move login from state to Command

src/main/kotlin/eventDemo/app/GameState.kt

@@ -41,73 +41,6 @@ data class GameState(
         return players.size == readyPlayers.size && players.all { readyPlayers.contains(it) }
     }
 
-    fun canBePlayThisCard(
-        player: Player,
-        card: Card,
-    ): Boolean {
-        if (!isReady) return false
-        val cardOnGame = lastCard?.card ?: return false
-
-        return when (cardOnGame) {
-            is Card.NumericCard -> {
-                when (card) {
-                    is Card.AllColorCard -> true
-                    is Card.NumericCard -> card.number == cardOnGame.number || card.color == cardOnGame.color
-                    is Card.ColorCard -> card.color == cardOnGame.color
-                }
-            }
-
-            is Card.ReverseCard -> {
-                when (card) {
-                    is Card.ReverseCard -> true
-                    is Card.AllColorCard -> true
-                    is Card.ColorCard -> card.color == cardOnGame.color
-                }
-            }
-
-            is Card.PassCard -> {
-                if (player.cardOnBoardIsForYou) {
-                    false
-                } else {
-                    when (card) {
-                        is Card.AllColorCard -> true
-                        is Card.ColorCard -> card.color == cardOnGame.color
-                    }
-                }
-            }
-
-            is Card.ChangeColorCard -> {
-                when (card) {
-                    is Card.AllColorCard -> true
-                    is Card.ColorCard -> card.color == lastColor
-                }
-            }
-
-            is Card.Plus2Card -> {
-                if (player.cardOnBoardIsForYou && card is Card.Plus2Card) {
-                    true
-                } else {
-                    when (card) {
-                        is Card.AllColorCard -> true
-                        is Card.Plus2Card -> true
-                        is Card.ColorCard -> card.color == cardOnGame.color
-                    }
-                }
-            }
-
-            is Card.Plus4Card -> {
-                if (player.cardOnBoardIsForYou && card is Card.Plus4Card) {
-                    true
-                } else {
-                    when (card) {
-                        is Card.AllColorCard -> true
-                        is Card.ColorCard -> card.color == lastColor
-                    }
-                }
-            }
-        }
-    }
-
     private val lastPlayerIndex: Int? get() {
         val i = players.indexOf(lastPlayer)
         return if (i == -1) {
@@ -130,9 +63,9 @@ data class GameState(
 
     val nextPlayer: Player = players.elementAt(nextPlayerIndex)
 
-    private val Player.currentIndex: Int get() = players.indexOf(this)
+    val Player.currentIndex: Int get() = players.indexOf(this)
 
-    private fun Player.playerDiffIndex(nextPlayer: Player): Int =
+    fun Player.playerDiffIndex(nextPlayer: Player): Int =
         if (direction == Direction.CLOCKWISE) {
             nextPlayer.currentIndex + this.currentIndex
         } else {

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

@@ -18,7 +18,6 @@ import kotlinx.serialization.Serializable
 data class IWantToPlayCardCommand(
     override val payload: Payload,
 ) : GameCommand {
-    override val name: String = "PlayCard"
     override val id: CommandId = CommandId()
 
     @Serializable
@@ -33,13 +32,7 @@ data class IWantToPlayCardCommand(
         playerNotifier: (String) -> Unit,
         eventStream: GameEventStream,
     ) {
-        val commandCardCanBeExecuted: Boolean =
-            state.canBePlayThisCard(
-                payload.player,
-                payload.card,
-            )
-
-        if (commandCardCanBeExecuted) {
+        if (state.canBePlayThisCard()) {
             eventStream.publish(
                 CardIsPlayedEvent(
                     payload.gameId,
@@ -48,7 +41,70 @@ data class IWantToPlayCardCommand(
                 ),
             )
         } else {
-            playerNotifier("Command cannot be executed")
+            playerNotifier("You cannot play this card")
+        }
+    }
+
+    fun GameState.canBePlayThisCard(): Boolean {
+        if (!isReady) return false
+        val cardOnBoard = lastCard?.card ?: return false
+        return when (cardOnBoard) {
+            is Card.NumericCard -> {
+                when (payload.card) {
+                    is Card.AllColorCard -> true
+                    is Card.NumericCard -> payload.card.number == cardOnBoard.number || payload.card.color == cardOnBoard.color
+                    is Card.ColorCard -> payload.card.color == cardOnBoard.color
+                }
+            }
+
+            is Card.ReverseCard -> {
+                when (payload.card) {
+                    is Card.ReverseCard -> true
+                    is Card.AllColorCard -> true
+                    is Card.ColorCard -> payload.card.color == cardOnBoard.color
+                }
+            }
+
+            is Card.PassCard -> {
+                if (payload.player.cardOnBoardIsForYou) {
+                    false
+                } else {
+                    when (payload.card) {
+                        is Card.AllColorCard -> true
+                        is Card.ColorCard -> payload.card.color == cardOnBoard.color
+                    }
+                }
+            }
+
+            is Card.ChangeColorCard -> {
+                when (payload.card) {
+                    is Card.AllColorCard -> true
+                    is Card.ColorCard -> payload.card.color == lastColor
+                }
+            }
+
+            is Card.Plus2Card -> {
+                if (payload.player.cardOnBoardIsForYou && payload.card is Card.Plus2Card) {
+                    true
+                } else {
+                    when (payload.card) {
+                        is Card.AllColorCard -> true
+                        is Card.Plus2Card -> true
+                        is Card.ColorCard -> payload.card.color == cardOnBoard.color
+                    }
+                }
+            }
+
+            is Card.Plus4Card -> {
+                if (payload.player.cardOnBoardIsForYou && payload.card is Card.Plus4Card) {
+                    true
+                } else {
+                    when (payload.card) {
+                        is Card.AllColorCard -> true
+                        is Card.ColorCard -> payload.card.color == lastColor
+                    }
+                }
+            }
         }
     }
 }

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

@@ -17,7 +17,6 @@ import kotlinx.serialization.Serializable
 data class IamReadyToPlayCommand(
     override val payload: Payload,
 ) : GameCommand {
-    override val name: String = "Ready"
     override val id: CommandId = CommandId()
 
     @Serializable