content: {-# LANGUAGE DeriveDataTypeable, CPP #-}
  
  import PGF (PGF)
  import qualified PGF
  import Cache
  import FastCGIUtils
  import URLEncoding
  
  import Data.Maybe
  import Network.FastCGI
  import Text.JSON
  import qualified Data.ByteString.Lazy as BS
  import qualified Codec.Binary.UTF8.String as UTF8 (encodeString, decodeString)
  
  import Control.Monad
  import Control.Exception
  import Control.Concurrent(forkIO)
  import System.Environment(getArgs)
  import System.Time
  import System.Locale
  import System.FilePath
  import Database.HSQL.MySQL
  import Database.HSQL.Types(toSqlValue)
  
  logFile :: FilePath
  logFile = "content-error.log"
  
  
  main :: IO ()
  main = do
    args <- getArgs
    case args of
      []      -> do stderrToFile logFile
                    cache <- newCache dbConnect
  
  #ifndef mingw32_HOST_OS
                    runFastCGIConcurrent' forkIO 100 (cgiMain cache)
  #else
                    runFastCGI (cgiMain cache)
  #endif
      [fpath] -> do c <- dbConnect fpath
                    dbInit c
  
  getPath = getVarWithDefault "SCRIPT_FILENAME" ""
  
  cgiMain :: Cache Connection -> CGI CGIResult
  cgiMain cache = handleErrors . handleCGIErrors $
                    cgiMain' cache =<< getPath
  
  cgiMain' :: Cache Connection -> FilePath -> CGI CGIResult
  cgiMain' cache path =
      do c <- liftIO $ readCache cache path
         mb_command <- liftM (liftM (urlDecodeUnicode . UTF8.decodeString)) (getInput "command")
         case mb_command of
           Just "update_grammar"
                         -> do mb_pgf <- getFile
                               id     <- getGrammarId
                               name   <- getFileName
                               descr  <- getDescription
                               userId <- getUserId
                               doUpdateGrammar c mb_pgf id name descr userId
           Just "delete_grammar"
                         -> do id <- getGrammarId
                               userId <- getUserId
                               doDeleteGrammar c id userId
           Just "grammars"
                         -> do userId <- getUserId
                               doGrammars c userId
           Just "save"   -> doSave c =<< getId
           Just "load"   -> doLoad c =<< getId
           Just "search" -> doSearch c =<< getQuery
           Just "delete" -> doDelete c =<< getIds
           Just cmd      -> throwCGIError 400 "Unknown command" ["Unknown command: " ++ show cmd]
           Nothing       -> do mb_uri <- getIdentity
                               mb_email <- getEMail
                               doLogin c mb_uri mb_email
    where
      getUserId :: CGI (Maybe String)
      getUserId = getInput "userId"
  
      getId :: CGI (Maybe Int)
      getId = readInput "id"
  
      getIds :: CGI [Int]
      getIds = fmap (map read) (getMultiInput "id")
  
      getQuery :: CGI String
      getQuery = fmap (fromMaybe "") (getInput "query")
  
      getGrammarId :: CGI String
      getGrammarId = do 
        mb_url <- getInput "url"
        return (maybe "null" (reverse . takeWhile (/='/') . drop 4 . reverse) mb_url)
  
      getFile :: CGI (Maybe BS.ByteString)
      getFile = do
        getInputFPS "file"
  
      getFileName :: CGI String
      getFileName = do
        mb_name0 <- getInput "name"
        let mb_name | mb_name0 == Just "" = Nothing
                    | otherwise           = mb_name0
        mb_file <- getInputFilename "file"
        return (fromMaybe "" (mb_name `mplus` mb_file))
  
      getDescription :: CGI String
      getDescription = fmap (fromMaybe "") (getInput "description")
  
      getIdentity :: CGI (Maybe String)
      getIdentity = getInput "openid.identity"
  
      getEMail :: CGI (Maybe String)
      getEMail = getInput "openid.ext1.value.email"
  
