Add cli arg parsing for starting in given mode

1 files changed, 18 insertions, 0 deletions

diff --git a/src/Chelleport/Args.hs b/src/Chelleport/Args.hs
new file mode 100644
index 0000000..8c36c85
--- /dev/null
+++ b/src/Chelleport/Args.hs
@@ -0,0 +1,18 @@
+module Chelleport.Args where
+
+import Chelleport.Types
+import Data.Default (Default (def))
+
+parseArgs :: [String] -> Either String Configuration
+parseArgs [] = Right def
+parseArgs (arg : args)
+  | arg `elem` ["-h", "--help"] = Right $ def {configShowHelp = True}
+  | arg `elem` ["-m", "--mode"] = case args of
+      [] -> Left "Missing value for mode"
+      (mode : rest) -> parseArgs rest >>= updateMode mode
+  | otherwise = Left $ "Unrecognized argument: " ++ arg
+
+updateMode :: String -> Configuration -> Either String Configuration
+updateMode "hints" cfg = Right cfg {configMode = defaultHintsMode}
+updateMode "search" cfg = Right cfg {configMode = defaultSearchMode}
+updateMode mode _ = Left $ "Invalid mode: " ++ mode