Remove I/O format knowledge from library functions

1 files changed, 29 insertions, 0 deletions

diff --git a/cmd/Main/Output.hs b/cmd/Main/Output.hs
new file mode 100644
index 0000000..107e8fd
--- /dev/null
+++ b/cmd/Main/Output.hs
@@ -0,0 +1,29 @@
+{-
+This modules describes output data for the command line utlity.
+-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
+
+module Main.Output
+  ( Output
+  , encode
+  ) where
+
+import GHC.Generics (Generic)
+
+import Data.Aeson (ToJSON)
+
+import Malodivo.Types.Bill (Bill)
+import Malodivo.Types.District (DistrictFunds, DistrictInfo, df2di)
+
+type Output = [BillBudget]
+
+-- | JSON-friendly type. It describes contribution of each district into a bill.
+data BillBudget = BillBudget
+  { bill :: Bill
+  , districts :: [DistrictInfo]
+  } deriving (Generic, ToJSON)
+
+-- | Translate into JSON-friendly format.
+encode :: [(Bill, DistrictFunds)] -> Output
+encode = map (\(b, df) -> BillBudget {bill = b, districts = df2di df})