-- Implicit CAD. Copyright (C) 2011, Christopher Olah (chris@colah.ca)
-- Released under the GNU GPL, see LICENSE

{-# LANGUAGE ViewPatterns #-}

-- Let's make it convenient to run our extended openscad format code

-- Let's be explicit about what we're getting from where :)
import System.Environment (getArgs)
import System.IO (openFile, IOMode (ReadMode), hGetContents, hClose)
import Graphics.Implicit (runOpenscad, writeSVG, writeSTL, writeOBJ, writeSCAD3, writeSCAD2, writeGCodeHacklabLaser, writeTHREEJS)
import Graphics.Implicit.ExtOpenScad.Definitions (OpenscadObj (ONum))
import Graphics.Implicit.ObjectUtil (getBox2, getBox3)
import Graphics.Implicit.Definitions (xmlErrorOn, errorMessage)
import Data.Map as Map
import Text.ParserCombinators.Parsec (errorPos, sourceLine)
import Text.ParserCombinators.Parsec.Error
import Data.IORef (writeIORef)

-- | strip a .scad or .escad file to its basename.
strip :: String -> String
strip filename = case reverse filename of
	'd':'a':'c':'s':'.':xs     -> reverse xs
	'd':'a':'c':'s':'e':'.':xs -> reverse xs
	_                          -> filename

-- | Get the file type ending of a file
--  eg. "foo.stl" -> "stl"
fileType filename = reverse $ beforeFirstPeriod $ reverse filename
	where
		beforeFirstPeriod []       = [] 
		beforeFirstPeriod ('.':xs) = []
		beforeFirstPeriod (  x:xs) = x : beforeFirstPeriod xs

getRes (Map.lookup "$res" -> Just (ONum res), _, _) = res

getRes (_, _, obj:_) = min (minimum [x,y,z]/2) ((x*y*z)**(1/3) / 22)
	where
		((x1,y1,z1),(x2,y2,z2)) = getBox3 obj
		(x,y,z) = (x2-x1, y2-y1, z2-z1)

getRes (_, obj:_, _) = min (min x y/2) ((x*y)**0.5 / 30)
	where
		((x1,y1),(x2,y2)) = getBox2 obj
		(x,y) = (x2-x1, y2-y1)

getRes _ = 1

-- | Give an openscad object to run and the basename of 
--   the target to write to... write an object!
executeAndExport :: String -> String -> IO ()
executeAndExport content targetname = case runOpenscad content of
	Left err -> 
		let
			line = sourceLine . errorPos $ err
			msgs = errorMessages err
		in errorMessage line $ showErrorMessages 
			"or" "unknown parse error" "expecting" "unexpected" "end of input"
            (errorMessages err)
	Right openscadProgram -> do 
		s@(vars, obj2s, obj3s) <- openscadProgram 
		let
			res = getRes s
		case s of 
			(_, [], [])   -> putStrLn "Nothing to render"
			(_, x:xs, []) -> do
				putStrLn $ "Rendering 2D object to " ++ targetname ++ ".svg"
				putStrLn $ show x
				writeSVG res (targetname ++ ".svg") x
			(_, _, x:xs)  -> do
				putStrLn $ "Rendering 3D object to " ++ targetname++ ".stl"
				putStrLn $ show x
				writeSTL res (targetname ++ ".stl") x

-- | Give an openscad object to run and the basename of 
--   the target to write to... write an object!
executeAndExportSpecifiedTargetType :: String -> String -> String -> IO ()
executeAndExportSpecifiedTargetType content targetname formatname = case runOpenscad content of
	Left err -> putStrLn $ show $ err
	Right openscadProgram -> do 
		s@(vars, obj2s, obj3s) <- openscadProgram 
		let
			res = getRes s
		case (formatname, s) of 
			(_, (_, [], []))   -> putStrLn "Nothing to render"
			("svg", (_, x:xs, _)) -> do
				putStrLn $ "Rendering 2D object to " ++ targetname
				writeSVG res targetname x
			("ngc", (_, x:xs, _)) -> do
				putStrLn $ "Rendering 2D object to " ++ targetname
				writeGCodeHacklabLaser res targetname x
			("scad", (_, x:xs, _))  -> do
				putStrLn $ "Rendering 3D object to " ++ targetname
				writeSCAD2 res targetname x
			("stl", (_, _, x:xs))  -> do
				putStrLn $ "Rendering 3D object to " ++ targetname
				writeSTL res targetname x
			("scad", (_, _, x:xs))  -> do
				putStrLn $ "Rendering 3D object to " ++ targetname
				writeSCAD3 res targetname x
			("obj", (_, _, x:xs))  -> do
				putStrLn $ "Rendering 3D object to " ++ targetname
				writeOBJ res targetname x
			("js", (_, _, x:xs))  -> do
				putStrLn $ "Rendering 3D object to " ++ targetname
				writeTHREEJS res targetname x
			(otherFormat, _) -> putStrLn $ "Unrecognized format: " ++ otherFormat

		

main :: IO()
main = do
	args <- getArgs
	if Prelude.null args || args == ["--help"] || args == ["-help"]
		then putStrLn $ 
			"syntax: extopenscad inputfile.escad [outputfile.format]\n"
			++ "eg. extopenscad input.escad out.stl"
		else do
			let
				args' = if head args == "-xml-error" then tail args else args
			writeIORef xmlErrorOn (head args == "-xml-error")
			case length args' of
				0 -> putStrLn $ 
					"syntax: extopenscad inputfile.escad [outputfile.format]\n"
					++ "eg. extopenscad input.escad out.stl"
				1 -> do
					f <- openFile (args' !! 0) ReadMode
					content <- hGetContents f 
					executeAndExport content (strip $ args' !! 0)
					hClose f
				2 -> do
					f <- openFile (args' !! 0) ReadMode
					content <- hGetContents f 
					executeAndExportSpecifiedTargetType 
						content (args' !! 1) (fileType $ args' !! 1)
					hClose f