Implemented custom fsm to make the code more readable

2026-01-05 12:25:30 +01:00 · 2018-07-02 16:22:07 +02:00
parent 55bae1a221
commit c613d09508
17 changed files with 659 additions and 533 deletions
--- a/server/src/main/scala/com/lbs/server/actor/Account.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Account.scala
@@ -27,78 +27,55 @@ import akka.actor.{ActorRef, Props}
 import com.lbs.bot.model.{Button, Command}
 import com.lbs.bot.{Bot, _}
 import com.lbs.server.actor.Account._
-import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.Login._
+import com.lbs.server.actor.conversation.Conversation
 import com.lbs.server.lang.{Localizable, Localization}
 import com.lbs.server.service.DataService

-class Account(val userId: UserId, bot: Bot, dataService: DataService, val localization: Localization, router: ActorRef) extends SafeFSM[FSMState, FSMData] with Localizable {
+class Account(val userId: UserId, bot: Bot, dataService: DataService, val localization: Localization, router: ActorRef) extends Conversation[Unit] with Localizable {

-  startWith(AskAction, null)
-
-  whenSafe(AskAction) {
-    case Event(Next, _) =>
+  def askAction: QA =
+    question { _ =>
      val credentials = dataService.getUserCredentials(userId.userId)
      val currentAccount = credentials.find(c => c.accountId == userId.accountId).getOrElse(sys.error("Can't determine current account"))
      val buttons = Seq(Button(lang.addAccount, -1L), Button(lang.deleteAccount, -2L)) ++ credentials.map(c => Button(s"🔐️ ${c.username}", c.accountId))
      bot.sendMessage(userId.source, lang.pleaseChooseAccount(currentAccount.username), inlineKeyboard = createInlineKeyboard(buttons, columns = 1))
-      goto(AwaitAction)
-  }
-
-  whenSafe(AwaitAction) {
-    case Event(cmd@Command(_, _, Some(actionStr)), _) =>
-      val action = actionStr.toLong
-      action match {
-        case -1L =>
-          router ! cmd.copy(message = cmd.message.copy(text = Some("/login")))
-          goto(AskAction) using null
-        case -2L =>
-          bot.sendMessage(userId.source, "Not implemented yet")
-          goto(AskAction) using null
-        case accountId =>
-          val accountMaybe = dataService.findUserCredentialsByAccountId(userId.userId, accountId)
-          accountMaybe match {
-            case Some(account) => //account was found
-              val userMaybe = dataService.findUser(userId.userId)
-              userMaybe.foreach { user =>
-                user.activeAccountId = accountId
-                dataService.saveUser(user)
-                router ! SwitchUser(UserId(account.userId, account.accountId, userId.source))
-                bot.sendMessage(userId.source, lang.accountSwitched(account.username))
-              }
-              goto(AskAction) using null
-            case None =>
-              error(s"This is not user [#${userId.userId}] account [#$accountId]")
-              goto(AskAction) using null
-          }
-      }
-  }
-
-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      invokeNext()
-      goto(AskAction) using null
-    case e: Event =>
-      error(s"Unhandled event in state:$stateName. Event: $e")
-      stay()
-  }
-
-  initialize()
+    } answer {
+      case Msg(cmd@Command(_, _, Some(actionStr)), _) =>
+        val action = actionStr.toLong
+        action match {
+          case -1L =>
+            router ! cmd.copy(message = cmd.message.copy(text = Some("/login")))
+            stay()
+          case -2L =>
+            bot.sendMessage(userId.source, "Not implemented yet")
+            stay()
+          case accountId =>
+            val accountMaybe = dataService.findUserCredentialsByAccountId(userId.userId, accountId)
+            accountMaybe match {
+              case Some(account) => //account was found
+                val userMaybe = dataService.findUser(userId.userId)
+                userMaybe.foreach { user =>
+                  user.activeAccountId = accountId
+                  dataService.saveUser(user)
+                  router ! SwitchUser(UserId(account.userId, account.accountId, userId.source))
+                  bot.sendMessage(userId.source, lang.accountSwitched(account.username))
+                }
+                stay()
+              case None =>
+                error(s"This is not user [#${userId.userId}] account [#$accountId]")
+                stay()
+            }
+        }
+    }

+  entryPoint(askAction)
 }

 object Account {
  def props(userId: UserId, bot: Bot, dataService: DataService, localization: Localization, router: ActorRef): Props =
    Props(new Account(userId, bot, dataService, localization, router))

-  object AskAction extends FSMState
-
-  object AwaitAction extends FSMState
-
-  object AddAccount extends FSMState
-
-  object RemoveAccount extends FSMState
-
  case class SwitchUser(userId: UserId)

 }
--- a/server/src/main/scala/com/lbs/server/actor/Book.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Book.scala
@@ -34,6 +34,7 @@ import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.DatePicker.{DateFromMode, DateToMode}
 import com.lbs.server.actor.Login.UserId
 import com.lbs.server.actor.StaticData.StaticDataConfig
+import com.lbs.server.actor.conversation.Conversation.{InitConversation, StartConversation}
 import com.lbs.server.lang.{Localizable, Localization}
 import com.lbs.server.repository.model.Monitoring
 import com.lbs.server.service.{ApiService, DataService, MonitoringService}
@@ -81,6 +82,7 @@ class Book(val userId: UserId, bot: Bot, apiService: ApiService, dataService: Da

  whenSafe(RequestDateFrom) {
    case Event(_, bookingData: BookingData) =>
+      datePicker ! StartConversation
      datePicker ! DateFromMode
      datePicker ! bookingData.dateFrom
      goto(AwaitDateFrom)
@@ -257,8 +259,8 @@ class Book(val userId: UserId, bot: Bot, apiService: ApiService, dataService: Da

  private def reinit() = {
    invokeNext()
-    datePicker ! Init
-    staticData ! Init
+    datePicker ! InitConversation
+    staticData ! InitConversation
    termsPager ! Init
    goto(RequestCity) using BookingData()
  }
--- a/server/src/main/scala/com/lbs/server/actor/Bug.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Bug.scala
@@ -23,95 +23,70 @@
  */
 package com.lbs.server.actor

-import akka.actor.{PoisonPill, Props}
+import akka.actor.Props
 import com.lbs.bot.model.{Button, Command}
 import com.lbs.bot.{Bot, _}
 import com.lbs.server.actor.Bug._
-import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.Login.UserId
+import com.lbs.server.actor.conversation.Conversation
+import com.lbs.server.actor.conversation.Conversation.{InitConversation, StartConversation}
 import com.lbs.server.lang.{Localizable, Localization}
 import com.lbs.server.repository.model
 import com.lbs.server.service.DataService
 import com.lbs.server.util.MessageExtractors

 class Bug(val userId: UserId, bot: Bot, dataService: DataService, bugPagerActorFactory: ByUserIdWithOriginatorActorFactory,
-          val localization: Localization) extends SafeFSM[FSMState, FSMData] with Localizable {
+          val localization: Localization) extends Conversation[Unit] with Localizable {

  private val bugPager = bugPagerActorFactory(userId, self)

-  startWith(RequestAction, null)
-
-  whenSafe(RequestAction) {
-    case Event(Next, _) =>
+  def askAction: Step =
+    question { _ =>
      bot.sendMessage(userId.source, lang.bugAction, inlineKeyboard =
        createInlineKeyboard(Seq(Button(lang.createNewBug, Tags.SubmitNew), Button(lang.showSubmittedBugs, Tags.ListSubmitted))))
-      goto(AwaitAction)
-  }
+    } answer {
+      case Msg(Command(_, _, Some(Tags.SubmitNew)), _) =>
+        goto(askBugDescription)
+      case Msg(Command(_, _, Some(Tags.ListSubmitted)), _) =>
+        goto(displaySubmittedBugs)
+    }

