main :: IO()
main = do
    print $ "hello world"
    print $ "Enter some text right in console!"

plus :: Int -> Int -> Int
plus x y = x + y

minus :: Int -> Int -> Int
minus x y = x - y

mult :: Int -> Int -> Int
mult x y = x * y

divs :: Int -> Int -> Int
divs x y = x / y

divs' :: Int -> Int -> Int
divs' x y = div x y

mods :: Int -> Int -> Int
mods x y = mod x y

addThree :: Int -> Int -> Int -> Int
addThree x y z = x + y + z

factorial :: Int -> Int
factorial n = product [1..n]

bigger :: Int -> Int -> Bool
bigger x y = if x > y then x else y

lucky :: Int -> String
lucky 7 = "You got the right number!"
lucky x = "Sorry, you're out of luck!"

sayMe :: Int -> String
sayMe 1 = "One"
sayMe 2 = "Two"
sayMe 3 = "Three"
sayMe 4 = "Four"
sayMe 5 = "Five"
sayMe x = "Not between 1 and 5"

factorial' :: Int -> Int
factorial' 0 = 1
factorial' 1 = 1
factorial' n = n * factorial (n-1)

charName :: Char -> String
charName 'a' = "Albert"
charName 'b' = "Broseph"
charName 'c' = "Cercil"

addVectors1 :: (Ord a, Num a) => (a,a) -> (a,a) -> (a,a)
addVectors1 x y = (fst x + fst y, snd x + snd y)

addVectors2 :: (Ord a, Num a) => (a,a) -> (a,a) -> (a,a)
addVectors2 (x1,y1) (x2,y2) = (x1+x2,y1+y2)

first :: (a,b,c) -> a
first (x, _, _) = x

second :: (a,b,c) -> b
second (_, y, _) = y

third :: (a,b,c) -> c
third (_, _, z) = z

head :: [Int] -> Int
head [] = error "Can't call head on empty list, dummy"
head (x:_) = x

-- here we don't care about our first argument

length :: [Int] -> Int
length [] = 0
length (_:xs) = 1 + length xs

-- but here we are interested in our first argument

sum :: [Int] -> Int
sum [] = 0
sum (x:xs) = x + sum xs

bmiTell :: (RealFloat a) => a -> String
bmiTell bmi
    | bmi <= 18.5 = "You are underweight"
    | bmi <= 25.0 = "You are normal weight"
    | bmi <= 30.0 = "You are overweight"
    | otherwise = "If you contunue to eat, you are gonna die"

bmiTell1 :: (RealFloat a) => a -> a -> String
bmiTell1 weight height
    | weight / height ^ 2 <= 18.5 = "You are underweight"
    | weight / height ^ 2 <= 25.0 = "You are normal weight"
    | weight / height ^ 2 <= 30.0 = "You are overweight"
    | otherwise = "You are a whale, congratulations"

bmiTell2 :: (RealFloat a) => a -> a -> String
bmiTell2 weight height
    | bmi <= 18.5 = "You are underweight"
    | bmi <= 25.0 = "You are normal weight"
    | bmi <= 30.0 = "You are overweight"
    | otherwise = "You are a whale, congratulations"
        where
            bmi = weight / height ^ 2

bmiTell3 :: (RealFloat a) => a -> a -> String
bmiTell3 weight height
    | bmi <= skinny = "You are underweight"
    | bmi <= normal = "You are normal weight"
    | bmi <= overweight = "You are overweight"
    | otherwise = "You are a whale, congratulations"

max1 :: Int -> Int -> Int
max1 a b
    | a > b = a
    | otherwise = b

min1 :: Int -> Int -> Int
min1 a b
    | a > b = b
    | otherwise = a

maxThree :: Int -> Int -> Int -> Int
maxThree a b c = if (a > b) && (a > c) then a else if (b > a) && (b > c) then b else c

maxThree1 :: Int -> Int -> Int -> Int
maxThree1 a b c
    | (a > b) && (a > c) = a
    | (b > a) && (b > c) = b
    | otherwise = c

myCompare :: Int -> Int -> String
myCompare a b
    | a > b = "GT"
    | a < b = "LT"
    | otherwise = "EQ"