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{-# LANGUAGE RecordWildCards #-}
module Main where
import Control.Exception
import Control.Monad
import Data.Bool
import Data.Foldable
import Opts
import System.Exit
import System.FilePath
import System.IO
import System.IO.Temp
import System.Process
import qualified Toks
import Debug.Trace
-- TODO: the diff w
rundiff f1 f2 out = do
st <-
withFile out WriteMode $ \oh ->
withCreateProcess
(proc
"diff" -- TODO: from WERGE_DIFF env
[ "--text"
, "--new-line-format=+%L"
, "--old-line-format=-%L"
, "--unchanged-line-format= %L"
, f1
, f2
])
{std_in = NoStream, std_out = UseHandle oh, std_err = Inherit} $ \_ _ _ ->
waitForProcess
when (st == ExitFailure 2) $ error "diff failed"
unless (st `elem` [ExitSuccess, ExitFailure 1])
$ error "diff failed for unknown reason (is GNU diffutils installed?)"
data Op
= Del
| Keep
| Add
deriving (Show, Eq)
pdiff path = map go . lines <$> readFile path
where
go [] = error "empty line from diff"
go ('-':s) = (Del, s)
go (' ':s) = (Keep, s)
go ('+':s) = (Add, s)
data Merged
= Ok [String]
| Conflict [String] [String] [String]
deriving (Show)
align :: [(Op, String)] -> [(Op, String)] -> [Merged]
align [] [] = []
align ((Keep, m):ms) ((Keep, y):ys)
| m == y = Ok [m] : align ms ys
align ((Del, m):ms) ((Del, y):ys)
| m == y = Conflict [] [m] [] : align ms ys
align ((Del, m):ms) ((Keep, y):ys)
| m == y = Conflict [] [m] [m] : align ms ys
align ((Keep, m):ms) ((Del, y):ys)
| m == y = Conflict [m] [m] [] : align ms ys
align ((Add, m):ms) ys = Conflict [m] [] [] : align ms ys
align ms ((Add, y):ys) = Conflict [] [] [y] : align ms ys
align _ _ = error "diffs do not align"
-- TODO this is quadratic, call regroup first and case it
regroup :: [Merged] -> [Merged]
regroup [] = []
regroup (Ok []:xs) = regroup xs
regroup (Ok a:Ok b:xs) = regroup (Ok (a ++ b) : xs)
regroup (Conflict [] [] []:xs) = regroup xs
regroup (Conflict m1 o1 y1:Conflict m2 o2 y2:xs) =
regroup (Conflict (m1 ++ m2) (o1 ++ o2) (y1 ++ y2) : xs)
regroup (x:xs) = x : regroup xs
expand :: Int -> [Merged] -> [Merged]
expand n = go
where
go [] = []
go (Conflict m1 o1 y1:Ok a:Conflict m2 o2 y2:xs)
| length a <= n =
go $ Conflict (m1 ++ a ++ m2) (o1 ++ a ++ o2) (y1 ++ a ++ y2) : xs
go (x:xs) = x : go xs
zeal (Conflict m o y) =
before' ++ (Conflict (reverse m'') o (reverse y'') : after')
where
((m', y'), before) = pops m y
((m'', y''), rafter) = pops (reverse m') (reverse y')
before' =
case before of
[] -> []
xs -> [Ok xs]
after' =
case rafter of
[] -> []
xs -> [Ok $ reverse xs]
pops (m:ms) (y:ys)
| m == y = (m :) <$> pops ms ys
pops ms ys = ((ms, ys), [])
zeal x = [x]
resolve Config {..} c@(Conflict m o y)
| m == o && o == y = Ok o
| m == o && cfgResolveSeparate = Ok y
| o == y && cfgResolveSeparate = Ok m
| m == y && cfgResolveOverlaps = Ok m
resolve _ x = x
merge cfg@Config {..} ms ys =
regroup
. map (resolve cfg)
. regroup
. bool id (concatMap zeal) cfgZealous
. expand cfgContext
. regroup
$ align ms ys
format :: Config -> [Merged] -> IO Bool
format Config {..} = go False
where
go c [] = pure c
go c (Ok x:xs) = do
putStr (Toks.glueToks x)
go c xs
go c (Conflict m o y:xs) = do
putStr
$ mconcat
[ cfgLabelStart
, Toks.glueToks m
, cfgLabelMyOld
, Toks.glueToks o
, cfgLabelOldYour
, Toks.glueToks y
, cfgLabelEnd
]
go True xs
runCmd CmdDiff3 {..} cfg =
withSystemTempDirectory "werge-diff3" $ \workdir -> do
let [fMy, fOld, fYour, fdMy, fdYour] =
map (workdir </>) ["my", "old", "your", "mydiff", "yourdiff"]
for_ [(d3my, fMy), (d3old, fOld), (d3your, fYour)] $ \(path, tmp) ->
readFile path >>= writeFile tmp . Toks.split -- TODO cfg
rundiff fOld fMy fdMy
rundiff fOld fYour fdYour
conflicted <- merge cfg <$> pdiff fdMy <*> pdiff fdYour >>= format cfg
if conflicted
then exitWith (ExitFailure 1)
else exitSuccess
runCmd _ _ = error "not implemented yet"
main :: IO ()
main = catch go bad
where
go = do
(cfg, cmd) <- parseOpts
runCmd cmd cfg
bad e = do
hPutStrLn stderr $ "fatal: " ++ displayException (e :: IOException)
exitWith (ExitFailure 2)
|
