module Main where

import Data.Array.Unboxed
import Data.List (maximumBy, sortBy, sortOn, groupBy)
import Data.Ord (comparing)
-- import Data.Ratio

import Input

main :: IO ()
main = do
    inp <- getInput 10
    let h = length inp
        w = length (head inp)
        arr = array ((0, 0), (w-1, h-1)) [((x, y), c == '#') | (y, row) <- zip [0..] inp, (x, c) <- zip [0..] row]
                :: UArray (Int, Int) Bool
        asts = map fst (filter snd (assocs arr))
        sight (a,b) (x,y) =
            let dx = (x - a) `div` g
                dy = (y - b) `div` g
                g = gcd (abs (x - a)) (abs (y - b))
                pts = [(a + i * dx, b + i * dy) | i <- [1..g-1]]
            in all (not . (arr !)) pts
        numVisible p = length (filter (\q -> q /= p && sight p q) asts)
        -- (cent@(centx, centy), centNumVis) = maximumBy (comparing snd) (zip asts (map numVisible asts))
        (cent@(centx, centy), centNumVis) = ((8, 3), 42)

    print centNumVis

    print cent

    let -- atan2R' dy dx
        --     | dy <= 0, dx < 0 = abs dy % abs dx : -inf -> 0
        --     | dy > 0, dx < 0 = abs dy % abs dx : 0 -> inf
        --     | dy > 0, dx == 0 = 0
        --     | dy > 0, dx > 0 = abs dy % abs dx : inf -> 0
        --     | dy <= 0, dx > 0 = abs dy % abs dx : 0 -> -inf
        --     | dy < 0, dx == 0 = 1
        --     | otherwise = undefined  -- (dx, dy) == (0, 0)
        threeLine (cx, cy) (a, b) (x, y) = (a - cx) * (y - cy) == (x - cx) * (b - cy)
        distsq (a, b) (x, y) = (x - a) * (x - a) + (y - b) * (y - b)
        otherAsts = sortOn (\(x, y) -> atan2 (fromIntegral (centx - x) :: Double) (fromIntegral (y - centy)))
                           (filter (/= cent) asts)
        groups' = map (sortBy (comparing (distsq cent))) (groupBy (threeLine cent) otherAsts)
        groups = last groups' : init groups'
        zapRound l = (map head l, filter (not . null) (map tail l))
        zapped = concat (takeWhile (not . null) (map fst (tail (iterate (zapRound . snd) (undefined, groups)))))

    mapM_ print groups
    print zapped
    print (zapped !! 199)

    -- let (n200x, n200y) = otherAsts !! 199
    -- print (n200x * 100 + n200y)