Files
gf-core/src/server/PGFService.hs
2009-10-24 10:38:21 +00:00

213 lines
9.1 KiB
Haskell

{-# LANGUAGE DeriveDataTypeable, CPP #-}
import PGF (PGF)
import qualified PGF
import Cache
import FastCGIUtils
import URLEncoding
import Network.FastCGI
import Text.JSON
import qualified Codec.Binary.UTF8.String as UTF8 (encodeString, decodeString)
import Control.Concurrent
import Control.Monad
import Data.Char
import Data.Function (on)
import Data.List (sortBy)
import qualified Data.Map as Map
import Data.Maybe
import System.Directory
import System.FilePath
import System.Process
logFile :: FilePath
logFile = "pgf-error.log"
main :: IO ()
main = do stderrToFile logFile
cache <- newCache PGF.readPGF
#ifndef mingw32_HOST_OS
runFastCGIConcurrent' forkIO 100 (handleErrors (handleCGIErrors (cgiMain cache)))
#else
runFastCGI (handleErrors (handleCGIErrors (cgiMain cache)))
#endif
cgiMain :: Cache PGF -> CGI CGIResult
cgiMain cache =
do path <- getVarWithDefault "SCRIPT_FILENAME" ""
pgf <- liftIO $ readCache cache path
command <- liftM (maybe "grammar" (urlDecodeUnicode . UTF8.decodeString)) (getInput "command")
pgfMain pgf command
pgfMain :: PGF -> String -> CGI CGIResult
pgfMain pgf command =
case command of
"parse" -> return (doParse pgf) `ap` getText `ap` getCat `ap` getFrom >>= outputJSONP
"complete" -> return (doComplete pgf) `ap` getText `ap` getCat `ap` getFrom `ap` getLimit >>= outputJSONP
"linearize" -> return (doLinearize pgf) `ap` getTree `ap` getTo >>= outputJSONP
"random" -> getCat >>= \c -> getLimit >>= liftIO . doRandom pgf c >>= outputJSONP
"translate" -> return (doTranslate pgf) `ap` getText `ap` getCat `ap` getFrom `ap` getTo >>= outputJSONP
"grammar" -> return (doGrammar pgf) `ap` requestAcceptLanguage >>= outputJSONP
"abstrtree" -> getTree >>= liftIO . doGraphvizAbstrTree pgf >>= outputPNG
"parsetree" -> getTree >>= \t -> getFrom >>= \(Just l) -> liftIO (doGraphvizParseTree pgf l t) >>= outputPNG
"alignment" -> getTree >>= liftIO . doGraphvizAlignment pgf >>= outputPNG
_ -> throwCGIError 400 "Unknown command" ["Unknown command: " ++ show command]
where
getText :: CGI String
getText = liftM (maybe "" (urlDecodeUnicode . UTF8.decodeString)) $ getInput "input"
getTree :: CGI PGF.Tree
getTree = do mt <- getInput "tree"
t <- maybe (throwCGIError 400 "No tree given" ["No tree given"]) return mt
maybe (throwCGIError 400 "Bad tree" ["Bad tree: " ++ t]) return (PGF.readExpr t)
getCat :: CGI (Maybe PGF.Type)
getCat =
do mcat <- getInput "cat"
case mcat of
Nothing -> return Nothing
Just "" -> return Nothing
Just cat -> case PGF.readType cat of
Nothing -> throwCGIError 400 "Bad category" ["Bad category: " ++ cat]
Just typ | typ `elem` PGF.categories pgf -> return $ Just typ
| otherwise -> throwCGIError 400 "Unknown category" ["Unknown category: " ++ PGF.showType [] typ]
getFrom :: CGI (Maybe PGF.Language)
getFrom = getLang "from"
getTo :: CGI (Maybe PGF.Language)
getTo = getLang "to"
getLimit :: CGI (Maybe Int)
getLimit = readInput "limit"
getLang :: String -> CGI (Maybe PGF.Language)
getLang i =
do mlang <- getInput i
case mlang of
Nothing -> return Nothing
Just "" -> return Nothing
Just l -> case PGF.readLanguage l of
Nothing -> throwCGIError 400 "Bad language" ["Bad language: " ++ l]
Just lang | lang `elem` PGF.languages pgf -> return $ Just lang
| otherwise -> throwCGIError 400 "Unknown language" ["Unknown language: " ++ l]
doListGrammars :: IO JSValue
doListGrammars =
do cwd <- getCurrentDirectory
ps <- getDirectoryContents cwd
let fs = filter ((== ".pgf") . map toLower . takeExtension) $ map takeFileName ps
return $ showJSON $ map toJSObject [[("name", f)] | f <- fs]
doTranslate :: PGF -> String -> Maybe PGF.Type -> Maybe PGF.Language -> Maybe PGF.Language -> JSValue
doTranslate pgf input mcat mfrom mto =
showJSON
[toJSObject [("from", showJSON (PGF.showLanguage from)),
("tree", showJSON tree),
("linearizations",showJSON [toJSObject [("to", PGF.showLanguage to),("text",output)]
| (to,output) <- linearize' pgf mto tree])
]
| (from,trees) <- parse' pgf input mcat mfrom,
tree <- trees]
