{-
Make text match the capitalization, punctuation, and spacing of the
1st amendment.

Copyright 2016 Ken Takusagawa

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
-}

-- originally from simple-cipher/cipher.ll
{-# LANGUAGE ScopedTypeVariables, LambdaCase #-}
module Main(main) where {
import Control.Category((>>>));
import Prelude hiding((>>));
import Data.List;
import Data.Char;

import System.Environment(getArgs);

main :: IO();
main = getArgs >>= \case{
-- expecting a series of numbers 0..25 to be mapped to letters
["digits"] -> getContents >>= (words >>> map (read >>> numtochar) >>> do_fst_amd >>> putStrLn);
_ -> getContents >>= (do_fst_amd >>> putStrLn);
};

data Template = Punctuation Char | Modify_case (Char -> Char);  -- no Show derivable because function

one_template :: [Template] -> String -> Maybe (Char,([Template],String));
one_template [] [] = Nothing;
one_template (Punctuation p:trest) s = Just (p,(trest,s));  -- final punctuation gets in
one_template _ [] = Nothing;
one_template (Modify_case f:trest) (s1:rest) = Just (f s1, (trest,rest));
one_template [] _ = error "ran out of template"; -- should have used cycle

apply_template :: [Template] -> String -> String;
apply_template t s = unfoldr (uncurry one_template) (cycle t,s);

to_template :: Char -> Template;
to_template c = if isAlpha c
then Modify_case (if isUpper c then toUpper else toLower)
else Punctuation c;

--- Filler to so the text is unchanged when the program is run on
--- itself for fun: uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
--- uuuuuuuuuuuuuuuuuuuuuuuuuuuu

first_amendment :: String;
first_amendment = "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.  ";  -- spaces needed at the end for cycle

--- 222 alpha characters

do_fst_amd :: String -> String;
do_fst_amd = filter isAlpha >>> apply_template (map to_template first_amendment);

numtochar :: Integer -> Char;
numtochar = fromInteger >>> (+) (fromEnum 'a') >>> toEnum;

} --end