{-# LANGUAGE CPP #-}
-- Copyright (c) Tuomo Valkonen 2004.
-- Copyright (c) Don Stewart 2004-5.
-- Copyright (c) Jean-Philippe Bernardy 2006,2007.

-- | This is the main module of Yi, called with configuration from the user.
-- Here we mainly process command line arguments.

module Yi.Main (main, projectName) where

import Prelude ()
import {-# SOURCE #-} Yi.Boot
import Yi.Config
import Yi.Config.Default
import Yi.Core
import Yi.Dired
import HConf (hconfOptions)
import qualified HConf
import Paths_yi
import Distribution.Text (display)
#ifdef TESTING
import qualified TestSuite
#endif

#ifdef FRONTEND_COCOA
import HOC (withAutoreleasePool)
#endif

import Data.Char
import Data.List                ( intersperse, map )
import Control.Monad.Error
import Control.Monad.Trans.Error (Error(..))
import Control.Monad (foldM)
import System.Console.GetOpt
import System.Environment       ( getArgs )
import System.Exit
#include "ghcconfig.h"

frontendNames :: [String]
frontendNames = fmap fst' availableFrontends
  where fst' :: (a,UIBoot) -> a
        fst' (x,_) = x

data Err = Err String ExitCode

instance Error Err where
    strMsg s = Err s (ExitFailure 1)

-- ---------------------------------------------------------------------
-- | Argument parsing. Pretty standard.

data Opts = Help
          | Version
          | LineNo String
          | EditorNm String
          | File String
          | Frontend String
          | ConfigFile String
          | SelfCheck
          | Debug
          | HConfOption

-- | List of editors for which we provide an emulation.
editors :: [(String,Config -> Config)]
editors = [("emacs", toEmacsStyleConfig),
           ("vim",   toVimStyleConfig),
           ("cua",   toCuaStyleConfig)]

options :: [OptDescr Opts]
options = [
    Option []     ["self-check"]  (NoArg SelfCheck) "run self-checks",
    Option ['f']  ["frontend"]    (ReqArg Frontend "[frontend]")
        ("Select frontend, which can be one of:\n" ++
         (concat . intersperse ", ") frontendNames),
    Option ['y']  ["config-file"] (ReqArg ConfigFile  "path") "Specify a configuration file",
    Option ['V']  ["version"]     (NoArg Version) "Show version information",
    Option ['h']  ["help"]        (NoArg Help)    "Show this help",
    Option []     ["debug"]       (NoArg Debug)   "Write debug information in a log file",
    Option ['l']  ["line"]        (ReqArg LineNo "[num]") "Start on line number",
    Option []     ["as"]          (ReqArg EditorNm "[editor]")
        ("Start with editor keymap, where editor is one of:\n" ++
                (concat . intersperse ", " . fmap fst) editors)
    ] ++ (map (fmap $ const HConfOption) (hconfOptions defaultHConfParams))

-- | usage string.
usage, versinfo :: String
usage = usageInfo ("Usage: " ++ projectName ++ " [option...] [file]") options

versinfo = projectName ++ ' ' : display version

-- | Transform the config with options
do_args :: Config -> [String] -> Either Err Config
do_args cfg args =
    case (getOpt (ReturnInOrder File) options args) of
        (o, [], []) -> foldM getConfig cfg o
        (_, _, errs) -> fail (concat errs)

-- | Update the default configuration based on a command-line option.
getConfig :: Config -> Opts -> Either Err Config
getConfig cfg opt =
    case opt of
      Frontend f -> case lookup f availableFrontends of
                      Just frontEnd -> return cfg { startFrontEnd = frontEnd }
                      Nothing       -> fail "Panic: frontend not found"
      Help          -> throwError $ Err usage ExitSuccess
      Version       -> throwError $ Err versinfo ExitSuccess
      Debug         -> return cfg { debugMode = True }
      LineNo l      -> case startActions cfg of
                         x : xs -> return cfg { startActions = x:makeAction (gotoLn (read l)):xs }
                         []     -> fail "The `-l' option must come after a file argument"
      File filename -> prependAction (fnewE filename)
      EditorNm emul -> case lookup (fmap toLower emul) editors of
             Just modifyCfg -> return $ modifyCfg cfg
             Nothing -> fail $ "Unknown emulation: " ++ show emul
      _ -> return cfg
  where 
    prependAction a = return $ cfg { startActions = makeAction a : startActions cfg}

-- ---------------------------------------------------------------------
-- | Static main. This is the front end to the statically linked
-- application, and the real front end, in a sense. 'dynamic_main' calls
-- this after setting preferences passed from the boot loader.
--
main :: Config -> Maybe Editor -> IO ()
main cfg state = do
#ifdef FRONTEND_COCOA
       withAutoreleasePool $ do
#endif
         args <- getArgs
#ifdef TESTING
         when ("--self-check" `elem` args)
              TestSuite.main
#endif
         case do_args cfg args of
              Left (Err err code) ->
                do putStrLn err
                   exitWith code
              Right finalCfg ->
                do when (debugMode finalCfg) $ initDebug ".yi.dbg"
                   startEditor finalCfg state