-  whenSafe(AwaitAction) {
-    case Event(Command(_, _, Some(Tags.SubmitNew)), _) =>
-      bot.sendMessage(userId.source, lang.enterIssueDetails)
-      goto(AwaitBugDescription)
-    case Event(Command(_, _, Some(Tags.ListSubmitted)), _) =>
-      invokeNext()
-      goto(RequestData)
-  }
-
-  whenSafe(RequestData) {
-    case Event(Next, _) =>
+  def displaySubmittedBugs: IC =
+    internalConfig { _ =>
      val bugs = dataService.getBugs(userId.userId)
-      bugPager ! Init
+      bugPager ! InitConversation
+      bugPager ! StartConversation
      bugPager ! Right[Throwable, Seq[model.Bug]](bugs)
-      goto(AwaitPage)
-  }
+      goto(processResponseFromPager)
+    }

-  whenSafe(AwaitPage) {
-    case Event(cmd: Command, _) =>
-      bugPager ! cmd
-      stay()
-    case Event(Pager.NoItemsFound, _) =>
-      bot.sendMessage(userId.source, lang.noSubmittedIssuesFound)
-      goto(RequestData)
-  }
+  def processResponseFromPager: M =
+    monologue {
+      case Msg(cmd: Command, _) =>
+        bugPager ! cmd
+        stay()
+      case Msg(Pager.NoItemsFound, _) =>
+        bot.sendMessage(userId.source, lang.noSubmittedIssuesFound)
+        end()
+    }

-  whenSafe(AwaitBugDescription) {
-    case Event(Command(_, MessageExtractors.Text(details), _), _) =>
-      val bugId = dataService.submitBug(userId.userId, userId.source.sourceSystem.id, details)
-      bot.sendMessage(userId.source, lang.bugHasBeenCreated(bugId.getOrElse(-1L)))
-      goto(RequestAction) using null
-  }
+  def askBugDescription: Step =
+    question { _ =>
+      bot.sendMessage(userId.source, lang.enterIssueDetails)
+    } answer {
+      case Msg(Command(_, MessageExtractors.Text(details), _), _) =>
+        val bugId = dataService.submitBug(userId.userId, userId.source.sourceSystem.id, details)
+        bot.sendMessage(userId.source, lang.bugHasBeenCreated(bugId.getOrElse(-1L)))
+        end()
+    }

-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      invokeNext()
-      bugPager ! Init
-      goto(RequestAction)
-  }
-
-  initialize()
-
-  override def postStop(): Unit = {
-    bugPager ! PoisonPill
-    super.postStop()
-  }
+  entryPoint(askAction)
 }

 object Bug {
  def props(userId: UserId, bot: Bot, dataService: DataService, bugPagerActorFactory: ByUserIdWithOriginatorActorFactory, localization: Localization): Props =
    Props(new Bug(userId, bot, dataService, bugPagerActorFactory, localization))

-  object RequestBugDetails extends FSMState
-
-  object AwaitBugDescription extends FSMState
-
-  object RequestAction extends FSMState
-
-  object AwaitAction extends FSMState
-
-  object RequestData extends FSMState
-
-  object AwaitPage extends FSMState
-
  object Tags {
    val SubmitNew = "submit"
    val ListSubmitted = "list"
--- a/server/src/main/scala/com/lbs/server/actor/Chat.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Chat.scala
@@ -28,6 +28,7 @@ import com.lbs.bot.model.Command
 import com.lbs.common.Logger
 import com.lbs.server.actor.Chat._
 import com.lbs.server.actor.Login.UserId
+import com.lbs.server.actor.conversation.Conversation.{InitConversation, StartConversation}
 import com.lbs.server.service.{DataService, MonitoringService}
 import com.lbs.server.util.MessageExtractors._

@@ -66,7 +67,8 @@ class Chat(val userId: UserId, dataService: DataService, monitoringService: Moni

  when(HistoryChat, historyActor) {
    case Event(Command(_, Text("/history"), _), _) =>
-      historyActor ! Init
+      historyActor ! InitConversation
+      historyActor ! StartConversation
      stay()
  }

@@ -78,25 +80,29 @@ class Chat(val userId: UserId, dataService: DataService, monitoringService: Moni

  when(BugChat, bugActor) {
    case Event(Command(_, Text("/bug"), _), _) =>
-      bugActor ! Init
+      bugActor ! InitConversation
+      bugActor ! StartConversation
      goto(BugChat)
  }

  when(MonitoringsChat, monitoringsActor) {
    case Event(Command(_, Text("/monitorings"), _), _) =>
-      monitoringsActor ! Init
+      monitoringsActor ! InitConversation
+      monitoringsActor ! StartConversation
      stay()
  }

  when(SettingsChat, settingsActor) {
    case Event(Command(_, Text("/settings"), _), _) =>
-      settingsActor ! Init
+      settingsActor ! InitConversation
+      settingsActor ! StartConversation
      stay()
  }

  when(AccountChat, accountActor) {
    case Event(Command(_, Text("/accounts"), _), _) =>
-      accountActor ! Init
+      accountActor ! InitConversation
+      accountActor ! StartConversation
      stay()
  }

--- a/server/src/main/scala/com/lbs/server/actor/DatePicker.scala
+++ b/server/src/main/scala/com/lbs/server/actor/DatePicker.scala
@@ -29,9 +29,9 @@ import java.time.{LocalTime, ZonedDateTime}
 import akka.actor.{ActorRef, Props}
 import com.lbs.bot.model.{Button, Command}
 import com.lbs.bot.{Bot, _}
-import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.DatePicker._
 import com.lbs.server.actor.Login.UserId
+import com.lbs.server.actor.conversation.Conversation
 import com.lbs.server.lang.{Localizable, Localization}

 /**
@@ -42,59 +42,48 @@ import com.lbs.server.lang.{Localizable, Localization}
  * ⬇   ⬇    ⬇
  *
  */
-class DatePicker(val userId: UserId, val bot: Bot, val localization: Localization, originator: ActorRef) extends SafeFSM[FSMState, ZonedDateTime] with Localizable {
-
-  startWith(AwaitMode, null)
+class DatePicker(val userId: UserId, val bot: Bot, val localization: Localization, originator: ActorRef) extends Conversation[ZonedDateTime] with Localizable {

  private var mode: Mode = DateFromMode

-  whenSafe(AwaitMode) {
-    case Event(newMode: Mode, _) =>
-      mode = newMode
-      goto(RequestDate)
-  }
+  entryPoint(configure)

-  whenSafe(RequestDate) {
-    case Event(initialDate: ZonedDateTime, _) =>
+  def configure: EC =
+    externalConfig {
+      case Msg(newMode: Mode, _) =>
+        mode = newMode
+        stay()
+      case Msg(initialDate: ZonedDateTime, _) =>
+        goto(requestDate) using initialDate
+    }
+
+  def requestDate: QA =
+    question { initialDate =>
      val message = mode match {
        case DateFromMode => lang.chooseDateFrom
        case DateToMode => lang.chooseDateTo
      }
      bot.sendMessage(userId.source, message, inlineKeyboard = dateButtons(initialDate))
-      goto(AwaitDate) using initialDate
-  }
+    } answer {
+      case Msg(Command(_, msg, Some(Tags.Done)), finalDate) =>
+        val (message, updatedDate) = mode match {
+          case DateFromMode =>
+            val startOfTheDay = finalDate.`with`(LocalTime.MIN)
+            val dateFrom = if (startOfTheDay.isBefore(ZonedDateTime.now())) finalDate else startOfTheDay
+            lang.dateFromIs(dateFrom) -> dateFrom
+          case DateToMode =>
+            val dateTo = finalDate.`with`(LocalTime.MAX).minusHours(2)
+            lang.dateToIs(dateTo) -> dateTo
+        }
+        bot.sendEditMessage(userId.source, msg.messageId, message)
+        originator ! updatedDate
+        goto(configure) using null

