{-# LANGUAGE TemplateHaskell, QuasiQuotes, ScopedTypeVariables #-}
-- | A generator is executed at compile time to load a list of entries
-- to embed into the subsite.  This module contains several basic generators,
-- but the design of generators and entries is such that it is straightforward
-- to make custom generators for your own specific purposes, see <#g:4 this section>.
module Yesod.EmbeddedStatic.Generators (
  -- * Generators
    Location
  , embedFile
  , embedFileAt
  , embedDir
  , embedDirAt
  , concatFiles
  , concatFilesWith

  -- * Compression options for 'concatFilesWith'
  , jasmine
  , uglifyJs
  , yuiJavascript
  , yuiCSS
  , closureJs
  , compressTool
  , tryCompressTools

  -- * Util
  , pathToName

  -- * Custom Generators

  -- $example
) where

import Control.Applicative as A ((<$>), (<*>))
import Control.Exception (try, SomeException)
import Control.Monad (forM, when)
import Data.Char (isDigit, isLower)
import Data.Default (def)
import Data.Maybe (isNothing)
import Language.Haskell.TH
import Network.Mime (defaultMimeLookup)
import System.Directory (doesDirectoryExist, getDirectoryContents, findExecutable)
import System.FilePath ((</>))
import Text.Jasmine (minifym)
import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy as BL
import Conduit
import qualified Data.Text as T
import qualified System.Process as Proc
import System.Exit (ExitCode (ExitSuccess))
import Control.Concurrent.Async (Concurrently (..))
import System.IO (hClose)
import Data.List (sort)

import Yesod.EmbeddedStatic.Types

-- | Embed a single file.  Equivalent to passing the same string twice to 'embedFileAt'.
embedFile :: FilePath -> Generator
embedFile :: FilePath -> Generator
embedFile FilePath
f = FilePath -> FilePath -> Generator
embedFileAt FilePath
f FilePath
f

-- | Embed a single file at a given location within the static subsite and generate a
--   route variable based on the location via 'pathToName'.  The @FilePath@ must be a relative
--   path to the directory in which you run @cabal build@.  During development, the file located
--   at this filepath will be reloaded on every request.  When compiling for production, the contents
--   of the file will be embedded into the executable and so the file does not need to be
--   distributed along with the executable.
embedFileAt :: Location -> FilePath -> Generator
embedFileAt :: FilePath -> FilePath -> Generator
embedFileAt FilePath
loc FilePath
f = do
    let mime :: ByteString
mime = FileName -> ByteString
defaultMimeLookup forall a b. (a -> b) -> a -> b
$ FilePath -> FileName
T.pack FilePath
f
    let entry :: Entry
entry = forall a. Default a => a
def {
                    ebHaskellName :: Maybe Name
ebHaskellName = forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$ FilePath -> Name
pathToName FilePath
loc
                  , ebLocation :: FilePath
ebLocation = FilePath
loc
                  , ebMimeType :: ByteString
ebMimeType = ByteString
mime
                  , ebProductionContent :: IO ByteString
ebProductionContent = forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap ByteString -> ByteString
BL.fromStrict (FilePath -> IO ByteString
BS.readFile FilePath
f)
                  , ebDevelReload :: ExpQ
ebDevelReload = [| fmap BL.fromStrict
                                       (BS.readFile $(litE $ stringL f)) |]
                  }
    forall (m :: * -> *) a. Monad m => a -> m a
return [Entry
entry]

-- | List all files recursively in a directory
getRecursiveContents :: Location -- ^ The directory to search
                     -> FilePath   -- ^ The prefix to add to the filenames
                     -> IO [(Location,FilePath)]
getRecursiveContents :: FilePath -> FilePath -> IO [(FilePath, FilePath)]
getRecursiveContents FilePath
prefix FilePath
topdir = do
  [FilePath]
names <- forall a. Ord a => [a] -> [a]
sort forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> FilePath -> IO [FilePath]
getDirectoryContents FilePath
topdir
  let properNames :: [FilePath]
properNames = forall a. (a -> Bool) -> [a] -> [a]
filter (forall (t :: * -> *) a. (Foldable t, Eq a) => a -> t a -> Bool
`notElem` [FilePath
".", FilePath
".."]) [FilePath]
names
  [[(FilePath, FilePath)]]
paths <- forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
t a -> (a -> m b) -> m (t b)
forM [FilePath]
properNames forall a b. (a -> b) -> a -> b
$ \FilePath
name -> do
    let path :: FilePath
path = FilePath
topdir FilePath -> FilePath -> FilePath
</> FilePath
name
    let loc :: FilePath
loc = if forall (t :: * -> *) a. Foldable t => t a -> Bool
null FilePath
prefix then FilePath
name else FilePath
prefix forall a. [a] -> [a] -> [a]
++ FilePath
"/" forall a. [a] -> [a] -> [a]
++ FilePath
name
    Bool
isDirectory <- FilePath -> IO Bool
doesDirectoryExist FilePath
path
    if Bool
isDirectory
      then FilePath -> FilePath -> IO [(FilePath, FilePath)]
getRecursiveContents FilePath
loc FilePath
path
      else forall (m :: * -> *) a. Monad m => a -> m a
return [(FilePath
loc, FilePath
path)]
  forall (m :: * -> *) a. Monad m => a -> m a
return (forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat [[(FilePath, FilePath)]]
paths)

