module snug

import StdEnv
import StdMaybe

import Data.Error
import Data.Func
import Data.List
import System.CommandLine
import System.File
import System.FilePath
import System.Process
import Text

import MIPS.MIPS32
import Snug.Compile
import Snug.Parse
import Snug.Syntax

/* Note: after compiling with
 *   snug program.snug
 * an assembly file program.s is generated, which can be run with SPIM using
 *   spim -delayed_branches <(cat driver.s program.s)
 */

Start w
	# ([prog:args],w) = getCommandLine w
	| length args <> 1 = abort ("Usage: " +++ prog +++ " INPUT\n")
	# input = hd args
	  output = dropExtension input +++ ".s"
	# (mbInput,w) = readFile input w
	  input = fromJust mbInput
	| isNone mbInput = abort "Failed to read input\n"
	# mbDefs = parseSnug input
	  defs = fromOk mbDefs
	| isError mbDefs = abort ("Failed to parse: " +++ fromError mbDefs +++ "\n")
	| any (\d -> d=:TestDef _ _ _ _) defs
		= doTests output defs w
		= doCompile output defs w

doTests :: !String ![Definition] !*World -> *World
doTests output all_defs w = seqSt doTest tests w
where
	(tests,defs) = partition (\d -> d=:TestDef _ _ _ _) all_defs

	doTest :: !Definition !*World -> *World
	doTest (TestDef name type expr expected) w
		# w = log 0 (concat3 "\033[36mTesting " name "...\033[0m\n") w
		# w = doCompile output [FunDef "main" [] type expr : defs] w
		# (mbResult,w) = callProcessAndCollectOutput "spim" ["-quiet","-delayed_branches",output] ?None w
		  (exitCode,output,error) = fromOk mbResult
		| isError mbResult = abort ("Failed to run spim: " +++ snd (fromError mbResult) +++ "\n")
		# w = log 1 output w
		# w = if (error <> "") (logErr 1 error w) w
		| exitCode <> 0 || error <> "" || trim output <> expected
			# w = log 0 (concat3 "\033[31mFailed; expected:\033[0m\n\t" expected "\n") w
			= setReturnCode 1 w
		= w
	where
		log indent s w
			# (io,w) = stdio w
			# io = io <<< {#c \\ c <- repeatn indent '\t'} <<< s
			# (_,w) = fclose io w
			= w
		logErr indent s w
			# err = stderr <<< {#c \\ c <- repeatn indent '\t'} <<< s
			# (_,w) = fclose err w
			= w

doCompile :: !String ![Definition] !*World -> *World
doCompile output defs w
	# mbAssembly = compile "main" defs
	  assembly = join "\n" (map toString (fromOk mbAssembly))
	| isError mbAssembly = abort ("Failed to compile: " +++ fromError mbAssembly +++ "\n")
	# (mbDriver,w) = readFile "driver.s" w
	  driver = fromJust mbDriver
	| isNone mbDriver = abort "Failed to read driver code\n"
	# (mbErr,w) = writeFile output ({c \\ c <- driver} +++ assembly) w
	| isError mbErr = abort ("Failed to write output: " +++ toString (fromError mbErr) +++ "\n")
	| otherwise = w

readFile :: !FilePath !*World -> (!?[Char], !*World)
readFile path w
	# (ok,f,w) = fopen path FReadData w
	| not ok = (?None, w)
	# (contents,f) = read [] f
	# (_,w) = fclose f w
	= (?Just contents, w)
where
	read :: ![Char] !*File -> (![Char], !*File)
	read acc f
		# (ok,c,f) = freadc f
		| not ok = (reverse acc, f)
		| otherwise = read [c:acc] f