-- |
-- Module      :  Melodics.Executable
-- Copyright   :  (c) OleksandrZhabenko 2019-2020
-- License     :  MIT
-- Maintainer  :  olexandr543@yahoo.com
--
-- A program and a library that can be used as a musical instrument synthesizer or for Ukrainian speech synthesis 
-- especially for poets, translators and writers. 
--

module Melodics.Executable where

import Data.Char (isSpace, isControl)
import Data.Maybe (isJust,fromJust,fromMaybe)
import System.IO
import System.IO.Unsafe (unsafePerformIO)
import System.Process (callProcess)
import System.Directory (removeFile,findExecutable)
import Control.Exception (bracketOnError)
import EndOfExe (showE)
import Melodics.Ukrainian (appendS16LEFile, convertToProperUkrainian)
import UkrainianLControl

-- | Is used to repeat the cycle of creation of the sound files in the current directory for the @mmsyn6ukr@  executable. 
circle :: String -> IO ()
circle zs = bracketOnError (do
  putStrLn "Please, specify the name of the resulting sound file. Please, do NOT use '}' character and space or control characters!"
  nameOfSoundFile <- getLine
  let nameSF = filter (\x -> not (isSpace x) && not (isControl x) && x /= '}') nameOfSoundFile
  return (zs, nameSF)) (\(zs, nameSF) -> do
    putStr "Notice, there was (may be) CmdLineArgument exception. To avoid it, please, specify the command line argument (if needed) in the form \"ABC\""
    putStr " where A is either a letter \'f\', \'o\', \'w\' or a digit and B and C are both digits! The exception (may be) arose from "
    putStrLn $ "the command line arguments " ++ show zs ++ " for the file: " ++ show nameSF ++ 
       ". Please, check also whether the SoX was installed with the support for needed codec.") 
        (\(zs, nameSF) -> workWithInput zs nameSF >> circle zs)

-- | Interactively creates sound files in the current directory for the Ukrainian text input. Is used internally in the 'circle'
workWithInput :: String -> String -> IO ()
workWithInput zs nameSF 
 | null nameSF = putStrLn "The program circles now because there is no valid file name provided to be created. "
 | otherwise = do
     xs <- getContents
     let ys = take (nSymbols . fst . genControl $ zs) xs
     withBinaryFile (nameSF ++ ".raw") AppendMode (appendS16LEFile (convertToProperUkrainian ys))
     putStrLn "The .raw file was created by the program. If there is SoX installed then it will run further. "
     let ts = showE "sox" 
     if isJust ts
       then rawToSoundFile zs nameSF (fromJust ts)
       else printInfoF

-- | Converts RAW sound to the sound file of the needed format in the current directory accordingly to the 'genControl' for the first 'String' argument. 
-- Is used internally in the 'workWithInput'.
rawToSoundFile :: String -> String -> FilePath -> IO ()
rawToSoundFile zs nameSF executablePath 
  | null zs = do 
     callProcess executablePath ["-r22050","-c1","-L","-esigned-integer","-b16", nameSF ++ ".raw", nameSF ++ ".wav"]
     removeFile $ nameSF ++ ".raw"
  | otherwise = do
     let ws = snd . genControl $ zs
     callProcess executablePath ["-r22050","-c1","-L","-esigned-integer","-b16", nameSF ++ ".raw", fst ws, nameSF ++ snd ws] 
     removeFile $ nameSF ++ ".raw"

-- | Prints informational message about ending of the possible for the given data program operation on sound files. Is used internally in the 'workWithInput'.
-- Is used internally in the 'workWithInput'.
printInfoF :: IO ()
printInfoF = do 
  putStr "You have a resulting file in a raw PCM format with bitrate 22050 Hz and 1 channel (mono) in the .raw format. "
  putStr "You can further process it by yourself manually, otherwise, please, install FFMpeg or LibAV executables in the directory mentioned in the variable PATH"
  putStrLn " and then run: "
  putStrLn "\"name_of_FFMpeg_or_LibAV_executable\" -f s16le -acodec pcm_s16le -ac 1 -ar 22050 -i \"name_Of_the_sound_file\" \"the_same_name_without_.raw_ending_and_with_.wav_ending\""
  putStrLn ""
  putStrLn "OR you can install SoX executable in the directory mentioned in the variable PATH and then run: "
  putStrLn "\"Path_to_the_SoX_executable\" -b16 -r22050 -c1 -e signed-integer -L \"name_of_the_file_in_raw_format_with_new._prefix\" \"name_of_the_file_in_raw_format_with_new._prefix\" in the terminal."