module Exercise01 where

import Test.QuickCheck

{-H1.1a)-}
myPair :: Integer -> Integer -> Integer
myPair x y = 2^y*(2*x+1)-1 

{-H1.1b)-}
mySnd :: Integer -> Integer
mySnd n
  | mod n 2 == 0 = 0
  | otherwise = mySnd (div n 2) + 1

{-H1.1c)-}
myFst :: Integer -> Integer
myFst n
  | mod n 2 == 0 = div n 2
  | otherwise = myFst (div n 2)

{-H1.1d)-}
prop_myPair :: Integer -> Integer -> Integer -> Property
prop_myPair p x y = p >= 0 && x >= 0 && y >= 0 ==> myPair x y == p 

--prop_myF :: Integer -> Integer -> Property
--prop_myF x y = x >= 0 && y >= 0 ==> myFst (myPair x y) == x
--
--prop_myS :: Integer -> Integer -> Property
--prop_myS x y = x >= 0 && y >= 0 ==> mySnd (myPair x y) == y



{-H2-}
digitToEo :: Integer -> String
digitToEo 0 = "nul"
digitToEo 1 = "unu"
digitToEo 2 = "du"
digitToEo 3 = "tri"
digitToEo 4 = "kvar"
digitToEo 5 = "kvin"
digitToEo 6 = "ses"
digitToEo 7 = "sep"
digitToEo 8 = "ok"
digitToEo 9 = "nau"


{-WETT-}
pwToEo :: Integer -> String
pwToEo n 
  | n == 0 = ""
  | n == 1 = "dek"
  | n == 2 = "cent"
  | n == 3 = "mil"
  | n == 6 = "miliono"
  | n == 9 = "miliardo"
  | mod n 6 == 0 = x ++ "iliono"
  | otherwise = x ++ "iliardo"
  where
    x = numberToEo (div n 6)

helper1 :: Integer -> Integer -> String -> String
helper1 a s c
  | c == "" = ""
  | s == 0 = c
  | a < 2 && s < 6 = ""
  | otherwise = c ++ " "

helper2 :: Integer -> Integer -> String
helper2 a s
  | (s == 0 && a > 0) || (a > 1) = digitToEo a 
  | otherwise = ""

numberToEoB :: Integer -> Integer -> Integer -> Integer -> String
numberToEoB n s mm dd
  | n == 0 = ""
  | a == 0 = x
  | x == "" = b
  | otherwise = x ++ " " ++ b
  where 
    x = numberToEoB (div n mm) (s+dd) mm dd
    a = mod n mm
    c = numberToEoB a 0 10 1
    addJ
      | a > 1 && s > 3 && dd > 1 = "j"
      | otherwise = ""
    d
      | dd == 3 = helper1 a s c
      | otherwise = helper2 a s
    b = d ++ pwToEo s ++ addJ
   
numberToEo :: Integer -> String
numberToEo n
  | n < 10 = digitToEo n
  | otherwise = numberToEoB n 0 1000 3
{-TTEW-}