-- |
-- Module      :  MMSyn7l
-- Copyright   :  (c) OleksandrZhabenko 2020
-- License     :  MIT
--
-- Stability   :  Experimental
-- Maintainer  :  olexandr543@yahoo.com
--
-- A program and a library to modify the amplitude of the sound representations for 
-- the Ukrainian language created by mmsyn7ukr package or somehow otherwise.
--

module MMSyn7l where

import Data.Char (toUpper, isDigit)
import qualified SoXBasics as SB
import qualified SoXBasics1 as SB1
import qualified Data.Vector as V
import Control.Exception (onException)
import CaseBi (getBFst')

-- | Function 'changeVolume' is used to change the amplitude of the sound. 
-- For the proper proceeding you specify a @String@, which consists of 4 
-- digits (and it may be preceded by a symbol \"-\"). If the @String@ 
-- begins with the \"-\", then a sound amplitude decreases, otherwise 
-- the amplitude increases. The level of increase / decrease is 
-- determined by the magnitude of the absolute value of integer numbers. 
-- The greater is the number -- the greater is the amplitude change. 
-- The count begins with \"0000\" and ends with \"9999\" (the sign is not 
-- taken into consideration). If there is less than 4 digits in a @String@, 
-- then the @String@ is equivalent to that one with the appropriate number 
-- of zeroes preceding to fulfill to the 4 needed digits (for example, 
-- \"657\" is equivalent to \"0657\", \"-2\" is equivalent to \"-0002\" etc.) 
-- In such a case, for the @String@s without the 
-- initial sign \"-\" (the sound increases) an interval between the 
-- maximum by modulus value of the amlitude (which is represented by the 
-- parts of 1) and 1.0 is divided into 10 equal parts (starting a count 
-- from 0) and then that one of them is selected, which has a number 
-- determined by the first digit in the @String@ writing. Then (if specified 
-- further) the interval between this amplitude value and a value, 
-- which corresponds to the selection on the previous step the next 
-- first digit in the writing (for example, after \"4\" -- \"5\", 
-- after \"7\" -- \"8\" etc.), greater by 1 than the actually selected one, 
-- is also divided again into 10 equal parts and that one is selected, 
-- which corresponds to the number determined by the second digit in the 
-- String writing (again beginning with \"0\" and ending with \"9\") and so on 
-- until the 4th level. The greater exactness is not needed because our 
-- hearing ability hardly distinguish such a subtle sound changes. If 
-- the @String@ has as a first element the \'-\' @Char@ (the sound decreases), 
-- then everything is analogously the same, but an interval between the 
-- maximum by modulus amplitude value and 0.0 is divided into 10 equal parts 
-- and so on.
changeVolume :: FilePath -> IO ()
changeVolume file = do
  SB.playA file
  let sound = getBFst' ("е", V.fromList . zip ["A.wav", "B.wav", "C.wav", "D.wav", "E.wav", "F.wav", "G.wav", "H.wav", 
        "I.wav", "J.wav", "K.wav", "L.wav", "M.wav", "N.wav", "O.wav", "P.wav", "Q.wav", "R.wav", 
          "S.wav", "T.wav", "U.wav", "V.wav", "W.wav", "X.wav", "Y.wav", "Z.wav", "a.wav", "b.wav", "c.wav", 
            "d.wav", "e.wav", "f.wav"] $ ["а","б","в","г","д","дж","дз", "е","ж","з","и","й","к","л","м","н","о","п","р",
              "с","сь","т","у","ф","х","ц","ць","ч","ш","ь","і","ґ"]) file
  putStrLn $ "You can now change the volume for the played sound representation for the Ukrainian sound " ++ show (map toUpper sound)
  putStrLn ""
  putStr "Please, specify the change by passing a String of digits (with may be a preceding symbol \'-\'). "
  putStr ""
  putStr "For the proper proceeding you specify a String, which consists of 4 "
  putStr "digits (and it may be preceded by a symbol \"-\"). If the String "
  putStr "begins with the \"-\", then a sound amplitude decreases, otherwise "
  putStr "the amplitude increases. The level of increase / decrease is "
  putStr "determined by the magnitude of the absolute value of integer numbers. "
  putStr "The greater is the number -- the greater is the amplitude change. "
  putStr "The count begins with \"0000\" and ends with \"9999\" (the sign is not "
  putStr "taken into consideration). If there is less than 4 digits in a String, "
  putStr "then the String is equivalent to that one with the appropriate number "
  putStr "of zeroes preceding to fulfill to the 4 needed digits (for example, "
  putStr "\"657\" is equivalent to \"0657\", \"-2\" is equivalent to \"-0002\" etc.). "
  putStr "In such a case, for the Strings without the "
  putStr "initial sign \"-\" (the sound increases) an interval between the "
  putStr "maximum by modulus value of the amlitude (which is represented by the "
  putStr "parts of 1) and 1.0 is divided into 10 equal parts (starting a count "
  putStr "from 0) and then that one of them is selected, which has a number "
  putStr "determined by the first digit in the String writing. Then (if specified "
  putStr "further) the interval between this amplitude value and a value, "
  putStr "which corresponds to the selection on the previous step the next "
  putStr "first digit in the writing (for example, after \"4\" -- \"5\", "
  putStr "after \"7\" -- \"8\" etc.), greater by 1 than the actually selected one, "
  putStr "is also divided again into 10 equal parts and that one is selected, "
  putStr "which corresponds to the number determined by the second digit in the "
  putStr "String writing (again beginning with \"0\" and ending with \"9\") and so on "
  putStr "until the 4th level. The greater exactness is not needed because our "
  putStr "hearing ability hardly distinguish such a subtle sound changes. If "
  putStr "the String has as a first element the \'-\' Char (the sound decreases), "
  putStr "then everything is analogously the same, but an interval between the "
  putStr "maximum by modulus amplitude value and 0.0 is divided into 10 equal parts "
  putStrLn "and so on. "
  onException (specifyVol file) (do
    putStrLn ""
    putStrLn "Something went wrong for the sound representation, please, check the input value and repeat once more! "
    specifyVol file)