-- | Embed all files in a directory into the static subsite.
-- 
-- Equivalent to passing the empty string as the location to 'embedDirAt',
-- so the directory path itself is not part of the resource locations (and so
-- also not part of the generated route variable names).
embedDir :: FilePath -> Generator
embedDir :: FilePath -> Generator
embedDir = FilePath -> FilePath -> Generator
embedDirAt FilePath
""

-- | Embed all files in a directory to a given location within the static subsite.
--
-- The directory tree rooted at the 'FilePath' (which must be relative to the directory in
-- which you run @cabal build@) is embedded into the static subsite at the given
-- location.  Also, route variables will be created based on the final location
-- of each file.  For example, if a directory \"static\" contains the files
--
-- * css/bootstrap.css
--
-- * js/jquery.js
--
-- * js/bootstrap.js
-- 
-- then @embedDirAt \"somefolder\" \"static\"@ will
--
-- * Make the file @static\/css\/bootstrap.css@ available at the location
--   @somefolder\/css\/bootstrap.css@ within the static subsite and similarly
--   for the other two files.
--
-- * Create variables @somefolder_css_bootstrap_css@, @somefolder_js_jquery_js@,
--   @somefolder_js_bootstrap_js@ all of type @Route EmbeddedStatic@.
--
-- * During development, the files will be reloaded on every request.  During
--   production, the contents of all files will be embedded into the executable.
--
-- * During development, files that are added to the directory while the server
--   is running will not be detected.  You need to recompile the module which
--   contains the call to @mkEmbeddedStatic@.  This will also generate new route
--   variables for the new files.
embedDirAt :: Location -> FilePath -> Generator
embedDirAt :: FilePath -> FilePath -> Generator
embedDirAt FilePath
loc FilePath
dir = do
    [(FilePath, FilePath)]
files <- forall a. IO a -> Q a
runIO forall a b. (a -> b) -> a -> b
$ FilePath -> FilePath -> IO [(FilePath, FilePath)]
getRecursiveContents FilePath
loc FilePath
dir
    forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (forall a b c. (a -> b -> c) -> (a, b) -> c
uncurry FilePath -> FilePath -> Generator
embedFileAt) [(FilePath, FilePath)]
files

-- | Concatinate a list of files and embed it at the location.  Equivalent to passing @return@ to
--   'concatFilesWith'.
concatFiles :: Location -> [FilePath] -> Generator
concatFiles :: FilePath -> [FilePath] -> Generator
concatFiles FilePath
loc [FilePath]
files = FilePath
-> (ByteString -> IO ByteString) -> [FilePath] -> Generator
concatFilesWith FilePath
loc forall (m :: * -> *) a. Monad m => a -> m a
return [FilePath]
files

