Use EitherT

H1rono · Feb 23, 2024 · 07ef930 · 07ef930
1 parent 113a3ce
commit 07ef930
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Showing 2 changed files with 42 additions and 11 deletions.
diff --git a/src/main/scala/h1rono/BotHandler.scala b/src/main/scala/h1rono/BotHandler.scala
@@ -9,26 +9,57 @@ import cats.effect._
 import org.http4s._
 import org.http4s.circe._
 import cats.syntax.all._
+import cats.data.EitherT
 
 trait BotHandler[F[_]] {
   def bot(req: Request[F]): F[Status]
 }
 
 object BotHandler {
-  def impl[F[_]: Async: std.Console]: BotHandler[F] = new BotHandler[F] {
+  final case class Config(verificationToken: String, accessToken: String)
+
+  def impl[F[_]: Async: std.Console](conf: Config): BotHandler[F] = new BotHandler[F] {
     def bot(req: Request[F]): F[Status] = for {
-      payload <- req.as[Json]
-      eventType = getHeaderValue(req, CIString("x-traq-bot-event")).getOrElse(
-        throw new Exception("x-traq-bot-event not found")
+      req <- botInner(req).value
+      // TODO: Do something with req
+    } yield req match {
+      case Left(HandleResults.BadInput)        => Status.BadRequest
+      case Left(HandleResults.Success)         => Status.NoContent
+      case Left(HandleResults.UnexpectedError) => Status.InternalServerError
+      case Right(_)                            => Status.NoContent
+    }
+
+    private sealed trait HandleResults
+    private object HandleResults {
+      case object Success extends HandleResults
+      case object BadInput extends HandleResults
+      case object UnexpectedError extends HandleResults
+    }
+
+    private def botInner(req: Request[F]): EitherT[F, HandleResults, (String, Json)] = for {
+      payload <- EitherT.right(req.as[Json])
+      eventType <- checkRequest(req)
+      _ <- EitherT.right(std.Console[F].println(s"event type is $eventType"))
+      _ <- EitherT.right(std.Console[F].println(payload))
+    } yield (eventType, payload)
+
+    private def checkRequest(req: Request[F]): EitherT[F, HandleResults, String] = for {
+      eventType <- EitherT.fromOption[F](
+        getHeaderValue(req, CIString("x-traq-bot-event")),
+        HandleResults.BadInput
+      )
+      token <- EitherT.fromOption[F](
+        getHeaderValue(req, CIString("x-traq-bot-token")),
+        HandleResults.BadInput
       )
-      token = getHeaderValue(req, CIString("x-traq-bot-token")).getOrElse(
-        throw new Exception("x-traq-bot-token not found")
+      res <- EitherT.cond(
+        token == conf.verificationToken,
+        eventType,
+        HandleResults.BadInput: HandleResults
       )
-      _ <- std.Console[F].println(s"event type is $eventType")
-      _ <- std.Console[F].println(payload)
-    } yield Status.NoContent
+    } yield res
 
-    private def getHeaderValue[F[_]](req: Request[F], key: CIString): Option[String] = for {
+    private def getHeaderValue(req: Request[F], key: CIString): Option[String] = for {
       headers <- req.headers.get(key)
       header <- headers.get(0)
     } yield header.value

diff --git a/src/main/scala/h1rono/BotServer.scala b/src/main/scala/h1rono/BotServer.scala
@@ -15,7 +15,7 @@ object BotServer {
 
     val helloWorldAlg = HelloWorld.impl[F]
     val dumpReqAlg = DumpReq.impl[F]
-    val botHandlerAlg = BotHandler.impl[F]
+    val botHandlerAlg = BotHandler.impl[F](BotHandler.Config(verificationToken, accessToken))
 
     // Combine Service Routes into an HttpApp.
     // Can also be done via a Router if you