Support many bills

3 files changed, 86 insertions, 0 deletions

diff --git a/cmd/Main/DistrictInfo.hs b/cmd/Main/DistrictInfo.hs
new file mode 100644
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+++ b/cmd/Main/DistrictInfo.hs
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+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
+
+module Main.DistrictInfo
+  ( DistrictInfo(..)
+  , di2df
+  , df2di
+  ) where
+
+import Control.Arrow ((&&&))
+import GHC.Generics (Generic)
+
+import Data.Aeson (FromJSON, ToJSON)
+import qualified Data.HashMap.Strict as HM
+
+import Malodivo.Budget (DistrictFunds)
+import Malodivo.Types.District (District)
+
+{-|
+We use this data type instead of 'DistrictFunds', because
+maps other than @HashMap Text _@ are hard to decode/encode see
+<https://github.com/bos/aeson/issues/79>.  Anyway, we still have type-checked
+typos-proof structure, and build 'DistrictFunds' out of it.
+-}
+data DistrictInfo = DistrictInfo
+  { name :: District
+  , amount :: Integer
+  } deriving (Generic, FromJSON, ToJSON)
+
+di2df :: [DistrictInfo] -> DistrictFunds
+di2df = HM.fromListWith (+) . map (name &&& amount)
+
+df2di :: DistrictFunds -> [DistrictInfo]
+df2di = map (\(n, a) -> DistrictInfo {name = n, amount = a}) . HM.toList
diff --git a/cmd/Main/Input.hs b/cmd/Main/Input.hs
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+++ b/cmd/Main/Input.hs
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+{-
+This modules describes input data for the command line utlity.
+-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
+
+module Main.Input
+  ( Input(..)
+  ) where
+
+import GHC.Generics (Generic)
+
+import Data.Aeson (FromJSON)
+
+import Malodivo.Types.Bill (Bill)
+
+import Main.DistrictInfo (DistrictInfo)
+
+data Input = Input
+  { bills :: [Bill]
+  , districts :: [DistrictInfo]
+  } deriving (Generic, FromJSON)
diff --git a/cmd/Main/Output.hs b/cmd/Main/Output.hs
new file mode 100644
index 0000000..1024ecd
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+++ b/cmd/Main/Output.hs
@@ -0,0 +1,30 @@
+{-
+This modules describes output data for the command line utlity.
+-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
+
+module Main.Output
+  ( BillBudget(..)
+  , zipBills
+  ) where
+
+import GHC.Generics (Generic)
+
+import Data.Aeson (ToJSON)
+
+import Malodivo.Budget (DistrictFunds)
+import Malodivo.Types.Bill (Bill)
+
+import Main.DistrictInfo (DistrictInfo, df2di)
+
+-- | This is output type. It describes contribution of each district into a bill.
+data BillBudget = BillBudget
+  { bill :: Bill
+  , districts :: [DistrictInfo]
+  } deriving (Generic, ToJSON)
+
+zipBills :: [Bill] -> [DistrictFunds] -> [BillBudget]
+zipBills = zipWith zipper
+  where
+    zipper b df = BillBudget {bill = b, districts = df2di df}