResponse [Contract])
+myContracts = do
+  listContracts' Pagination{limit=20, page=1, total=0}
+  where
+    listContracts' :: Pagination -> SpaceTradersT (APIResponse [Contract])
+    listContracts' p = do
+      resp <- sendPaginated (Just p) $ setRequestPath "/v2/my/contracts" :: SpaceTradersT (APIPaginatedResponse [Contract])
+      case resp of
+        Left e -> return $ Left e
+        Right (APIMessage r (Just p')) -> do
+          mapM_ setContract r
+          if (limit p' * page p' < total p') then listContracts' (nextPage p')
+                                             else Right <$> getContracts
+        _ -> undefined

haskell/src/SpaceTraders/Database/Agents.hs

@@ -8,7 +8,6 @@ module SpaceTraders.Database.Agents
 
 import Control.Monad.Reader
 import Data.Aeson
-import Data.Maybe
 import qualified Database.SQLite.Simple as S
 
 import SpaceTraders
@@ -16,17 +15,10 @@ import SpaceTraders.Model.Agent
 import SpaceTraders.Utils
 
 addAgent :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => Agent -> m ()
-addAgent agent = do
+addAgent agent = execute "INSERT INTO agents(data) VALUES (json(?));" (S.Only (encode agent))
-  env <- ask
-  liftIO $ S.execute (getConn env) "INSERT INTO agents(data) VALUES (json(?));" (S.Only (encode agent))
 
 getAgent :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => m Agent
-getAgent = do
+getAgent = one_ "SELECT data FROM agents";
-  env <- ask
-  ret <- liftIO $ S.query_ (getConn env) "SELECT data FROM agents;"
-  return . head . catMaybes $ map (decodeText . head) ret
 
 setAgent :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => Agent -> m ()
-setAgent agent = do
+setAgent agent = execute "UPDATE agents SET data = json(?);" (S.Only (encode agent))
-  env <- ask
-  liftIO $ S.execute (getConn env) "UPDATE agents SET data = json(?);" (S.Only (encode agent))

haskell/src/SpaceTraders/Database/Contracts.hs

@@ -9,7 +9,6 @@ module SpaceTraders.Database.Contracts
 
 import Control.Monad.Reader
 import Data.Aeson
-import Data.Maybe
 import qualified Database.SQLite.Simple as S
 
 import SpaceTraders
@@ -17,24 +16,16 @@ import SpaceTraders.Model.Contract
 import SpaceTraders.Utils
 
 addContract :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => Contract -> m ()
-addContract contract = do
+addContract contract = execute "INSERT INTO contracts(data) VALUES (json(?));" (S.Only (encode contract))
-  env <- ask
-  liftIO $ S.execute (getConn env) "INSERT INTO contracts(data) VALUES (json(?));" (S.Only (encode contract))
 
 getContracts :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => m [Contract]
-getContracts = do
+getContracts = query_ "SELECT data FROM contracts;"
-  env <- ask
-  ret <- liftIO $ S.query_ (getConn env) "SELECT data FROM contracts;"
-  return . catMaybes $ map (decodeText . head) ret
 
-setContract :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => Contract -> m ()
+setContract :: (HasDatabaseConn env, MonadFail m, MonadIO m, MonadReader env m) => Contract -> m ()
 setContract contract = do
-  env <- ask
+  c <- count "SELECT count(id) FROM contracts WHERE data->>'contractId' = ?;" (S.Only $ contractId contract)
-  count <- liftIO (S.query (getConn env) "SELECT count(id) FROM contracts WHERE data->>'contractId' = ?;" (S.Only $ contractId contract) :: IO [[Int]])
+  if c == 0 then addContract contract
-  if count == [[0]] then addContract contract
+            else updateContract contract
-                    else updateContract contract
 
 updateContract :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => Contract -> m ()
-updateContract contract = do
+updateContract contract = execute "UPDATE contracts SET data = json(?) WHERE data->>'contractId' = ?;" (encode contract, contractId contract)
-  env <- ask
-  liftIO $ S.execute (getConn env) "UPDATE contracts SET data = json(?) WHERE data->>'contractId' = ?;" (encode contract, contractId contract)

haskell/src/SpaceTraders/Database/Ships.hs

@@ -7,10 +7,8 @@ module SpaceTraders.Database.Ships
   , updateShip
   ) where
 
-import Control.Monad.Except
 import Control.Monad.Reader
 import Data.Aeson
-import Data.Maybe
 import qualified Database.SQLite.Simple as S
 
 import SpaceTraders
@@ -18,24 +16,16 @@ import SpaceTraders.Model.Ship
 import SpaceTraders.Utils
 
 addShip :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => Ship -> m ()
-addShip ship = do
+addShip ship = execute "INSERT INTO ships(data) VALUES (json(?));" (S.Only $ encode ship)
-  env <- ask
-  liftIO $ S.execute (getConn env) "INSERT INTO ships(data) VALUES (json(?));" (S.Only $ encode ship)
 
 getShips :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => m [Ship]
-getShips = do
+getShips = query_ "SELECT data FROM ships;"
-  env <- ask
-  ret <- liftIO $ S.query_ (getConn env) "SELECT data FROM ships;"
-  return . catMaybes $ map (decodeText . head) ret
 
