Calculate best rearrange in Discworld MUD.

rearrange.hs

module Rearrange where

import Control.Applicative
import Data.List

main :: IO ()
main = do
  putStrLn $ show (getMaxStats maPo)

data Stats = Stats { str :: Int,
                     dex :: Int,
                     con :: Int,
                     int :: Int,
                     wis :: Int
                   } deriving (Show)

data StatDistr = StatDistr {s1 :: Int,
                     s2 :: Int,
                     s3 :: Int,
                     s4 :: Int,
                     s5 :: Int
                   } deriving (Show)

-- All possible stats, with the specified constraints, str >= 14, or gpRegen == 3 for example.
stats :: (Stats -> StatDistr) -> [Stats]
stats gpSkill = map (\(s,d,c,i,w) -> Stats { str=s,dex=d,con=c,int=i,wis=w}) $ 
        filter (\(a, b, c, d, e) -> 
                 a+b+c+d+e == 65 && 
                 (gpRegen Stats {str=a,dex=b,con=c,int=d,wis=e} gpSkill) == 3 && a >= 14) 
        ( (,,,,) <$> [8..23] <*> [8..23] <*> [8..23] <*> [8..23] <*> [8..23] )
        
gpRegen :: Integral b => t -> (t -> StatDistr) -> b
gpRegen stats gpSkill = floor $ sqrt (175 * m(gpSkill stats)) - 10

-- http://bonuses.irreducible.org/formulas.php
m :: StatDistr -> Float
m (StatDistr { s1=s,s2=d,s3=c,s4=i,s5=w}) = (1.0/9.8) * log((fromIntegral s) *
                                                            (fromIntegral d) *
                                                            (fromIntegral c) *
                                                            (fromIntegral i) *
                                                            (fromIntegral w)) - 0.25

r :: Int -> Int
r levels
  |  0 <= levels, levels <= 20 =   5 * levels
  | 21 <= levels, levels <= 40 = (floor $ 2.5 * (fromIntegral $ levels-20)) + 100
  | 41 <= levels, levels <= 60 =   1 * (levels-40) + 150
  | 61 <= levels               = (floor $ 0.5 * (fromIntegral $ levels-60)) + 170 


bonus :: Int -> StatDistr -> Int
bonus level stats = round $ m stats * (fromIntegral $ r level)

-- Skills to balance stats after
skills :: [(String, Stats -> StatDistr)]
--skills = [("daggers", fiMeDa), ("dodge", fiDeDo), ("shields", faDeSe)]
skills = [("heavy-sword", fiMeHs), ("parry", fiDePa)]


--faDeSe, fiMeDa, fiDeDo :: Stats -> StatDistr
--faDeSe Stats {str=s,dex=d,con=c,int=i,wis=w} = StatDistr {s1=d,s2=d,s3=i,s4=w,s5=w}
--faPo Stats {str=s,dex=d,con=c,int=i,wis=w}   = StatDistr {s1=c,s2=i,s3=i,s4=w,s5=w}
fiMeHs Stats {str=s,dex=d,con=c,int=i,wis=w} = StatDistr {s1=c,s2=d,s3=s,s4=s,s5=s}
fiDePa Stats {str=s,dex=d,con=c,int=i,wis=w} = StatDistr {s1=d,s2=d,s3=d,s4=d,s5=s}
--fiMeDa Stats {str=s,dex=d,con=c,int=i,wis=w} = StatDistr {s1=d,s2=d,s3=d,s4=d,s5=s}
--fiDeDo Stats {str=s,dex=d,con=c,int=i,wis=w} = StatDistr {s1=d,s2=d,s3=d,s4=d,s5=w}
--faPo Stats {str=s,dex=d,con=c,int=i,wis=w} = StatDistr {s1=c,s2=i,s3=i,s4=w,s5=w}
maPo Stats {str=s,dex=d,con=c,int=i,wis=w} = StatDistr {s1=i,s2=i,s3=s,s4=w,s5=w}

getBonuses :: [(String, (Stats -> StatDistr))] -> Stats -> ([Int], Stats)
getBonuses skills stats = ( map (\skill -> bonus 800 $ ((snd skill) stats)) skills, stats)

-- Call this to get the best stats for the chosen skills and constraints.
getMaxStats gpSkill = maximumBy (\lhs rhs -> (fst lhs) `compare` (fst rhs)) $
              map (\myStats ->  getBonuses skills myStats) (stats gpSkill)

Added so you can easily change which GP skill should be used, maPo for example is currently specified in the main function, but now you can change to fiPo if you want.