1 files changed, 43 insertions, 0 deletions

diff --git a/scaffolder/src/Text/Edifact/Fetcher/Configuration.hs b/scaffolder/src/Text/Edifact/Fetcher/Configuration.hs
new file mode 100644
index 0000000..a074641
--- /dev/null
+++ b/scaffolder/src/Text/Edifact/Fetcher/Configuration.hs
@@ -0,0 +1,43 @@
+{-# LANGUAGE FlexibleContexts  #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module Text.Edifact.Fetcher.Configuration
+  ( -- * Fetching environment
+    FetchingEnv(..)
+    -- * Parsing helpers
+  , readSelectMessages
+    -- * Shortcuts for reading the environment
+  , getTargetRevision
+  , getHome
+  , getSelectedMessages
+  ) where
+
+import           Text.Edifact.Scaffolder.Commons (MessageCode, Revision,
+                                                  messageCodeParser)
+
+import           Control.Monad.Reader.Class      (MonadReader, asks)
+import           Data.List.NonEmpty              (NonEmpty, nonEmpty)
+import           Text.Parsec                     (char, parse, sepBy1)
+
+data FetchingEnv = FetchingEnv { fetchingRevision  :: Revision
+                               , specificationHome :: FilePath
+                               , selectedMessages  :: Maybe (NonEmpty MessageCode)
+                               }
+
+getTargetRevision :: MonadReader FetchingEnv m => m Revision
+getTargetRevision = asks fetchingRevision
+
+getHome :: MonadReader FetchingEnv m => m FilePath
+getHome = asks specificationHome
+
+getSelectedMessages :: MonadReader FetchingEnv m => m (Maybe (NonEmpty MessageCode))
+getSelectedMessages = asks selectedMessages
+
+readSelectMessages :: Maybe String -> Maybe (NonEmpty MessageCode)
+readSelectMessages value =
+  let tryParse p s = toMaybe . parse p s
+      toMaybe (Right v) = Just v
+      toMaybe _         = Nothing
+      messageCodesParser = messageCodeParser `sepBy1` comma
+      comma = char ','
+  in value >>= tryParse messageCodesParser "" >>= nonEmpty