{-# OPTIONS_HADDOCK show-extensions #-}

-- |
-- Module      :  Interpreter.StringConversion
-- Copyright   :  (c) OleksandrZhabenko 2021
-- License     :  MIT
-- Stability   :  Experimental
-- Maintainer  :  olexandr543@yahoo.com
--
-- A library that has commonly used function for the phonetic-languages implementations.

module Interpreter.StringConversion where

import Text.Read (readMaybe)
import Data.Maybe
import Data.Char (isDigit)
import Data.List (sort,nub,intercalate,(\\))
import Data.Monoid (mappend)

convStringInterpreter :: String -> String -> String
convStringInterpreter contrs xs
 | null contrs = xs
 | length (nub . filter (\t -> t >= '1' && [t] <= show (length . words $ xs)) $ contrs) < 2 = xs
 | otherwise = let cntrs = nub . filter (\t -> t >= '1' && [t] <= show (length . words $ xs)) $ contrs
                   tss = words xs in
                     case length cntrs of
                      2 -> let pos = fromJust (readMaybe (take 1 cntrs)::Maybe Int)
                               number = fromJust (readMaybe (drop 1 cntrs)::Maybe Int)
                               (zss,yss) = splitAt (pos - 1) tss
                               (kss,lss) = splitAt number yss in
                                 if length tss < pos + number - 1 then xs
                                 else if null zss then concat kss `mappend` " " `mappend` intercalate " " lss
                                      else intercalate " " zss `mappend` " " `mappend` concat kss `mappend` " " `mappend` intercalate " " lss
                      _ -> let idxs = map (\x -> fromJust (readMaybe [x]::Maybe Int)) $ cntrs
                               wordsN = map (\i -> tss !! (i - 1)) idxs
                               restWords = tss \\ wordsN
                                 in intercalate " " restWords `mappend` " " `mappend` concat wordsN