minecraft resizing structures

module Main where

import Data.List

main = writeFile "testoutput.txt" $ resize 22

root = "summon MinecartCommandBlock ~ ~1 ~ {"
slime = "Riding:{id:Slime,Size:-2,"
cart = "Riding:{id:MinecartCommandBlock,"
kill = "kill @e[type=MinecartCommandBlock,r=1]"
c1 = ",Command:"
c2 = "}"

carts = cycle . reverse $ (slime ++ cart) : replicate 8 cart
cartsN :: Int -> String
cartsN n = concat . reverse . take n $ carts

nines :: [a] -> [[a]]
nines (a:b:c:d:e:f:g:h:i:xs) = [a,b,c,d,e,f,g,h,i] : nines xs
nines xs = [xs]

format :: [String] -> String
format = concat . concat . intersperse [c2] . map reverse . nines . map ((c1++).(++c2)) . (kill:) . reverse

compress :: [String] -> String
compress [] = []
compress xs = root ++ cartsN (length xs) ++ tail (format xs)


data D = X|Y|Z
posRel1 :: D -> Int -> String
posRel1 X n = " ~"++show n++" ~-2 ~1"
posRel1 Y n = " ~1 ~"++show (n-3)++" ~1"
posRel1 Z n = " ~1 ~-2 ~"++show n

posRel2 :: Int -> D -> Int -> String
posRel2 m X n = " ~"++show n++" ~"++show (m-3)++" ~"++show m
posRel2 m Y n = " ~"++show m++" ~"++show (n-3)++" ~"++show m
posRel2 m Z n = " ~"++show m++" ~"++show (m-3)++" ~"++show n

resize' :: D -> Int -> [String]
resize' d n = (fromToWidth n (2*n) 1):steps n
  where
    fromToWidth a b w = "clone" ++ posRel1 d a ++ posRel2 (2*n) d (a+w-1) ++ posRel1 d b
    steps 1 = []
    steps 2 = [fromToWidth 2 3 1, fromToWidth 1 2 1]
    steps n = let n' = n-1 in fromToWidth n' (2*n') 2 : steps n'

resize n = compress $ concatMap (flip resize' n) [Y,X,Z]