module Main where

import PascalParser

import System

import Control.Monad

import Data.Either

import Data.List

import Data.Graph

import Data.Maybe

unident :: Identificator -> String

unident (Identificator s) = s

extractUnits :: PascalUnit -> (String, [String])

extractUnits (Program (Identificator name) (Implementation (Uses idents) _ _) _) = ("program " ++ name, map unident idents)

extractUnits (Unit (Identificator name) (Interface (Uses idents1) _) (Implementation (Uses idents2) _ _) _ _) = (name, map unident $ idents1 ++ idents2)

f :: [(String, [String])] -> String

f = unlines . map showSCC . stronglyConnComp . map (\(a, b) -> (a, a, b))

    where

    showSCC (AcyclicSCC v) = v

    showSCC (CyclicSCC vs) = intercalate ", " vs

myf :: [(String, [String])] -> String

myf d = unlines . map (findCycle . fst) $ d

    where

    findCycle :: String -> String

    findCycle searched = searched ++ ": " ++ (intercalate ", " $ fc searched [])

        where

        fc :: String -> [String] -> [String]

        fc curSearch visited = let uses = curSearch `lookup` d; res = dropWhile null . map t $ fromJust uses in if isNothing uses || null res then [] else head res

            where

            t u =

                if u == searched then

                    [u]

                    else

                    if u `elem` visited then

                        []

                        else

                        let chain = fc u (u:visited) in if null chain then [] else u:chain

main = do

    fileNames <- getArgs

    files <- mapM readFile fileNames

    putStrLn . myf . map extractUnits . rights . map parsePascalUnit $ files