-- | Concatinate a list of files into a single 'BL.ByteString', run the resulting content through the given
--   function, embed it at the given location, and create a haskell variable name for the route based on
--   the location.
--
--   The processing function is only run when compiling for production, and the processing function is
--   executed at compile time.  During development, on every request the files listed are reloaded,
--   concatenated, and served as a single resource at the given location without being processed.
concatFilesWith :: Location -> (BL.ByteString -> IO BL.ByteString) -> [FilePath] -> Generator
concatFilesWith :: FilePath
-> (ByteString -> IO ByteString) -> [FilePath] -> Generator
concatFilesWith FilePath
loc ByteString -> IO ByteString
process [FilePath]
files = do
    let load :: IO ByteString
load = do FilePath -> IO ()
putStrLn forall a b. (a -> b) -> a -> b
$ FilePath
"Creating " forall a. [a] -> [a] -> [a]
++ FilePath
loc
                  [ByteString] -> ByteString
BL.concat forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM FilePath -> IO ByteString
BL.readFile [FilePath]
files forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= ByteString -> IO ByteString
process
        expFiles :: ExpQ
expFiles = forall (m :: * -> *). Quote m => [m Exp] -> m Exp
listE forall a b. (a -> b) -> a -> b
$ forall a b. (a -> b) -> [a] -> [b]
map (forall (m :: * -> *). Quote m => Lit -> m Exp
litE forall b c a. (b -> c) -> (a -> b) -> a -> c
. FilePath -> Lit
stringL) [FilePath]
files
        expCt :: ExpQ
expCt = [| BL.concat <$> mapM BL.readFile $expFiles |]
        mime :: ByteString
mime = FileName -> ByteString
defaultMimeLookup forall a b. (a -> b) -> a -> b
$ FilePath -> FileName
T.pack FilePath
loc
    forall (m :: * -> *) a. Monad m => a -> m a
return [forall a. Default a => a
def { ebHaskellName :: Maybe Name
ebHaskellName = forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$ FilePath -> Name
pathToName FilePath
loc
                , ebLocation :: FilePath
ebLocation = FilePath
loc
                , ebMimeType :: ByteString
ebMimeType = ByteString
mime
                , ebProductionContent :: IO ByteString
ebProductionContent = IO ByteString
load
                , ebDevelReload :: ExpQ
ebDevelReload = ExpQ
expCt
                }]

-- | Convienient rexport of 'minifym' with a type signature to work with 'concatFilesWith'.
jasmine :: BL.ByteString -> IO BL.ByteString
jasmine :: ByteString -> IO ByteString
jasmine ByteString
ct = forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a c b. (a -> c) -> (b -> c) -> Either a b -> c
either (forall a b. a -> b -> a
const ByteString
ct) forall a. a -> a
id forall a b. (a -> b) -> a -> b
$ ByteString -> Either FilePath ByteString
minifym ByteString
ct

-- | Use <https://github.com/mishoo/UglifyJS2 UglifyJS2> to compress javascript.
-- Assumes @uglifyjs@ is located in the path and uses options @[\"-m\", \"-c\"]@
-- to both mangle and compress and the option \"-\" to cause uglifyjs to read from
-- standard input.
uglifyJs :: BL.ByteString -> IO BL.ByteString
uglifyJs :: ByteString -> IO ByteString
uglifyJs = FilePath -> [FilePath] -> ByteString -> IO ByteString
compressTool FilePath
"uglifyjs" [FilePath
"-", FilePath
"-m", FilePath
"-c"]

-- | Use <http://yui.github.io/yuicompressor/ YUI Compressor> to compress javascript.
-- Assumes a script @yuicompressor@ is located in the path.  If not, you can still
-- use something like
--
-- > compressTool "java" ["-jar", "/path/to/yuicompressor.jar", "--type", "js"]
yuiJavascript :: BL.ByteString -> IO BL.ByteString
yuiJavascript :: ByteString -> IO ByteString
yuiJavascript = FilePath -> [FilePath] -> ByteString -> IO ByteString
compressTool FilePath
"yuicompressor" [FilePath
"--type", FilePath
"js"]

-- | Use <http://yui.github.io/yuicompressor/ YUI Compressor> to compress CSS.
-- Assumes a script @yuicompressor@ is located in the path.
yuiCSS :: BL.ByteString -> IO BL.ByteString
yuiCSS :: ByteString -> IO ByteString
yuiCSS = FilePath -> [FilePath] -> ByteString -> IO ByteString
compressTool FilePath
"yuicompressor" [FilePath
"--type", FilePath
"css"]

-- | Use <https://developers.google.com/closure/compiler/ Closure> to compress
-- javascript using the default options.  Assumes a script @closure@ is located in
-- the path. If not, you can still run using
--
-- > compressTool "java" ["-jar", "/path/to/compiler.jar"]
closureJs :: BL.ByteString -> IO BL.ByteString
closureJs :: ByteString -> IO ByteString
closureJs = FilePath -> [FilePath] -> ByteString -> IO ByteString
compressTool FilePath
"closure" []

