-- Helper function to map over the error case (Left)
mapLeft :: (e -> e') -> Either e a -> Either e' a
mapLeft f (Left e)  = Left (f e)
mapLeft _ (Right a) = Right a

-- Define placeholder types
newtype Location = Location Int deriving Show
newtype LocationError = LocationError String deriving Show
newtype Weather = Weather String deriving Show
newtype WeatherError = WeatherError String deriving Show
newtype Conditions = Conditions String deriving Show
newtype ConditionsError = ConditionsError String deriving Show

-- Mock functions
getLocation :: String -> Either LocationError Location
getLocation _ = Right (Location 1) -- Example success

getWeather :: Location -> Either WeatherError Weather
getWeather _ = Right (Weather "Sunny") -- Example success

toConditions :: Weather -> Either ConditionsError Conditions
toConditions _ = Right (Conditions "Clear Sky") -- Example success

-- Main logic using do notation
printConditionsAt :: String -> IO ()
printConditionsAt locationId = do
    let result = do
            location <- mapLeft (\e -> "Could not get location by ID: " ++ show e) $ 
                        getLocation locationId
            
            weather <- mapLeft (\e -> "Could not get the weather at location " ++ show location ++ ": " ++ show e) $ 
                       getWeather location
            
            conditions <- mapLeft (\e -> "Could not convert weather to conditions: " ++ show e) $ 
                          toConditions weather
            
            return $ "Weather at " ++ show location ++ ": " ++ show weather ++ " - " ++ show conditions

    case result of
        Left err  -> putStrLn err
        Right msg -> putStrLn msg

-- The entry point that was missing
main :: IO ()
main = printConditionsAt "123"