content: {-# LANGUAGE OverloadedStrings #-}
  {-# LANGUAGE TemplateHaskell #-}
  
  {-
    Copyright 2020 The CodeWorld Authors. All rights reserved.
  
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at
  
        http://www.apache.org/licenses/LICENSE-2.0
  
    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
  -}
  
  module Util.EmbedAsUrl
    ( embedAsUrl,
    )
  where
  
  import qualified Data.ByteString as B
  import qualified Data.ByteString.Base64 as B64
  import qualified Data.ByteString.Char8 as BC
  import qualified Data.ByteString.Unsafe as B
  import qualified Data.Text.Encoding as T
  import Language.Haskell.TH.Syntax
  import System.IO.Unsafe
  
  embedAsUrl :: String -> FilePath -> Q Exp
  embedAsUrl contentType f = do
    qAddDependentFile f
    payload <- runIO $ B64.encode <$> B.readFile f
    let uri = "data:" <> BC.pack contentType <> ";base64," <> payload
    [e|
      T.decodeUtf8 $ unsafePerformIO $
        B.unsafePackAddressLen
          $(return $ LitE $ IntegerL $ fromIntegral $ B.length uri)
          $(return $ LitE $ StringPrimL $ B.unpack uri)
      |]
  