lookupSariulClass: better handling of bad classes

3 files changed, 14 insertions, 8 deletions

diff --git a/src/Data/Classes.hs b/src/Data/Classes.hs
index 1e9df43..b7386d6 100644
--- a/src/Data/Classes.hs
+++ b/src/Data/Classes.hs
@@ -22,9 +22,14 @@ sariulClasses =
 zeroScores :: ScoresList
 zeroScores = foldr ((:) . (,emptyScore)) [] sariulClasses
 
-lookupSariulClass                :: Int -> Int -> Class
-lookupSariulClass grade theClass = (head . filter choose) sariulClasses
-  where
-    choose (Class g n _) = theClass == n && process grade == g
-    process 5 = sariulGrade5
-    process 6 = sariulGrade6
+lookupSariulClass                :: Int -> Int -> Maybe Class
+lookupSariulClass grade theClass = do
+    grade' <- case grade of
+        5 -> Just sariulGrade5
+        6 -> Just sariulGrade6
+        _ -> Nothing
+    let choose (Class g n _) = theClass == n && grade' == g
+        classes = filter choose sariulClasses
+    case classes of
+        []     -> Nothing
+        (x:xs) -> Just x
diff --git a/src/Types/Session.hs b/src/Types/Session.hs
index b7ff979..a4dba93 100644
--- a/src/Types/Session.hs
+++ b/src/Types/Session.hs
@@ -63,5 +63,5 @@ parseClassCookie s =
 parseClassCookie' :: String -> Maybe Class
 parseClassCookie' s =
     case splitOn "-" s of
-        g:c:[] -> Just $ lookupSariulClass (read g) (read c)
+        g:c:[] -> lookupSariulClass (read g) (read c)
         _      -> Nothing
diff --git a/src/Utils/ScoresFile.hs b/src/Utils/ScoresFile.hs
index 247c1b6..4028efa 100644
--- a/src/Utils/ScoresFile.hs
+++ b/src/Utils/ScoresFile.hs
@@ -12,6 +12,7 @@ import System.Directory (getDirectoryContents, getCurrentDirectory)
 import System.FilePath (takeExtension)
 import Control.Monad (liftM)
 import Data.List.Split (splitOn)
+import Data.Maybe (fromJust)
 
 scoresToCSV :: ScoresList -> String
 scoresToCSV = unlines . foldr step []
@@ -26,7 +27,7 @@ scoresFromCSV csv = foldr step [] (lines csv)
      step line scores = (theClass, Score (read scoreString) (read timeString)) : scores
       where
         classString:scoreString:timeString:[] = splitOn "," line
-        theClass = lookupSariulClass ((head . read) classString) ((last . read) classString)
+        theClass = fromJust $ lookupSariulClass ((head . read) classString) ((last . read) classString)
 
 -- read to scores-XX.csv where XX is largest timestamp
 readScoresFile :: IO (Maybe ScoresList)