  
  doLogin c mb_uri mb_email = do
    path <- scriptName
    r <- liftIO $ handleSql (return . Left) $ do
           s <- query c ("call getUserId("++toSqlValue mb_uri++","++toSqlValue mb_email++")")
           [id] <- collectRows getUserId s
           return (Right id)
    case r of
      Right mb_id -> outputHTML (startupHTML mb_id mb_uri mb_email (Just path))
      Left  e     -> throwCGIError 400 "Login failed" (lines (show e))
    where
      getUserId s = do
        id <- getFieldValueMB s "userId"
        return (id :: Maybe Int)
  
  doGrammars c mb_userId = do
    path <- scriptName
    r <- liftIO $ handleSql (return . Left) $ do
           s <- query c ("call getGrammars("++toSqlValue mb_userId++")")
           rows <- collectRows (getGrammar path) s
           return (Right rows)
    case r of
      Right rows -> outputJSONP rows
      Left  e    -> throwCGIError 400 "Loading failed" (lines (show e))
    where
      getGrammar path s = do
        id <- getFieldValue s "id"
        name <- getFieldValue s "name"
        description <- getFieldValue s "description"
        return $ toJSObject [ ("url",  showJSON (dropExtension path ++ '/':addExtension (show (id :: Int)) "pgf"))
                            , ("name", showJSON (name :: String))
                            , ("description", showJSON (description :: String))
                            ]
  
  doUpdateGrammar c mb_pgf id name descr mb_userId = do
    r <- liftIO $ handleSql (return . Left) $ do
           s <- query c ("call updateGrammar("++id++","++toSqlValue name++","++toSqlValue descr++","++toSqlValue mb_userId++")")
           [id] <- collectRows (\s -> getFieldValue s "id") s
           return (Right id)
    nid <- case r of
             Right id -> return (id :: Int)
             Left  e  -> throwCGIError 400 "Saving failed" (lines (show e))
    path <- pathTranslated
    case mb_pgf of
      Just pgf -> if pgf /= BS.empty
                    then liftIO (BS.writeFile (dropExtension  path </> addExtension (show nid) "pgf") pgf)
                    else if id == "null"
                           then throwCGIError 400 "Grammar update failed" []
                           else return ()
      Nothing  -> return ()
    outputHTML ""
  
  doDeleteGrammar c id mb_userId = do
    r <- liftIO $ handleSql (return . Left) $ do
           execute c ("call deleteGrammar("++id++","++toSqlValue mb_userId++")")
           return (Right "")
    case r of
      Right x -> outputJSONP ([] :: [(String,String)])
      Left  e -> throwCGIError 400 "Saving failed" (lines (show e))
  
  doSave c mb_id = do
    body <- getBody
    r <- liftIO $ handleSql (return . Left) $ do
           s <- query c ("call saveDocument("++toSqlValue mb_id++","++toSqlValue body++")")
           [id] <- collectRows (\s -> getFieldValue s "id") s
           return (Right id)
    case r of
      Right id -> outputJSONP (toJSObject [("id", id :: Int)])
      Left  e  -> throwCGIError 400 "Saving failed" (lines (show e))
  
  doLoad c Nothing   = throwCGIError 400 "Loading failed" ["Missing ID"]
  doLoad c (Just id) = do
    r <- liftIO $ handleSql (return . Left) $ do
           s <- query c ("SELECT id,title,created,modified,content\n"++
                         "FROM Documents\n"++
                         "WHERE id="++toSqlValue id)
           rows <- collectRows getDocument s
           return (Right rows)
    case r of
      Right [row] -> outputJSONP row
      Right _     -> throwCGIError 400 "Missing document" ["ID="++show id]
      Left  e     -> throwCGIError 400 "Loading failed" (lines (show e))
    where
      getDocument s = do
        id <- getFieldValue s "id"
        title <- getFieldValue s "title"
        created <- getFieldValue s "created" >>= pt
        modified <- getFieldValue s "modified" >>= pt
        content <- getFieldValue s "content"
        return $ toJSObject [ ("id",      showJSON (id :: Int))
                            , ("title",   showJSON (title :: String))
                            , ("created", showJSON (created :: String))
                            , ("modified", showJSON (modified :: String))
                            , ("content", showJSON (content :: String))
                            ]
  
