Open connection with sqlite only once

berlin-scraper/app/Main.hs

@@ -21,6 +21,7 @@ import Database.SQLite.Simple
 import GHC.Generics
 import Network.HTTP.Client.OpenSSL
 import Network.Wreq hiding (Options)
+import Network.Wreq qualified as Wreq
 import Options.Generic
 import Servant.Client (mkClientEnv)
 import System.Exit (exitFailure)
@@ -28,16 +29,18 @@ import Telegram.Bot.API
 import Telegram.Bot.Simple
 import Telegram.Bot.Simple.Debug
 import Text.HTML.Scalpel
-import qualified Network.Wreq as Wreq
 
 main :: IO ()
 main = withOpenSSL $ do
-  opts <- unwrapRecord "Berlin Scrapper"
+  opts :: Options Unwrapped <- unwrapRecord "Berlin Scrapper"
   token <- getEnvToken "TELEGRAM_BOT_TOKEN"
   httpMgr <- newOpenSSLManager
+  dbConn <- open opts.dbFile
+  createTable dbConn
   let clientEnv = mkClientEnv httpMgr (botBaseUrl token)
       wreqOpts = Wreq.defaults & Wreq.manager .~ Right httpMgr
-  startBot (traceBotDefault $ botApp opts wreqOpts) clientEnv >>= \case
+      env = Env {..}
+  startBot (traceBotDefault $ botApp env) clientEnv >>= \case
     Left err -> do
       putStrLn $ "Bot failed with: " <> show err
       exitFailure
@@ -73,6 +76,11 @@ data IBWResponse = IBWResponse
 
 instance FromJSON IBWResponse
 
+data Env = Env
+  { dbConn :: Connection,
+    wreqOpts :: Wreq.Options
+  }
+
 -- * Parsing
 
 queryIBW :: Wreq.Options -> IO IBWResponse
@@ -174,13 +182,13 @@ type Model = ()
 newtype Action = StartChat Chat
   deriving (Show)
 
-botApp :: Options Unwrapped -> Wreq.Options -> BotApp Model Action
-botApp opts wreqOpts =
+botApp :: Env -> BotApp Model Action
+botApp env =
   BotApp
     { botInitialModel = (),
       botAction = action,
       botHandler = handler,
-      botJobs = [scrapeJob opts wreqOpts]
+      botJobs = [scrapeJob env]
     }
 
 action :: Update -> Model -> Maybe Action
@@ -196,25 +204,23 @@ handler (StartChat chat) model =
   model <# do
     liftIO $ putStrLn $ "Chat started! " <> ppAsJSON chat
 
-scrapeJob :: Options Unwrapped -> Wreq.Options -> BotJob Model Action
-scrapeJob opts wreqOpts =
+scrapeJob :: Env -> BotJob Model Action
+scrapeJob env =
   BotJob
     { botJobSchedule = "* * * * *",
-      botJobTask = scrapeJobTask opts wreqOpts
+      botJobTask = scrapeJobTask env
     }
 
-scrapeJobTask :: Options Unwrapped -> Wreq.Options -> Model -> Eff Action Model
-scrapeJobTask opts wreqOpts m =
+scrapeJobTask :: Env -> Model -> Eff Action Model
+scrapeJobTask env m =
   m <# do
     liftIO $ putStrLn "Starting scrape job"
-    res <- liftIO $ queryIBW wreqOpts
+    res <- liftIO $ queryIBW env.wreqOpts
     let offers = fromJust $ scrapeStringLike res.searchresults scrapeOffers
     liftIO $ putStrLn "Fetched offers"
-    conn <- liftIO $ open (dbFile opts)
-    liftIO $ createTable conn
     mapM_
       ( \offer -> do
-          isNewOffer <- liftIO $ saveOffer conn offer
+          isNewOffer <- liftIO $ saveOffer env.dbConn offer
           when isNewOffer $ do
             liftIO $ putStrLn "Found a new offer"
             notify offer