module Text.Help.Fungi (
    help
  ) where

import Data.ByteSize (byteSize)
import Data.Char (toLower)
import Data.Int
import Data.List (sort, intercalate, nub)
import Data.Maybe (fromMaybe)

import System.Environment (getProgName)
import System.FilePath (dropExtension)

import Text.PrintOption

-----------------------------------------------------------

p :: Char -> String -> String -> IO ()
p = printOption

b :: Char -> String -> String -> IO ()
b = printOptionWith defaultPrintSettings { bulletDelim = Just "***" }

supportedSizes :: String
supportedSizes = intercalate ", " $ map show $ sort $ nub $ map (fromMaybe 0) [
    byteSize (0 :: Integer)
  , byteSize (0 :: Int)
  , byteSize (0 :: Int8)
  , byteSize (0 :: Int16)
  , byteSize (0 :: Int32)
  , byteSize (0 :: Int64)
  ]

fingerprints :: String
fingerprints = intercalate ", " $ sort [
    "BASE"
  , "BOOL"
  , "CPLI"
  , "FIXP"
  , "MODE"
  , "MODU"
  , "NULL"
  , "ORTH"
  , "REFC"
  , "ROMA"
  ]

line :: IO ()
line = putStrLn $ replicate 80 '-'

help :: IO ()
help = do
  line
  progName <- fmap (map toLower . dropExtension) getProgName
  putStrLn $ "Usage: " ++ progName ++ " [OPTIONS] [PROGRAM FILE] [PROGRAM ARGS]"
  line
  putStrLn $ "Options:"
  p '?' "help" "Display this help message."
  b 'd' "debug [MODE=1]" $ concat [
      "Run program using debugger."
    , "***MODE=1,on,true: Run debugger in step mode."
    , "***MODE=0,off,false: Run without debugger."
    , "\nDefault is off."
    ]
  p 's' "cell-size SIZE" $ concat [
      "Set the funge cell byte size to SIZE.\n"
    , "Supported sizes are " ++ supportedSizes ++ ".\n"
    , "If SIZE <= 0 then cell size is unbounded.\n"
    , "Default is " ++ show (fromMaybe 0 $ byteSize (0 :: Int)) ++ "."
    ]
  b 'n' "dim DIM" $ concat [
      "Set the funge dimensions to DIM."
    , "\nDefault depends on file extension:"
    , "***uf u98: 1"
    , "***bf b98: 2"
    , "***tf t98: 3"
    , "\nAll other extensions default to 2."
    , "\nAllowed values: 0 < DIM <= " ++ show (maxBound :: Int) ++ "."
    ]
  b 'u' "unknown MODE" $ concat [
      "What to do when encountering an unknown instruction."
    , "***MODE=reverse: Reverse on unknown instruction."
    , "***MODE=debug: Launch debugger on unknown instruction. Instruction reverses."
    , "***MODE=fail: Terminate program on unknown instruction."
    , "\nDefault is reverse."
    ]
  line
  p ' ' "FINGERPRINTS--" fingerprints
  line