Working on hostile NPCs, fixing darklands mode for battle zone

server/tests/LocationGameStateTests.cpp

@@ -148,6 +148,52 @@ int main()
 		return fail("Disabled player interacted with location entities");
 	}
 
+	auto& hostileNpc = *state.npcs.at("npc");
+	hostileNpc.enabled = true;
+	hostileNpc.canAttack = true;
+	hostileNpc.hp = hostileNpc.initialHp = 75.f;
+	hostileNpc.position = Eigen::Vector3f::Zero();
+	hostileNpc.homePosition = {5.f, 0.f, 0.f};
+	hostileNpc.stopInPlace();
+
+	auto playerOne = std::make_shared<FRG::CharacterState>();
+	playerOne->configureAsPlayer();
+	playerOne->enabled = true;
+	playerOne->position = {3.f, 0.f, 0.f};
+	auto playerTwo = std::make_shared<FRG::CharacterState>();
+	playerTwo->configureAsPlayer();
+	playerTwo->enabled = true;
+	playerTwo->position = {2.f, 0.f, 0.f};
+	FRG::PlayerStateMap combatPlayers{
+		{"player", playerOne}, {"player2", playerTwo}};
+
+	state.update(100, combatPlayers, false);
+	if (hostileNpc.attackTargetId != "player2") {
+		return fail("Hostile NPC did not select the nearest player");
+	}
+
+	playerOne->position = {1.f, 0.f, 0.f};
+	playerTwo->position = {4.f, 0.f, 0.f};
+	state.update(100, combatPlayers, false);
+	if (hostileNpc.attackTargetId != "player2") {
+		return fail("Hostile NPC did not retain its living target lock");
+	}
+
+	playerTwo->hp = 0.f;
+	state.update(100, combatPlayers, false);
+	if (hostileNpc.attackTargetId != "player") {
+		return fail("Hostile NPC did not acquire a replacement after target death");
+	}
+
+	playerOne->enabled = false;
+	state.update(100, combatPlayers, false);
+	if (!hostileNpc.attackTargetId.empty() ||
+		hostileNpc.battle_state != 0 ||
+		(hostileNpc.requestedWalkTarget - hostileNpc.homePosition).norm() >
+			FRG::CharacterState::kWalkThreshold) {
+		return fail("Hostile NPC did not return home after losing its target");
+	}
+
 	FRG::CampaignConfig battleZone;
 	battleZone.id = "battle_zone";
 	battleZone.questsPath = "resources/config/quests_battle_zone.json";