sheet-parser-hs/lib/DND/Sheet/Parser.hs

72 lines
2.4 KiB
Haskell

module DND.Sheet.Parser
( parseSheet
, createExample
, getName
, getStat
, getSkill
, getSkillNames
, getStatNames
, getSkillScore
, getProficiency
) where
import Control.Monad
import Data.Aeson
import qualified Data.ByteString.Lazy as B
import qualified Data.ByteString.Lazy.UTF8 as BSU
import Data.Maybe (fromJust)
import DND.Bob (bob)
import DND.Sheet.Content
import qualified Data.Map as Map
parseSheet :: FilePath -> IO Character
parseSheet x = unwrap . decode =<< B.readFile x
where unwrap (Just y) = return y
unwrap Nothing = error $ "Failed to parse character sheet: " ++ x
createExample :: FilePath -> IO ()
createExample = flip encodeFile bob
getName :: Character -> String
getName = charName . preamble
getStat :: Character -> String -> Stat
getStat char s = head . filter (\a -> statName a == s) . stats $ char
getSkill :: Character -> String -> Skill
getSkill char s = head . filter (\a -> skillName a == s) . skills $ char
getSkillNames :: Character -> [String]
getSkillNames = map skillStat . skills
getStatNames :: Character -> [String]
getStatNames = map statName . stats
getProficiency :: Character -> Int
getProficiency = fromJust . flip Map.lookup profTable . charLevel . preamble
-- https://www.nerdsandscoundrels.com/how-to-calculate-proficiency-bonus-5e/
-- for some fucking reason there appears to be no simple mathematical way to get a character's proficiency bonus
where profTable = Map.fromList
[ (1,2), (2,2), (3,2), (4,2)
, (5,3), (6,3), (7,3), (8,3)
, (9,4), (10,4), (11,4), (12,4)
, (13,5), (14,5), (15,5), (16,5)
, (17,6), (18,6), (19,6), (20,6)
]
-- https://worldbuildersjunction.com/dungeon-and-dragons-ability-scores-explained-for-beginners/
-- from the Go implementation
-- return (stat.Score - 10) / 2
getSkillScore :: Character -> String -> Int
getSkillScore char skillString = let
skill = getSkill char skillString
stat = getStat char $ skillStat skill
prof = getProficiency char
modifier = case skillMod skill of
Proficient -> prof
Expertise -> prof * 2
Half -> div prof 2
None -> 0
in (modifier +) . (`div` 2) $ statScore stat - 10