fix(plugin24): do not offer impossible push moves

Author: xeruf

plugin/src/main/kotlin/sc/plugin2024/GameState.kt

@@ -143,14 +143,14 @@ data class GameState @JvmOverloads constructor(
                 if(minDistance < 1)
                     return@flatMap emptyList()
                 (minDistance..info.distance)
-                        .map { dist ->
+                        .mapNotNull { dist ->
                             Move(listOfNotNull(Accelerate(info.costUntil(dist) + (if(dist == info.distance && info.problem == AdvanceProblem.SHIP_ALREADY_IN_TARGET) 1 else 0) - currentShip.movement).takeUnless { it.acc == 0 || dist < 1 },
                                     turn, Advance(dist),
                                     if(currentShip.position + (direction.vector * dist) == otherShip.position) {
                                         val currentRotation = board.findSegment(otherShip.position)?.direction
                                         getPossiblePushs(otherShip.position, direction).maxByOrNull {
                                             currentRotation?.turnCountTo(it.direction)?.absoluteValue ?: 2
-                                        }
+                                        } ?: return@mapNotNull null
                                     } else null
                             ))
                         }

plugin/src/main/kotlin/sc/plugin2024/Ship.kt

@@ -60,6 +60,12 @@ data class Ship(
 ): PublicCloneable<Ship> {
     override fun clone(): Ship =
             this.copy()
+    
+    fun accelerateBy(diff: Int) {
+        speed += diff
+        movement += diff
+    }
+    
     fun readResolve(): Ship {
         freeAcc = 1
         movement = speed

plugin/src/test/kotlin/sc/plugin2024/GameStateTest.kt

@@ -188,16 +188,27 @@ class GameStateTest: FunSpec({
             moves shouldHaveSize 3
         }
         test("costly move") {
+            ship.accelerateBy(1)
             ship.coal = 0
-            ship.speed = 2
-            ship.movement = 2
             ship.freeAcc = 0
             ship.freeTurns = 0
             ship.direction = CubeDirection.DOWN_RIGHT
             gameState.getSensibleMoves() shouldHaveSingleElement Move(Advance(1))
             ship.movement = 3
             gameState.getSensibleMoves() shouldHaveSingleElement Move(Advance(2))
         }
+        test("unpushable opponent") {
+            val state = GameState(
+                    Board(listOf(Segment (CubeDirection.RIGHT, CubeCoordinates.ORIGIN, arrayOf(arrayOf(Field.WATER, Field.WATER, Field.WATER))))),
+                    ships = listOf(
+                            Ship(CubeCoordinates(-1, -2), Team.ONE),
+                            Ship(CubeCoordinates(-1, 0), Team.TWO),
+                    )
+            )
+            state.getSensibleMoves() shouldBe listOf(Move(Turn(CubeDirection.DOWN_RIGHT), Advance(1)))
+            state.currentShip.accelerateBy(2)
+            state.getSensibleMoves() shouldBe listOf(Move(Accelerate(-2), Turn(CubeDirection.DOWN_RIGHT), Advance(1)))
+        }
     }
 
     context("current works when board is truncated") {

sdk/src/main/server-api/sc/api/plugins/CubeCoordinates.kt

@@ -95,6 +95,9 @@ enum class CubeDirection(val vector: CubeCoordinates) {
     UP_LEFT(CubeCoordinates(0, -1)),
     UP_RIGHT(CubeCoordinates(+1, -1));
 
+    val angle
+        get() = ordinal * 60
+    
     /** @return an array of this and the two neighboring directions. */
     fun withNeighbors() = arrayOf(rotatedBy(-1), this, rotatedBy(1))