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-- Server implementation based on Happstack
module Server where
import Control.Applicative (optional)
import Control.Monad (msum, mzero, unless)
import Control.Monad.IO.Class (liftIO)
import Data.Acid
import Data.Acid.Advanced
import Data.ByteString.Char8 (unpack)
import Data.Char (toLower)
import Data.Text (Text)
import qualified Data.Text as T
import Data.Time
import Happstack.Server hiding (Session)
import Blog
import BlogDB hiding (updateEntry)
import Locales
import RSS
instance FromReqURI BlogLang where
fromReqURI sub =
case map toLower sub of
"de" -> Just DE
"en" -> Just EN
_ -> Nothing
tmpPolicy :: BodyPolicy
tmpPolicy = defaultBodyPolicy "/tmp" 0 200000 1000
runBlog :: AcidState Blog -> Int -> String -> IO ()
runBlog acid port respath =
simpleHTTP nullConf {port = port} $ tazBlog acid respath
tazBlog :: AcidState Blog -> String -> ServerPart Response
tazBlog acid resDir = do
msum [ path $ \(lang :: BlogLang) -> blogHandler acid lang
, dir "admin" $ msum [
adminHandler acid -- this checks auth
, method GET >> (ok $ toResponse adminLogin)
, method POST >> processLogin acid ]
, dir "static" $ staticHandler resDir
, blogHandler acid EN
, notFound $ toResponse $ showError NotFound DE
]
blogHandler :: AcidState Blog -> BlogLang -> ServerPart Response
blogHandler acid lang =
msum [ path $ \(eId :: Integer) -> showEntry acid lang $ EntryId eId
, nullDir >> showIndex acid lang
, dir "rss" $ nullDir >> showRSS acid lang
, dir "rss.xml" $ nullDir >> showRSS acid lang
, notFound $ toResponse $ showError NotFound lang
]
staticHandler :: String -> ServerPart Response
staticHandler resDir = do
setHeaderM "cache-control" "max-age=630720000"
setHeaderM "expires" "Tue, 20 Jan 2037 04:20:42 GMT"
serveDirectory DisableBrowsing [] resDir
serveBlogStyle :: ServerPart Response
serveBlogStyle = do
setHeaderM "content-type" "text/css"
setHeaderM "cache-control" "max-age=630720000"
setHeaderM "expires" "Tue, 20 Jan 2037 04:20:42 GMT"
ok $ toResponse $ blogStyle
adminHandler :: AcidState Blog -> ServerPart Response
adminHandler acid = do
guardSession acid
msum [ dir "entry" $ method POST >> postEntry acid
, dir "entry" $ path $ \(entry :: Integer) -> msum [
method GET >> editEntry acid entry
, method POST >> updateEntry acid entry ]
, dir "entrylist" $ path $ \(lang :: BlogLang) -> entryList acid lang
, ok $ toResponse $ adminIndex "tazjin"
]
showEntry :: AcidState Blog -> BlogLang -> EntryId -> ServerPart Response
showEntry acid lang eId = do
entry <- query' acid (GetEntry eId)
tryEntry entry lang
tryEntry :: Maybe Entry -> BlogLang -> ServerPart Response
tryEntry Nothing lang = notFound $ toResponse $ showError NotFound lang
tryEntry (Just entry) _ = ok $ toResponse $ blogTemplate eLang eTitle $ renderEntry entry
where
eTitle = T.append ": " (title entry)
eLang = lang entry
showIndex :: AcidState Blog -> BlogLang -> ServerPart Response
showIndex acid lang = do
entries <- query' acid (LatestEntries lang)
(page :: Maybe Int) <- optional $ lookRead "page"
ok $ toResponse $ blogTemplate lang "" $
renderEntries False (eDrop page entries) (Just $ showLinks page lang)
where
eDrop :: Maybe Int -> [a] -> [a]
eDrop (Just i) = drop ((i-1) * 6)
eDrop Nothing = drop 0
showRSS :: AcidState Blog -> BlogLang -> ServerPart Response
showRSS acid lang = do
entries <- query' acid (LatestEntries lang)
feed <- liftIO $ renderFeed lang $ take 6 entries
setHeaderM "content-type" "text/xml"
ok $ toResponse feed
{- ADMIN stuff -}
postEntry :: AcidState Blog -> ServerPart Response
postEntry acid = do
nullDir
decodeBody tmpPolicy
now <- liftIO getCurrentTime
let eId = timeToId now
lang <- look "lang"
nBtext <- lookText' "btext"
nMtext <- lookText' "mtext"
nEntry <- Entry <$> pure eId
<*> getLang lang
<*> readCookieValue "sUser"
<*> lookText' "title"
<*> pure nBtext
<*> pure nMtext
<*> pure now
update' acid (InsertEntry nEntry)
seeOther ("/" ++ lang ++ "/" ++ show eId) (toResponse())
where
timeToId :: UTCTime -> EntryId
timeToId t = EntryId . read $ formatTime defaultTimeLocale "%s" t
getLang :: String -> ServerPart BlogLang
getLang "de" = return DE
getLang _ = return EN -- English is default
entryList :: AcidState Blog -> BlogLang -> ServerPart Response
entryList acid lang = do
entries <- query' acid (LatestEntries lang)
ok $ toResponse $ adminEntryList entries
editEntry :: AcidState Blog -> Integer -> ServerPart Response
editEntry acid entryId = do
(Just entry) <- query' acid (GetEntry $ EntryId entryId)
ok $ toResponse $ editPage entry
updateEntry :: AcidState Blog -> Integer -> ServerPart Response
updateEntry acid entryId = do
decodeBody tmpPolicy
(Just entry) <- query' acid (GetEntry $ EntryId entryId)
nTitle <- lookText' "title"
nBtext <- lookText' "btext"
nMtext <- lookText' "mtext"
let newEntry = entry { title = nTitle
, btext = nBtext
, mtext = nMtext}
update' acid (UpdateEntry newEntry)
seeOther (concat $ intersperse' "/" [show $ lang entry, show entryId])
(toResponse ())
guardSession :: AcidState Blog -> ServerPartT IO ()
guardSession acid = do
(sId :: Text) <- readCookieValue "session"
(uName :: Text) <- readCookieValue "sUser"
now <- liftIO getCurrentTime
mS <- query' acid (GetSession $ SessionID sId)
case mS of
Nothing -> mzero
(Just Session{..}) -> unless ((uName == username user) && sessionTimeDiff now sdate)
mzero
where
sessionTimeDiff :: UTCTime -> UTCTime -> Bool
sessionTimeDiff now sdate = diffUTCTime now sdate < 43200
processLogin :: AcidState Blog -> ServerPart Response
processLogin acid = do
decodeBody tmpPolicy
account <- lookText' "account"
password <- look "password"
login <- query' acid (CheckUser (Username account) password)
if login
then createSession account
else unauthorized $ toResponse adminLogin
where
createSession account = do
now <- liftIO getCurrentTime
let sId = hashString $ show now
addCookie (MaxAge 43200) (mkCookie "session" $ unpack sId)
addCookie (MaxAge 43200) (mkCookie "sUser" $ T.unpack account)
(Just user) <- query' acid (GetUser $ Username account)
let nSession = Session (T.pack $ unpack sId) user now
update' acid (AddSession nSession)
seeOther ("/admin?do=login" :: Text) (toResponse())
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