src/Remove.hs

   1 {-
   2     Remove.hs
   3
   4     Copyright 2013 Louis-Guillaume Gagnon <louis.guillaume.gagnon@gmail.com>
   5
   6     This program is free software: you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation, either version 3 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 -}
  19
  20 module Remove (
  21     remove,
  22     usageRemove
  23 ) where
  24
  25 import Data.Char (isDigit)
  26 import System.IO (hFlush,stdout)
  27
  28 import Tools.Constants
  29 import Tools.Filter (rowToString)
  30 import Tools.Operation (isHelp)
  31 import Tools.SQL (getEntry, removeEntry)
  32
  33 remove :: [String] -> IO ()
  34 remove [] = error $ "remove: too few arguments ('" ++ progName ++
  35                     " remove help' for help)"
  36 remove argv | length argv > 1 = error $  "remove: too many arguments ('" ++
  37                                           progName ++ " remove help') for help"
  38             | isHelp (argv!!0)            = putStrLn usageRemove
  39             | or (map (not . isDigit) id) = error $ "remove: invalid id: " ++ id
  40             | otherwise                   = askRemove id
  41             where id = argv!!0
  42
  43 askRemove :: String -> IO ()
  44 askRemove id = do
  45     entry <- getEntry $ read id
  46     case entry of
  47         Left msg  -> error $ "remove: " ++ msg
  48         Right row -> do putStrLn $ rowToString row
  49                         putStr "Remove this entry? [y/n] "
  50                         hFlush stdout
  51                         answer <- getLine
  52                         case answer of
  53                             "y" -> removeEntry $ read id
  54                             _   -> return ()
  55
  56 usageRemove :: String
  57 usageRemove = "usage: " ++ progName ++ " remove <id>"