blog-proxy/src/Server.hs
2025-02-10 20:03:25 -08:00

45 lines
1.6 KiB
Haskell

{-# LANGUAGE OverloadedStrings #-}
module Server (
servePages
) where
import Control.Applicative ((<|>))
import Network.Wai (Application, Response, responseLBS, Request (pathInfo))
import Network.Wai.Handler.Warp (run)
import qualified Network.HTTP.Types as H
import qualified Data.Map as Map
import Data.Map (Map)
import qualified Data.Text as T
import TemplatePage (PageContext, PageTemplate, buildPage)
import qualified Data.ByteString as BS
import Data.ByteString (ByteString)
import Control.Concurrent (MVar, readMVar, tryPutMVar)
app :: Map String PageTemplate -> MVar PageContext -> MVar () -> Application
app templates context updateNotify request respond = do
let path = T.unpack $ T.intercalate "/" $ filter (not . T.null) $ pathInfo request
slashPath = if path /= "" then '/' : path else path
indexPath = slashPath ++ "/index.html"
template = Map.lookup path templates <|> Map.lookup indexPath templates
putStrLn $ "Page requested: " ++ slashPath
context' <- readMVar context
-- Unblock pageview cache if waiting for a request.
_ <- tryPutMVar updateNotify ()
respond $ respMaybe $ buildPage context' <$> template
respMaybe :: Maybe ByteString -> Response
respMaybe Nothing = notFound
respMaybe (Just text) = responseLBS H.status200 [("content-type", "text/html")] $ BS.fromStrict text
notFound :: Response
notFound = responseLBS H.status404 [(H.hContentType, "text/plain")] "404 - File not found"
servePages :: Int -> Map String PageTemplate -> MVar PageContext -> MVar () -> IO ()
servePages port templates context updateNotify = run port $ app templates context updateNotify