Add telegram bot UI (#3)

.gitignore

@@ -4,3 +4,4 @@
 target
 project/target
 .bsp
+secret

bot/src/main/scala/com/github/mmvpm/bot/Main.scala

@@ -0,0 +1,27 @@
+package com.github.mmvpm.bot
+
+import cats.effect.{IO, IOApp}
+import com.github.mmvpm.bot.model.MessageID
+import com.github.mmvpm.bot.render.RendererImpl
+import com.github.mmvpm.bot.state.{State, StateManagerImpl, StorageImpl}
+import com.github.mmvpm.bot.util.ResourceUtils
+import org.asynchttpclient.Dsl.asyncHttpClient
+import sttp.client3.asynchttpclient.cats.AsyncHttpClientCatsBackend
+
+object Main extends IOApp.Simple {
+
+  override def run: IO[Unit] =
+    for {
+      _ <- IO.println("Starting telegram bot...")
+
+      token = ResourceUtils.readTelegramToken()
+      sttpBackend = AsyncHttpClientCatsBackend.usingClient[IO](asyncHttpClient)
+      renderer = new RendererImpl
+      manager = new StateManagerImpl[IO]
+      stateStorage = new StorageImpl[State](State.Started)
+      lastMessageStorage = new StorageImpl[Option[MessageID]](None)
+      bot = new OfferServiceBot[IO](token, sttpBackend, renderer, manager, stateStorage, lastMessageStorage)
+
+      _ <- bot.startPolling()
+    } yield ()
+}

bot/src/main/scala/com/github/mmvpm/bot/OfferServiceBot.scala

@@ -0,0 +1,87 @@
+package com.github.mmvpm.bot
+
+import cats.effect.Concurrent
+import cats.implicits.toFlatMapOps
+import cats.syntax.functor._
+import com.bot4s.telegram.api.declarative.{Callbacks, Command, Commands}
+import com.bot4s.telegram.cats.{Polling, TelegramBot}
+import com.bot4s.telegram.methods.{EditMessageText, SendDice, SendMessage}
+import com.bot4s.telegram.models._
+import com.github.mmvpm.bot.model.MessageID
+import com.github.mmvpm.bot.render.Renderer
+import com.github.mmvpm.bot.state.{State, StateManager, Storage}
+import com.github.mmvpm.bot.state.State._
+import sttp.client3.SttpBackend
+
+class OfferServiceBot[F[_]: Concurrent](
+    token: String,
+    sttpBackend: SttpBackend[F, Any],
+    renderer: Renderer,
+    manager: StateManager[F],
+    stateStorage: Storage[State],
+    lastMessageStorage: Storage[Option[MessageID]])
+  extends TelegramBot[F](token, sttpBackend)
+  with Polling[F]
+  with Commands[F]
+  with Callbacks[F] {
+
+  // user sent a message (text, image, etc) to the chat
+  onMessage { implicit message =>
+    command(message) match {
+      case Some(Command("roll", _)) => roll
+      case Some(Command("start", _)) => start
+      case None =>
+        getNextStateTag(stateStorage.get) match {
+          case UnknownTag => fail
+          case nextTag => replyResolved(nextTag)
+        }
+    }
+  }
+
+  // user pressed the button
+  onCallbackQuery { implicit cq =>
+    replyResolved(cq.data.get)(cq.message.get)
+  }
+
+  // scenarios
+
+  private def roll(implicit message: Message): F[Unit] =
+    request(SendDice(message.chat.id)).void
+
+  private def start(implicit message: Message): F[Unit] =
+    requestLogged(renderer.render(stateStorage.get, lastMessageStorage.get)).void
+
+  private def replyResolved(tag: String)(implicit message: Message): F[Unit] =
+    for {
+      nextState <- manager.getNextState(tag, stateStorage.get)
+      _ = stateStorage.set(withoutError(nextState))
+      reply = renderer.render(nextState, lastMessageStorage.get)
+      _ <- requestLogged(reply)
+    } yield ()
+
+  private def fail(implicit message: Message): F[Unit] =
+    reply("Не понял вас :(").void
+
+  // internal
+
+  private def withoutError(state: State): State =
+    state match {
+      case Error(returnTo, _) => returnTo
+      case _ => state
+    }
+
+  private def requestLogged(req: Either[EditMessageText, SendMessage]): F[Unit] =
+    req match {
+      case Left(toEdit) =>
+        for {
+          sent <- request(toEdit)
+          _ = println(s"Edit $sent")
+        } yield ()
+      case Right(toSend) =>
+        for {
+          sent <- request(toSend)
+          _ = lastMessageStorage.set(Some(sent.messageId))(sent)
+          _ = println(s"Sent $sent")
+        } yield ()
+    }
+}

bot/src/main/scala/com/github/mmvpm/bot/model/Draft.scala

@@ -0,0 +1,7 @@
+package com.github.mmvpm.bot.model
+
+case class Draft(
+    name: Option[String] = None,
+    price: Option[Long] = None,
+    description: Option[String] = None,
+    photos: Seq[String] = Seq.empty)

bot/src/main/scala/com/github/mmvpm/bot/model/package.scala

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+package com.github.mmvpm.bot
+
+package object model {
+  type ChatID = Long
+  type MessageID = Int
+  type Tag = String
+  type Button = String
+}

bot/src/main/scala/com/github/mmvpm/bot/render/Renderer.scala

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+package com.github.mmvpm.bot.render
+
+import com.bot4s.telegram.methods.{EditMessageText, SendMessage}
+import com.bot4s.telegram.models.Message
+import com.github.mmvpm.bot.model.MessageID
+import com.github.mmvpm.bot.state.State
+
+trait Renderer {
+
+  def render(
+      state: State,
+      editMessage: Option[MessageID]
+    )(implicit message: Message
+    ): Either[EditMessageText, SendMessage]
+}

bot/src/main/scala/com/github/mmvpm/bot/render/RendererImpl.scala

@@ -0,0 +1,29 @@
+package com.github.mmvpm.bot.render
+
+import com.bot4s.telegram.methods.{EditMessageText, SendMessage}
+import com.bot4s.telegram.models.{InlineKeyboardButton, InlineKeyboardMarkup, Message}
+import com.github.mmvpm.bot.model.MessageID
+import com.github.mmvpm.bot.state.State
+import com.github.mmvpm.bot.state.State._
+
+class RendererImpl extends Renderer {
+
+  override def render(
+      state: State,
+      editMessage: Option[MessageID] = None
+    )(implicit message: Message): Either[EditMessageText, SendMessage] = {
+    val buttons = state.next.map { tag =>
+      InlineKeyboardButton.callbackData(buttonBy(tag), tag)
+    }
+    val markup = Some(InlineKeyboardMarkup.singleColumn(buttons))
+
+    lazy val send = SendMessage(message.source, state.text, replyMarkup = markup)
+    lazy val edit = EditMessageText(Some(message.source), editMessage, text = state.text, replyMarkup = markup)
+
+    if (editMessage.contains(message.messageId)) // the last message was sent by the bot
+      Left(edit)
+    else
+      Right(send)
+  }
+}
+