-  whenSafe(AwaitDate) {
-    case Event(Command(_, msg, Some(Tags.Done)), finalDate: ZonedDateTime) =>
-
-      val (message, updatedDate) = mode match {
-        case DateFromMode =>
-          val startOfTheDay = finalDate.`with`(LocalTime.MIN)
-          val dateFrom = if (startOfTheDay.isBefore(ZonedDateTime.now())) finalDate else startOfTheDay
-          lang.dateFromIs(dateFrom) -> dateFrom
-        case DateToMode =>
-          val dateTo = finalDate.`with`(LocalTime.MAX).minusHours(2)
-          lang.dateToIs(dateTo) -> dateTo
-      }
-      bot.sendEditMessage(userId.source, msg.messageId, message)
-      originator ! updatedDate
-      goto(AwaitMode) using null
-
-    case Event(Command(_, msg, Some(tag)), date: ZonedDateTime) =>
-      val modifiedDate = modifyDate(date, tag)
-      bot.sendEditMessage(userId.source, msg.messageId, inlineKeyboard = dateButtons(modifiedDate))
-      stay() using modifiedDate
-  }
-
-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      goto(AwaitMode) using null
-    case e: Event =>
-      error(s"Unhandled event in state:$stateName. Event: $e")
-      stay()
-  }
-
-  initialize()
+      case Msg(Command(_, msg, Some(tag)), date) =>
+        val modifiedDate = modifyDate(date, tag)
+        bot.sendEditMessage(userId.source, msg.messageId, inlineKeyboard = dateButtons(modifiedDate))
+        stay() using modifiedDate
+    }

  private def modifyDate(date: ZonedDateTime, tag: String) = {
    val dateModifier = tag match {
@@ -127,12 +116,6 @@ object DatePicker {
  def props(userId: UserId, bot: Bot, localization: Localization, originator: ActorRef): Props =
    Props(new DatePicker(userId, bot, localization, originator))

-  object RequestDate extends FSMState
-
-  object AwaitDate extends FSMState
-
-  object AwaitMode extends FSMState
-
  trait Mode

  object DateFromMode extends Mode
--- a/server/src/main/scala/com/lbs/server/actor/Help.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Help.scala
@@ -23,17 +23,23 @@
  */
 package com.lbs.server.actor

-import akka.actor.{Actor, Props}
+import akka.actor.Props
 import com.lbs.bot.Bot
 import com.lbs.bot.model.Command
 import com.lbs.server.actor.Login.UserId
+import com.lbs.server.actor.conversation.Conversation
 import com.lbs.server.lang.{Localizable, Localization}

-class Help(val userId: UserId, bot: Bot, val localization: Localization) extends Actor with Localizable {
-  override def receive: Receive = {
-    case _: Command =>
-      bot.sendMessage(userId.source, lang.help)
-  }
+class Help(val userId: UserId, bot: Bot, val localization: Localization) extends Conversation[Unit] with Localizable {
+
+  entryPoint(displayHelp)
+
+  def displayHelp: M =
+    monologue {
+      case Msg(_: Command, _) =>
+        bot.sendMessage(userId.source, lang.help)
+        stay()
+    }
 }

 object Help {
--- a/server/src/main/scala/com/lbs/server/actor/History.scala
+++ b/server/src/main/scala/com/lbs/server/actor/History.scala
@@ -27,44 +27,38 @@ import akka.actor.{PoisonPill, Props}
 import com.lbs.api.json.model.HistoricVisit
 import com.lbs.bot.Bot
 import com.lbs.bot.model.Command
-import com.lbs.server.actor.Chat.Init
-import com.lbs.server.actor.History.{AwaitPage, RequestData}
 import com.lbs.server.actor.Login.UserId
+import com.lbs.server.actor.conversation.Conversation
+import com.lbs.server.actor.conversation.Conversation.{InitConversation, StartConversation}
 import com.lbs.server.lang.{Localizable, Localization}
 import com.lbs.server.service.ApiService

-class History(val userId: UserId, bot: Bot, apiService: ApiService, val localization: Localization, historyPagerActorFactory: ByUserIdWithOriginatorActorFactory) extends SafeFSM[FSMState, FSMData] with Localizable {
+class History(val userId: UserId, bot: Bot, apiService: ApiService, val localization: Localization, historyPagerActorFactory: ByUserIdWithOriginatorActorFactory) extends Conversation[Unit] with Localizable {

  private val historyPager = historyPagerActorFactory(userId, self)

-  startWith(RequestData, null)
+  entryPoint(prepareData)

-  whenSafe(RequestData) {
-    case Event(Next, _) =>
+  def prepareData: IC =
+    internalConfig { _ =>
      val visits = apiService.visitsHistory(userId.accountId)
+      historyPager ! InitConversation
+      historyPager ! StartConversation
      historyPager ! visits
-      goto(AwaitPage)
-  }
+      goto(processResponseFromPager)
+    }

-  whenSafe(AwaitPage) {
-    case Event(cmd: Command, _) =>
-      historyPager ! cmd
-      stay()
-    case Event(Pager.NoItemsFound, _) =>
-      bot.sendMessage(userId.source, lang.visitsHistoryIsEmpty)
-      goto(RequestData)
-    case Event(_: HistoricVisit, _) =>
-      goto(RequestData) using null
-  }
-
-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      invokeNext()
-      historyPager ! Init
-      goto(RequestData)
-  }
-
-  initialize()
+  def processResponseFromPager: M =
+    monologue {
+      case Msg(cmd: Command, _) =>
+        historyPager ! cmd
+        stay()
+      case Msg(Pager.NoItemsFound, _) =>
+        bot.sendMessage(userId.source, lang.visitsHistoryIsEmpty)
+        end()
+      case Msg(_: HistoricVisit, _) =>
+        end()
+    }

  override def postStop(): Unit = {
    historyPager ! PoisonPill
@@ -75,10 +69,4 @@ class History(val userId: UserId, bot: Bot, apiService: ApiService, val localiza
 object History {
  def props(userId: UserId, bot: Bot, apiService: ApiService, localization: Localization, historyPagerActorFactory: ByUserIdWithOriginatorActorFactory): Props =
    Props(new History(userId, bot, apiService, localization, historyPagerActorFactory))
-
-  object RequestData extends FSMState
-
-  object AwaitPage extends FSMState
-
-
 }
--- a/server/src/main/scala/com/lbs/server/actor/Login.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Login.scala
@@ -26,77 +26,61 @@ package com.lbs.server.actor
 import akka.actor.{ActorRef, Props}
 import com.lbs.bot.Bot
 import com.lbs.bot.model.{Command, MessageSource}
-import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.Login._
+import com.lbs.server.actor.conversation.Conversation
 import com.lbs.server.lang.{Localizable, Localization}
 import com.lbs.server.service.{ApiService, DataService}
 import com.lbs.server.util.MessageExtractors
 import org.jasypt.util.text.TextEncryptor