doParse :: PGF -> String -> Maybe PGF.Type -> Maybe PGF.Language -> JSValue
doParse pgf input mcat mfrom = showJSON $ map toJSObject
[[("from", PGF.showLanguage from),("tree",PGF.showExpr [] tree)]
| (from,trees) <- parse' pgf input mcat mfrom,
tree <- trees ]
doComplete :: PGF -> String -> Maybe PGF.Type -> Maybe PGF.Language -> Maybe Int -> JSValue
doComplete pgf input mcat mfrom mlimit = showJSON $ map toJSObject $ limit
[[("from", PGF.showLanguage from),("text",text)]
| (from,compls) <- complete' pgf input mcat mfrom,
text <- compls]
where
limit xs = maybe xs (\n -> take n xs) mlimit
doLinearize :: PGF -> PGF.Tree -> Maybe PGF.Language -> JSValue
doLinearize pgf tree mto = showJSON $ map toJSObject
[[("to", PGF.showLanguage to),("text",text)] | (to,text) <- linearize' pgf mto tree]
doRandom :: PGF -> Maybe PGF.Type -> Maybe Int -> IO JSValue
doRandom pgf mcat mlimit =
do trees <- random' pgf mcat
return $ showJSON $ map toJSObject [[("tree", PGF.showExpr [] tree)] | tree <- limit trees]
where limit = take (fromMaybe 1 mlimit)
doGrammar :: PGF -> Maybe (Accept Language) -> JSValue
doGrammar pgf macc = showJSON $ toJSObject
[("name", showJSON (PGF.abstractName pgf)),
("userLanguage", showJSON (selectLanguage pgf macc)),
("categories", showJSON categories),
("languages", showJSON languages)]
where languages = map toJSObject
[[("name", showJSON l),
("languageCode", showJSON $ fromMaybe "" (PGF.languageCode pgf l)),
("canParse", showJSON $ PGF.canParse pgf l)]
| l <- PGF.languages pgf]
categories = map toJSObject [[("cat", PGF.showType [] cat)] | cat <- PGF.categories pgf]
doGraphvizAbstrTree pgf tree = do
let dot = PGF.graphvizAbstractTree pgf (True,True) tree
readProcess "dot" ["-T","png"] dot
doGraphvizParseTree pgf lang tree = do
let dot = PGF.graphvizParseTree pgf lang tree
readProcess "dot" ["-T","png"] (UTF8.encodeString dot)
doGraphvizAlignment pgf tree = do
let dot = PGF.graphvizAlignment pgf tree
readProcess "dot" ["-T","png"] (UTF8.encodeString dot)
instance JSON PGF.CId where
readJSON x = readJSON x >>= maybe (fail "Bad language.") return . PGF.readLanguage
showJSON = showJSON . PGF.showLanguage
instance JSON PGF.Expr where
readJSON x = readJSON x >>= maybe (fail "Bad expression.") return . PGF.readExpr
showJSON = showJSON . PGF.showExpr []
-- * PGF utilities
cat :: PGF -> Maybe PGF.Type -> PGF.Type
cat pgf mcat = fromMaybe (PGF.startCat pgf) mcat
parse' :: PGF -> String -> Maybe PGF.Type -> Maybe PGF.Language -> [(PGF.Language,[PGF.Tree])]
parse' pgf input mcat mfrom =
[(from,ts) | from <- froms, PGF.canParse pgf from, let ts = PGF.parse pgf from cat input, not (null ts)]
where froms = maybe (PGF.languages pgf) (:[]) mfrom
cat = fromMaybe (PGF.startCat pgf) mcat
complete' :: PGF -> String -> Maybe PGF.Type -> Maybe PGF.Language -> [(PGF.Language,[String])]
complete' pgf input mcat mfrom =
[(from,order ss) | from <- froms, PGF.canParse pgf from, let ss = PGF.complete pgf from cat input, not (null ss)]
where froms = maybe (PGF.languages pgf) (:[]) mfrom
cat = fromMaybe (PGF.startCat pgf) mcat
order = sortBy (compare `on` map toLower)
linearize' :: PGF -> Maybe PGF.Language -> PGF.Tree -> [(PGF.Language,String)]
linearize' pgf mto tree =
case mto of
Nothing -> PGF.linearizeAllLang pgf tree
Just to -> [(to,PGF.linearize pgf to tree)]
random' :: PGF -> Maybe PGF.Type -> IO [PGF.Tree]
random' pgf mcat = PGF.generateRandom pgf (fromMaybe (PGF.startCat pgf) mcat)
selectLanguage :: PGF -> Maybe (Accept Language) -> PGF.Language
selectLanguage pgf macc = case acceptable of
[] -> case PGF.languages pgf of
[] -> error "No concrete syntaxes in PGF grammar."
l:_ -> l
Language c:_ -> fromJust (langCodeLanguage pgf c)
where langCodes = mapMaybe (PGF.languageCode pgf) (PGF.languages pgf)
acceptable = negotiate (map Language langCodes) macc
langCodeLanguage :: PGF -> String -> Maybe PGF.Language
langCodeLanguage pgf code = listToMaybe [l | l <- PGF.languages pgf, PGF.languageCode pgf l == Just code]
-- * General utilities
cleanFilePath :: FilePath -> FilePath
cleanFilePath = takeFileName