-- | Function 'specifyVol' is used internally in the 'changeVolume' to get the @String@ and to apply the needed change. 
specifyVol :: FilePath -> IO ()
specifyVol file = do   
  change0 <- getLine
  upperbound <- SB.upperBnd file
  (originalStr, bool) <- SB.selMaxAbs file (0::Int, upperbound)
  if bool 
    then changeVol3 file (change0, originalStr)
    else changeVol4 file (change0, originalStr)

-- | Function 'changeVol2' is used internally in the 'specifyVol' in case of decreasing of the sound.
changeVol2 :: FilePath -> String -> Double -> IO ()
changeVol2 file xs ampl = do 
  let ys = take 4 . filter isDigit $ xs
      coefA = 0.0001 * fromIntegral (read ys::Int)
      ratio = 1.0 - coefA
  SB1.volS file (ratio * ampl)
  
-- | Function 'changeVol3' is used internally in the 'specifyVol' in case of working with the maximum amplitude.
changeVol3 :: FilePath -> (String, String) -> IO ()
changeVol3 file (change0, originalStr) = do
  let ampl = read originalStr::Double
  if ampl > 0.0 
    then do 
      let delta = 1.0 - ampl
          xs = filter (\x -> isDigit x || x == '-') change0
      if take 1 xs == "-" 
        then changeVol2 file xs ampl
        else do 
          let ys = take 4 . takeWhile (isDigit) $ xs
              coefA = 0.0001 * fromIntegral (read ys::Int)
              ratio = 1.0 + (delta / ampl) * coefA
          SB1.volS file (ratio * ampl)
    else error "SoXBasics1: the volS function gave a strange result!"

-- | Function 'changeVol4' is used internally in the 'specifyVol' in case of working with the minimum amplitude.
changeVol4 :: FilePath -> (String, String) -> IO ()
changeVol4 file (change0, originalStr) = do
  let ampl = read originalStr::Double
  if ampl < 0.0
    then do 
      let delta = (-1.0) - ampl
          xs = filter (\x -> isDigit x || x == '-') change0
      if take 1 xs == "-" 
        then changeVol2 file xs ampl
        else do 
          let ys = take 4 . filter isDigit $ xs
              coefA = 0.0001 * fromIntegral (read ys::Int)
              ratio = 1.0 + (delta / ampl) * coefA
          SB1.volS file (ratio * ampl)
    else error "SoXBasics1: the volS function gave a strange result!"