-class Login(source: MessageSource, bot: Bot, dataService: DataService, apiService: ApiService, textEncryptor: TextEncryptor, val localization: Localization, originator: ActorRef) extends SafeFSM[FSMState, FSMData] with Localizable {
+class Login(source: MessageSource, bot: Bot, dataService: DataService, apiService: ApiService, textEncryptor: TextEncryptor, val localization: Localization, originator: ActorRef) extends Conversation[LoginData] with Localizable {

  protected var userId: UserId = _

-  startWith(LogIn, LoginData())
+  entryPoint(logIn)

  private var forwardCommand: ForwardCommand = _

-  whenSafe(LogIn) {
-    case Event(cmd: Command, LoginData(None, None)) =>
-      forwardCommand = ForwardCommand(cmd)
-      invokeNext()
-      goto(RequestUsername)
-    case Event(_, LoginData(Some(username), Some(password))) =>
+  def logIn: M =
+    monologue {
+      case Msg(cmd: Command, LoginData(None, None)) =>
+        forwardCommand = ForwardCommand(cmd)
+        goto(requestUsername)
+    }
+
+  def requestUsername: QA =
+    question { _ =>
+      bot.sendMessage(source, lang.provideUsername)
+    } answer {
+      case Msg(Command(_, MessageExtractors.TextOpt(username), _), _) =>
+        goto(requestPassword) using LoginData(username = username)
+    }
+
+  def requestPassword: QA =
+    question { _ =>
+      bot.sendMessage(source, lang.providePassword)
+    } answer {
+      case Msg(Command(_, MessageExtractors.TextOpt(password), _), loginData: LoginData) =>
+        goto(processLoginInformation) using loginData.copy(password = password.map(textEncryptor.encrypt))
+    }
+
+  def processLoginInformation: IC = {
+    internalConfig { case LoginData(Some(username), Some(password)) =>
      val loginResult = apiService.login(username, password)
      loginResult match {
        case Left(error) =>
          bot.sendMessage(source, error.getMessage)
-          invokeNext()
-          goto(RequestUsername) using LoginData()
+          goto(requestUsername)
        case Right(loggedIn) =>
          val credentials = dataService.saveCredentials(source, username, password)
          userId = UserId(credentials.userId, credentials.accountId, source)
          apiService.addSession(credentials.accountId, loggedIn.accessToken, loggedIn.tokenType)
          bot.sendMessage(source, lang.loginAndPasswordAreOk)
          originator ! LoggedIn(forwardCommand, credentials.userId, credentials.accountId)
-          stay() using null
+          end()
      }
+    }
  }
-
-  whenSafe(RequestUsername) {
-    case Event(Next, _) =>
-      bot.sendMessage(source, lang.provideUsername)
-      goto(AwaitUsername)
-  }
-
-  whenSafe(AwaitUsername) {
-    case Event(Command(_, MessageExtractors.TextOpt(username), _), loginData: LoginData) =>
-      invokeNext()
-      goto(RequestPassword) using loginData.copy(username = username)
-  }
-
-  whenSafe(RequestPassword) {
-    case Event(Next, _) =>
-      bot.sendMessage(source, lang.providePassword)
-      goto(AwaitPassword)
-  }
-
-  whenSafe(AwaitPassword) {
-    case Event(Command(_, MessageExtractors.TextOpt(password), _), loginData: LoginData) =>
-      invokeNext()
-      goto(LogIn) using loginData.copy(password = password.map(textEncryptor.encrypt))
-  }
-
-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      goto(LogIn) using LoginData()
-    case e: Event =>
-      error(s"Unhandled event in state:$stateName. Event: $e")
-      stay()
-  }
-
-  initialize()
-
 }

 object Login {
@@ -104,17 +88,7 @@ object Login {
  def props(source: MessageSource, bot: Bot, dataService: DataService, apiService: ApiService, textEncryptor: TextEncryptor, localization: Localization, originator: ActorRef): Props =
    Props(new Login(source, bot, dataService, apiService, textEncryptor, localization, originator))

-  object LogIn extends FSMState
-
-  object RequestUsername extends FSMState
-
-  object AwaitUsername extends FSMState
-
-  object RequestPassword extends FSMState
-
-  object AwaitPassword extends FSMState
-
-  case class LoginData(username: Option[String] = None, password: Option[String] = None) extends FSMData
+  case class LoginData(username: Option[String] = None, password: Option[String] = None)

  case class ForwardCommand(cmd: Command)

--- a/server/src/main/scala/com/lbs/server/actor/Monitorings.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Monitorings.scala
@@ -26,57 +26,54 @@ package com.lbs.server.actor
 import akka.actor.{PoisonPill, Props}
 import com.lbs.bot._
 import com.lbs.bot.model.{Button, Command}
-import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.Login.UserId
-import com.lbs.server.actor.Monitorings.{AwaitDecision, AwaitPage, RequestData, Tags}
+import com.lbs.server.actor.Monitorings.Tags
+import com.lbs.server.actor.conversation.Conversation
+import com.lbs.server.actor.conversation.Conversation.{InitConversation, StartConversation}
 import com.lbs.server.lang.{Localizable, Localization}
 import com.lbs.server.repository.model.Monitoring
 import com.lbs.server.service.MonitoringService

-class Monitorings(val userId: UserId, bot: Bot, monitoringService: MonitoringService, val localization: Localization, monitoringsPagerActorFactory: ByUserIdWithOriginatorActorFactory) extends SafeFSM[FSMState, Monitoring] with Localizable {
+class Monitorings(val userId: UserId, bot: Bot, monitoringService: MonitoringService, val localization: Localization, monitoringsPagerActorFactory: ByUserIdWithOriginatorActorFactory) extends Conversation[Monitoring] with Localizable {

  private val monitoringsPager = monitoringsPagerActorFactory(userId, self)

-  startWith(RequestData, null)
+  entryPoint(prepareData)

-  whenSafe(RequestData) {
-    case Event(Next, _) =>
+  def prepareData: IC =
+    internalConfig { _ =>
      val monitorings = monitoringService.getActiveMonitorings(userId.accountId)
+      monitoringsPager ! InitConversation
+      monitoringsPager ! StartConversation
      monitoringsPager ! Right[Throwable, Seq[Monitoring]](monitorings)
-      goto(AwaitPage)
-  }
+      goto(processResponseFromPager)
+    }

-  whenSafe(AwaitPage) {
-    case Event(cmd: Command, _) =>
-      monitoringsPager ! cmd
-      stay()
-    case Event(Pager.NoItemsFound, _) =>
-      bot.sendMessage(userId.source, lang.noActiveMonitorings)
-      goto(RequestData)
-    case Event(monitoring: Monitoring, _) =>
+  def processResponseFromPager: M =
+    monologue {
+      case Msg(cmd: Command, _) =>
+        monitoringsPager ! cmd
+        stay()
+      case Msg(Pager.NoItemsFound, _) =>
+        bot.sendMessage(userId.source, lang.noActiveMonitorings)
+        end()
+      case Msg(monitoring: Monitoring, _) =>
+        goto(askToDeactivateMonitoring) using monitoring
+    }
+
+  def askToDeactivateMonitoring: QA =
+    question { monitoring =>
      bot.sendMessage(userId.source, lang.deactivateMonitoring(monitoring), inlineKeyboard =
        createInlineKeyboard(Seq(Button(lang.no, Tags.No), Button(lang.yes, Tags.Yes))))
-      goto(AwaitDecision) using monitoring
-  }
-
-  whenSafe(AwaitDecision) {
-    case Event(Command(_, _, Some(Tags.No)), _) =>
-      bot.sendMessage(userId.source, lang.monitoringWasNotDeactivated)
-      goto(RequestData)
-    case Event(Command(_, _, Some(Tags.Yes)), monitoring: Monitoring) =>
-      monitoringService.deactivateMonitoring(monitoring.recordId)
-      bot.sendMessage(userId.source, lang.deactivated)
-      goto(RequestData)
-  }
-
-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      invokeNext()
-      monitoringsPager ! Init
-      goto(RequestData)
-  }
-
-  initialize()
+    } answer {
+      case Msg(Command(_, _, Some(Tags.No)), _) =>
+        bot.sendMessage(userId.source, lang.monitoringWasNotDeactivated)
+        end()
+      case Msg(Command(_, _, Some(Tags.Yes)), monitoring: Monitoring) =>
+        monitoringService.deactivateMonitoring(monitoring.recordId)
+        bot.sendMessage(userId.source, lang.deactivated)
+        end()
+    }

  override def postStop(): Unit = {
    monitoringsPager ! PoisonPill
@@ -88,12 +85,6 @@ object Monitorings {
  def props(userId: UserId, bot: Bot, monitoringService: MonitoringService, localization: Localization, monitoringsPagerActorFactory: ByUserIdWithOriginatorActorFactory): Props =
    Props(new Monitorings(userId, bot, monitoringService, localization, monitoringsPagerActorFactory))

