-- |
-- Module      : Text.Bytedump
-- License     : BSD-style
-- Maintainer  : Vincent Hanquez <vincent@snarc.org>
-- Stability   : experimental
-- Portability : unknown
--
-- A module containing some routines to debug data dump
--

module Text.Bytedump
	( hexString

	-- * Formatted string configuration
	, BytedumpConfig(..)
	, defaultConfig

	-- * Dump bytes into not formatted strings
	, dumpRaw
	, dumpRawS
	, dumpRawBS
	, dumpRawLBS

	-- * Dump bytes into formatted strings using a specific config
	, dumpWith
	, dumpWithS
	, dumpWithBS
	, dumpWithLBS

	-- * Dump bytes into formatted strings using default config
	, dump
	, dumpS
	, dumpBS
	, dumpLBS
	) where

import Data.List
import Data.Word
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString as B

-- | Configuration structure used for formatting functions
data BytedumpConfig = BytedumpConfig
	{ configRowSize      :: Int    -- ^ number of bytes per row.
	, configRowGroupSize :: Int    -- ^ number of bytes per group per row.
	, configRowGroupSep  :: String -- ^ string separating groups.
	, configRowLeft      :: String -- ^ string on the left of the row.
	, configRowRight     :: String -- ^ string on the right of the row.
	, configCellSep      :: String -- ^ string separating cells in row.
	, configPrintChar    :: Bool   -- ^ if the printable ascii table is displayed.
	} deriving (Show,Eq)

-- | Default Config using 16 bytes by row with a separation at the 8th byte, and
-- dumping printable ascii character on the right.
defaultConfig :: BytedumpConfig
defaultConfig = BytedumpConfig
	{ configRowSize      = 16
	, configRowGroupSize = 8
	, configRowGroupSep  = " : "
	, configRowLeft      = " | "
	, configRowRight     = " | "
	, configCellSep      = " "
	, configPrintChar    = True
	}

hex :: Int -> Char
hex 0  = '0'
hex 1  = '1'
hex 2  = '2'
hex 3  = '3'
hex 4  = '4'
hex 5  = '5'
hex 6  = '6'
hex 7  = '7'
hex 8  = '8'
hex 9  = '9'
hex 10 = 'a'
hex 11 = 'b'
hex 12 = 'c'
hex 13 = 'd'
hex 14 = 'e'
hex 15 = 'f'
hex _  = ' '

{-# INLINE hexBytes #-}
hexBytes :: Word8 -> (Char, Char)
hexBytes w = (hex h, hex l) where (h,l) = (fromIntegral w) `divMod` 16

-- | Dump one byte into a 2 hexadecimal characters.
hexString :: Word8 -> String
hexString i = [h,l] where (h,l) = hexBytes i

-- | Dump a list of word8 into a raw string of hex value
dumpRaw :: [Word8] -> String
dumpRaw = concatMap hexString

-- | Dump a string into a raw string of hex value
dumpRawS :: String -> String
dumpRawS = dumpRaw . map (toEnum.fromEnum)

-- | Dump a bytestring into a raw string of hex value
dumpRawBS :: B.ByteString -> String
dumpRawBS = dumpRaw . B.unpack

-- | Dump a lazy bytestring into a raw string of hex value
dumpRawLBS :: L.ByteString -> String
dumpRawLBS = dumpRaw . L.unpack

disptable :: BytedumpConfig -> [Word8] -> [String]
disptable _   [] = []
disptable cfg x  =
	let (pre, post) = splitAt (configRowSize cfg) x in
	tableRow pre : disptable cfg post
	where
		tableRow row =
			let l  = splitMultiple (configRowGroupSize cfg) $ map hexString row in
			let lb = intercalate (configRowGroupSep cfg) $ map (intercalate (configCellSep cfg)) l in
			let rb = map printChar row in
			let rowLen = 2 * configRowSize cfg
			           + (configRowSize cfg - 1) * length (configCellSep cfg)
			           + ((configRowSize cfg `div` configRowGroupSize cfg) - 1) * length (configRowGroupSep cfg) in
			configRowLeft cfg ++ lb ++ replicate (rowLen - length lb) ' ' ++ configRowRight cfg ++ (if configPrintChar cfg then rb else "")

		splitMultiple _ [] = []
		splitMultiple n l  = let (pre, post) = splitAt n l in pre : splitMultiple n post

		printChar :: Word8 -> Char
		printChar w
			| w >= 0x20 && w < 0x7f = toEnum $ fromIntegral w
			| otherwise             = '.'

-- | Dump a list of bytes into formatted strings using a specific config
dumpWith :: BytedumpConfig -> [Word8] -> String
dumpWith cfg l = intercalate "\n" rows
	where rows = disptable cfg l

-- | Dump a string into formatted strings using a specific config
dumpWithS :: BytedumpConfig -> String -> String
dumpWithS cfg = dumpWith cfg . map (toEnum.fromEnum)

-- | Dump a bytestring into formatted strings using a specific config
dumpWithBS :: BytedumpConfig -> B.ByteString -> String
dumpWithBS cfg = dumpWith cfg . B.unpack

-- | Dump a lazy bytestring into formatted strings using a specific config
dumpWithLBS :: BytedumpConfig -> L.ByteString -> String
dumpWithLBS cfg = dumpWith cfg . L.unpack

-- | Dump a list of word8 into a formatted string of hex value
dump :: [Word8] -> String
dump l = intercalate "\n" rows
	where rows = disptable defaultConfig l

-- | Dump a string into a formatted string of hex value
dumpS :: String -> String
dumpS = dump . map (toEnum.fromEnum)

-- | Dump a bytestring into a formatted string of hex value
dumpBS :: B.ByteString -> String
dumpBS = dump . B.unpack

-- | Dump a lazy bytestring into a formatted string of hex value
dumpLBS :: L.ByteString -> String
dumpLBS = dump . L.unpack