module Static
    ( serveStatic
    ) where

import qualified Network.Wai as Wai

import Data.Text (Text)
import Data.MonoTraversable (ointercalate, onull)
import Data.Text (unpack)
import Data.Sequences (isSuffixOf)
import Data.Text.Encoding (encodeUtf8)

serveStatic :: FilePath -> [Text] -> (Wai.Response -> IO Wai.ResponseReceived) -> IO Wai.ResponseReceived
serveStatic staticRoot pathInfo respond = do
    let path = renderPath pathInfo
    let contentType = guessMime path
    let fullPath = staticRoot <> "/" <> unpack path
    respond $ Wai.responseFile (toEnum 200) [("content-type", encodeUtf8 contentType)] fullPath Nothing

renderPath :: [Text] -> Text
renderPath =
    ointercalate "/"
    . filter (not . onull)
    . filter (/= "..") -- better choice would be to collapse with previous, but
                       -- ehh. User-agents usually expand it themselves.
    . filter (/= ".")

guessMime :: Text -> Text
guessMime fullPath
    | ".apng" `isSuffixOf` fullPath = "image/apng"
    | ".avif" `isSuffixOf` fullPath = "image/avif"
    | ".gif" `isSuffixOf` fullPath = "image/gif"
    | ".jpg" `isSuffixOf` fullPath = "image/jpeg"
    | ".jpeg" `isSuffixOf` fullPath = "image/jpeg"
    | ".png" `isSuffixOf` fullPath = "image/png"
    | ".svg" `isSuffixOf` fullPath = "image/svg+xml"
    | ".webp" `isSuffixOf` fullPath = "image/webp"
    | otherwise = "image/png" -- ehh UA'll figure it out