-  object RequestData extends FSMState
-
-  object AwaitPage extends FSMState
-
-  object AwaitDecision extends FSMState
-
  object Tags {
    val Yes = "yes"
    val No = "no"
--- a/server/src/main/scala/com/lbs/server/actor/Pager.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Pager.scala
@@ -27,57 +27,49 @@ import akka.actor.{ActorRef, Props}
 import com.lbs.bot.model.{Button, Command}
 import com.lbs.bot.{Bot, _}
 import com.lbs.common.Logger
-import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.Login.UserId
 import com.lbs.server.actor.Pager.{Tags, _}
+import com.lbs.server.actor.conversation.Conversation
 import com.lbs.server.lang.{Localizable, Localization}
 import com.lbs.server.util.MessageExtractors

 class Pager[Data](val userId: UserId, bot: Bot, makeMessage: (Data, Int, Int) => String,
                  makeHeader: (Int, Int) => String, selectionPrefix: Option[String],
                  val localization: Localization, originator: ActorRef)
-  extends SafeFSM[FSMState, FSMData] with Localizable with Logger {
-
-  private case class Page(page: Int, pages: Seq[Seq[Data]]) extends FSMData
+  extends Conversation[(Registry[Data], Option[String])] with Localizable with Logger {

  private val Selection = s"/${selectionPrefix.getOrElse("")}_(\\d+)_(\\d+)".r

-  startWith(PrepareData, null)
+  entryPoint(awaitForData)

-  whenSafe(PrepareData) {
-    case Event(Left(error: Throwable), _) =>
-      bot.sendMessage(userId.source, error.getMessage)
-      invokeNext()
-      goto(PrepareData)
-    case Event(Right(items: Seq[Data]), _) if items.isEmpty =>
-      originator ! NoItemsFound
-      goto(PrepareData) using null
-    case Event(Right(items: Seq[Data]), _) =>
-      invokeNext()
-      goto(RequestData) using Page(0, items.grouped(Pager.PageSize).toList)
-  }
+  private def awaitForData: EC =
+    externalConfig {
+      case Msg(Left(error: Throwable), _) =>
+        bot.sendMessage(userId.source, error.getMessage)
+        end()
+      case Msg(Right(items: Seq[Data]), _) if items.isEmpty =>
+        originator ! NoItemsFound
+        end()
+      case Msg(Right(items: Seq[Data]), _) =>
+        goto(displayPage) using Registry(0, items.grouped(Pager.PageSize).toList) -> None
+    }

-  whenSafe(RequestData) {
-    case Event(Next, page: Page) =>
-      sendPage(page.page, page.pages)
-      goto(AwaitData)
-  }
-
-  whenSafe(AwaitData) {
-    case Event(Command(_, msg, Some(Tags.Next)), termsData: Page) =>
-      val page = termsData.page + 1
-      sendPage(page, termsData.pages, Some(msg.messageId))
-      stay() using termsData.copy(page = page)
-    case Event(Command(_, msg, Some(Tags.Previous)), termsData: Page) =>
-      val page = termsData.page - 1
-      sendPage(page, termsData.pages, Some(msg.messageId))
-      stay() using termsData.copy(page = page)
-    case Event(Command(_, MessageExtractors.Text(Selection(pageStr, indexStr)), _), termsData: Page) if selectionPrefix.nonEmpty =>
-      val page = pageStr.toInt
-      val index = indexStr.toInt
-      originator ! termsData.pages(page)(index)
-      goto(PrepareData) using null
-  }
+  private def displayPage: QA =
+    question { case (registry, massageIdMaybe) =>
+      sendPage(registry.page, registry.pages, massageIdMaybe)
+    } answer {
+      case Msg(Command(_, msg, Some(Tags.Next)), (registry, _)) =>
+        val page = registry.page + 1
+        goto(displayPage) using registry.copy(page = page) -> Some(msg.messageId)
+      case Msg(Command(_, msg, Some(Tags.Previous)), (registry, _)) =>
+        val page = registry.page - 1
+        goto(displayPage) using registry.copy(page = page) -> Some(msg.messageId)
+      case Msg(Command(_, MessageExtractors.Text(Selection(pageStr, indexStr)), _), (registry, _)) if selectionPrefix.nonEmpty =>
+        val page = pageStr.toInt
+        val index = indexStr.toInt
+        originator ! registry.pages(page)(index)
+        end()
+    }

  private def sendPage(page: Int, data: Seq[Seq[Data]], messageId: Option[String] = None): Unit = {
    val pages = data.length
@@ -94,31 +86,16 @@ class Pager[Data](val userId: UserId, bot: Bot, makeMessage: (Data, Int, Int) =>
        bot.sendMessage(userId.source, message, inlineKeyboard = createInlineKeyboard(buttons))
    }
  }
-
-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      goto(PrepareData) using null
-    case e: Event =>
-      error(s"Unhandled event in state:$stateName. Event: $e")
-      stay()
-  }
-
-  initialize()
 }

 object Pager {
-
  def props[Data](userId: UserId, bot: Bot,
                  makeMessage: (Data, Int, Int) => String, makeHeader: (Int, Int) => String, dataPrefix: Option[String], localization: Localization, originator: ActorRef): Props =
    Props(new Pager[Data](userId, bot, makeMessage, makeHeader, dataPrefix, localization, originator))

  val PageSize = 5

-  object PrepareData extends FSMState
-
-  object RequestData extends FSMState
-
-  object AwaitData extends FSMState
+  case class Registry[Data](page: Int, pages: Seq[Seq[Data]])

  object NoItemsFound

--- a/server/src/main/scala/com/lbs/server/actor/Settings.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Settings.scala
@@ -26,57 +26,42 @@ package com.lbs.server.actor
 import akka.actor.Props
 import com.lbs.bot.model.{Button, Command}
 import com.lbs.bot.{Bot, _}
-import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.Login.UserId
 import com.lbs.server.actor.Settings._
+import com.lbs.server.actor.conversation.Conversation
 import com.lbs.server.lang.{Lang, Localizable, Localization}
 import com.lbs.server.service.DataService

-class Settings(val userId: UserId, bot: Bot, dataService: DataService, val localization: Localization) extends SafeFSM[FSMState, FSMData] with Localizable {
+class Settings(val userId: UserId, bot: Bot, dataService: DataService, val localization: Localization) extends Conversation[Unit] with Localizable {

-  startWith(RequestAction, null)
+  entryPoint(askForAction)

-  whenSafe(RequestAction) {
-    case Event(Next, _) =>
+  def askForAction: QA =
+    question { _ =>
      bot.sendMessage(userId.source, lang.settingsHeader, inlineKeyboard =
        createInlineKeyboard(Seq(Button(lang.language, Tags.Language))))
-      goto(AwaitAction)
-  }
+    } answer {
+      case Msg(Command(_, _, Some(Tags.Language)), _) =>
+        goto(askLanguage)
+    }

