{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE OverloadedStrings #-}

{- |  This module implements parsing of additional arguments embedded in a
      comment when Stack is invoked as a script interpreter

  ===Specifying arguments in script interpreter mode
  @/stack/@ can execute a Haskell source file using @/runghc/@ and if required
  it can also install and setup the compiler and any package dependencies
  automatically.

  For using a Haskell source file as an executable script on a Unix like OS,
  the first line of the file must specify @stack@ as the interpreter using a
  shebang directive e.g.

  > #!/usr/bin/env stack

  Additional arguments can be specified in a haskell comment following the
  @#!@ line. The contents inside the comment must be a single valid stack
  command line, starting with @stack@ as the command and followed by the
  options to use for executing this file.

  The comment must be on the line immediately following the @#!@ line. The
  comment must start in the first column of the line. When using a block style
  comment the command can be split on multiple lines.

  Here is an example of a single line comment:

  > #!/usr/bin/env stack
  > -- stack --resolver lts-3.14 --install-ghc runghc --package random

  Here is an example of a multi line block comment:

@
  #!\/usr\/bin\/env stack
  {\- stack
    --resolver lts-3.14
    --install-ghc
    runghc
    --package random
  -\}
@

  When the @#!@ line is not present, the file can still be executed
  using @stack \<file name\>@ command if the file starts with a valid stack
  interpreter comment. This can be used to execute the file on Windows for
  example.

  Nested block comments are not supported.
-}

module Data.Attoparsec.Interpreter
    ( interpreterArgsParser -- for unit tests

    , getInterpreterArgs
    ) where

import           Data.Attoparsec.Args
import           Data.Attoparsec.Text ((<?>))
import qualified Data.Attoparsec.Text as P
import           Data.Char (isSpace)
import           Conduit
import           Data.Conduit.Attoparsec
import           Data.List (intercalate)
import           Data.Text (pack)
import           Stack.Prelude
import           System.FilePath (takeExtension)
import           System.IO (hPutStrLn)

-- | Parser to extract the Stack command line embedded inside a comment

-- after validating the placement and formatting rules for a valid

-- interpreter specification.

interpreterArgsParser :: Bool -> String -> P.Parser String
interpreterArgsParser :: Bool -> [Char] -> Parser [Char]
interpreterArgsParser Bool
isLiterate [Char]
progName = forall (f :: * -> *) a. Alternative f => a -> f a -> f a
P.option [Char]
"" Parser [Char]
sheBangLine forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> Parser [Char]
interpreterComment
  where
    sheBangLine :: Parser [Char]
sheBangLine =   Text -> Parser Text
P.string Text
"#!"
                 forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> forall (f :: * -> *) a b. Alternative f => f a -> f b -> f [a]
P.manyTill Parser Char
P.anyChar Parser ()
P.endOfLine

    commentStart :: Parser Text a -> Parser Text
commentStart Parser Text a
psr =   (Parser Text a
psr forall i a. Parser i a -> [Char] -> Parser i a
<?> ([Char]
progName forall a. [a] -> [a] -> [a]
++ [Char]
" options comment"))
                      forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> Parser ()
P.skipSpace
                      forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> (Text -> Parser Text
P.string ([Char] -> Text
pack [Char]
progName) forall i a. Parser i a -> [Char] -> Parser i a
<?> forall a. Show a => a -> [Char]
show [Char]
progName)

    -- Treat newlines as spaces inside the block comment

    anyCharNormalizeSpace :: Parser Char
anyCharNormalizeSpace = let normalizeSpace :: Char -> Char
normalizeSpace Char
c = if Char -> Bool
isSpace Char
c then Char
' ' else Char
c
                            in forall a. (Char -> a) -> (a -> Bool) -> Parser a
P.satisfyWith Char -> Char
normalizeSpace forall a b. (a -> b) -> a -> b
$ forall a b. a -> b -> a
const Bool
True

