{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE ScopedTypeVariables #-}
module OpenlabTools where
import Control.Concurrent.STM hiding (atomically, readTVarIO)
import Control.DeepSeq (NFData, deepseq)
import Control.Monad.Logger qualified as Logger
import Control.Monad.Logger.CallStack
import Control.Monad.Reader
import Data.Aeson.BetterErrors qualified as Json
import Data.CaseInsensitive qualified as CaseInsensitive
import Data.Error.Tree
import Data.HashMap.Strict qualified as HashMap
import Data.List qualified as List
import Data.Maybe (listToMaybe)
import Data.Text qualified as Text
import Data.Time (NominalDiffTime, UTCTime (utctDayTime), diffUTCTime, getCurrentTime)
import Data.Time qualified as Time
import Data.Time.Clock (addUTCTime)
import Data.Time.Format qualified as Time.Format
import Debug.Trace
import FieldParser (FieldParser' (..))
import FieldParser qualified as Field
import GHC.Records (HasField (..))
import GHC.Stack qualified
import IHP.HSX.QQ (hsx)
import Json qualified
import Label
import Network.HTTP.Client.Conduit qualified as Http
import Network.HTTP.Simple qualified as Http
import Network.HTTP.Types
import Network.HTTP.Types qualified as Http
import Network.Wai qualified as Wai
import Network.Wai.Handler.Warp qualified as Warp
import Network.Wai.Parse qualified as Wai
import OpenTelemetry.Trace qualified as Otel hiding (getTracer, inSpan, inSpan')
import OpenTelemetry.Trace.Core qualified as Otel hiding (inSpan, inSpan')
import OpenTelemetry.Trace.Monad qualified as Otel
import Parse (Parse)
import Parse qualified
import PossehlAnalyticsPrelude
import Pretty
import System.Environment qualified as Env
import System.IO qualified as IO
import Text.Blaze.Html.Renderer.Pretty qualified as Html.Pretty
import Text.Blaze.Html.Renderer.Utf8 qualified as Html
import Text.Blaze.Html5 qualified as Html
import Text.HTML.TagSoup qualified as Soup
import UnliftIO hiding (Handler, newTVarIO)
import Prelude hiding (span, until)
mapallSpaceOla :: Text
mapallSpaceOla = "https://mapall.space/heatmap/show.php?id=OpenLab+Augsburg"
mainPage :: Html.Html
mainPage =
Html.docTypeHtml
[hsx|
<head>
<title>Openlab Augsburg Tools</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
<p>Welcome to the OpenLab Augsburg tools thingy. The idea is to provide some services that can be embedded into our other pages.</p>
<h2>What’s there</h2>
<ul>
<li>
A <a href="snips/table-opening-hours-last-week">table displaying the opening hours last week</a>, courtesy of <a href={mapallSpaceOla}>mapall.space</a>.
</li>
</ul>
<h2>Show me the code/how to contribute</h2>
<p>The source code can be found <a href="https://code.tvl.fyi/tree/users/Profpatsch/openlab-tools">in my user dir in the tvl repo</a>.</p>
<p>To build the server, clone the repository from <a href="https://code.tvl.fyi/depot.git">https://code.tvl.fyi/depot.git</a>.
Then <code>cd</code> into <code>users/Profpatsch</code>, run <code>nix-shell</code>.
</p>
<p>You can now run the server with <code>cabal repl openlab-tools/`</code> by executing the <code>main</code> function inside the GHC repl. It starts on port <code>9099</code>.
<br>
To try out changes to the code, stop the server with <kbd><kbd>Ctrl</kbd>+<kbd>z</kbd></kbd> and type <code>:reload</code>, then <code>main</code> again.
<br>
Finally, from within <code>users/Profpatsch</code> you can start a working development environment by installing <var>vscode</var> or <var>vscodium</var> and the <var>Haskell</var> extension. Then run <code>code .</code> from within the directory.
</p>
<p>Once you have a patch, <a href="https://matrix.to/#/@profpatsch:augsburg.one">contact me on Matrix</a> or DM me at <code>irc/libera</code>, nick <code>Profpatsch</code>.