-  whenSafe(AwaitAction) {
-    case Event(Command(_, _, Some(Tags.Language)), _) =>
+  def askLanguage: QA =
+    question { _ =>
      bot.sendMessage(userId.source, lang.chooseLanguage,
        inlineKeyboard = createInlineKeyboard(Lang.Langs.map(l => Button(l.label, l.id)), columns = 1))
-      goto(AwaitLanguage)
-  }
-
-  whenSafe(AwaitLanguage) {
-    case Event(Command(_, _, Some(langIdStr)), _) =>
-      val langId = langIdStr.toInt
-      localization.updateLanguage(userId.userId, Lang(langId))
-      bot.sendMessage(userId.source, lang.languageUpdated)
-      goto(RequestAction) using null
-  }
-
-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      invokeNext()
-      goto(RequestAction)
-  }
-
-  initialize()
+    } answer {
+      case Msg(Command(_, _, Some(langIdStr)), _) =>
+        val langId = langIdStr.toInt
+        localization.updateLanguage(userId.userId, Lang(langId))
+        bot.sendMessage(userId.source, lang.languageUpdated)
+        end()
+    }
 }

 object Settings {
  def props(userId: UserId, bot: Bot, dataService: DataService, localization: Localization): Props =
    Props(new Settings(userId, bot, dataService, localization))

-  object AwaitLanguage extends FSMState
-
-  object RequestAction extends FSMState
-
-  object AwaitAction extends FSMState
-
  object Tags {
    val Language = "language"
  }
--- a/server/src/main/scala/com/lbs/server/actor/StaticData.scala
+++ b/server/src/main/scala/com/lbs/server/actor/StaticData.scala
@@ -27,94 +27,73 @@ import akka.actor.{ActorRef, Props}
 import com.lbs.api.json.model.IdName
 import com.lbs.bot.model.{Button, Command, TaggedButton}
 import com.lbs.bot.{Bot, _}
-import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.Login.UserId
 import com.lbs.server.actor.StaticData._
+import com.lbs.server.actor.conversation.Conversation
 import com.lbs.server.lang.{Localizable, Localization}

-class StaticData(val userId: UserId, bot: Bot, val localization: Localization, originator: ActorRef) extends SafeFSM[FSMState, IdName] with Localizable {
+class StaticData(val userId: UserId, bot: Bot, val localization: Localization, originator: ActorRef) extends Conversation[List[TaggedButton]] with Localizable {

  private def anySelectOption: List[TaggedButton] = if (config.isAnyAllowed) List(Button(lang.any, -1L)) else List()

-  startWith(AwaitConfig, null)
-
  private var config: StaticDataConfig = _

-  private var callbackTags: List[TaggedButton] = List()
+  entryPoint(AwaitConfig)

-  whenSafe(AwaitConfig) {
-    case Event(newConfig: StaticDataConfig, _) =>
-      config = newConfig
-      invokeNext()
-      goto(RequestStaticData)
-  }
+  def AwaitConfig: EC =
+    externalConfig {
+      case Msg(newConfig: StaticDataConfig, _) =>
+        config = newConfig
+        goto(askForLatestOption)
+    }

-  whenSafe(RequestStaticData) {
-    case Event(Next, _) =>
+  def askForLatestOption: QA =
+    question { _ =>
      originator ! LatestOptions
-      stay()
-    case Event(LatestOptions(options), _) if options.isEmpty =>
-      callbackTags = anySelectOption
-      bot.sendMessage(userId.source, lang.pleaseEnterStaticDataNameOrAny(config),
-        inlineKeyboard = createInlineKeyboard(callbackTags))
-      goto(AwaitStaticData)
-    case Event(LatestOptions(options), _) if options.nonEmpty =>
-      callbackTags = anySelectOption ++ options.map(data => Button(data.name, data.id))
+    } answer {
+      case Msg(LatestOptions(options), _) if options.isEmpty =>
+        val callbackTags = anySelectOption
+        goto(askForUserInput) using callbackTags
+      case Msg(LatestOptions(options), _) if options.nonEmpty =>
+        val callbackTags = anySelectOption ++ options.map(data => Button(data.name, data.id))
+        goto(askForUserInput) using callbackTags
+    }
+
+  def askForUserInput: QA =
+    question { callbackTags =>
      bot.sendMessage(userId.source, lang.pleaseEnterStaticDataNameOrPrevious(config),
        inlineKeyboard = createInlineKeyboard(callbackTags, columns = 1))
-      goto(AwaitStaticData)
-  }
+    } answer {
+      case Msg(Command(_, msg, Some(tag)), callbackTags) =>
+        val id = tag.toLong
+        val label = callbackTags.find(_.tag == tag).map(_.label).getOrElse(sys.error("Unable to get callback tag label"))
+        bot.sendEditMessage(userId.source, msg.messageId, lang.staticDataIs(config, label))
+        originator ! IdName(id, label)
+        end()

-  whenSafe(AwaitStaticData) {
-    case Event(Command(_, msg, Some(tag)), _) =>
-      val id = tag.toLong
-      val label = callbackTags.find(_.tag == tag).map(_.label).getOrElse(sys.error("Unable to get callback tag label"))
-      bot.sendEditMessage(userId.source, msg.messageId, lang.staticDataIs(config, label))
-      originator ! IdName(id, label)
-      goto(AwaitConfig)
+      case Msg(Command(_, msg, _), _) =>
+        val searchText = msg.text.get.toLowerCase
+        originator ! FindOptions(searchText)
+        stay()

-    case Event(Command(_, msg, _), _) =>
-      val searchText = msg.text.get.toLowerCase
-      originator ! FindOptions(searchText)
-      stay()
+      case Msg(FoundOptions(Right(options)), _) if options.nonEmpty =>
+        val callbackTags = anySelectOption ::: options.map(c => Button(c.name, c.id))
+        goto(askForUserInput) using callbackTags

-    case Event(FoundOptions(Right(options)), _) if options.nonEmpty =>
-      callbackTags = anySelectOption ::: options.map(c => Button(c.name, c.id))
-      bot.sendMessage(userId.source, lang.pleaseChooseStaticDataNameOrAny(config),
-        inlineKeyboard = createInlineKeyboard(callbackTags, columns = 1))
-      stay()
+      case Msg(FoundOptions(Right(options)), _) if options.isEmpty =>
+        val callbackTags = anySelectOption
+        goto(askForUserInput) using callbackTags

-    case Event(FoundOptions(Right(options)), _) if options.isEmpty =>
-      callbackTags = anySelectOption
-      bot.sendMessage(userId.source, lang.staticNotFound(config), inlineKeyboard = createInlineKeyboard(callbackTags))
-      stay()
-
-    case Event(FoundOptions(Left(ex)), _) =>
-      bot.sendMessage(userId.source, ex.getMessage)
-      stay()
-  }
-
-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      goto(AwaitConfig) using null
-    case e: Event =>
-      error(s"Unhandled event in state:$stateName. Event: $e")
-      stay()
-  }
-
-  initialize()
+      case Msg(FoundOptions(Left(ex)), _) =>
+        bot.sendMessage(userId.source, ex.getMessage)
+        end()
+    }
 }

 object StaticData {
  def props(userId: UserId, bot: Bot, localization: Localization, originator: ActorRef): Props =
    Props(new StaticData(userId, bot, localization, originator))

