Make selected flee province optional, and must not be set if no flee provinces are available (#2985)

* make it optional

* make the flee province optional

* fix test to allow for optional flee province id

* add tests for incorrect flee province settings

src/main/protobuf/net/eagle0/eagle/api/selected_command.proto

@@ -96,7 +96,7 @@ message ControlWeatherSelectedCommand {
 }
 
 message DefendSelectedCommand {
-    int32 flee_province_id = 1;
+    .google.protobuf.Int32Value flee_province_id = 1;
     repeated .net.eagle0.eagle.common.CombatUnit defending_units = 2;
 }
 

src/main/scala/net/eagle0/eagle/library/actions/impl/command/DefendCommand.scala

@@ -19,7 +19,7 @@ case class DefendCommand(
     defendingPlayer: FactionId,
     provinceId: ProvinceId,
     defendingUnits: Seq[CombatUnit],
-    fleeProvinceId: ProvinceId
+    fleeProvinceId: Option[ProvinceId]
 ) extends DeterministicSingleResultCommand(gameState, sc) {
   override def immediateExecute: ActionResult = {
     commandRequire(
@@ -52,7 +52,7 @@ case class DefendCommand(
             Army(
               factionId = defendingPlayer,
               units = defendingUnits.toVector,
-              fleeProvinceId = Some(fleeProvinceId)
+              fleeProvinceId = fleeProvinceId
             )
           )
         )
@@ -76,12 +76,26 @@ object DefendCommand
       s"Tried to defend with ${defendingUnits.length} units (max is $maxUnitCount)"
     )
 
-    commandRequire(
-      availableCommand.availableFleeProvinceIds.contains(
-        selectedCommand.fleeProvinceId
-      ),
-      s"Selected flee province ${selectedCommand.fleeProvinceId} is not in available ${availableCommand.availableFleeProvinceIds}"
-    )
+    // If there are any eligible flee provinces, one must be chosen; if there are none, the flee province must be empty
+    if (availableCommand.availableFleeProvinceIds.isEmpty)
+      commandRequire(
+        selectedCommand.fleeProvinceId.isEmpty,
+        s"Flee province ${selectedCommand.fleeProvinceId.get} was selected, but none were available"
+      )
+    else {
+      commandRequire(
+        selectedCommand.fleeProvinceId.nonEmpty,
+        s"Flee provinces ${availableCommand.availableFleeProvinceIds} are available, but none was selected"
+      )
+
+      commandRequire(
+        availableCommand.availableFleeProvinceIds
+          .contains(
+            selectedCommand.fleeProvinceId.get
+          ),
+        s"Selected flee province ${selectedCommand.fleeProvinceId.get} is not in available ${availableCommand.availableFleeProvinceIds}"
+      )
+    }
 
     DefendCommand(
       sc = selectedCommand,

src/main/scala/net/eagle0/eagle/library/util/command_choice_helpers/CommandChoiceHelpers.scala

@@ -1167,8 +1167,8 @@ object CommandChoiceHelpers {
                 val fleeProvinceId = provinces
                   .find(_.rulingFactionId.contains(actingFactionId))
                   .orElse(provinces.find(_.rulingFactionId.isEmpty))
-                  .getOrElse(provinces.head)
-                  .id
+                  .orElse(provinces.headOption)
+                  .map(_.id)
 
                 DefendSelectedCommand(
                   defendingUnits = defendingUnits(gameState, defendCommand),

src/test/scala/net/eagle0/eagle/library/actions/impl/command/BUILD.bazel

@@ -104,6 +104,7 @@ scala_test(
     name = "defend_command_test",
     srcs = ["DefendCommandTest.scala"],
     deps = [
+        "//src/main/protobuf/net/eagle0/eagle/api:available_command_scala_proto",
         "//src/main/protobuf/net/eagle0/eagle/common:action_result_type_scala_proto",
         "//src/main/protobuf/net/eagle0/eagle/common:combat_unit_scala_proto",
         "//src/main/protobuf/net/eagle0/eagle/common:unaffiliated_hero_scala_proto",
@@ -120,6 +121,7 @@ scala_test(
         "//src/main/scala/net/eagle0/eagle/library/actions/impl/command:deterministic_single_result_command",
         "//src/main/scala/net/eagle0/eagle/library/actions/impl/common:action",
         "//src/main/scala/net/eagle0/eagle/library/actions/impl/common:deterministic_single_result_action",
+        "//src/main/scala/net/eagle0/eagle/library/settings",
         "//src/test/scala/net/eagle0/eagle/library/actions/impl:action_impl_pkg",
     ],
 )

src/test/scala/net/eagle0/eagle/library/actions/impl/command/DefendCommandTest.scala

@@ -1,5 +1,7 @@
 package net.eagle0.eagle.library.actions.impl.command
 
+import net.eagle0.eagle.SettingsKeys
+import net.eagle0.eagle.api.available_command.DefendAvailableCommand
 import net.eagle0.eagle.api.selected_command.DefendSelectedCommand
 import net.eagle0.eagle.common.action_result_type.ActionResultType.DEFEND
 import net.eagle0.eagle.common.combat_unit.CombatUnit
@@ -15,10 +17,15 @@ import net.eagle0.eagle.internal.game_state.GameState
 import net.eagle0.eagle.internal.hero.Hero
 import net.eagle0.eagle.internal.province.Province
 import net.eagle0.eagle.library.EagleCommandException
+import net.eagle0.eagle.library.settings.Settings
+import org.scalatest.BeforeAndAfterEach
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
 