</p>
</body>
|]
debug :: Bool
debug = False
runApp :: IO ()
runApp = withTracer $ \tracer -> do
let renderHtml =
if debug
then Html.Pretty.renderHtml >>> stringToText >>> textToBytesUtf8 >>> toLazyBytes
else Html.renderHtml
let appT = withRunInIO $ \runInIO -> Warp.run 9099 $ \req respond -> do
let catchAppException act =
try act >>= \case
Right a -> pure a
Left (AppException err) -> do
runInIO (logError err)
respond (Wai.responseLBS Http.status500 [] "")
let h extra res = Wai.responseLBS Http.ok200 (("Content-Type", "text/html") : extra) res
catchAppException $
runInIO $
runHandlers
[ Handler
{ path = "",
body =
Body
(pure ())
(\((), _) -> pure $ h [] (renderHtml mainPage))
},
Handler
{ path = "snips/table-opening-hours-last-week",
body =
Body
((label @"ifModifiedSince" <$> parseIfModifiedSince))
( \(req', cache) -> liftIO $ do
now <- getCurrentTime <&> mkSecondTime
new <- runInIO $ updateCacheIfNewer now cache heatmap
let cacheToHeaders =
[ ("Last-Modified", new.lastModified & formatHeaderTime),
("Expires", new.until & formatHeaderTime),
( "Cache-Control",
let maxAge = new.until `diffSecondTime` now
in [fmt|max-age={maxAge & floor @NominalDiffTime @Int & show}, immutable|]
)
]
if
-- If the last cache update is newer or equal to the requested version, we can tell the browser it’s fine
| Just modifiedSince <- req'.ifModifiedSince,
modifiedSince >= new.lastModified ->
pure $ Wai.responseLBS Http.status304 cacheToHeaders ""
| otherwise ->
pure $ h cacheToHeaders (new.result & toLazyBytes)
)
}
]
req
(\resp -> liftIO $ respond resp)
runReaderT (appT :: AppT IO ()).unAppT Context {..}
where
-- "https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Last-Modified#syntax"
headerFormat = "%a, %d %b %0Y %T GMT"
formatHeaderTime (SecondTime t) =
t
& Time.Format.formatTime
@UTCTime
Time.Format.defaultTimeLocale
headerFormat
& stringToText
& textToBytesUtf8
parseHeaderTime =
Field.utf8
>>> ( FieldParser $ \t ->
t
& textToString
& Time.Format.parseTimeM
@Maybe
@UTCTime
{-no leading whitespace -} False
Time.Format.defaultTimeLocale
headerFormat
& annotate [fmt|Cannot parse header timestamp "{t}"|]
)
parseIfModifiedSince :: Parse Wai.Request (Maybe SecondTime)
parseIfModifiedSince =
lmap
( (.requestHeaders)
>>> findMaybe
( \(h, v) ->
if "If-Modified-Since" == CaseInsensitive.mk h then Just v else Nothing
)
)
(Parse.maybe $ Parse.fieldParser parseHeaderTime)
& rmap (fmap mkSecondTime)
parseRequest :: (MonadThrow f, MonadIO f) => Otel.Span -> Parse from a -> from -> f a
parseRequest span parser req =
Parse.runParse "Unable to parse the HTTP request" parser req
& assertM span id
data Handler m = Handler
{ path :: Text,
body :: Body m
}
data Body m
= forall a.
