extract action command

src/main/kotlin/eventDemo/app/command/GameCommandHandler.kt

@@ -2,14 +2,12 @@ package eventDemo.app.command
 
 import eventDemo.app.GameState
 import eventDemo.app.command.command.GameCommand
+import eventDemo.app.command.command.IWantToPlayCardCommand
 import eventDemo.app.command.command.IamReadyToPlayCommand
-import eventDemo.app.command.command.IwantToPlayCardCommand
 import eventDemo.app.entity.Player
 import eventDemo.app.event.GameEventStream
 import eventDemo.app.event.buildStateFromEventStream
-import eventDemo.app.event.event.CardIsPlayedEvent
 import eventDemo.app.event.event.GameEvent
-import eventDemo.app.event.event.PlayerReadyEvent
 import io.ktor.websocket.Frame
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -29,7 +27,7 @@ class GameCommandHandler(
     outgoing: SendChannel<Frame>,
 ) {
     private val commandStream = GameCommandStream(incoming, outgoing)
-    private val playerNotifier = outgoing
+    private val playerNotifier: (String) -> Unit = { runBlocking { outgoing.send(Frame.Text(it)) } }
 
     /**
      * Init the handler
@@ -41,48 +39,20 @@ class GameCommandHandler(
                     nack()
                 }
 
-                val state = command.buildState()
+                val gameState = command.buildGameState()
 
                 when (command) {
-                    is IwantToPlayCardCommand -> {
+                    is IWantToPlayCardCommand -> {
-                        // Check the command can be executed
+                        command.run(gameState, playerNotifier, eventStream)
-                        if (state.commandCardCanBeExecuted(command)) {
-                            eventStream.publish(
-                                CardIsPlayedEvent(
-                                    command.payload.gameId,
-                                    command.payload.card,
-                                    command.payload.player,
-                                ),
-                            )
-                        } else {
-                            runBlocking {
-                                playerNotifier.send(Frame.Text("Command cannot be executed"))
-                            }
-                        }
                     }
 
                     is IamReadyToPlayCommand -> {
-                        if (state.playerIsAlreadyReady(command.payload.player)) {
+                        command.run(gameState, playerNotifier, eventStream)
-                            nack()
-                        } else {
-                            PlayerReadyEvent(
-                                command.payload.gameId,
-                                command.payload.player,
-                            )
-                        }
                     }
                 }
             }
         }
     }
 
-    private fun GameState.playerIsAlreadyReady(player: Player): Boolean = readyPlayers.contains(player)
+    private fun GameCommand.buildGameState(): GameState = payload.gameId.buildStateFromEventStream(eventStream)
-
-    private fun GameState.commandCardCanBeExecuted(command: IwantToPlayCardCommand): Boolean =
-        canBePlayThisCard(
-            command.payload.player,
-            command.payload.card,
-        )
-
-    private fun GameCommand.buildState(): GameState = payload.gameId.buildStateFromEventStream(eventStream)
 }

src/main/kotlin/eventDemo/app/command/command/IWantToPlayCardCommand.kt

@@ -0,0 +1,54 @@
+package eventDemo.app.command.command
+
+import eventDemo.app.GameState
+import eventDemo.app.entity.Card
+import eventDemo.app.entity.GameId
+import eventDemo.app.entity.Player
+import eventDemo.app.event.GameEventStream
+import eventDemo.app.event.event.CardIsPlayedEvent
+import eventDemo.libs.command.CommandId
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * A command to perform an action to play a new card
+ */
+@Serializable
+@SerialName("PlayCard")
+data class IWantToPlayCardCommand(
+    override val payload: Payload,
+) : GameCommand {
+    override val name: String = "PlayCard"
+    override val id: CommandId = CommandId()
+
+    @Serializable
+    data class Payload(
+        override val gameId: GameId,
+        override val player: Player,
+        val card: Card,
+    ) : GameCommand.Payload
+
+    fun run(
+        state: GameState,
+        playerNotifier: (String) -> Unit,
+        eventStream: GameEventStream,
+    ) {
+        val commandCardCanBeExecuted: Boolean =
+            state.canBePlayThisCard(
+                payload.player,
+                payload.card,
+            )
+
+        if (commandCardCanBeExecuted) {
+            eventStream.publish(
+                CardIsPlayedEvent(
+                    payload.gameId,
+                    payload.card,
+                    payload.player,
+                ),
+            )
+        } else {
+            playerNotifier("Command cannot be executed")
+        }
+    }
+}

src/main/kotlin/eventDemo/app/command/command/IamReadyToPlayCommand.kt

@@ -1,7 +1,10 @@
 package eventDemo.app.command.command
 
+import eventDemo.app.GameState
 import eventDemo.app.entity.GameId
 import eventDemo.app.entity.Player
+import eventDemo.app.event.GameEventStream
+import eventDemo.app.event.event.PlayerReadyEvent
 import eventDemo.libs.command.CommandId
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
@@ -22,4 +25,23 @@ data class IamReadyToPlayCommand(
         override val gameId: GameId,
         override val player: Player,
     ) : GameCommand.Payload
+
+    fun run(
+        state: GameState,
+        playerNotifier: (String) -> Unit,
+        eventStream: GameEventStream,
+    ) {
+        val playerIsAlreadyReady: Boolean = state.readyPlayers.contains(payload.player)
+
+        if (playerIsAlreadyReady) {
+            playerNotifier("You are already ready")
+        } else {
+            eventStream.publish(
+                PlayerReadyEvent(
+                    payload.gameId,
+                    payload.player,
+                ),
+            )
+        }
+    }
 }

src/main/kotlin/eventDemo/app/command/command/IwantToPlayCardCommand.kt

@@ -1,27 +0,0 @@
-package eventDemo.app.command.command
-
-import eventDemo.app.entity.Card
-import eventDemo.app.entity.GameId
-import eventDemo.app.entity.Player
-import eventDemo.libs.command.CommandId
-import kotlinx.serialization.SerialName
-import kotlinx.serialization.Serializable
-
-/**
- * A command to perform an action to play a new card
- */
-@Serializable
-@SerialName("PlayCard")
-data class IwantToPlayCardCommand(
-    override val payload: Payload,
-) : GameCommand {
-    override val name: String = "PlayCard"
-    override val id: CommandId = CommandId()
-
-    @Serializable
-    data class Payload(
-        override val gameId: GameId,
-        override val player: Player,
-        val card: Card,
-    ) : GameCommand.Payload
-}