-class DefendCommandTest extends AnyFlatSpec with Matchers {
+class DefendCommandTest
+    extends AnyFlatSpec
+    with Matchers
+    with BeforeAndAfterEach {
   import net.eagle0.eagle.library.actions.impl._
 
   val fleeProvinceId = 19
@@ -66,6 +73,83 @@ class DefendCommandTest extends AnyFlatSpec with Matchers {
 
   private val selectedCommand = DefendSelectedCommand()
 
+  override def beforeEach(): Unit = {
+    Settings.addSettings(
+      Vector(
+        SettingsKeys.maxCombatUnitCountPerSide -> "10"
+      )
+    )
+  }
+
+  "make" should "throw if a flee province is selected when none were available" in {
+    val availableCommand = DefendAvailableCommand(
+      suitableBattalionsForHeroes = Map(),
+      availableFleeProvinceIds = Vector(),
+      availableBattalions = Vector(),
+      availableHeroIds = Vector(),
+      recommendedUnits = Vector(),
+      actingProvinceId = 7
+    )
+
+    val gs = GameState()
+    val sc = DefendSelectedCommand(fleeProvinceId = Some(fleeProvinceId))
+
+    the[EagleCommandException] thrownBy {
+      DefendCommand.make(
+        actingFactionId = 1,
+        gameState = gs,
+        availableCommand = availableCommand,
+        selectedCommand = sc
+      )
+    } should have message "requirement failed: Flee province 19 was selected, but none were available"
+  }
+
+  it should "throw if flee provinces are available and none is selected" in {
+    val availableCommand = DefendAvailableCommand(
+      suitableBattalionsForHeroes = Map(),
+      availableFleeProvinceIds = Vector(5, 6),
+      availableBattalions = Vector(),
+      availableHeroIds = Vector(),
+      recommendedUnits = Vector(),
+      actingProvinceId = 7
+    )
+
+    val gs = GameState()
+    val sc = DefendSelectedCommand(fleeProvinceId = None)
+
+    the[EagleCommandException] thrownBy {
+      DefendCommand.make(
+        actingFactionId = 1,
+        gameState = gs,
+        availableCommand = availableCommand,
+        selectedCommand = sc
+      )
+    } should have message "requirement failed: Flee provinces Vector(5, 6) are available, but none was selected"
+  }
+
+  it should "throw if the selected flee province is not among the available ones" in {
+    val availableCommand = DefendAvailableCommand(
+      suitableBattalionsForHeroes = Map(),
+      availableFleeProvinceIds = Vector(5, 6),
+      availableBattalions = Vector(),
+      availableHeroIds = Vector(),
+      recommendedUnits = Vector(),
+      actingProvinceId = 7
+    )
+
+    val gs = GameState()
+    val sc = DefendSelectedCommand(fleeProvinceId = Some(fleeProvinceId))
+
+    the[EagleCommandException] thrownBy {
+      DefendCommand.make(
+        actingFactionId = 1,
+        gameState = gs,
+        availableCommand = availableCommand,
+        selectedCommand = sc
+      )
+    } should have message "requirement failed: Selected flee province 19 is not in available Vector(5, 6)"
+  }
+
   "Execute" should "throw if there is no hostile army in specified province" in {
     val startingState = GameState(
       heroes = HeroMap(heroes),
@@ -81,7 +165,7 @@ class DefendCommandTest extends AnyFlatSpec with Matchers {
       defendingPlayer = 4,
       provinceId = 7,
       defendingUnits = defenders,
-      fleeProvinceId = fleeProvinceId
+      fleeProvinceId = Some(fleeProvinceId)
     )
 
     the[EagleCommandException] thrownBy {
@@ -101,7 +185,7 @@ class DefendCommandTest extends AnyFlatSpec with Matchers {
       defendingPlayer = 4,
       provinceId = 7,
       defendingUnits = defenders,
-      fleeProvinceId = fleeProvinceId
+      fleeProvinceId = Some(fleeProvinceId)
     )
 
     the[EagleCommandException] thrownBy {
@@ -122,7 +206,7 @@ class DefendCommandTest extends AnyFlatSpec with Matchers {
       defendingPlayer = 4,
       provinceId = 7,
       defendingUnits = defenders,
-      fleeProvinceId = fleeProvinceId
+      fleeProvinceId = Some(fleeProvinceId)
     )
 
     val results = command.resultsOfExecute
@@ -143,7 +227,7 @@ class DefendCommandTest extends AnyFlatSpec with Matchers {
       defendingPlayer = 4,
       provinceId = 7,
       defendingUnits = defenders,
-      fleeProvinceId = fleeProvinceId
+      fleeProvinceId = Some(fleeProvinceId)
     )
 
     val results = command.resultsOfExecute