Body
(Parse Wai.Request a)
((a, TVar (Cache ByteString)) -> m Wai.Response)
runHandlers ::
(Otel.MonadTracer m, MonadUnliftIO m, MonadThrow m) =>
[Handler m] ->
Wai.Request ->
(Wai.Response -> m Wai.ResponseReceived) ->
m Wai.ResponseReceived
runHandlers handlers req respond = do
withCaches ::
[ T2
"handler"
(Handler m)
"cache"
(TVar (Cache ByteString))
] <-
handlers
& traverse
( \h -> do
cache <- liftIO $ newCache "nothing yet"
pure $ T2 (label @"handler" h) (label @"cache" cache)
)
let mHandler =
withCaches
& List.find
( \h ->
(h.handler.path)
== (req & Wai.pathInfo & Text.intercalate "/")
)
case mHandler of
Nothing -> respond $ Wai.responseLBS Http.status404 [] "nothing here (yet)"
Just handler -> do
inSpan' "TODO" $ \span -> do
let h :: Handler m = handler.handler
case h.body of
Body parse runHandler -> do
req' <- req & parseRequest span parse
resp <- runHandler (req', handler.cache)
respond resp
heatmap :: AppT IO ByteString
heatmap = do
Http.httpBS [fmt|GET {mapallSpaceOla}|]
<&> (.responseBody)
<&> Soup.parseTags
<&> Soup.canonicalizeTags
<&> findHeatmap
<&> fromMaybe (htmlToTags [hsx|<p>Uh oh! could not fetch the table from <a href={mapallSpaceOla}>{mapallSpaceOla}</a></p>|])
<&> Soup.renderTags
where
firstSection f t = t & Soup.sections f & listToMaybe
match :: Soup.Tag ByteString -> Soup.Tag ByteString -> Bool
match x (t :: Soup.Tag ByteString) = (Soup.~==) @ByteString t x
findHeatmap t =
t
& firstSection (match (Soup.TagOpen ("") [("class", "heatmap")]))
>>= firstSection (match (Soup.TagOpen "table" []))
<&> getTable
<&> (<> htmlToTags [hsx|<figcaption>source: <a href={mapallSpaceOla} target="_blank">mapall.space</a></figcaption>|])
<&> wrapTagStream (T2 (label @"el" "figure") (label @"attrs" []))
-- get the table from opening tag to closing tag (allowing nested tables)
getTable = go 0
where
go _ [] = []
go d (el : els)
| match (Soup.TagOpen "table" []) el = el : go (d + 1) els
| match (Soup.TagClose "table") el = if d <= 1 then [el] else el : go (traceShowId $ d - 1) els
| otherwise = el : go d els
htmlToTags :: Html.Html -> [Soup.Tag ByteString]
htmlToTags h = h & Html.renderHtml & toStrictBytes & Soup.parseTags
-- TODO: this is dog-slow because of the whole list recreation!
wrapTagStream ::
T2 "el" ByteString "attrs" [Soup.Attribute ByteString] ->
[Soup.Tag ByteString] ->
[Soup.Tag ByteString]
wrapTagStream tag inner = (Soup.TagOpen (tag.el) tag.attrs : inner) <> [Soup.TagClose tag.el]
main :: IO ()
main =
runApp
-- ( do
-- -- todo: trace that to the init functions as well
-- Otel.inSpan "whatcd-resolver main function" Otel.defaultSpanArguments $ do
-- _ <- runTransaction migrate
-- htmlUi
-- )
inSpan :: (MonadUnliftIO m, Otel.MonadTracer m) => Text -> m a -> m a
inSpan name = Otel.inSpan name Otel.defaultSpanArguments
inSpan' :: (MonadUnliftIO m, Otel.MonadTracer m) => Text -> (Otel.Span -> m a) -> m a
-- inSpan' name = Otel.inSpan' name Otel.defaultSpanArguments
inSpan' _name act = act (error "todo telemetry disabled")
zipT2 ::
forall l1 l2 t1 t2.
