module Main where

import Control.Monad (forM_)
import System.Directory (canonicalizePath)
import System.Environment (getArgs)
import IO (stderr, hPutStrLn)

import qualified System.IO.UTF8 as U

import Codec.Archive.LibZip

import DB
import Book

-- title-info of the FB2 file is expected to be found within first 8 kbytes.
fbHeadSize :: Int
fbHeadSize = 8*1024

main :: IO ()
main = do
  db <- initDB
  args <- getArgs
  forM_ args $ \arg -> do
    catchZipError $ do
      zipfile <- canonicalizePath arg
      withZip zipfile [] $ \z -> do
        files <- getFiles z []
        forM_ files $ \file -> do
          -- TODO: implement lazy reading in LibZip
          txt <- readZipFileHead' z file [] fbHeadSize
          sz <- getFileSize z file []
          let info = let i = readBookInfo $ toString txt
                     in  i { archive = zipfile, path = file, size = sz }
          catchSql (insert file db info)
            $ \e -> putErr $ "DB error: " ++ file ++ ": " ++ (seErrorMsg e)
    $ \e -> putErr $ "Archive error: " ++ arg ++ ": " ++ (show e)
  where
    insert :: String -> Connection -> Book -> IO ()
    insert fname db info = do
      withTransaction db $ \db' -> insertBook db' info
      U.putStrLn $ fname ++ ":" ++ (concat $ take 2 $ lines $ show info)

putErr :: String -> IO ()
putErr msg = hPutStrLn stderr msg

toString :: [Word8] -> String
toString = map w2c
  where w2c = toEnum . fromEnum