-----------------------------------------------------------------------------
-- |
-- Module      :  XMonad.Prompt.Pass
-- Description :  A prompt for interacting with @pass(1)@.
-- Copyright   :  (c) 2014 Igor Babuschkin, Antoine R. Dumont
-- License     :  BSD3-style (see LICENSE)
--
-- Maintainer  :  Antoine R. Dumont <eniotna.t@gmail.com>
-- Stability   :  unstable
-- Portability :  unportable
--
-- A thin wrapper around the standard @pass(1)@ UNIX utility.
--
-- This module provides several prompts to ease password manipulation
-- (generate, read, edit, remove); all of them benefit from the
-- completion system provided by "XMonad.Prompt".  Specifically, we
-- provide
--
-- - two functions to lookup passwords in the password-store:
--
--     - 'passPrompt' copies the password directly to the clipboard.
--
--     - 'passTypePrompt' uses @xdotool@ to type the password
--       directly.
--
-- - 'passGeneratePrompt' generates a password for a given password
--   label that the user inputs.
--
-- - 'passEditPrompt' edits a password for a given password label that
--   the user inputs.
--
-- - 'passRemovePrompt' deletes a stored password for a given password
--   label that the user inputs.
--
-- The password store is setup through an environment variable
-- @$PASSWORD_STORE_DIR@, or @$HOME\/.password-store@ if it is unset.
-- The editor is determined from the environment variable @$EDITOR@.
--
-- Source:
--
-- - The <https://www.passwordstore.org/ password store>
--   implementation is <http://git.zx2c4.com/password-store here>.
--
-- - Inspired by <http://babushk.in/posts/combining-xmonad-and-pass.html>
--
-----------------------------------------------------------------------------

module XMonad.Prompt.Pass
    ( -- * Usage
      -- $usage

      -- * Retrieving passwords
      passPrompt
    , passTypePrompt

      -- * Editing passwords
    , passEditPrompt
    , passRemovePrompt
    , passGeneratePrompt
    , passGenerateAndCopyPrompt

      -- * Misc
    , passOTPPrompt
    ) where

import System.Directory (getHomeDirectory)
import System.FilePath (combine, dropExtension, takeExtension)
import System.Posix.Env (getEnv)
import XMonad.Core
import XMonad.Prompt ( XPrompt
                     , showXPrompt
                     , commandToComplete
                     , nextCompletion
                     , getNextCompletion
                     , XPConfig
                     , mkXPrompt
                     , searchPredicate)
import XMonad.Util.Run (runProcessWithInput)

-- $usage
-- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@:
--
-- > import XMonad.Prompt.Pass
--
-- Then add a keybinding for 'passPrompt', 'passGeneratePrompt',
-- 'passRemovePrompt', 'passEditPrompt' or 'passTypePrompt':
--
-- >   , ((modMask , xK_p)                              , passPrompt def)
-- >   , ((modMask .|. controlMask, xK_p)               , passGeneratePrompt def)
-- >   , ((modMask .|. shiftMask, xK_p)                 , passEditPrompt def)
-- >   , ((modMask .|. controlMask  .|. shiftMask, xK_p), passRemovePrompt def)
--
-- For detailed instructions on:
--
-- - editing your key bindings, see "XMonad.Doc.Extending#Editing_key_bindings".
--
-- - how to setup the password store, see <http://git.zx2c4.com/password-store/about/>
--   or @man 1 pass@.
--

type Predicate = String -> String -> Bool

getPassCompl :: [String] -> Predicate -> String -> IO [String]
getPassCompl :: [String] -> Predicate -> String -> IO [String]
getPassCompl [String]
compls Predicate
p String
s = [String] -> IO [String]
forall (m :: * -> *) a. Monad m => a -> m a
return ([String] -> IO [String]) -> [String] -> IO [String]
forall a b. (a -> b) -> a -> b
$ (String -> Bool) -> [String] -> [String]
forall a. (a -> Bool) -> [a] -> [a]
filter (Predicate
p String
s) [String]
compls

type PromptLabel = String

newtype Pass = Pass PromptLabel

instance XPrompt Pass where
  showXPrompt :: Pass -> String
showXPrompt       (Pass String
prompt) = String
prompt String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
": "
  commandToComplete :: Pass -> String -> String
commandToComplete Pass
_ String
c           = String
c
  nextCompletion :: Pass -> String -> [String] -> String
nextCompletion      Pass
_           = String -> [String] -> String
getNextCompletion

-- | Default password store folder in @$HOME/.password-store@.
--
passwordStoreFolderDefault :: String -> String
passwordStoreFolderDefault :: String -> String
passwordStoreFolderDefault String
home = String -> String -> String
combine String
home String
".password-store"