( HasField l1 (T2 l1 [t1] l2 [t2]) [t1],
HasField l2 (T2 l1 [t1] l2 [t2]) [t2]
) =>
T2 l1 [t1] l2 [t2] ->
[T2 l1 t1 l2 t2]
zipT2 xs =
zipWith
(\t1 t2 -> T2 (label @l1 t1) (label @l2 t2))
(getField @l1 xs)
(getField @l2 xs)
unzipT2 :: forall l1 t1 l2 t2. [T2 l1 t1 l2 t2] -> T2 l1 [t1] l2 [t2]
unzipT2 xs = xs <&> toTup & unzip & fromTup
where
toTup :: forall a b. T2 a t1 b t2 -> (t1, t2)
toTup (T2 a b) = (getField @a a, getField @b b)
fromTup :: (a, b) -> T2 l1 a l2 b
fromTup (t1, t2) = T2 (label @l1 t1) (label @l2 t2)
unzipT3 :: forall l1 t1 l2 t2 l3 t3. [T3 l1 t1 l2 t2 l3 t3] -> T3 l1 [t1] l2 [t2] l3 [t3]
unzipT3 xs = xs <&> toTup & unzip3 & fromTup
where
toTup :: forall a b c. T3 a t1 b t2 c t3 -> (t1, t2, t3)
toTup (T3 a b c) = (getField @a a, getField @b b, getField @c c)
fromTup :: (a, b, c) -> T3 l1 a l2 b l3 c
fromTup (t1, t2, t3) = T3 (label @l1 t1) (label @l2 t2) (label @l3 t3)
newtype Optional a = OptionalInternal (Maybe a)
mkOptional :: a -> Optional a
mkOptional defaultValue = OptionalInternal $ Just defaultValue
defaults :: Optional a
defaults = OptionalInternal Nothing
instance HasField "withDefault" (Optional a) (a -> a) where
getField (OptionalInternal m) defaultValue = case m of
Nothing -> defaultValue
Just a -> a
httpJson ::
( MonadIO m,
MonadThrow m
) =>
(Optional (Label "contentType" ByteString)) ->
Otel.Span ->
Json.Parse ErrorTree b ->
Http.Request ->
m b
httpJson opts span parser req = do
let opts' = opts.withDefault (label @"contentType" "application/json")
Http.httpBS req
>>= assertM
span
( \resp -> do
let statusCode = resp & Http.responseStatus & (.statusCode)
contentType =
resp
& Http.responseHeaders
& List.lookup "content-type"
<&> Wai.parseContentType
<&> (\(ct, _mimeAttributes) -> ct)
if
| statusCode == 200,
Just ct <- contentType,
ct == opts'.contentType ->
Right $ (resp & Http.responseBody)
| statusCode == 200,
Just otherType <- contentType ->
Left [fmt|Server returned a non-json body, with content-type "{otherType}"|]
| statusCode == 200,
Nothing <- contentType ->
Left [fmt|Server returned a body with unspecified content type|]
| code <- statusCode -> Left [fmt|Server returned an non-200 error code, code {code}: {resp & showPretty}|]
)
>>= assertM
span
( \body ->
Json.parseStrict parser body
& first (Json.parseErrorTree "could not parse redacted response")
)
assertM :: (MonadThrow f, MonadIO f) => Otel.Span -> (t -> Either ErrorTree a) -> t -> f a
assertM span f v = case f v of
Right a -> pure a
Left err -> appThrowTree span err
-- | UTC time that is only specific to the second
newtype SecondTime = SecondTime {unSecondTime :: UTCTime}
deriving newtype (Show, Eq, Ord)
mkSecondTime :: UTCTime -> SecondTime
mkSecondTime utcTime = SecondTime utcTime {utctDayTime = Time.secondsToDiffTime $ floor utcTime.utctDayTime}
diffSecondTime :: SecondTime -> SecondTime -> NominalDiffTime
diffSecondTime (SecondTime a) (SecondTime b) = diffUTCTime a b
data Cache a = Cache
{ until :: !SecondTime,
lastModified :: !SecondTime,
result :: !a
}
newCache :: a -> IO (TVar (Cache a))
newCache result = do
until <- getCurrentTime <&> mkSecondTime
let lastModified = until
newTVarIO $ Cache {..}
updateCache :: (NFData a, Eq a) => SecondTime -> TVar (Cache a) -> a -> STM (Cache a)
updateCache now cache result' = do
-- make sure we don’t hold onto the world by deepseq-ing and evaluating to WHNF
let !result = deepseq result' result'
let until = mkSecondTime $ (5 * 60) `addUTCTime` now.unSecondTime
!toWrite <- do
old <- readTVar cache
-- only update the lastModified time iff the content changed (this is helpful for HTTP caching with If-Modified-Since)
if old.result == result
then do
let lastModified = old.lastModified
pure $ Cache {..}
else do
let lastModified = now
pure $ Cache {..}
_ <- writeTVar cache $! toWrite
pure toWrite
-- | Run the given action iff the cache is stale, otherwise just return the item from the cache.