-setShip :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => Ship -> m ()
+setShip :: (HasDatabaseConn env, MonadFail m, MonadIO m, MonadReader env m) => Ship -> m ()
 setShip ship = do
-  env <- ask
+  c <- count "SELECT count(id) FROM ships WHERE data->>'symbol' = ?;" (S.Only $ symbol ship)
-  count <- liftIO (S.query (getConn env) "SELECT count(id) FROM ships WHERE data->>'symbol' = ?;" (S.Only $ symbol ship) :: IO [[Int]])
+  if c == 0 then addShip ship
-  if count == [[0]] then addShip ship
+            else updateShip ship
-                    else updateShip ship
 
 updateShip :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => Ship -> m ()
-updateShip ship = do
+updateShip ship = execute "UPDATE ships SET data = json(?) WHERE data->>'symbol' = ?;" (encode ship, symbol ship)
-  env <- ask
-  liftIO $ S.execute (getConn env) "UPDATE ships SET data = json(?) WHERE data->>'symbol' = ?;" (encode ship, symbol ship)

haskell/src/SpaceTraders/Database/Systems.hs

@@ -7,7 +7,6 @@ module SpaceTraders.Database.Systems
 
 import Control.Monad.Reader
 import Data.Aeson
-import Data.Maybe
 import qualified Database.SQLite.Simple as S
 
 import SpaceTraders
@@ -21,7 +20,4 @@ addSystems systems = do
   liftIO $ S.withTransaction conn $ S.executeMany conn "INSERT INTO systems(data) VALUES (json(?));" $ S.Only <$> map encode systems
 
 getSystems :: (HasDatabaseConn env, MonadIO m, MonadReader env m) => m [System]
-getSystems = do
+getSystems = query_ "SELECT data FROM systems;"
-  env <- ask
-  ret <- liftIO $ S.query_ (getConn env) "SELECT data FROM systems;"
-  return . catMaybes $ map (decodeText . head) ret

haskell/src/SpaceTraders/Utils.hs

@@ -1,22 +1,58 @@
 module SpaceTraders.Utils
-  ( decodeText
+  ( count
+  , decodeText
+  , execute
   , fromJSONValue
   , int2ByteString
+  , one_
+  , query
+  , query_
   ) where
 
+import Control.Monad.Reader
 import Data.Aeson
 import Data.Aeson.Types
 import qualified Data.ByteString as B
 import qualified Data.ByteString.Builder as B
 import qualified Data.ByteString.Internal as B
+import Data.Maybe
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as T
+import qualified Database.SQLite.Simple as S
+
+import SpaceTraders
 
 decodeText :: FromJSON a => T.Text -> Maybe a
 decodeText = decode . B.toLazyByteString . T.encodeUtf8Builder
 
+execute :: (HasDatabaseConn env, MonadReader env m, MonadIO m, S.ToRow t) => S.Query -> t -> m ()
+execute q t = do
+  env <- ask
+  liftIO $ S.execute (getConn env) q t
+
 fromJSONValue :: FromJSON a => Value -> Either String a
 fromJSONValue = parseEither parseJSON
 
 int2ByteString :: Int -> B.ByteString
 int2ByteString = B.pack . map B.c2w . show
+
+one_ :: (FromJSON b, HasDatabaseConn env, MonadReader env m, MonadIO m) => S.Query -> m b
+one_ q = query_ q >>= pure . head
+
+count :: (HasDatabaseConn env, MonadFail m, MonadReader env m, MonadIO m, S.ToRow t) => S.Query -> t -> m Int
+count q t = do
+  env <- ask
+  [[ret]] <- liftIO (S.query (getConn env) q t :: IO [[Int]])
+  return ret
+
+query :: (FromJSON b, HasDatabaseConn env, MonadReader env m, MonadIO m, S.ToRow t) => S.Query -> t -> m [b]
+query q t = do
+  env <- ask
+  ret <- liftIO $ S.query (getConn env) q t
+  return . catMaybes $ map (decodeText . head) ret
+
+query_ :: (FromJSON b, HasDatabaseConn env, MonadReader env m, MonadIO m) => S.Query -> m [b]
+query_ q = do
+  env <- ask
+  ret <- liftIO $ S.query_ (getConn env) q
+  return . catMaybes $ map (decodeText . head) ret