-- | Helper to convert a process into a compression function.  The process
-- should be set up to take input from standard input and write to standard output.
compressTool :: FilePath -- ^ program
             -> [String] -- ^ options
             -> BL.ByteString -> IO BL.ByteString
compressTool :: FilePath -> [FilePath] -> ByteString -> IO ByteString
compressTool FilePath
f [FilePath]
opts ByteString
ct = do
    Maybe FilePath
mpath <- FilePath -> IO (Maybe FilePath)
findExecutable FilePath
f
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (forall a. Maybe a -> Bool
isNothing Maybe FilePath
mpath) forall a b. (a -> b) -> a -> b
$
        forall (m :: * -> *) a. MonadFail m => FilePath -> m a
fail forall a b. (a -> b) -> a -> b
$ FilePath
"Unable to find " forall a. [a] -> [a] -> [a]
++ FilePath
f
    let p :: CreateProcess
p = (FilePath -> [FilePath] -> CreateProcess
Proc.proc FilePath
f [FilePath]
opts)
                { std_in :: StdStream
Proc.std_in = StdStream
Proc.CreatePipe
                , std_out :: StdStream
Proc.std_out = StdStream
Proc.CreatePipe
                }
    (Just Handle
hin, Just Handle
hout, Maybe Handle
_, ProcessHandle
ph) <- CreateProcess
-> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
Proc.createProcess CreateProcess
p
    (ByteString
compressed, (), ExitCode
code) <- forall a. Concurrently a -> IO a
runConcurrently forall a b. (a -> b) -> a -> b
$ (,,)
        forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
A.<$> forall a. IO a -> Concurrently a
Concurrently (forall (m :: * -> *) r. Monad m => ConduitT () Void m r -> m r
runConduit forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) i.
MonadIO m =>
Handle -> ConduitT i ByteString m ()
sourceHandle Handle
hout forall (m :: * -> *) a b c r.
Monad m =>
ConduitT a b m () -> ConduitT b c m r -> ConduitT a c m r
.| forall (m :: * -> *) lazy strict o.
(Monad m, LazySequence lazy strict) =>
ConduitT strict o m lazy
sinkLazy)
        forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
A.<*> forall a. IO a -> Concurrently a
Concurrently (Handle -> ByteString -> IO ()
BL.hPut Handle
hin ByteString
ct forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Handle -> IO ()
hClose Handle
hin)
        forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
A.<*> forall a. IO a -> Concurrently a
Concurrently (ProcessHandle -> IO ExitCode
Proc.waitForProcess ProcessHandle
ph)
    if ExitCode
code forall a. Eq a => a -> a -> Bool
== ExitCode
ExitSuccess
        then do
            FilePath -> IO ()
putStrLn forall a b. (a -> b) -> a -> b
$ FilePath
"Compressed successfully with " forall a. [a] -> [a] -> [a]
++ FilePath
f
            forall (m :: * -> *) a. Monad m => a -> m a
return ByteString
compressed
        else forall a. HasCallStack => FilePath -> a
error forall a b. (a -> b) -> a -> b
$ FilePath
"compressTool: compression failed with " forall a. [a] -> [a] -> [a]
++ FilePath
f


-- | Try a list of processing functions (like the compressions above) one by one until
-- one succeeds (does not raise an exception).  Once a processing function succeeds,
-- none of the remaining functions are used.  If none succeeds, the input is just
-- returned unprocessed.  This is helpful if you are distributing
-- code on hackage and do not know what compressors the user will have installed.  You
-- can list several and they will be tried in order until one succeeds.
tryCompressTools :: [BL.ByteString -> IO BL.ByteString] -> BL.ByteString -> IO BL.ByteString
tryCompressTools :: [ByteString -> IO ByteString] -> ByteString -> IO ByteString
tryCompressTools [] ByteString
x = forall (m :: * -> *) a. Monad m => a -> m a
return ByteString
x
tryCompressTools (ByteString -> IO ByteString
p:[ByteString -> IO ByteString]
ps) ByteString
x = do
    Either SomeException ByteString
mres <- forall e a. Exception e => IO a -> IO (Either e a)
try forall a b. (a -> b) -> a -> b
$ ByteString -> IO ByteString
p ByteString
x
    case Either SomeException ByteString
mres of
        Left (SomeException
err :: SomeException) -> do
            FilePath -> IO ()
putStrLn forall a b. (a -> b) -> a -> b
$ forall a. Show a => a -> FilePath
show SomeException
err
            [ByteString -> IO ByteString] -> ByteString -> IO ByteString
tryCompressTools [ByteString -> IO ByteString]
ps ByteString
x
        Right ByteString
res -> forall (m :: * -> *) a. Monad m => a -> m a
return ByteString
res

