module Generics where

import Data.Map (Map)
import qualified Data.Map as M

data Name = Persons | Events | Else
	deriving (Show, Ord, Eq)

maxMsg :: Name -> Int
maxMsg Persons = 3
maxMsg Events = 2
maxMsg Else = 4

messagesMap :: Map Name [String]
messagesMap = M.fromList messages

messages :: [(Name, [String])]
messages =
	[ (Events,
		[ "Mustard eating competition"
		, "Procrastinating"
		, "Boooooze"
		, "Random rants"
		])
	, (Persons,
		[ "Leeroy Jenkins"
		, "Teckno Vicking"
		, "Truck"
		, "Standing cat"
		])
	, (Else,
		[ "Go away!"
		, "Dschungelgelöt"
		, "legacy Code"
		, "42"
		])
	]

transform :: (Ord ki, Ord ko) => ((ki, vi) -> (ko, vo)) -> Map ki vi -> Map ko vo
transform f input = M.fromList $ map f (M.toList input)

cropByName :: (Name, [String]) -> (Name, [String])
cropByName (name, messages) = (name, take (maxMsg name) messages)

countByKey :: (k, [v]) -> (k, Int)
countByKey (key, values) = (key, length values)

main :: IO ()
main = do
	putStrLn $ show messagesMap
	putStrLn $ show $ transform cropByName messagesMap
	putStrLn $ show $ transform countByKey messagesMap
	return ()