import Data.Group
import Data.Hourglass
import Quixotic
import Quixotic.Users

  , hours :: Hours

  , seconds :: Seconds

  }

  } deriving Eq

winningBids :: Foldable f -> Auction -> f Bid -> [Bid]
winningBids = 
  let 

instance Ord Bid where
  (<=) b1 b2 = 
    costRatio b1 <= costRatio b2
    where costRatio bid = (toRational . seconds $ bid) / (toRational . runBTC . btcAmount $ bid) 
-- lowest bids of seconds/btc win
winningBids :: Auction -> [Bid] -> [Bid]
winningBids auction bids = 
  let takeWinningBids :: BTC -> [Bid] -> [Bid]
      takeWinningBids total (x : xs)
        -- if the total is fully within the raise amount
        | total ++ btcAmount x < raiseAmount auction = 
          x : (takeWinningBids (total ++ btcAmount x) xs)
        -- if the last bid will exceed the raise amount, reduce it to fit
        | total < raiseAmount auction = 
          let remainder = raiseAmount auction <> invert total
              winFraction = (toRational . runBTC $ remainder) / (toRational . runBTC $ btcAmount x)
              remainderSeconds = Seconds . round $ winFraction * (toRational . seconds $ x)
          in  [Bid (userId x) remainderSeconds remainder]
        | otherwise = []
        
      takeWinningBids _ [] = []
  in  takeWinningBids mempty $ sort bids

import Quixotic

newtype UserId = UserId Int

newtype UserId = UserId Int deriving (Show, Eq)

  , BTC(..)

--import Database.PostgreSQL.Simple.FromField

import Data.Group

newtype BTC = BTC { runBTC :: Integer } deriving (Show, Eq, Ord)
instance Semigroup BTC where
  (<>) b1 b2 = BTC $ runBTC b1 + runBTC b2
instance Monoid BTC where
  mempty = BTC 0
  mappend = (<>)
instance Group BTC where
  invert b = BTC . negate . runBTC $ b
instance Abelian BTC where

  build-depends:      base                 >= 4     && < 5
                    , bifunctors
                    , classy-prelude       >= 0.10.1
                    , aeson                >= 0.8.0.2
                    , cassandra-cql        >= 0.4.0.1
                    , containers           >= 0.5.5.1
                    , either               >= 4.3.1
                    , lens                 >= 4.4.0.2
                    , old-locale
                    , sqlite               == 0.5.2.2
                    , text                 >= 1.2.0.0
                    , time                 >= 1.4.2    && < 1.5

  build-depends:      
      base                 >= 4     && < 5
    , bifunctors
    , classy-prelude       >= 0.10.1
    , aeson                >= 0.8.0.2
    , cassandra-cql        >= 0.4.0.1
    , containers           >= 0.5.5.1
    , either               >= 4.3.1
    , lens                 >= 4.4.0.2
    , old-locale
    , sqlite               == 0.5.2.2
    , text                 >= 1.2
    , time                 >= 1.4.2    && < 1.5
    , hourglass            >= 0.2.6    && < 0.3
    , groups               >= 0.4

  build-depends:      quixotic
                    , base
                    , aeson
                    , containers
                    , text
                    , time
                    , hspec >= 1.8.1

  build-depends:    
      quixotic
    , base
    , aeson
    , containers
    , text
    , time
    , hspec >= 1.8.1

    , optparse-applicative      >= 0.9.0    && < 0.10
    , bytestring                >= 0.9.1    && < 0.11

    , optparse-applicative      >= 0.9.0 && < 0.10
    , bytestring                >= 0.9.1 && < 0.11