    comment :: Parser Text a -> Parser Text b -> Parser [Char]
comment Parser Text a
start Parser Text b
end = forall {a}. Parser Text a -> Parser Text
commentStart Parser Text a
start
      forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> ((Parser Text b
end forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> forall (f :: * -> *) a. Applicative f => a -> f a
pure [Char]
"")
          forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> (Parser Char
P.space forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> (forall (f :: * -> *) a b. Alternative f => f a -> f b -> f [a]
P.manyTill Parser Char
anyCharNormalizeSpace Parser Text b
end forall i a. Parser i a -> [Char] -> Parser i a
<?> [Char]
"-}")))

    horizontalSpace :: Parser Char
horizontalSpace = (Char -> Bool) -> Parser Char
P.satisfy Char -> Bool
P.isHorizontalSpace

    lineComment :: Parser [Char]
lineComment =  forall {a} {b}. Parser Text a -> Parser Text b -> Parser [Char]
comment Parser Text
"--" (Parser ()
P.endOfLine forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> forall t. Chunk t => Parser t ()
P.endOfInput)
    literateLineComment :: Parser [Char]
literateLineComment = forall {a} {b}. Parser Text a -> Parser Text b -> Parser [Char]
comment
      (Parser Text
">" forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> Parser Char
horizontalSpace forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> Parser Text
"--")
      (Parser ()
P.endOfLine forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> forall t. Chunk t => Parser t ()
P.endOfInput)
    blockComment :: Parser [Char]
blockComment = forall {a} {b}. Parser Text a -> Parser Text b -> Parser [Char]
comment Parser Text
"{-" (Text -> Parser Text
P.string Text
"-}")

    literateBlockComment :: Parser [Char]
literateBlockComment =
      (Parser Text
">" forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> Parser Char
horizontalSpace forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> Parser Text
"{-")
      forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> forall (f :: * -> *) a. Alternative f => f a -> f ()
P.skipMany ((Text
"" forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ Parser Char
horizontalSpace) forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> (Parser ()
P.endOfLine forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> Parser Text
">"))
      forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> (Text -> Parser Text
P.string ([Char] -> Text
pack [Char]
progName) forall i a. Parser i a -> [Char] -> Parser i a
<?> [Char]
progName)
      forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> forall (m :: * -> *) a b. MonadPlus m => m a -> m b -> m [a]
P.manyTill' ((Char -> Bool) -> Parser Char
P.satisfy (Bool -> Bool
not forall b c a. (b -> c) -> (a -> b) -> a -> c
. Char -> Bool
P.isEndOfLine)
                       forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> (Char
' ' forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ (Parser ()
P.endOfLine forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> Parser Text
">" forall i a. Parser i a -> [Char] -> Parser i a
<?> [Char]
">"))) Parser Text
"-}"

    interpreterComment :: Parser [Char]
interpreterComment = if Bool
isLiterate
                            then Parser [Char]
literateLineComment forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> Parser [Char]
literateBlockComment
                            else Parser [Char]
lineComment forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> Parser [Char]
blockComment

