Add generic derivations and To/FromJSON instances

src/Dodge/Save.hs

@@ -3,13 +3,38 @@ module Dodge.Save
     , loadSaveSlot
     , doQuicksave
     , saveLevelStartSlot
+    , writeSaveSlot
+    , readSaveSlot
     ) where
 import Dodge.Data
 
+import Text.Read (readMaybe)
 import qualified Data.Map.Strict as M
 --import Data.Maybe
 import Control.Lens
 --import qualified Data.Set as S
+import System.Directory
+
+writeSaveSlot :: SaveSlot -> Universe -> IO ()
+writeSaveSlot ss u = do
+    createDirectoryIfMissing True "saveSlot"
+    writeFile (saveSlotPath ss) (show $ u ^. uvWorld . cWorld)
+
+saveSlotPath :: SaveSlot -> String
+saveSlotPath (SaveSlotNum i) = "saveSlot/" ++ show i
+saveSlotPath QuicksaveSlot = "saveSlot/QuickSave"
+saveSlotPath LevelStartSlot = "saveSlot/LevelStartSave"
+
+readSaveSlot :: SaveSlot -> Universe -> IO Universe
+readSaveSlot ss uv = do
+    fExists <- doesFileExist $ saveSlotPath ss
+    if fExists
+    then do
+        cwstr <- readFile $ saveSlotPath ss
+        case readMaybe cwstr of
+            Nothing -> putStrLn "loadSaveSlot failed to read saved file" >> return uv
+            Just cw -> return $ uv & uvWorld . cWorld .~ cw
+    else putStrLn "loadSaveSlot failed to find saved file" >> return uv
 
 saveWorldInEmptySlot :: SaveSlot -> Universe -> Universe
 saveWorldInEmptySlot slot w = case M.lookup slot $ _savedWorlds w of