( Interval, interval, start, end 

  ( Interval, interval, start, end, ilen

ilen :: Interval -> NominalDiffTime
ilen i = diffUTCTime (end i) (start i)

type Payouts = Map BtcAddr Rational

payouts :: [LogEntry] -> Map BtcAddr Rational
payouts = undefined

sumLogIntervals :: [LogInterval] -> Rational
sumLogIntervals ivals = F.foldl' (+) (fromInteger 0) $ fmap (toRational . ilen . workInterval) ivals

payouts :: WorkIndex -> Payouts
payouts widx = let addIntervalDiff total ivals = (\dt -> (dt + total, dt)) $ sumLogIntervals ivals 
                   (totalTime, keyTimes) = M.mapAccum addIntervalDiff (fromInteger 0) $ M.map snd widx
               in M.map (\kt -> kt / totalTime) keyTimes

appendLogEntry workIndex entry = let acc = reduce $ pushEntry entry workIndex 

appendLogEntry workIndex entry = let acc = reduceToIntervals $ pushEntry entry workIndex 

reduce :: ([LogEntry], [LogInterval]) -> ([LogEntry], [LogInterval])
reduce ((LogEntry addr end StopWork) : (LogEntry _ start StartWork) : xs, intervals) = (xs, (LogInterval addr (interval start end)) : intervals)
reduce other = other

reduceToIntervals :: ([LogEntry], [LogInterval]) -> ([LogEntry], [LogInterval])
reduceToIntervals ((LogEntry addr end StopWork) : (LogEntry _ start StartWork) : xs, intervals) = (xs, (LogInterval addr (interval start end)) : intervals)
reduceToIntervals misaligned = misaligned