{-# LANGUAGE TypeApplications #-}
module Main (main) where

import System.Environment
import TreeSitter.Unmarshal
import TreeSitter.Python.AST
import TreeSitter.Python
import Source.Range
import Source.Span
import Data.ByteString.Char8
import Data.ByteString (pack, readFile, ByteString)
import System.IO (FilePath)
import Options.Applicative hiding (style)
import Data.Semigroup ((<>))
import Text.Pretty.Simple (pPrint, pPrintNoColor)
import Data.Traversable (for)

data SemanticAST = SemanticAST
  { format :: Format
  , color  :: Bool
  , source :: Either [FilePath] Prelude.String
  }

-- Usage: semantic-ast --format ARG [--no-color] [--sourceString STRING] [FILEPATHS…]
parseAST :: Parser SemanticAST
parseAST = SemanticAST
  <$> option auto
    ( long "format"
    <> help "Specify desired output: show, json, sexpression" )
  <*> switch
    ( long "no-color"
    <> help "Print with color: --color"
    )
  <*> (Left <$> some
    (Options.Applicative.argument str (metavar "FILEPATH(S)"))
    <|> Right <$> strOption
      ( long "sourceString"
      <> metavar "STRING"
      <> help "Specify source input to parse"
      ))

main :: IO ()
main = generateAST =<< execParser opts

generateAST :: SemanticAST -> IO ()
generateAST (SemanticAST format color source) = do
  bytestrings <- case source of
    Left filePaths -> do
      traverse Data.ByteString.readFile filePaths
    Right source -> do
      pure [Data.ByteString.Char8.pack source]
  ast <- for bytestrings $ \bytestring -> do parseByteString @TreeSitter.Python.AST.Module @(Range, Span) tree_sitter_python bytestring
  case format of
    Show   -> print ast
    Pretty -> pPrint ast
  case color of
    Prelude.True   -> pPrintNoColor ast
    Prelude.False  -> pPrint ast

opts :: ParserInfo SemanticAST
opts = info (parseAST <**> helper)
  ( fullDesc
 <> progDesc "Parse source code and produce an AST"
 <> header "semantic-ast is a package used to parse source code" )

-- TODO: Define formats for json, sexpression, etc.
data Format = Show | Pretty
  deriving (Read)