-- | Compute the password store's location.
-- Use the @$PASSWORD_STORE_DIR@ environment variable to set the password store.
-- If empty, return the password store located in user's home.
--
passwordStoreFolder :: IO String
passwordStoreFolder :: IO String
passwordStoreFolder =
  String -> IO (Maybe String)
getEnv String
"PASSWORD_STORE_DIR" IO (Maybe String) -> (Maybe String -> IO String) -> IO String
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= Maybe String -> IO String
computePasswordStoreDir
  where computePasswordStoreDir :: Maybe String -> IO String
computePasswordStoreDir Maybe String
Nothing         = (String -> String) -> IO String -> IO String
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap String -> String
passwordStoreFolderDefault IO String
getHomeDirectory
        computePasswordStoreDir (Just String
storeDir) = String -> IO String
forall (m :: * -> *) a. Monad m => a -> m a
return String
storeDir

-- | A pass prompt factory.
--
mkPassPrompt :: PromptLabel -> (String -> X ()) -> XPConfig -> X ()
mkPassPrompt :: String -> (String -> X ()) -> XPConfig -> X ()
mkPassPrompt String
promptLabel String -> X ()
passwordFunction XPConfig
xpconfig = do
  [String]
passwords <- IO [String] -> X [String]
forall (m :: * -> *) a. MonadIO m => IO a -> m a
io (IO String
passwordStoreFolder IO String -> (String -> IO [String]) -> IO [String]
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= String -> IO [String]
getPasswords)
  Pass
-> XPConfig -> (String -> IO [String]) -> (String -> X ()) -> X ()
forall p.
XPrompt p =>
p
-> XPConfig -> (String -> IO [String]) -> (String -> X ()) -> X ()
mkXPrompt (String -> Pass
Pass String
promptLabel) XPConfig
xpconfig ([String] -> Predicate -> String -> IO [String]
getPassCompl [String]
passwords (Predicate -> String -> IO [String])
-> Predicate -> String -> IO [String]
forall a b. (a -> b) -> a -> b
$ XPConfig -> Predicate
searchPredicate XPConfig
xpconfig) String -> X ()
passwordFunction

-- | A prompt to retrieve a password from a given entry.
--
passPrompt :: XPConfig -> X ()
passPrompt :: XPConfig -> X ()
passPrompt = String -> (String -> X ()) -> XPConfig -> X ()
mkPassPrompt String
"Select password" String -> X ()
selectPassword

-- | A prompt to retrieve a OTP from a given entry.  Note that you will
-- need to use the <https://github.com/tadfisher/pass-otp pass-otp>
-- extension for this to work.
--
passOTPPrompt :: XPConfig -> X ()
passOTPPrompt :: XPConfig -> X ()
passOTPPrompt = String -> (String -> X ()) -> XPConfig -> X ()
mkPassPrompt String
"Select OTP" String -> X ()
selectOTP

-- | A prompt to generate a password for a given entry.
-- This can be used to override an already stored entry.
-- (Beware that no confirmation is asked)
--
passGeneratePrompt :: XPConfig -> X ()
passGeneratePrompt :: XPConfig -> X ()
passGeneratePrompt = String -> (String -> X ()) -> XPConfig -> X ()
mkPassPrompt String
"Generate password" String -> X ()
generatePassword

-- | A prompt to generate a password for a given entry and immediately copy it
-- to the clipboard.  This can be used to override an already stored entry.
-- (Beware that no confirmation is asked)
--
passGenerateAndCopyPrompt :: XPConfig -> X ()
passGenerateAndCopyPrompt :: XPConfig -> X ()
passGenerateAndCopyPrompt = String -> (String -> X ()) -> XPConfig -> X ()
mkPassPrompt String
"Generate and copy password" String -> X ()
generateAndCopyPassword

-- | A prompt to remove a password for a given entry.
-- (Beware that no confirmation is asked)
--
passRemovePrompt :: XPConfig -> X ()
passRemovePrompt :: XPConfig -> X ()
passRemovePrompt = String -> (String -> X ()) -> XPConfig -> X ()
mkPassPrompt String
"Remove password" String -> X ()
removePassword

-- | A prompt to type in a password for a given entry.
-- This doesn't touch the clipboard.
--
passTypePrompt :: XPConfig -> X ()
passTypePrompt :: XPConfig -> X ()
passTypePrompt = String -> (String -> X ()) -> XPConfig -> X ()
mkPassPrompt String
"Type password" String -> X ()
typePassword

-- | A prompt to edit a given entry.
-- This doesn't touch the clipboard.
--
passEditPrompt :: XPConfig -> X ()
passEditPrompt :: XPConfig -> X ()
passEditPrompt = String -> (String -> X ()) -> XPConfig -> X ()
mkPassPrompt String
"Edit password" String -> X ()
editPassword