-  object AwaitConfig extends FSMState
-
-  object RequestStaticData extends FSMState
-
-  object AwaitStaticData extends FSMState
-
  case class StaticDataConfig(name: String, example: String, isAnyAllowed: Boolean)

  object LatestOptions
--- a/server/src/main/scala/com/lbs/server/actor/StaticDataForBooking.scala
+++ b/server/src/main/scala/com/lbs/server/actor/StaticDataForBooking.scala
@@ -1,26 +1,26 @@
 /**
- * MIT License
- *
- * Copyright (c) 2018 Yevhen Zadyra
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
+  * MIT License
+  *
+  * Copyright (c) 2018 Yevhen Zadyra
+  *
+  * Permission is hereby granted, free of charge, to any person obtaining a copy
+  * of this software and associated documentation files (the "Software"), to deal
+  * in the Software without restriction, including without limitation the rights
+  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  * copies of the Software, and to permit persons to whom the Software is
+  * furnished to do so, subject to the following conditions:
+  *
+  * The above copyright notice and this permission notice shall be included in all
+  * copies or substantial portions of the Software.
+  *
+  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+  * SOFTWARE.
+  */
 package com.lbs.server.actor

 import akka.actor.ActorRef
@@ -28,6 +28,7 @@ import com.lbs.api.json.model.IdName
 import com.lbs.bot.model.Command
 import com.lbs.server.actor.Book.BookingData
 import com.lbs.server.actor.StaticData.{FindOptions, FoundOptions, LatestOptions, StaticDataConfig}
+import com.lbs.server.actor.conversation.Conversation.{InitConversation, StartConversation}

 trait StaticDataForBooking extends SafeFSM[FSMState, FSMData] {

@@ -53,6 +54,8 @@ trait StaticDataForBooking extends SafeFSM[FSMState, FSMData] {
  protected def requestStaticData(requestState: FSMState, awaitState: FSMState, staticDataConfig: => StaticDataConfig)(functions: BookingData => FSMState => StateFunction)(requestNext: FSMState): Unit = {
    whenSafe(requestState) {
      case Event(_, _) =>
+        staticData ! InitConversation
+        staticData ! StartConversation
        staticData ! staticDataConfig
        goto(awaitState)
    }
--- a/server/src/main/scala/com/lbs/server/actor/Visits.scala
+++ b/server/src/main/scala/com/lbs/server/actor/Visits.scala
@@ -27,59 +27,56 @@ import akka.actor.{PoisonPill, Props}
 import com.lbs.api.json.model.ReservedVisit
 import com.lbs.bot.model.{Button, Command}
 import com.lbs.bot.{Bot, _}
-import com.lbs.server.actor.Chat.Init
 import com.lbs.server.actor.Login.UserId
-import com.lbs.server.actor.Visits.{AwaitDecision, AwaitPage, RequestData, Tags}
+import com.lbs.server.actor.Visits.Tags
+import com.lbs.server.actor.conversation.Conversation
+import com.lbs.server.actor.conversation.Conversation.{InitConversation, StartConversation}
 import com.lbs.server.lang.{Localizable, Localization}
 import com.lbs.server.service.ApiService

 class Visits(val userId: UserId, bot: Bot, apiService: ApiService, val localization: Localization,
-             visitsPagerActorFactory: ByUserIdWithOriginatorActorFactory) extends SafeFSM[FSMState, ReservedVisit] with Localizable {
+             visitsPagerActorFactory: ByUserIdWithOriginatorActorFactory) extends Conversation[ReservedVisit] with Localizable {

  private val reservedVisitsPager = visitsPagerActorFactory(userId, self)

-  startWith(RequestData, null)
+  entryPoint(prepareData)

-  whenSafe(RequestData) {
-    case Event(Next, _) =>
+  def prepareData: IC =
+    internalConfig { _ =>
      val visits = apiService.reservedVisits(userId.accountId)
+      reservedVisitsPager ! InitConversation
+      reservedVisitsPager ! StartConversation
      reservedVisitsPager ! visits
-      goto(AwaitPage)
-  }
+      goto(processResponseFromPager)
+    }

-  whenSafe(AwaitPage) {
-    case Event(cmd: Command, _) =>
-      reservedVisitsPager ! cmd
-      stay()
-    case Event(Pager.NoItemsFound, _) =>
-      bot.sendMessage(userId.source, lang.noUpcomingVisits)
-      goto(RequestData)
-    case Event(visit: ReservedVisit, _) =>
+  def processResponseFromPager: M =
+    monologue {
+      case Msg(cmd: Command, _) =>
+        reservedVisitsPager ! cmd
+        stay()
+      case Msg(Pager.NoItemsFound, _) =>
+        bot.sendMessage(userId.source, lang.noUpcomingVisits)
+        end()
+      case Msg(visit: ReservedVisit, _) =>
+        goto(askToCancelVisit) using visit
+    }
+
+  def askToCancelVisit: QA =
+    question { visit =>
      bot.sendMessage(userId.source, lang.areYouSureToCancelAppointment(visit),
        inlineKeyboard = createInlineKeyboard(Seq(Button(lang.no, Tags.No), Button(lang.yes, Tags.Yes))))
-      goto(AwaitDecision) using visit
-  }
-
-  whenSafe(AwaitDecision) {
-    case Event(Command(_, _, Some(Tags.No)), _) =>
-      bot.sendMessage(userId.source, lang.appointmentWasNotCancelled)
-      goto(RequestData)
-    case Event(Command(_, _, Some(Tags.Yes)), visit: ReservedVisit) =>
-      apiService.deleteReservation(userId.accountId, visit.reservationId) match {
-        case Left(ex) => bot.sendMessage(userId.source, lang.unableToCancelUpcomingVisit(ex.getMessage))
-        case Right(r) => bot.sendMessage(userId.source, lang.appointmentHasBeenCancelled)
-      }
-      goto(RequestData)
-  }
-
-  whenUnhandledSafe {
-    case Event(Init, _) =>
-      invokeNext()
-      reservedVisitsPager ! Init
-      goto(RequestData)
-  }
-
-  initialize()
+    } answer {
+      case Msg(Command(_, _, Some(Tags.No)), _) =>
+        bot.sendMessage(userId.source, lang.appointmentWasNotCancelled)
+        end()
+      case Msg(Command(_, _, Some(Tags.Yes)), visit: ReservedVisit) =>
+        apiService.deleteReservation(userId.accountId, visit.reservationId) match {
+          case Left(ex) => bot.sendMessage(userId.source, lang.unableToCancelUpcomingVisit(ex.getMessage))
+          case Right(r) => bot.sendMessage(userId.source, lang.appointmentHasBeenCancelled)
+        }
+        end()
+    }

  override def postStop(): Unit = {
    reservedVisitsPager ! PoisonPill
@@ -92,12 +89,6 @@ object Visits {
            visitsPagerActorFactory: ByUserIdWithOriginatorActorFactory): Props =
    Props(new Visits(userId, bot, apiService, localization, visitsPagerActorFactory))

