{-# LANGUAGE DuplicateRecordFields, OverloadedLists #-}
{-# OPTIONS_GHC -Wall #-}
module Rubyhs (main) where

import Data.Foldable (traverse_)
import Data.Language.Ruby (Block)
import Data.Map (Map)
import Data.Set (Set)
import Data.Tree (Tree(Node), Forest)
import Frelude
import Options.Applicative (Parser)
import qualified Data.Aeson as Aeson
import qualified Data.ByteString.Lazy.Char8 as ByteString
import qualified Data.Graphviz as Graphviz
import qualified Data.Language.Ruby as Ruby
import qualified Data.Text.IO as Text
import qualified Options.Applicative as Options
import qualified Rubyhs.References

main :: IO ()
main = do
  Command{targets, printAST, maybeDotPath} <- getCommand
  blocks <- parseInput @Block targets
  let
    act block = do
      let res@(Rubyhs.References.Result x) = Rubyhs.References.references $ block
      putEncoded res
      ByteString.putStrLn . Aeson.encode . toJSONForest . Rubyhs.References.graph $ block
      case maybeDotPath of
        Nothing -> pure ()
        Just dotPath -> drawDot dotPath x
  if printAST
  then traverse_ @[] putEncoded blocks
  else traverse_ act blocks

drawDot :: FilePath -> Map Rubyhs.References.Node (Set Rubyhs.References.Node)  -> IO ()
drawDot p
  = Text.writeFile p
  . Graphviz.digraph
  . fmap (fmap (qoutes . Rubyhs.References.prettyContext) . \(x, xs) -> x :| toList xs)
  . toList

qoutes :: Text -> Text
qoutes x = "\"" <> x <> "\""

toJSONForest :: Forest Rubyhs.References.Node -> Aeson.Value
toJSONForest = Aeson.Object . fromList . fmap go
  where
  go (Node x xs) = (Rubyhs.References.prettyContext x, toJSONForest xs)

-- | If arguments is non-empty treat all arguments as filepaths and
-- parse the modules at those locations.  If there are no arguments,
-- parse from stdin.
parseInput :: FromJSON a => [FilePath] -> IO [a]
parseInput = \case
  [] -> ByteString.getContents >>= fmap pure . Ruby.parse
  ps -> traverse Ruby.parseFile ps

putEncoded :: ToJSON a => a -> IO ()
putEncoded = ByteString.putStrLn . Aeson.encode

data Command = Command
  { targets       :: [FilePath]
  , printAST      :: Bool
  , maybeDotPath  :: Maybe FilePath
  }

command :: Parser Command
command = Command <$> targets <*> printAST <*> dotPath
  where
  targets = many (Options.argument Options.str (Options.metavar "TARGET"))
  printAST = Options.switch
    $  Options.long "print-ast"
    <> Options.help "Print AST and exit"
  dotPath
    = Options.optional
    $ Options.strOption
    $ Options.long "dot"
    <> Options.metavar "PATH"
    <> Options.help "Write dot graph"

getCommand :: IO Command
getCommand = Options.execParser opts
  where
    opts = Options.info (Options.helper <*> command)
      ( Options.fullDesc
     <> Options.progDesc "Static analysis of Ruby"
     <> Options.header "rubyhs - Static analysis of Ruby" )