module Clock (addDelta, fromHourMin, toString) where

data Clock = Clock {clockHour :: Int
                    , clockMinute :: Int
                    } deriving (Eq, Show)

fromHourMin :: Int -> Int -> Clock
fromHourMin hour min = do
    let
        initialHour =
            if hour == 0
                then 0
                else
                    if hour > 0
                        then hour
                        else 24 - (rem (abs hour) 24)
        initialMinutes =
            if min == 0
                then 0
                else
                    if min > 0
                        then min
                        else 60 - (abs min)
        -- initialHour and initialMinutes are positive only
        hourMinusMinuteCheck =
            if min < 0
                then initialHour - 1
                else initialHour
        secondaryHour =
            if initialMinutes > 0
                then hourMinusMinuteCheck + (quot initialMinutes 60)
                else hourMinusMinuteCheck - (quot initialMinutes 60)
        finalHour =
            if secondaryHour > 23
                then rem secondaryHour 24
                else secondaryHour
        finalMinutes =
            if initialMinutes == 60
                then 0
                else rem initialMinutes 60
    Clock {clockHour = finalHour, clockMinute = finalMinutes}

toString :: Clock -> String
toString clock = convertToDoubleDigitString (clockHour clock) ++ ":" ++ convertToDoubleDigitString (clockMinute clock)

addDelta :: Int -> Int -> Clock -> Clock
addDelta hour min clock = error "You need to implement this function."

convertToDoubleDigitString :: Int -> String
convertToDoubleDigitString int =
    if (int < 10)
        then "0" ++ (show int)
        else (show int)