-- | Select a password.
--
selectPassword :: String -> X ()
selectPassword :: String -> X ()
selectPassword String
passLabel = String -> X ()
forall (m :: * -> *). MonadIO m => String -> m ()
spawn (String -> X ()) -> String -> X ()
forall a b. (a -> b) -> a -> b
$ String
"pass --clip \"" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String -> String
escapeQuote String
passLabel String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
"\""

-- | Select an OTP.
--
selectOTP :: String -> X ()
selectOTP :: String -> X ()
selectOTP String
passLabel = String -> X ()
forall (m :: * -> *). MonadIO m => String -> m ()
spawn (String -> X ()) -> String -> X ()
forall a b. (a -> b) -> a -> b
$ String
"pass otp --clip \"" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String -> String
escapeQuote String
passLabel String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
"\""

-- | Generate a 30 characters password for a given entry.
-- If the entry already exists, it is updated with a new password.
--
generatePassword :: String -> X ()
generatePassword :: String -> X ()
generatePassword String
passLabel = String -> X ()
forall (m :: * -> *). MonadIO m => String -> m ()
spawn (String -> X ()) -> String -> X ()
forall a b. (a -> b) -> a -> b
$ String
"pass generate --force \"" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String -> String
escapeQuote String
passLabel String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
"\" 30"

-- | Generate a 30 characters password for a given entry.
-- If the entry already exists, it is updated with a new password.
-- After generating the password, it is copied to the clipboard.
--
generateAndCopyPassword :: String -> X ()
generateAndCopyPassword :: String -> X ()
generateAndCopyPassword String
passLabel = String -> X ()
forall (m :: * -> *). MonadIO m => String -> m ()
spawn (String -> X ()) -> String -> X ()
forall a b. (a -> b) -> a -> b
$ String
"pass generate --force -c \"" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String -> String
escapeQuote String
passLabel String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
"\" 30"

-- | Remove a password stored for a given entry.
--
removePassword :: String -> X ()
removePassword :: String -> X ()
removePassword String
passLabel = String -> X ()
forall (m :: * -> *). MonadIO m => String -> m ()
spawn (String -> X ()) -> String -> X ()
forall a b. (a -> b) -> a -> b
$ String
"pass rm --force \"" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String -> String
escapeQuote String
passLabel String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
"\""

-- | Edit a password stored for a given entry.
--
editPassword :: String -> X ()
editPassword :: String -> X ()
editPassword String
passLabel = String -> X ()
forall (m :: * -> *). MonadIO m => String -> m ()
spawn (String -> X ()) -> String -> X ()
forall a b. (a -> b) -> a -> b
$ String
"pass edit \"" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String -> String
escapeQuote String
passLabel String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
"\""

-- | Type a password stored for a given entry using xdotool.
--
typePassword :: String -> X ()
typePassword :: String -> X ()
typePassword String
passLabel = String -> X ()
forall (m :: * -> *). MonadIO m => String -> m ()
spawn (String -> X ()) -> String -> X ()
forall a b. (a -> b) -> a -> b
$ String
"pass \"" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String -> String
escapeQuote String
passLabel
  String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
"\"|head -n1|tr -d '\n'|xdotool type --clearmodifiers --file -"

escapeQuote :: String -> String
escapeQuote :: String -> String
escapeQuote = (Char -> String) -> String -> String
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap Char -> String
escape
  where escape :: Char -> String
        escape :: Char -> String
escape Char
'"' = String
"\\\""
        escape Char
x   = [Char
x]

-- | Retrieve the list of passwords from the password store 'passwordStoreDir
--
getPasswords :: FilePath -> IO [String]
getPasswords :: String -> IO [String]
getPasswords String
passwordStoreDir = do
  String
files <- String -> [String] -> String -> IO String
forall (m :: * -> *).
MonadIO m =>
String -> [String] -> String -> m String
runProcessWithInput String
"find" [
    String
"-L", -- Traverse symlinks
    String
passwordStoreDir,
    String
"-type", String
"f",
    String
"-name", String
"*.gpg",
    String
"-printf", String
"%P\n"] []
  [String] -> IO [String]
forall (m :: * -> *) a. Monad m => a -> m a
return ([String] -> IO [String])
-> ([String] -> [String]) -> [String] -> IO [String]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (String -> String) -> [String] -> [String]
forall a b. (a -> b) -> [a] -> [b]
map String -> String
removeGpgExtension ([String] -> IO [String]) -> [String] -> IO [String]
forall a b. (a -> b) -> a -> b
$ String -> [String]
lines String
files

removeGpgExtension :: String -> String
removeGpgExtension :: String -> String
removeGpgExtension String
file | String -> String
takeExtension String
file Predicate
forall a. Eq a => a -> a -> Bool
== String
".gpg" = String -> String
dropExtension String
file
                        | Bool
otherwise                    = String
file