module main

import StdFile
import StdBool
import StdMisc
import StdFunc
import StdTuple
import StdList
import StdString
import Data.Either
import Data.Maybe
import Data.Func
import System.CommandLine
import GenPrint
from Text import class Text(concat), instance Text String

import parse
import lex
from yard import :: Error, instance toString Error

:: Opts = {
	program :: String,
	lex :: Bool,
	parse :: Bool,
	fp :: Maybe String,
	help :: Bool}

derive gPrint TokenValue

Start :: *World -> *World
Start w
# (args, w) = parseArgs w
| args.help
	# (out, w) = stdio w
	# out = out <<< "Usage: " <<< args.program <<< " [opts] [FILENAME]\n"
		<<< "\t--help  Show this help\n"
		<<< "\t--[no-]lex   Lexer output(default: disabled)\n"
		<<< "\t--[no-]parse Parser output(default: enabled)\n\n"
		<<< "\tFILENAME   File to parse, when unspecified stdin is parsed\n"
	= snd $ fclose out w
# (stdin, w) = stdio w
# (contents, stdin, w) = readFileOrStdin stdin args.fp w
= case contents of
	(Left cs) = snd $ fclose (stdin <<< cs) w
	(Right cs)
	# lexOut = lexer cs
	# stdin = if (not args.lex) stdin (case lexOut of
		(Right toks) = 
			stdin <<< "---LEXER\n" <<< printTokens toks <<< "---LEXER\n"
		_ = stdin)
	# parseOut = parser lexOut
	# stdin = if (not args.parse) stdin (case parser lexOut of
		(Right ast) = 
			stdin <<<  "---PARSER\n" <<< toString ast <<< "---PARSER\n" 
		(Left parse) = stdin <<< toString parse)
	= snd $ fclose stdin w
		where
			printTokens :: [Token] -> String
			printTokens ts = concat $ flatten $ map pt ts
				where
					pt {line,column,token} = [toString line, ":", 
						toString column, ": ", printToString token, "\n"]

parseArgs :: *World -> (Opts, *World)
parseArgs w
# ([p:args], w) = getCommandLine w
= (pa args {program=p, lex=False, parse=True, fp=Nothing, help=False}, w)
where
	pa :: [String] Opts -> Opts
	pa [] o = o
	pa ["--help":r] o = pa r {o & help=True}
	pa ["--lex":r] o = pa r {o & lex=True}
	pa ["--no-lex":r] o = pa r {o & lex=False}
	pa ["--parse":r] o = pa r {o & parse=True}
	pa ["--no-parse":r] o = pa r {o & parse=False}
	pa [x:r] o = pa r {o & fp=Just x}

readFileOrStdin :: *File (Maybe String) *World -> *(Either String [Char], *File, *World)
readFileOrStdin stdin Nothing w
# (cs, stdin) = readEntireFile stdin
= (Right cs, stdin, w)
readFileOrStdin stdin (Just fp) w
# (b, fin, w) = fopen fp FReadText w
| not b = (Left "Unable to open file", stdin, w)
# (cs, 	fin) = readEntireFile fin
# (b, w) = fclose fin w
| not b = (Left "Unable to close file", stdin, w)
= (Right cs, stdin, w)

readEntireFile :: *File -> *([Char], *File)
readEntireFile f
# (b, c, f) = freadc f
| not b = ([], f)
# (cs, f) = readEntireFile f
= ([c:cs], f)