updateCacheIfNewer :: (MonadUnliftIO m, NFData b, Eq b) => SecondTime -> TVar (Cache b) -> m b -> m (Cache b)
updateCacheIfNewer now cache act = withRunInIO $ \runInIO -> do
old <- readTVarIO cache
if old.until <= now
then do
res <- runInIO act
atomically $ updateCache now cache res
else pure old
-- pgFormat <- readTools (label @"toolsEnvVar" "OPENLAB_TOOLS_TOOLS") (readTool "pg_format")
-- let config = label @"logDatabaseQueries" LogDatabaseQueries
-- pgConnPool <-
-- Pool.newPool $
-- Pool.defaultPoolConfig
-- {- resource init action -} (Postgres.connectPostgreSQL (db & TmpPg.toConnectionString))
-- {- resource destruction -} Postgres.close
-- {- unusedResourceOpenTime -} 10
-- {- max resources across all stripes -} 20
-- transmissionSessionId <- newEmptyMVar
-- let newAppT = do
-- logInfo [fmt|Running with config: {showPretty config}|]
-- logInfo [fmt|Connected to database at {db & TmpPg.toDataDirectory} on socket {db & TmpPg.toConnectionString}|]
-- appT
-- runReaderT newAppT.unAppT Context {..}
withTracer :: (Otel.Tracer -> IO c) -> IO c
withTracer f = do
setDefaultEnv "OTEL_SERVICE_NAME" "whatcd-resolver"
bracket
-- Install the SDK, pulling configuration from the environment
Otel.initializeGlobalTracerProvider
-- Ensure that any spans that haven't been exported yet are flushed
Otel.shutdownTracerProvider
-- Get a tracer so you can create spans
(\tracerProvider -> f $ Otel.makeTracer tracerProvider "whatcd-resolver" Otel.tracerOptions)
setDefaultEnv :: String -> String -> IO ()
setDefaultEnv envName defaultValue = do
Env.lookupEnv envName >>= \case
Just _env -> pure ()
Nothing -> Env.setEnv envName defaultValue
data Context = Context
{ tracer :: Otel.Tracer
}
newtype AppT m a = AppT {unAppT :: ReaderT Context m a}
deriving newtype (Functor, Applicative, Monad, MonadIO, MonadUnliftIO, MonadThrow)
data AppException = AppException Text
deriving stock (Show)
deriving anyclass (Exception)
-- | A specialized variant of @addEvent@ that records attributes conforming to
-- the OpenTelemetry specification's
-- <https://github.com/open-telemetry/opentelemetry-specification/blob/49c2f56f3c0468ceb2b69518bcadadd96e0a5a8b/specification/trace/semantic_conventions/exceptions.md semantic conventions>
--
-- @since 0.0.1.0
recordException ::
( MonadIO m,
HasField "message" r Text,
HasField "type_" r Text
) =>
Otel.Span ->
r ->
m ()
recordException span dat = liftIO $ do
callStack <- GHC.Stack.whoCreated dat.message
newEventTimestamp <- Just <$> Otel.getTimestamp
Otel.addEvent span $
Otel.NewEvent
{ newEventName = "exception",
newEventAttributes =
HashMap.fromList
[ ("exception.type", Otel.toAttribute @Text dat.type_),
("exception.message", Otel.toAttribute @Text dat.message),
("exception.stacktrace", Otel.toAttribute @Text $ Text.unlines $ map stringToText callStack)
],
..
}
appThrowTree :: (MonadThrow m, MonadIO m) => Otel.Span -> ErrorTree -> m a
appThrowTree span exc = do
let msg = prettyErrorTree exc
-- recordException
-- span
-- ( T2
-- (label @"type_" "AppException")
-- (label @"message" msg)
-- )
throwM $ AppException msg
orAppThrowTree :: (MonadThrow m, MonadIO m) => Otel.Span -> Either ErrorTree a -> m a
orAppThrowTree span = \case
Left err -> appThrowTree span err
Right a -> pure a
instance (MonadIO m) => MonadLogger (AppT m) where
monadLoggerLog loc src lvl msg = liftIO $ Logger.defaultOutput IO.stderr loc src lvl (Logger.toLogStr msg)
instance (Monad m) => Otel.MonadTracer (AppT m) where
getTracer = AppT $ asks (.tracer)