-- | Clean up a path to make it a valid haskell name by replacing all non-letters
--   and non-numbers by underscores.  In addition, if the path starts with a capital
--   letter or number add an initial underscore.
pathToName :: FilePath -> Name
pathToName :: FilePath -> Name
pathToName FilePath
f = Name
routeName
    where
      replace :: Char -> Char
replace Char
c
        | Char
'A' forall a. Ord a => a -> a -> Bool
<= Char
c Bool -> Bool -> Bool
&& Char
c forall a. Ord a => a -> a -> Bool
<= Char
'Z' = Char
c
        | Char
'a' forall a. Ord a => a -> a -> Bool
<= Char
c Bool -> Bool -> Bool
&& Char
c forall a. Ord a => a -> a -> Bool
<= Char
'z' = Char
c
        | Char
'0' forall a. Ord a => a -> a -> Bool
<= Char
c Bool -> Bool -> Bool
&& Char
c forall a. Ord a => a -> a -> Bool
<= Char
'9' = Char
c
        | Bool
otherwise = Char
'_'
      name :: FilePath
name = forall a b. (a -> b) -> [a] -> [b]
map Char -> Char
replace FilePath
f
      routeName :: Name
routeName = FilePath -> Name
mkName forall a b. (a -> b) -> a -> b
$
            case () of
                ()
                    | forall (t :: * -> *) a. Foldable t => t a -> Bool
null FilePath
name -> forall a. HasCallStack => FilePath -> a
error FilePath
"null-named file"
                    | Char -> Bool
isDigit (forall a. [a] -> a
head FilePath
name) -> Char
'_' forall a. a -> [a] -> [a]
: FilePath
name
                    | Char -> Bool
isLower (forall a. [a] -> a
head FilePath
name) -> FilePath
name
                    | Bool
otherwise -> Char
'_' forall a. a -> [a] -> [a]
: FilePath
name


-- $example
-- Here is an example of creating your own custom generator.
-- Because of template haskell stage restrictions, you must define generators in a
-- different module from where you use them.  The following generator will embed a
-- JSON document that contains the compile time.
--
-- >{-# LANGUAGE TemplateHaskell, QuasiQuotes, OverloadedStrings #-}
-- >module CompileTime where
-- >
-- >import Data.Aeson
-- >import Data.Default
-- >import Data.Time
-- >import Yesod.EmbeddedStatic.Generators
-- >import Yesod.EmbeddedStatic.Types
-- >import qualified Data.ByteString.Lazy as BL
-- >
-- >getTime :: IO BL.ByteString
-- >getTime = do
-- >    t <- getCurrentTime
-- >    return $ encode $
-- >        object [ "compile_time" .= show t ]
-- >
-- >timeGenerator :: Location -> Generator
-- >timeGenerator loc =
-- >    return $ [def
-- >        { ebHaskellName = Just $ pathToName loc
-- >        , ebLocation    = loc
-- >        , ebMimeType    = "application/json"
-- >        , ebProductionContent = getTime
-- >        , ebDevelReload = [| getTime |]
-- >        }]
--
-- Notice how the @getTime@ action is given as both 'ebProductionContent' and
-- 'ebDevelReload'.  The result is that during development, the @getTime@ action
-- will be re-executed on every request so the time returned will be different
-- for each reload.  When compiling for production, the @getTime@ action will
-- be executed once at compile time to produce the content to embed and never
-- called at runtime.
--
-- Here is a small example yesod program using this generator.  Try toggling
-- the development argument to @mkEmbeddedStatic@.
-- 
-- >{-# LANGUAGE TemplateHaskell, QuasiQuotes, TypeFamilies #-}
-- >module Main where
-- >
-- >import Yesod
-- >import Yesod.EmbeddedStatic
-- >import CompileTime (timeGenerator)
-- >
-- >mkEmbeddedStatic True "eStatic" [timeGenerator "compile-time.json"]
-- >
-- >-- The above will generate variables
-- >-- eStatic :: EmbeddedStatic
-- >-- compile_time_json :: Route EmbeddedStatic
-- >
-- >data MyApp = MyApp { getStatic :: EmbeddedStatic }
-- >
-- >mkYesod "MyApp" [parseRoutes|
-- >/ HomeR GET
-- >/static StaticR EmbeddedStatic getStatic
-- >|]
-- >
-- >instance Yesod MyApp
-- >
-- >getHomeR :: Handler Html
-- >getHomeR = defaultLayout $ [whamlet|
-- ><h1>Hello
-- ><p>Check the 
-- >    <a href=@{StaticR compile_time_json}>compile time
-- >|]
-- >
-- >main :: IO ()
-- >main = warp 3000 $ MyApp eStatic