  doSearch c q = do
    r <- liftIO $ handleSql (return . Left) $ do
           s <- query c ("SELECT id,title,created,modified\n"++
                         "FROM Documents"++
                         if null q
                           then ""
                           else "\nWHERE MATCH(content) AGAINST ("++toSqlValue q++" IN BOOLEAN MODE)")
           rows <- collectRows getDocument s
           return (Right rows)
    case r of
      Right rows -> outputJSONP rows
      Left  e    -> throwCGIError 400 "Saving failed" (lines (show e))
    where
      getDocument s = do
        id <- getFieldValue s "id"
        title <- getFieldValue s "title"
        created <- getFieldValue s "created" >>= pt
        modified <- getFieldValue s "modified" >>= pt
        return $ toJSObject [ ("id",      showJSON (id :: Int))
                            , ("title",   showJSON (title :: String))
                            , ("created", showJSON (created :: String))
                            , ("modified", showJSON (modified :: String))
                            ]
                            
  pt ct = liftM (formatCalendarTime defaultTimeLocale "%d %b %Y") (toCalendarTime ct)
  
  doDelete c ids = do
    liftIO $
      inTransaction c $ \c ->
        mapM_ (\id -> execute c ("DELETE FROM Documents WHERE id = "++toSqlValue id)) ids
    outputJSONP (toJSObject ([] :: [(String,String)]))
  
  dbConnect fpath = do
    [host,db,user,pwd] <- fmap words $ readFile fpath
    connect host db user pwd
  
  startupHTML mb_id mb_uri mb_email mb_path = unlines [
    "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">",
    "<html>",
    "   <head>",
    "      <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">",
    "      <title>Editor</title>",
    "      <script type=\"text/javascript\" language=\"javascript\" src=\"org.grammaticalframework.ui.gwt.EditorApp/org.grammaticalframework.ui.gwt.EditorApp.nocache.js\"></script>",
    "   </head>",
    "   <body onload=\"window.__gfInit = new Object(); "++
                      maybe "" (\id    -> "window.__gfInit.userId = "++show id++"; ") mb_id++
                      maybe "" (\uri   -> "window.__gfInit.userURI = '"++uri++"'; ") mb_uri++
                      maybe "" (\email -> "window.__gfInit.userEMail = '"++email++"'; ") mb_email++
                      maybe "" (\path  -> "window.__gfInit.contentURL = '"++path++"'; ") mb_path++
                      "\">",
    "      <iframe src=\"javascript:''\" id=\"__gwt_historyFrame\" tabIndex='-1' style=\"position:absolute;width:0;height:0;border:0\"></iframe>",
    "   </body>",
    "</html>"]
  
