--  wwffwfwf - generates truth tables from logic expressions
--  Copyright (C) 2024 VegOwOtenks
--
--  This program is free software: you can redistribute it and/or modify
--  it under the terms of the GNU Affero 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 Affero General Public License for more details.
--
--  You should have received a copy of the GNU Affero General Public License
--  along with this program.  If not, see <https://www.gnu.org/licenses/>.
--
--  contact me via vegowotenks at jossco dot de
module Main (main) where

import Lib

import qualified Data.Set as Set
import qualified Data.Map as Map
import Data.Either (rights, lefts)
import Data.List (intercalate)

parseInputLine :: Int -> String -> Either ParseError Expression
parseInputLine n s = parseFullString ("stdin:" ++ show n) s

title :: [String] -> String
title ns = " " ++ intercalate " | " ns

header :: [Int] -> String
header ws = intercalate "|" . map (flip replicate '-' . (+2) ) $ ws

row :: [Int] -> [Bool] -> String
row ws rs = intercalate "|" $ (zipWith row' ws rs)
    where
        row' :: Int -> Bool -> String
        row' w b = replicate (left+1) ' ' ++ (if b then "1" else "0") ++ replicate (right+1) ' '
            where
                left  = (w-1) `div` 2
                right = (w-1) - left

main :: IO ()
main = do
    equation_strings <- fmap lines getContents
    let equation_expressions = zipWith parseInputLine [0..] equation_strings

-- TODO: Show proper error messages
    _ <- mapM putStrLn . map show . lefts $ equation_expressions

    let variable_names     = Set.toAscList . Set.unions . map collectVariableNames . rights $ equation_expressions
    let value_combinations = mapM (const [True, False]) [1..length variable_names]
    let value_maps         = map Map.fromList $ zipWith (zipWith (,)) (cycle [variable_names]) value_combinations

    let expression_strings = variable_names ++ equation_strings
    let column_widths      = map length expression_strings

    putStrLn . title  $ expression_strings
    putStrLn . header $ column_widths

    let expressions        = rights $ map (parseFullString "<internal>") variable_names ++ equation_expressions

    let results = map (\m -> map (evaluate m) expressions) value_maps

    mapM_ putStrLn . map (row column_widths) $ results