{-# LANGUAGE OverloadedStrings #-}

import qualified Data.ByteString.Lazy as L
import Data.VCDIFF
import Text.XXD

source :: L.ByteString
source = "It could be said that Joe was here. I don't know what to do about it."

source2 :: L.ByteString
source2 = "It could be said that Joe was not here. I don't know what to do about it."

target :: L.ByteString
target = "It could be said that Joe, the magnificent, was here.  I don't know what to do about it."

delta :: Result VCDIFF
delta = computeDiff defaultConfig source target

delta2 :: Result VCDIFF
delta2 = computeDiff defaultConfig  source target

delta3 :: Result VCDIFF
delta3 = computeDiff defaultConfig { flags = XD3_ADLER32 } source target

delta4 :: Result VCDIFF
delta4 = computeDiff defaultConfig { flags = XD3_ADLER32 } source target



dump title bs kont = do
    putStrLn title
    mapM_ putStrLn $ xxd2 0 (L.toStrict bs)
    kont

main = do
    dump "source" source $ putStrLn ""
    dump "target" target $ putStrLn ""
    go source "default" delta
    go source "default" delta2
    go source "XD3_ADLER32" delta3
    go source "XD3_ADLER32" delta4
    go source2 "default" delta
    go source2 "default" delta2
    go source2 "XD3_ADLER32" delta3
    go source2 "XD3_ADLER32" delta4

go source flgs delta = do
    putStrLn ""
    case delta of
        Result δ me -> do
            let dif = encodeVCDIFF δ
            dump ("diff("++flgs++ ")") dif $ print me >> putStrLn ""
            let Result patched pe = applyPatch defaultConfig source δ
            dump ("patched("++flgs++")") patched $ print pe