-  object RequestData extends FSMState
-
-  object AwaitPage extends FSMState
-
-  object AwaitDecision extends FSMState
-
  object Tags {
    val Yes = "yes"
    val No = "no"
--- a/server/src/main/scala/com/lbs/server/actor/conversation/Conversation.scala
+++ b/server/src/main/scala/com/lbs/server/actor/conversation/Conversation.scala
@@ -0,0 +1,120 @@
+package com.lbs.server.actor.conversation
+
+import akka.actor.Actor
+import com.lbs.common.Logger
+import com.lbs.server.actor.conversation.Conversation.{ContinueConversation, InitConversation, StartConversation}
+
+trait Conversation[D] extends Actor with Domain[D] with Logger {
+  private var currentData: D = _
+
+  private var currentStep: Step = _
+
+  private var startWithData: D = _
+
+  private var startWithStep: Step = _
+
+  private val defaultMsgHandler: AnswerFn = {
+    case Msg(any, data) =>
+      debug(s"Unhandled fact message received. [$any, $data]")
+      NextStep(currentStep, Some(data))
+  }
+
+  private var msgHandler: AnswerFn = defaultMsgHandler
+
+  private var runAfterInit: () => Unit = () => {}
+
+  override def receive: Receive = {
+    case InitConversation => init()
+    case StartConversation | ContinueConversation =>
+      currentStep match {
+        case qa: QuestionAnswer => qa.question.questionFn(currentData)
+        case InternalConfiguration(fn) =>
+          val nextStep = fn(currentData)
+          moveToNextStep(nextStep)
+        case _ => //do nothing
+      }
+    case any => makeTransition(any)
+  }
+
+  private def moveToNextStep(nextStep: NextStep): Unit = {
+    currentStep = nextStep.step
+    nextStep.data.foreach { data =>
+      currentData = data
+    }
+  }
+
+  private def makeTransition(any: Any): Unit = {
+    def handle[X](unit: X, fn: PartialFunction[X, NextStep], defaultFn: PartialFunction[X, NextStep]): Unit = {
+      val nextStep = if (fn.isDefinedAt(unit)) fn(unit) else defaultFn(unit)
+      moveToNextStep(nextStep)
+    }
+
+    currentStep match {
+      case ExternalConfiguration(fn) =>
+        val conf = Msg(any, currentData)
+        handle(conf, fn, msgHandler)
+      case QuestionAnswer(_, Answer(fn)) =>
+        val fact = Msg(any, currentData)
+        handle(fact, fn, msgHandler)
+      case Monologue(fn) =>
+        val fact = Msg(any, currentData)
+        handle(fact, fn, msgHandler)
+      case _ => //do nothing
+    }
+  }
+
+  private def init(): Unit = {
+    require(startWithStep != null, "Entry point must be defined")
+    currentStep = startWithStep
+    currentData = startWithData
+    runAfterInit()
+  }
+
+  override def preStart(): Unit = {
+    init()
+  }
+
+  protected def monologue(answerFn: AnswerFn): Monologue = Monologue(answerFn)
+
+  protected def question(questionFn: D => Unit): Question = Question(questionFn)
+
+  protected def externalConfig(receiveConfFunction: ExternalConfigFn): ExternalConfiguration = ExternalConfiguration(receiveConfFunction)
+
+  protected def internalConfig(receiveConfFunction: InternalConfigFn): InternalConfiguration = InternalConfiguration(receiveConfFunction)
+
+  protected def end(): NextStep = NextStep(End)
+
+  protected def goto(step: Step): NextStep = {
+    self ! ContinueConversation
+    NextStep(step)
+  }
+
+  protected def stay(): NextStep = NextStep(currentStep)
+
+  protected def whenUnhandledMsg(receiveMsgFn: AnswerFn): Unit = {
+    msgHandler = receiveMsgFn orElse defaultMsgHandler
+  }
+
+  protected def afterInit(fn: => Unit): Unit = {
+    runAfterInit = () => fn
+  }
+
+  protected def entryPoint(step: Step, data: D): Unit = {
+    startWithStep = step
+    startWithData = data
+  }
+
+  protected def entryPoint(step: Step): Unit = {
+    entryPoint(step, null.asInstanceOf[D])
+  }
+}
+
+object Conversation {
+
+  object StartConversation
+
+  object ContinueConversation
+
+  object InitConversation
+
+}
--- a/server/src/main/scala/com/lbs/server/actor/conversation/Domain.scala
+++ b/server/src/main/scala/com/lbs/server/actor/conversation/Domain.scala
@@ -0,0 +1,50 @@
+package com.lbs.server.actor.conversation
+
+trait Domain[D] {
+  protected type QuestionFn = D => Unit
+
+  protected type AnswerFn = PartialFunction[Msg, NextStep]
+
+  protected type ExternalConfigFn = AnswerFn
+
+  protected type InternalConfigFn = D => NextStep
+
+  protected case class Msg(message: Any, data: D)
+
+  sealed trait Step
+
+  private[conversation] object End extends Step
+
+  protected case class ExternalConfiguration(configFn: ExternalConfigFn) extends Step
+
+  protected case class InternalConfiguration(configFn: InternalConfigFn) extends Step
+
+  protected case class QuestionAnswer(question: Question, answer: Answer) extends Step
+
+  protected case class Monologue(answerFn: AnswerFn) extends Step
+
+  private[conversation] case class NextStep(step: Step, data: Option[D] = None)
+
+  private[conversation] case class Question(questionFn: QuestionFn)
+
+  private[conversation] case class Answer(answerFn: AnswerFn)
+
+  protected type QA = QuestionAnswer
+
+  protected type EC = ExternalConfiguration
+
+  protected type IC = InternalConfiguration
+
+  protected type M = Monologue
+
+  protected implicit class RichQuestion(question: Question) {
+    def answer(answerFn: AnswerFn): QuestionAnswer = QuestionAnswer(question, Answer(answerFn))
+  }
+
+  protected implicit class NextStepOps(nextStep: NextStep) {
+    def using(data: D): NextStep = {
+      nextStep.copy(data = Some(data))
+    }
+  }
+
+}
--- a/server/src/test/scala/com/lbs/server/actor/conversation/ConversationSpec.scala
+++ b/server/src/test/scala/com/lbs/server/actor/conversation/ConversationSpec.scala
@@ -0,0 +1,119 @@
+package com.lbs.server.actor.conversation
+
+import akka.actor.{ActorRef, Props}
+import akka.testkit.TestProbe
+import com.lbs.server.actor.AkkaTestKit
+import com.lbs.server.actor.conversation.Conversation.{InitConversation, StartConversation}
+
+class ConversationSpec extends AkkaTestKit {
+
+  "Actor must send complete data" when {
+    "conversation is done" in {
+
+      case class Data(configured: Boolean = false, hello: String = null, world: String = null, people: String = null)
+
+      object Hello
+
+      object World
+
+      object Dialogue
+
+      class TestActor(originator: ActorRef) extends Conversation[Data] {
+
+        private var conf: String = _
+
+        def configure: EC =
+          externalConfig {
+            case Msg(confStr: String, data) =>
+              conf = confStr
+              goto(askHello) using data.copy(configured = true)
+          }
+
+        def askHello: QA =
+          question { data =>
+            self ! Hello
+          } answer {
+            case Msg(Hello, data) =>
+              goto(askWorld) using data.copy(hello = "hello")
+          }
+
+        def askWorld: QA =
+          question { data =>
+            self ! World
+          } answer {
+            case Msg(World, data) =>
+              goto(askDialogue) using data.copy(world = "world")
+          }
+
+        def askDialogue: QA =
+          question { data =>
+            self ! Dialogue
+          } answer {
+            case Msg(Dialogue, data) =>
+              originator ! data.copy(people = "dialogue") -> conf
+              end()
+          }
+
+        entryPoint(configure, Some(Data()))
+      }
+
+      val expected = Data(configured = true, "hello", "world", "dialogue") -> "myconf"
+
+      val originator = TestProbe()
+      val actor = system.actorOf(Props(new TestActor(originator.ref)))
+      actor ! StartConversation
+      actor ! expected._2
+      originator.expectMsg(expected)
+
+      //reinit
+      actor ! InitConversation
+      actor ! StartConversation
+      actor ! expected._2
+      originator.expectMsg(expected)
+    }
+
+    "configuration is done" in {
+
+      case class Data(configured: Boolean = false, message1: String = null, message2: String = null)
+
+      object InvokeEnrichMessage
+
+      class TestActor(originator: ActorRef) extends Conversation[Data] {
+
+        def configure1: IC =
+          internalConfig { _ =>
+            goto(configure2) using Data(configured = true)
+          }
+
+        def configure2: IC =
+          internalConfig { data =>
+            goto(askMessage2) using data.copy(message1 = "hello")
+          }
+
+        def askMessage2: QA =
+          question { _ =>
+            self ! InvokeEnrichMessage
+          } answer {
+            case Msg(InvokeEnrichMessage, data) =>
+              originator ! data.copy(message2 = "world")
+              end()
+          }
+
+        entryPoint(configure1, Some(Data()))
+      }
+
+      val expected = Data(configured = true, message1 = "hello", message2 = "world")
+
+      val originator = TestProbe()
+      val actor = system.actorOf(Props(new TestActor(originator.ref)))
+      actor ! StartConversation
+      originator.expectMsg(expected)
+
+      //reinit
+      actor ! InitConversation
+      actor ! StartConversation
+      originator.expectMsg(expected)
+    }
+  }
+
+}