  dbInit c = 
    handleSql (fail . show) $ do
      inTransaction c $ \c -> do
        execute c "DROP TABLE IF EXISTS GrammarUsers"
        execute c "DROP TABLE IF EXISTS Users"
        execute c "DROP TABLE IF EXISTS Grammars"
        execute c "DROP TABLE IF EXISTS Documents"
        execute c ("CREATE TABLE Users"++
                   "                (id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,\n"++
                   "                 identity VARCHAR(256) NOT NULL,\n"++
                   "                 email VARCHAR(128) NOT NULL,\n"++
                   "                 UNIQUE INDEX (identity))")
        execute c ("CREATE TABLE Grammars"++
                   "                (id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,"++
                   "                 name VARCHAR(64) NOT NULL,\n"++
                   "                 description VARCHAR(512) NOT NULL,\n"++
                   "                 created TIMESTAMP NOT NULL DEFAULT 0,\n"++
                   "                 modified TIMESTAMP NOT NULL DEFAULT 0)")
        execute c ("CREATE TABLE Documents"++
                   "                (id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,"++
                   "                 title VARCHAR(256) NOT NULL,\n"++
                   "                 created TIMESTAMP NOT NULL DEFAULT 0,\n"++
                   "                 modified TIMESTAMP NOT NULL DEFAULT 0,\n"++
                   "                 content TEXT NOT NULL,\n"++
                   "                 FULLTEXT INDEX (content)) TYPE=MyISAM")
        execute c ("CREATE TABLE GrammarUsers"++
                   "                (userId INTEGER NOT NULL,\n"++
                   "                 grammarId INTEGER NOT NULL,\n"++
                   "                 flags INTEGER NOT NULL,\n"++
                   "                 PRIMARY KEY (userId, grammarId),\n"++
                   "                 FOREIGN KEY (userId) REFERENCES Users(id) ON DELETE CASCADE,\n"++
                   "                 FOREIGN KEY (grammarId) REFERENCES Grammars(id) ON DELETE RESTRICT)")
        execute c "DROP PROCEDURE IF EXISTS saveDocument"
        execute c ("CREATE PROCEDURE saveDocument(IN id INTEGER, content TEXT)\n"++
                   "BEGIN\n"++
                   "   IF id IS NULL THEN\n"++
                   "     INSERT INTO Documents(title,content,created,modified) VALUES (content,content,NOW(),NOW());\n"++
                   "     SELECT LAST_INSERT_ID() as id;\n"++
                   "   ELSE\n"++
                   "     UPDATE Documents d SET content = content, modified=NOW() WHERE d.id = id;\n"++
                   "     select id;\n"++
                   "   END IF;\n"++
                   "END")
        execute c "DROP PROCEDURE IF EXISTS updateGrammar"
        execute c ("CREATE PROCEDURE updateGrammar(IN id INTEGER, name VARCHAR(64), description VARCHAR(512), userId INTEGER)\n"++
                   "BEGIN\n"++
                   "   IF id IS NULL THEN\n"++
                   "     INSERT INTO Grammars(name,description,created,modified) VALUES (name,description,NOW(),NOW());\n"++
                   "     SET id = LAST_INSERT_ID();\n"++
                   "     INSERT INTO GrammarUsers(grammarId,userId,flags) VALUES (id,userId,0);\n"++
                   "   ELSE\n"++
                   "     UPDATE Grammars gr SET name = name, description=description, modified=NOW() WHERE gr.id = id;\n"++
                   "   END IF;\n"++
                   "   SELECT id;\n"++
                   "END")
        execute c "DROP PROCEDURE IF EXISTS deleteGrammar"
        execute c ("CREATE PROCEDURE deleteGrammar(IN aGrammarId INTEGER, aUserId INTEGER)\n"++
                   "BEGIN\n"++
                   "   DECLARE deleted INTEGER;\n"++
                   "   DELETE FROM GrammarUsers\n"++
                   "   WHERE grammarId = aGrammarId AND userId = aUserId;\n"++
                   "   IF NOT EXISTS(SELECT * FROM GrammarUsers gu WHERE gu.grammarId = aGrammarId) THEN\n"++
                   "     DELETE FROM Grammars WHERE id = aGrammarId;\n"++
                   "     SET deleted = 1;\n"++
                   "   ELSE\n"++
                   "     SET deleted = 0;\n"++
                   "   END IF;\n"++
                   "   SELECT deleted;\n"++
                   "END")
        execute c "DROP PROCEDURE IF EXISTS getGrammars"
        execute c ("CREATE PROCEDURE getGrammars(IN userId INTEGER)\n"++
                   "BEGIN\n"++
                   "  SELECT g.id,g.name,g.description\n"++
                   "  FROM Grammars g JOIN GrammarUsers gu ON g.id = gu.grammarId\n"++
                   "  WHERE gu.userId = userId\n"++
                   "  ORDER BY g.name;\n"++
                   "END")
        execute c "DROP PROCEDURE IF EXISTS getUserId"
        execute c ("CREATE PROCEDURE getUserId(identity VARCHAR(256), email VARCHAR(128))\n"++
                   "BEGIN\n"++
                   "  DECLARE userId INTEGER;\n"++
                   "  IF identity IS NULL OR email IS NULL THEN\n"++
                   "    SET userId = NULL;\n"++
                   "  ELSE\n"++
                   "    SELECT id INTO userId FROM Users u WHERE u.identity = identity;\n"++
                   "    IF userId IS NULL THEN\n"++
                   "      INSERT INTO Users(identity, email) VALUES (identity, email);\n"++
                   "      SET userId = LAST_INSERT_ID();\n"++
                   "    END IF;\n"++
                   "  END IF;\n"++
                   "  SELECT userId;\n"++
                   "END")
  