Improve plugin interface

src/main/scala/org/congressodeiradicali/karlmarx/BanPlugin.scala

@@ -5,23 +5,21 @@ import com.bot4s.telegram.models.Message
 import scala.concurrent.{ExecutionContext, Future, blocking}
 
 class BanPlugin(localizer: Localizer, bot: Bot) extends Plugin with CommandImplicits {
-  override var handlers: Map[CommandFilterMagnet, Handler] = _
-
   def canBanUsers(msg: Message) : Boolean = msg.from.fold { false } {u =>
     val user = new BotUser(u, msg.chat, bot)
     // we should wait for the user to be ready
     user.syncAfterInit{user => user.canBanUsers}{_ => false}
   }
 
-  onCommand("ban") { implicit msg =>
-    Future {
+  override var handlers: Map[CommandFilterMagnet, Handler] = Map {
+    stringToCommandFilter("ban") -> { msg =>
       val text = msg.replyToMessage.fold {
         LocalizableString.BAN_FAILED_REPLY
-      } { message =>
-        message.from.fold {
+      } { reply =>
+        reply.from.fold {
           LocalizableString.BAN_FAILED_INVALID_USER
         } { u =>
-          val user = new BotUser(u, message.chat, bot)
+          val user = new BotUser(u, msg.chat, bot)
           blocking {
             user.syncAfterInit { botuser =>
               if (botuser.isAdmin || botuser.isCreator) {
@@ -35,7 +33,7 @@ class BanPlugin(localizer: Localizer, bot: Bot) extends Plugin with CommandImpli
         }
       }
 
-      Some(localizer.getString(text))
-    }(ExecutionContext.global)
+      Future {Some(localizer.getString(text))}(ExecutionContext.global)
+    }
   }
 }

src/main/scala/org/congressodeiradicali/karlmarx/EchoPlugin.scala

@@ -0,0 +1,12 @@
+package org.congressodeiradicali.karlmarx
+
+import com.bot4s.telegram.api.declarative.{CommandFilterMagnet, CommandImplicits}
+import com.bot4s.telegram.models.Message
+
+import scala.concurrent.{ExecutionContext, Future, blocking}
+
+class EchoPlugin(localizer: Localizer, bot: Bot) extends Plugin with CommandImplicits {
+  override var handlers: Map[CommandFilterMagnet, Handler] = Map {
+    stringToCommandFilter("echo") -> { msg => Future { msg.text }(ExecutionContext.global) }
+  }
+}

src/main/scala/org/congressodeiradicali/karlmarx/Plugin.scala

@@ -10,9 +10,4 @@ trait Plugin {
   type HandlerPair = (CommandFilterMagnet, Handler)
 
   var handlers: Map[CommandFilterMagnet, Handler]
-
-  def onCommand(filter: CommandFilterMagnet)(action: Handler): Unit = {
-    val pair: HandlerPair = (filter, action)
-    handlers += pair
-  }
 }