{-# LANGUAGE NoMonomorphismRestriction #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE StrictData #-}
{-# OPTIONS_GHC -Wno-missing-signatures #-}
module Hjugement.CLI.Voter where

import Control.Applicative (Applicative(..), Alternative(..))
import Control.Monad (Monad(..), forM, forM_, join, unless, void, when)
import Control.Monad.Trans.Class (MonadTrans(..))
import Control.Monad.Trans.Maybe (MaybeT(..))
import Control.Monad.Trans.Except (runExcept, runExceptT)
import Control.Monad.Trans.State.Strict (runState, runStateT)
import Data.Bits (setBit)
import Data.Bool
import Data.ByteString (ByteString)
import Data.Either (Either(..), either)
import Data.Eq (Eq(..))
import Data.Foldable (Foldable, foldMap, length, null, sum)
import Data.Function (($), (.), id, flip)
import Data.Functor ((<$>), (<$))
import Data.Int (Int)
import Data.Maybe (Maybe(..), maybe, fromMaybe, fromJust)
import Data.Monoid (Monoid(..))
import Data.Ord (Ord(..))
import Data.Proxy (Proxy(..))
import Data.Semigroup (Semigroup(..))
import Data.String (String)
import Data.Text (Text)
import Data.Traversable (sequence)
import GHC.Natural (minusNatural, minusNaturalMaybe)
import GHC.Prim (coerce)
import Numeric.Natural (Natural)
import Pipes ((>->))
import Prelude (logBase, ceiling, Num(..), (/), (^), fromIntegral, Double)
import Symantic.CLI as CLI
import System.IO (IO, FilePath)
import Text.Show (Show(..))
import qualified Crypto.Hash as Crypto
import qualified Data.Aeson as JSON
import qualified Data.ByteArray as ByteArray
import qualified Data.ByteString as BS
import qualified Data.ByteString.Char8 as BS8
import qualified Data.ByteString.Lazy as BSL
import qualified Data.ByteString.Lazy.Char8 as BSL8
import qualified Data.List as List
import qualified Data.Text as Text
import qualified Data.Text.Encoding as Text
import qualified Data.Text.Lazy as TL
import qualified Data.Text.Lazy.Builder as TLB
import qualified Data.Text.Lazy.Builder.Int as TLB
import qualified Data.Text.Lazy.Encoding as TL
import qualified Data.Text.Lazy.IO as TL
import qualified Data.Time as Time
import qualified Lens.Family as Lens
import qualified Lens.Family.State.Strict as Lens
import qualified Pipes as Pip
import qualified Pipes.Aeson as PipJSON (DecodingError(..))
import qualified Pipes.Aeson.Unchecked as PipJSON
import qualified Pipes.ByteString as PipBS
import qualified Pipes.Group as Pip
import qualified Pipes.Prelude as Pip
import qualified Pipes.Safe as Pip
import qualified Pipes.Safe.Prelude as Pip
import qualified Pipes.Text as PipText
import qualified Pipes.Text.Encoding as PipText
import qualified Pipes.Text.IO as PipText
import qualified Symantic.Document as Doc
import qualified System.FilePath as FP
import qualified System.IO as IO
import qualified System.Posix as Posix
import qualified System.Random as Rand
import qualified Voting.Protocol as VP
import qualified Voting.Protocol.Utils as VP

import Hjugement.CLI.Utils

-- * administrator
data Voter_Params = Voter_Params
 {
 } deriving (Show)

api_voter =
	"Commands for a voter."
	`helps`
	command "voter" $
		api_voter_vote
		<!> api_help False
run_voter globParams =
	run_voter_vote globParams
	:!: run_help api_voter

-- ** election
data VoterVote_Params = VoterVote_Params
 {   voterVote_privcred :: VP.Credential
 ,   voterVote_url      :: FilePath
 ,   voterVote_grades   :: [Text]
 } deriving (Show)

api_voter_vote =
	"Cast a vote on an election."
	`helps`
	command "vote" $
		rule "PARAMS"
		 (VoterVote_Params
			 <$> api_param_privcred
			 <*> api_param_url
			 <*> api_param_grades)
		<?> response @(Maybe ())
	where
	api_param_privcred =
		"Voter's private credential."
		`helps`
		requiredTag "privcred" (var "CREDENTIAL")
	api_param_grades =
		"The grades to evaluate the choices, from the lowest to the highest."
		`helps`
		many1Tag (TagLong "grade") $
			var @Text "STRING"

run_voter_vote
 Global_Params{..}
 o@VoterVote_Params{..}
 = runMaybeT $ do
	elecUnit <- loadJSON (voterVote_url FP.</> "election.json")
	VP.reifyElection elecUnit $ \(elec@VP.Election{..} :: VP.Election c) -> do
		outputInfo $ "Voted"<>Doc.from (show voterVote_grades)
		votes <- VP.isoZipWithM
		 (outputError $ "Mismatching number of cast grades ("<>
			Doc.from (List.length voterVote_grades)<>
			") and choices ("<>
			Doc.from (List.length election_questions)<>
			")")
		 (\VP.Question{..} grade -> do
			let bools = (grade ==) <$> question_choices
			let boolSum = sum $ (<$> bools) $ \b -> if b then 1 else 0 :: Natural
			unless (boolSum == 1) $
				outputError $
					"The election does not allow to cast a grade named: "<>Doc.from grade<>"\n"<>
					"Allowed grades are: "<>Doc.from (Text.intercalate ", " question_choices)
			return bools)
		 election_questions
		 voterVote_grades
		outputInfo $ Doc.from (show votes)
		let (secKey :: VP.SecretKey c) =
			VP.credentialSecretKey election_uuid voterVote_privcred
		ballot <- join $ Pip.liftIO $
			Rand.getStdRandom $ \gen ->
				case runExcept $ (`runStateT` gen) $
				 VP.encryptBallot elec (Just secKey) votes of
				 Left err -> (outputError $ Doc.from (show err), gen)
				 Right (ballot, gen') -> (return ballot, gen')
		Pip.liftIO $ BSL8.putStrLn $ JSON.encode ballot