core: support postgres backend (#5403)

* postgres: modules structure (#5401)

* postgres: schema, field conversions (#5430)

* postgres: rework chat list pagination query (#5441)

* prepare cabal for merge

* restore cabal changes

* simplexmq

* postgres: implementation wip (tests don't pass) (#5481)

* restore ios file

* postgres: implementation - tests pass (#5487)

* refactor DB options

* refactor

* line

* style

* style

* refactor

* $

* update simplexmq

* constraintError

* handleDBErrors

* fix

* remove param

* Ok

* case

* case

* case

* comment

---------

Co-authored-by: Evgeny Poberezkin <evgeny@poberezkin.com>

src/Simplex/Chat/Store/AppSettings.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE OverloadedStrings #-}
 
 module Simplex.Chat.Store.AppSettings where
@@ -6,10 +7,14 @@ import Control.Monad (join)
 import Control.Monad.IO.Class (liftIO)
 import qualified Data.Aeson as J
 import Data.Maybe (fromMaybe)
-import Database.SQLite.Simple (Only (..))
 import Simplex.Chat.AppSettings (AppSettings (..), combineAppSettings, defaultAppSettings, defaultParseAppSettings)
 import Simplex.Messaging.Agent.Store.AgentStore (maybeFirstRow)
-import qualified Simplex.Messaging.Agent.Store.SQLite.DB as DB
+import qualified Simplex.Messaging.Agent.Store.DB as DB
+#if defined(dbPostgres)
+import Database.PostgreSQL.Simple (Only (..))
+#else
+import Database.SQLite.Simple (Only (..))
+#endif
 
 saveAppSettings :: DB.Connection -> AppSettings -> IO ()
 saveAppSettings db appSettings = do