-- | Extract Stack arguments from a correctly placed and correctly formatted

-- comment when it is being used as an interpreter

getInterpreterArgs :: String -> IO [String]
getInterpreterArgs :: [Char] -> IO [[Char]]
getInterpreterArgs [Char]
file = do
  Either ParseError [Char]
eArgStr <- forall (m :: * -> *) (n :: * -> *) i a.
(MonadUnliftIO m, MonadIO n) =>
[Char] -> (ConduitM i ByteString n () -> m a) -> m a
withSourceFile [Char]
file forall {m :: * -> *}.
MonadThrow m =>
ConduitT () ByteString m () -> m (Either ParseError [Char])
parseFile
  case Either ParseError [Char]
eArgStr of
    Left ParseError
err -> forall {a}. IsString a => [Char] -> IO [a]
handleFailure forall a b. (a -> b) -> a -> b
$ ParseError -> [Char]
decodeError ParseError
err
    Right [Char]
str -> [Char] -> IO [[Char]]
parseArgStr [Char]
str
  where
    parseFile :: ConduitT () ByteString m () -> m (Either ParseError [Char])
parseFile ConduitT () ByteString m ()
src =
         forall (m :: * -> *) r. Monad m => ConduitT () Void m r -> m r
runConduit
       forall a b. (a -> b) -> a -> b
$ ConduitT () ByteString m ()
src
      forall (m :: * -> *) a b c r.
Monad m =>
ConduitT a b m () -> ConduitT b c m r -> ConduitT a c m r
.| forall (m :: * -> *). MonadThrow m => ConduitT ByteString Text m ()
decodeUtf8C
      forall (m :: * -> *) a b c r.
Monad m =>
ConduitT a b m () -> ConduitT b c m r -> ConduitT a c m r
.| forall a (m :: * -> *) b o.
(AttoparsecInput a, Monad m) =>
Parser a b -> ConduitT a o m (Either ParseError b)
sinkParserEither (Bool -> [Char] -> Parser [Char]
interpreterArgsParser Bool
isLiterate [Char]
stackProgName)

    isLiterate :: Bool
isLiterate = [Char] -> [Char]
takeExtension [Char]
file forall a. Eq a => a -> a -> Bool
== [Char]
".lhs"

    -- FIXME We should print anything only when explicit verbose mode is

    -- specified by the user on command line. But currently the

    -- implementation does not accept or parse any command line flags in

    -- interpreter mode. We can only invoke the interpreter as

    -- "stack <file name>" strictly without any options.

    stackWarn :: [Char] -> IO ()
stackWarn [Char]
s = Handle -> [Char] -> IO ()
hPutStrLn Handle
stderr forall a b. (a -> b) -> a -> b
$ [Char]
stackProgName forall a. [a] -> [a] -> [a]
++ [Char]
": WARNING! " forall a. [a] -> [a] -> [a]
++ [Char]
s

    handleFailure :: [Char] -> IO [a]
handleFailure [Char]
err = do
      forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ [Char] -> IO ()
stackWarn ([Char] -> [[Char]]
lines [Char]
err)
      [Char] -> IO ()
stackWarn [Char]
"Missing or unusable Stack options specification"
      [Char] -> IO ()
stackWarn [Char]
"Using runghc without any additional Stack options"
      forall (f :: * -> *) a. Applicative f => a -> f a
pure [a
"runghc"]

    parseArgStr :: [Char] -> IO [[Char]]
parseArgStr [Char]
str =
      case forall a. Parser a -> Text -> Either [Char] a
P.parseOnly (EscapingMode -> Parser [[Char]]
argsParser EscapingMode
Escaping) ([Char] -> Text
pack [Char]
str) of
        Left [Char]
err -> forall {a}. IsString a => [Char] -> IO [a]
handleFailure ([Char]
"Error parsing command specified in the "
                        forall a. [a] -> [a] -> [a]
++ [Char]
"Stack options comment: " forall a. [a] -> [a] -> [a]
++ [Char]
err)
        Right [] -> forall {a}. IsString a => [Char] -> IO [a]
handleFailure [Char]
"Empty argument list in Stack options comment"
        Right [[Char]]
args -> forall (f :: * -> *) a. Applicative f => a -> f a
pure [[Char]]
args

    decodeError :: ParseError -> [Char]
decodeError ParseError
e =
      case ParseError
e of
        ParseError [[Char]]
ctxs [Char]
_ (Position Int
l Int
col Int
_) ->
          if forall (t :: * -> *) a. Foldable t => t a -> Bool
null [[Char]]
ctxs
          then [Char]
"Parse error"
          else ([Char]
"Expecting " forall a. [a] -> [a] -> [a]
++ forall a. [a] -> [[a]] -> [a]
intercalate [Char]
" or " [[Char]]
ctxs)
          forall a. [a] -> [a] -> [a]
++ [Char]
" at line " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> [Char]
show Int
l forall a. [a] -> [a] -> [a]
++ [Char]
", column " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> [Char]
show Int
col
        ParseError
DivergentParser -> [Char]
"Divergent parser"