fix bug where player ships did not fire on enemy defense stations

src/lib/sim/ShipSystem.cpp

@@ -245,7 +245,7 @@ void ShipSystem::tickThreatResponse(const BuildingSystem& buildings)
 
         if (!s.isEnemy)
         {
-            // Player combat ship: target nearest enemy ship.
+            // Player combat ship: target nearest enemy ship or enemy building.
             if (!isTargetValid(s.threatResponse->currentTarget.value_or(kInvalidEntityId),
                                range, s, buildings))
             {
@@ -264,14 +264,39 @@ void ShipSystem::tickThreatResponse(const BuildingSystem& buildings)
                         s.threatResponse->currentTarget = candidate.id;
                     }
                 }
+
+                for (const Building& b : allBuildings)
+                {
+                    if (b.type != BuildingType::EnemyDefenceStation)
+                    {
+                        continue;
+                    }
+                    float dist = (buildingCenter(b) - s.position).length();
+                    if (dist < bestDist)
+                    {
+                        bestDist = dist;
+                        s.threatResponse->currentTarget = b.id;
+                    }
+                }
             }
 
             if (s.threatResponse->currentTarget)
             {
-                const Ship* target = findShip(*s.threatResponse->currentTarget);
+                QVector2D dest;
-                if (target && 3 > s.intent.priority)
+                const Ship* tShip = findShip(*s.threatResponse->currentTarget);
+                if (tShip)
                 {
-                    s.intent = MovementIntent{3, target->position};
+                    dest = tShip->position;
+                }
+                else
+                {
+                    const Building* tBld = buildings.findBuilding(
+                        *s.threatResponse->currentTarget);
+                    dest = tBld ? buildingCenter(*tBld) : s.position;
+                }
+                if (3 > s.intent.priority)
+                {
+                    s.intent = MovementIntent{3, dest};
                 }
             }
             else

src/test/CombatSystemTest.cpp

@@ -283,6 +283,47 @@ TEST_CASE("CombatSystem: enemy station fires at player ship in range", "[combat]
     REQUIRE(stationFired);
 }
 
+TEST_CASE("CombatSystem: player ship fires at enemy station in range", "[combat]")
+{
+    Simulation sim(loadConfig(), 42);
+
+    EntityId stationId = kInvalidEntityId;
+    QVector2D stationCenter;
+    for (const Building& b : sim.buildings().allBuildings())
+    {
+        if (b.type == BuildingType::EnemyDefenceStation)
+        {
+            stationId = b.id;
+            stationCenter = QVector2D(
+                b.anchor.x() + b.footprint.width()  / 2.0f,
+                b.anchor.y() + b.footprint.height() / 2.0f);
+            break;
+        }
+    }
+    REQUIRE(stationId != kInvalidEntityId);
+
+    const ShipDef* combatDef = findCombatShip(sim.config());
+    REQUIRE(combatDef != nullptr);
+
+    const EntityId playerId = sim.ships().spawn(
+        combatDef->id, 1,
+        QVector2D(stationCenter.x() - 1.0f, stationCenter.y()),
+        /*isEnemy=*/false);
+
+    sim.tick();
+
+    const std::vector<FireEvent> events = sim.drainFireEvents();
+    bool playerFiredAtStation = false;
+    for (const FireEvent& e : events)
+    {
+        if (e.shooter == playerId && e.target == stationId)
+        {
+            playerFiredAtStation = true;
+        }
+    }
+    REQUIRE(playerFiredAtStation);
+}
+
 // ---------------------------------------------------------------------------
 // Deaths & loot (tick step 9)
 // ---------------------------------------------------------------------------