Audit Report Generator in haskell

AuditReport.hs

import Prelude hiding (lookup)
import Data.Map (Map)
import qualified Data.Map as Map
import System.IO
import Data.List
import Data.List.Split

msgType = Map.fromList [("D", "NEW ORDER"), ("G", "MODIFY"), ("F", "CANCEL"), ("8", "EXECUTION"), ("9", "CANCEL"), ("i", "MASS QUOTE"), ("r", "QUOTE REQUEST"), ("b", "QUOTE ACK"), ("c", "SECURITY DEFINITION")]
ordStatus = Map.fromList [("0", "NEW ORDER ACK"), ("1", "PARTIAL FILL"), ("2", "COMPLETE FILL"), ("4", "CANCEL ACK"), ("5", "MODIFY ACK"), ("8", "ORDER REJECTED"), ("C", "EXPIRED"), ("H", "TRADE CANCEL")]
ordType = Map.fromList [("1", "MKT"), ("2", "LMT"), ("3", "STP"), ("4", "STP-LMT"), ("K", "MKT-LMT")]
timeInForce = Map.fromList [("0", "DAY"), ("1", "GTC"), ("6", "GTD"), ("3", "FAK")]
buysell = Map.fromList [("1", "B"), ("2", "S")]
syminfo = Map.fromList [("0", ["200", "207", "461"])]

ignoreMsgType = ["0", "1", "2", "4", "5", "r", "b", "A"]
cmeTag = ["S", "52", "1028", "207", "D", "50", "7928", "1", "49", "11", "37", "35", "39", "378", "58", "54", "38", "210", "107", "55", "200", "461", "44", "99", "31", "40", "59", "9702", "204"]
header = "Server Transaction Number, Server Datetime, Manual Order Identifier, Exchange Code, Message Direction, Tag 50 ID, SMP ID, Account Number, Session ID, Executing Firm, Client Order ID, Host Order Number, Message Type, Order Status,Execution Restatement Reason, Reason Code, Buy/Sell, Quantity, Max Show, Instrument Description, Product Code, Maturity Date, CFI Code, Limit Price, Stop Price, Fill Price, Order Type, Order Qualifier, Customer Type Indicator, Origin, Give-up Firm, Give-up Indicator"

main = do
	putStrLn header
	handle <- openFile "current.log" ReadMode
	contents <- hGetContents handle
	symbol <- openFile "symbols.csv" ReadMode
	symbolContent <- hGetContents symbol
	mapM_ (parseSymbol) $ lines symbolContent
	putStrLn $ unlines $ map (fixOutput) $ lines contents
	hClose handle
	
parseSymbol :: String -> Maybe a
parseSymbol input = 
	let
		fields = splitOn "," input
		firstChar = head $ head fields
		securityID = head $ drop 1 fields
		tag200 = head $ drop 4 fields
		tag207 = head $ drop 13 fields
		tag461 = head $ drop 14 fields
	in
		if firstChar == "#"
		then Nothing
		else  Map.insert securityID [tag200, tag207, tag461] syminfo


fixOutput :: String -> String
fixOutput input =
    let 
		timeMessage = splitOn " : " input
		fixMsgTags = splitOn "\1" $ last timeMessage
		fixMsgDict = Map.fromList (map (\a -> splitFixTag a) fixMsgTags)
		shortTags = foldr (\x acc -> parseTag x fixMsgDict : acc) [] cmeTag
		result = concat (intersperse "," shortTags)
	in  result

splitFixTag :: String -> (String, String)
splitFixTag input = 
 let fixTag = splitOn "=" input
 in (head fixTag, last fixTag)
 
parseTag :: String -> Map.Map String String -> String
parseTag tag fixMsgDict = 
 let v = Map.findWithDefault "" tag fixMsgDict
 in  case tag of 
		"35" ->
			if v == "9"
			then
				let tag434 = Map.findWithDefault "" "434" fixMsgDict
				in case tag434 of
					"2" -> "MODIFY"
					"1" -> "CANCEL"
			else Map.findWithDefault "" v msgType
		"39" -> 
			let msgtype = Map.findWithDefault "" "35" fixMsgDict
			in
				if msgtype == "9" then "REJECTED"
				else Map.findWithDefault "" v ordStatus
		"59" -> Map.findWithDefault "" v timeInForce
		"40" -> Map.findWithDefault "" v ordType
		"54" -> Map.findWithDefault "" v buysell
		"D"  -> if v == "O" then "To CME" else "From CME"
		"49" -> let
				direction = Map.findWithDefault "" "D" fixMsgDict
				senderCompID = init $ Map.findWithDefault "" "49" fixMsgDict
				targetCompID = init $ Map.findWithDefault "" "56" fixMsgDict
			in 
				if direction == "O" 
				then take 3 senderCompID ++ "," ++ drop 3 senderCompID 
				else take 3 targetCompID ++ "," ++ drop 3 targetCompID
		"38" -> let 
				msgtype = Map.findWithDefault "" "35" fixMsgDict
				ordstatus = Map.findWithDefault "" "39" fixMsgDict
				lastshares = Map.findWithDefault "" "32" fixMsgDict
			in 
				if msgtype == "8" && ordstatus /= "0" && ordstatus /= "8" 
				then lastshares 
				else v
		_ -> v