module Core where

import Prelude hiding ( readFile )
import System.IO.Strict
import System.FilePath
import System.Directory
import Control.Applicative

import Data.Time.Clock
import Data.Time.Format
import System.Locale

import Storage.Hashed.Plain
import Storage.Hashed.Darcs
import Storage.Hashed.Hash
import Storage.Hashed.Tree
import Storage.Hashed.AnchoredPath
import qualified Data.ByteString.Char8 as BSC

data Backup = Backup { root :: Hash
                     , date :: String
                     , path :: String }
              deriving Show

hencode = encodeBase64u
hdecode = decodeBase64u

showtime = formatTime defaultTimeLocale "%F.%R"

readrepo = map (wibble . words) . lines
    where wibble [h, d, p] = Backup (hdecode $ BSC.pack h) d p
          wibble x = error $ show x

repo path = getrepo path `catch` \_ -> makerepo path
listrepo r = putStr $ unlines . map line $ r
  where line (Backup h d p) = unwords [BSC.unpack $ hencode h, d, p]
listdir r h = do t <- expand =<< readDarcsHashed r (Nothing, h)
                 putStr $ unlines [ unwords [ BSC.unpack $ hencode $ itemHash i
                                            , anchorPath "" p ]
                                            | (p, i) <- list t ]

{- catpath r h p = do t <- expand =<< readDarcsHashed r (Nothing, h)
                   case findBlob t p of
                     Nothing -> fail $ showPath p ++ " does not exist." -}

writerepo r to = do
  putStrLn $ "writing repo to " ++ to
  createDirectoryIfMissing False to
  writeFile (to </> "list") (unlines $ map line r) >> return r
    where line (Backup r d p) = unwords [BSC.unpack $ hencode r, d, p]

makerepo path = writerepo [] path
getrepo path = readrepo `fmap` (readFile $ path </> "list")

make from to = do f <- darcsUpdateHashes =<< expand =<< readPlainTree from
                  hash <- writeDarcsHashed f to
                  dt <- getCurrentTime
                  path <- canonicalizePath from
                  r <- repo to
                  writerepo (r ++ [Backup hash (showtime dt) path]) to
                  putStrLn $ "new backup root: " ++ (BSC.unpack $ hencode hash)

restore repo to root = do createDirectory to
                          t <- expand =<< readDarcsHashed repo (Nothing, root)
                          writePlainTree t to