module Command.Graph (command) where

import Prelude

import Control.Applicative (many)
import Control.Monad (unless, when)
import Data.Aeson qualified as Json
import Data.Bool (bool)
import Data.ByteString.Lazy qualified as LB
import Data.ByteString.Lazy.UTF8 qualified as LBU8
import Language.PureScript qualified as P
import Language.PureScript.Errors.JSON (JSONResult(..), toJSONErrors)
import Options.Applicative qualified as Opts
import System.Console.ANSI qualified as ANSI
import System.Exit (exitFailure)
import System.Directory (getCurrentDirectory)
import System.FilePath.Glob (glob)
import System.IO (hPutStr, hPutStrLn, stderr)

data GraphOptions = GraphOptions
  { graphInput      :: [FilePath]
  , graphJSONErrors :: Bool
  }

graph :: GraphOptions -> IO ()
graph GraphOptions{..} = do
  input <- globWarningOnMisses (unless graphJSONErrors . warnFileTypeNotFound) graphInput
  when (null input && not graphJSONErrors) $ do
    hPutStr stderr $ unlines
      [ "purs graph: No input files."
      , "Usage: For basic information, try the `--help' option."
      ]
    exitFailure

  (makeResult, makeWarnings) <- P.graph input

  printWarningsAndErrors graphJSONErrors makeWarnings makeResult
    >>= (LB.putStr . Json.encode)

  where
  warnFileTypeNotFound :: String -> IO ()
  warnFileTypeNotFound =
    hPutStrLn stderr . ("purs graph: No files found using pattern: " <>)


command :: Opts.Parser (IO ())
command = graph <$> (Opts.helper <*> graphOptions)
  where
  graphOptions :: Opts.Parser GraphOptions
  graphOptions =
    GraphOptions <$> many inputFile
                 <*> jsonErrors

  inputFile :: Opts.Parser FilePath
  inputFile =
    Opts.strArgument $
      Opts.metavar "FILE" <>
      Opts.help "The input .purs file(s)."

  jsonErrors :: Opts.Parser Bool
  jsonErrors =
    Opts.switch $
      Opts.long "json-errors" <>
      Opts.help "Print errors to stderr as JSON"

-- | Arguments: use JSON, warnings, errors
printWarningsAndErrors :: Bool -> P.MultipleErrors -> Either P.MultipleErrors a -> IO a
printWarningsAndErrors False warnings errors = do
  pwd <- getCurrentDirectory
  cc <- bool Nothing (Just P.defaultCodeColor) <$> ANSI.hSupportsANSI stderr
  let ppeOpts = P.defaultPPEOptions { P.ppeCodeColor = cc, P.ppeFull = True, P.ppeRelativeDirectory = pwd }
  when (P.nonEmpty warnings) $
    hPutStrLn stderr (P.prettyPrintMultipleWarnings ppeOpts warnings)
  case errors of
    Left errs -> do
      hPutStrLn stderr (P.prettyPrintMultipleErrors ppeOpts errs)
      exitFailure
    Right res -> pure res
printWarningsAndErrors True warnings errors = do
  let verbose = True
  hPutStrLn stderr . LBU8.toString . Json.encode $
    JSONResult (toJSONErrors verbose P.Warning [] warnings)
               (either (toJSONErrors verbose P.Error []) (const []) errors)
  case errors of
    Left _errs -> exitFailure
    Right res -> pure res


globWarningOnMisses :: (String -> IO ()) -> [FilePath] -> IO [FilePath]
globWarningOnMisses warn = concatMapM globWithWarning
  where
  globWithWarning :: String -> IO [FilePath]
  globWithWarning pattern' = do
    paths <- glob pattern'
    when (null paths) $ warn pattern'
    return paths

  concatMapM :: (a -> IO [b]) -> [a] -> IO [b]
  concatMapM f = fmap concat . mapM f