module Network.Loli.Engine where
import Control.Monad.State hiding (join)
import Data.Default
import Data.List (find)
import Data.Maybe
import Hack
import Hack.Contrib.Middleware.NotFound
import Hack.Contrib.Response
import Hack.Contrib.Utils hiding (get, put)
import MPS
import Network.Loli.Config
import Network.Loli.Config
import Prelude hiding ((.), (/), (>), (^))
type RoutePath = (RequestMethod, String, AppUnit)
type EnvFilter = Env -> Env
type ResponseFilter = Response -> Response
type Param = (String, String)
data AppState = AppState
{
env :: Env
, response :: Response
}
instance Default AppState where
def = AppState def def
type AppUnitT a = StateT AppState IO a
type AppUnit = AppUnitT ()
run_app :: AppUnit -> Application
run_app unit = \env -> execStateT unit def {env} ^ response
router :: [RoutePath] -> Middleware
router h app' = \env'' ->
let path = env''.path_info
script = env''.script_name
mod_env location = env''
{ scriptName = script ++ location
, pathInfo = path.drop (location.length)
}
in
case h.find (match_route env'') of
Nothing -> app' env''
Just (_, template, app_state) -> do
let (location, params) = parse_params template path .fromJust
run_app app_state (mod_env location .merge_captured params)
where
match_route env' (method, template, _) =
env'.request_method.is method
&& env'.path_info.parse_params template .isJust
merge_captured params env' =
let loli_captures = params.map_fst (loli_captures_prefix ++)
new_hack_headers = env'.custom ++ loli_captures
in
env' {hackHeaders = new_hack_headers}
parse_params :: String -> String -> Maybe (String, [(String, String)])
parse_params t s =
let template_tokens = t.split "/"
url_tokens = s.split "/"
in
if url_tokens.length < template_tokens.length
then Nothing
else
let rs = zipWith capture template_tokens url_tokens
in
if rs.all isJust
then
let location = url_tokens.take (template_tokens.length).join "/"
in
Just $ (location, rs.map fromJust.filter isJust.map fromJust)
else Nothing
where
capture x y
| x.starts_with ":" = Just $ Just (x.tail, y)
| x == y = Just Nothing
| otherwise = Nothing
data Loli = Loli
{
routes :: [RoutePath]
, middlewares :: [Middleware]
, mimes :: [(String, String)]
}
instance Default Loli where
def = Loli def def def
type UnitT a = State Loli a
type Unit = UnitT ()
loli :: Unit -> Application
loli unit = run unit (not_found empty_app)
where
run :: Unit -> Middleware
run unit' =
let s = execState unit' def
paths = s.routes
loli_app = router paths
mime_filter = lookup_mime (s.mimes)
stack = s.middlewares.use
pre = pre_installed_middlewares.use
in
use [pre, mime_filter, stack, loli_app]
update :: (MonadState a m, Functor m) => (a -> a) -> m ()
update f = get ^ f >>= put
insert_last :: a -> [a] -> [a]
insert_last x xs = xs ++ [x]
add_route :: RoutePath -> Loli -> Loli
add_route r s = let xs = s.routes in s {routes = xs.insert_last r}
route :: RequestMethod -> String -> AppUnit -> Unit
route r s u = update $ add_route (r, s, u)
add_middleware :: Middleware -> Loli -> Loli
add_middleware x s =
let xs = s.middlewares in s {middlewares = xs.insert_last x}
add_mime :: String -> String -> Loli -> Loli
add_mime k v s = let xs = s.mimes in s {mimes = xs.insert_last (k, v)}
update_response :: ResponseFilter -> AppUnit
update_response f = update $ \s -> let x = s.response.f in s {response = x}
set_response :: Response -> AppUnit
set_response r = update_response $ const r
get_response :: AppUnitT Response
get_response = get ^ response
update_env :: EnvFilter -> AppUnit
update_env f = update $ \s -> let x = s.env.f in s {env = x}
get_env :: AppUnitT Env
get_env = get ^ env
lookup_mime :: [(String, String)] -> Middleware
lookup_mime h app env = do
r <- app env
case h.only_fst.find mime >>= flip lookup h of
Nothing -> return r
Just v -> return $ r.set_content_type v
where mime x = env.path_info.ends_with ('.' : x)