{-# OPTIONS_GHC -Wall #-}
module LogAnalysis where

import Log

-- Exercise 1

nthWord :: Int -> String -> String
nthWord n = (!! n) . words

firstWord :: String -> String
firstWord = nthWord 0

nthWordInt :: Int -> String -> Int
nthWordInt n = read . nthWord n

timeStamp :: String -> Int
timeStamp s
    | firstWord s == "E" = nthWordInt 2 s
    | otherwise = nthWordInt 1 s

restOfMessage :: String -> String
restOfMessage s
    | firstWord s == "E" = (unwords . drop 3 . words) s
    | otherwise = (unwords . drop 2 . words) s

parseMessage :: String -> LogMessage
parseMessage s
    | firstWord s == "I" = LogMessage Info (timeStamp s) (restOfMessage s)
    | firstWord s == "W" = LogMessage Warning (timeStamp s) (restOfMessage s)
    | firstWord s == "E" = LogMessage (Error (nthWordInt 1 s)) (timeStamp s) (restOfMessage s)
    | otherwise = Unknown s

parse :: String -> [LogMessage]
parse = map parseMessage . lines

-- Exercise 2

insert :: LogMessage -> MessageTree -> MessageTree
insert (Unknown _) t = t
insert _ t@(Node _ (Unknown _) _) = t -- should never happen
insert m Leaf = Node Leaf m Leaf
insert m@(LogMessage _ newTime _) (Node tl (LogMessage _ time _) tr)
    | newTime < time = insert m tl
    | otherwise = insert m tr