module Persistence 
    ( saveLastRead
    , loadLastRead 
    ) where

import System.Directory (getXdgDirectory, XdgDirectory(XdgData), createDirectoryIfMissing)
import System.FilePath ((</>))
import qualified Data.Text as T
import qualified Data.Text.IO as TIO
import Control.Exception (try, SomeException)
import Text.Read (readMaybe)

saveLastRead :: FilePath -> Int -> IO ()
saveLastRead bPath chapterIdx = do
    dataDir <- getXdgDirectory XdgData "svitak"
    createDirectoryIfMissing True dataDir
    
    let configFile = dataDir </> "last_read.txt"
    -- Line 1 = Path, Line 2 = Index
    let content = T.pack bPath <> T.pack "\n" <> T.pack (show chapterIdx)
    
    TIO.writeFile configFile content
    putStrLn $ "Progress saved to: " ++ configFile

loadLastRead :: IO (Maybe (FilePath, Int))
loadLastRead = do
  dataDir <- getXdgDirectory XdgData "svitak"
  let configFile = dataDir </> "last_read.txt"

  result <- try (TIO.readFile configFile) :: IO (Either SomeException T.Text)
  
  case result of
    Left _ -> pure Nothing
    Right content -> do
      let linesOfFile = T.lines content
      case linesOfFile of
        [path, idxStr] 
          | Just idx <- readMaybe (T.unpack idxStr) -> 
              pure $ Just (T.unpack path, idx)
        _ -> pure Nothing