Support many bills

4 files changed, 105 insertions, 33 deletions

diff --git a/cmd/Main.hs b/cmd/Main.hs
index bbc45cb..da28a98 100644
--- a/cmd/Main.hs
+++ b/cmd/Main.hs
@@ -1,32 +1,30 @@
-{-# LANGUAGE DeriveAnyClass #-}
-{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE QuasiQuotes #-}
 
 module Main
   ( main
   ) where
 
-import Control.Arrow ((&&&))
 import Control.Monad (when)
 import Data.Version (showVersion)
-import GHC.Generics (Generic)
 import System.Environment (getArgs)
 import System.Exit (die)
 
-import Data.Aeson (FromJSON, eitherDecode, encode)
+import Data.Aeson (eitherDecode, encode)
 import qualified Data.ByteString.Lazy as L
 import qualified Data.HashMap.Strict as HM
-import qualified System.Console.Docopt.NoTH as O
+import System.Console.Docopt.NoTH
+       (isPresent, longOption, parseArgsOrExit, parseUsageOrExit, usage)
 import Text.InterpolatedString.Perl6 (qc)
 
-import Malodivo.Budget (manyToOne)
-import Malodivo.Types.Bill (Bill)
-import Malodivo.Types.District (District)
+import Malodivo.Budget (manyToMany)
 
+import Main.DistrictInfo (di2df)
+import qualified Main.Input as I
+import qualified Main.Output as O
 import Paths_malodivo (version) -- from cabal
 
-usage :: String
-usage =
+usageHelp :: String
+usageHelp =
   "malodivo " ++
   showVersion version ++
   " - budget planning tool for the Kingdom of Malodivo" ++
@@ -41,36 +39,24 @@ Options:
 
   -h, --help               Show this message and exit
 
-
 |]
 
-data DistrictInfo = DistrictInfo
-  { name :: District
-  , availableFunds :: Integer
-  } deriving (Generic, FromJSON)
-
-data SimpleInput = SimpleInput
-  { bills :: [Bill]
-  , districts :: [DistrictInfo]
-  } deriving (Generic, FromJSON)
-
 process :: IO ()
 process = do
   input <- L.getContents
   case eitherDecode input of
     Left err -> die err
-    Right si -> do
-      let nbills = length . bills $ si
-          funds =
-            HM.fromListWith (+) . map (name &&& availableFunds) $ districts si
-      when (nbills /= 1) $ die "We needs exactly one bill in input"
-      when (HM.null funds) $ die "We needs at least one district"
-      L.putStr . encode $ manyToOne funds (head . bills $ si)
+    Right si ->
+      let allBills = I.bills si
+          billFunds = manyToMany suppliedFunds allBills
+          suppliedFunds = di2df $ I.districts si
+      in do when (HM.null suppliedFunds) $ die "We needs at least one district"
+            L.putStr . encode $ O.zipBills allBills billFunds
 
 main :: IO ()
 main = do
-  doco <- O.parseUsageOrExit usage
-  args <- O.parseArgsOrExit doco =<< getArgs
-  if args `O.isPresent` O.longOption "help"
-    then putStrLn $ O.usage doco
+  doco <- parseUsageOrExit usageHelp
+  args <- parseArgsOrExit doco =<< getArgs
+  if args `isPresent` longOption "help"
+    then putStrLn $ usage doco
     else process
diff --git a/cmd/Main/DistrictInfo.hs b/cmd/Main/DistrictInfo.hs
new file mode 100644
index 0000000..f4f9ff1
--- /dev/null
+++ b/cmd/Main/DistrictInfo.hs
@@ -0,0 +1,34 @@
+{-# 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
new file mode 100644
index 0000000..63e5942
--- /dev/null
+++ b/cmd/Main/Input.hs
@@ -0,0 +1,22 @@
+{-
+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
--- /dev/null
+++ 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}