feat(combat): add built-in basic attack

src/main/java/games/dmg/fantasystick/FantasyStickPlugin.java

@@ -44,6 +44,7 @@ public final class FantasyStickPlugin extends JavaPlugin {
     private games.dmg.fantasystick.session.AdventureModeLease gameModes;
     private games.dmg.fantasystick.session.SessionVitals vitals;
     private games.dmg.fantasystick.session.SessionVisuals sessionVisuals;
+    private games.dmg.fantasystick.combat.BasicAttack basicAttack;
     private java.util.concurrent.CompletionStage<Void> configurationDrain = java.util.concurrent.CompletableFuture.completedStage(null);
 
     @Override public void onEnable() {
@@ -121,7 +122,12 @@ public final class FantasyStickPlugin extends JavaPlugin {
                     var player = getServer().getPlayer(id);
                     return net.kyori.adventure.text.Component.text(name != null ? name : player == null ? id.toString() : player.getName());
                 });
-            sessionEvents = new EquipmentSessionEvents(sessions, nextTick, diagnostics, books);
+            var localBasicAttack = new games.dmg.fantasystick.combat.BasicAttack(sessions);
+            basicAttack = localBasicAttack;
+            sessionEvents = new EquipmentSessionEvents(sessions, nextTick, diagnostics, input -> {
+                books.accept(input);
+                localBasicAttack.accept(input);
+            });
             admin = new EquipmentAdminCommand(receipts, sessions, getServer(), nextTick,
                 problem -> getLogger().log(Level.WARNING, "Equipment admin " + problem.operation()
                     + " for player " + problem.player(), problem.cause()), adventureSettings);
@@ -136,6 +142,7 @@ public final class FantasyStickPlugin extends JavaPlugin {
             getServer().getPluginManager().registerEvents(partyEvents, this);
             getServer().getPluginManager().registerEvents(partyCombat, this);
             partyCombat.install(this);
+            getServer().getPluginManager().registerEvents(localBasicAttack, this);
             getServer().getPluginManager().registerEvents(books, this);
             getServer().getPluginManager().registerEvents(gameModes, this);
             sessionVisuals = new games.dmg.fantasystick.session.SessionVisuals(sessions,
@@ -173,6 +180,7 @@ public final class FantasyStickPlugin extends JavaPlugin {
         var closingModes = gameModes; gameModes = null;
         var closingVitals = vitals; vitals = null;
         var closingVisuals = sessionVisuals; sessionVisuals = null;
+        var closingBasicAttack = basicAttack; basicAttack = null;
         // Retire client resources independently of successful ordinary-equipment restoration.
         if (closingPresentation != null) cleanup("presentation", closingPresentation::close);
         if (closingProtocol != null) cleanup("protocol presentation", closingProtocol::close);
@@ -182,6 +190,7 @@ public final class FantasyStickPlugin extends JavaPlugin {
             cleanup("configuration", closingSettings::close);
         }
         if (closingBooks != null) cleanup("character book", closingBooks::close);
+        if (closingBasicAttack != null) cleanup("basic attack", closingBasicAttack::close);
         if (closingVisuals != null) cleanup("session particles", closingVisuals::close);
         if (closingParties != null) cleanup("parties", closingParties::close);
         if (closingPartyCombat != null) cleanup("party combat", closingPartyCombat::close);
@@ -193,6 +202,7 @@ public final class FantasyStickPlugin extends JavaPlugin {
         unregister(closingChat);
         unregister(closingPartyEvents);
         unregister(closingPartyCombat);
+        unregister(closingBasicAttack);
         unregister(closingBooks);
         unregister(closingEvents);
         unregister(closingCrafting);

src/main/java/games/dmg/fantasystick/combat/BasicAttack.java

@@ -0,0 +1,91 @@
+package games.dmg.fantasystick.combat;
+
+import games.dmg.fantasystick.progression.Stat;
+import games.dmg.fantasystick.session.ControlInput;
+import games.dmg.fantasystick.session.EquipmentSessions;
+import java.math.BigInteger;
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.UUID;
+import java.util.function.Consumer;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.EntityDamageByEntityEvent;
+
+/** Server-thread built-in attack consumer; the bound stick's vanilla attack is always contained upstream. */
+public final class BasicAttack implements Consumer<ControlInput>, Listener, AutoCloseable {
+    private static final Duration CADENCE = Duration.ofSeconds(1);
+    private final EquipmentSessions sessions;
+    private final Clock clock;
+    private final Map<UUID, Instant> readyAt = new HashMap<>();
+    private Pending pending;
+    private boolean closed;
+
+    private static final class Pending {
+        final ControlInput input;
+        final LivingEntity target;
+        final Instant attackedAt;
+        boolean accepted;
+        Pending(ControlInput input, LivingEntity target, Instant attackedAt) {
+            this.input = input; this.target = target; this.attackedAt = attackedAt;
+        }
+    }
+
+    public BasicAttack(EquipmentSessions sessions) {
+        this(sessions, Clock.systemUTC());
+    }
+
+    public BasicAttack(EquipmentSessions sessions, Clock clock) {
+        this.sessions = Objects.requireNonNull(sessions);
+        this.clock = Objects.requireNonNull(clock);
+    }
+
+    @Override public void accept(ControlInput input) {
+        if (closed || pending != null || input.kind() != ControlInput.Kind.BASIC_ATTACK
+                || input.gesture() != ControlInput.Gesture.ATTACK
+                || !(input.target() instanceof LivingEntity target) || !input.stillCurrent()) return;
+        var record = sessions.currentRecord(input.session()).orElse(null);
+        if (record == null) return;
+        Instant now = clock.instant();
+        Instant ready = readyAt.get(input.session().character());
+        if (ready != null && now.isBefore(ready)) return;
+        BigInteger damage = damage(record.stats().get(Stat.STR));
+        double nativeDamage = damage.bitLength() > 1023 ? Double.MAX_VALUE : damage.doubleValue();
+        var attempt = new Pending(input, target, now);
+        pending = attempt;
+        try {
+            target.damage(nativeDamage, input.player());
+        } finally {
+            if (pending == attempt) pending = null;
+            if (attempt.accepted) readyAt.put(input.session().character(), attempt.attackedAt.plus(CADENCE));
+        }
+    }
+
+    static BigInteger damage(BigInteger strength) {
+        Objects.requireNonNull(strength);
+        if (strength.signum() < 0) throw new IllegalArgumentException("Strength must not be negative");
+        return strength.subtract(BigInteger.TEN).divide(BigInteger.TWO).max(BigInteger.ONE);
+    }
+
+    /** MONITOR observes the synchronous native result; cancelled/zero damage never spends cadence. */
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void acceptedDamage(EntityDamageByEntityEvent event) {
+        var attempt = pending;
+        if (closed || attempt == null || event.isCancelled() || event.getFinalDamage() <= 0
+                || event.getDamager() != attempt.input.player() || event.getEntity() != attempt.target
+                || !attempt.input.stillCurrent() || !sessions.current(attempt.input.session())) return;
+        attempt.accepted = true;
+    }
+
+    @Override public void close() {
+        closed = true;
+        pending = null;
+        readyAt.clear();
+    }
+}

src/main/java/games/dmg/fantasystick/session/EquipmentSessions.java

@@ -202,6 +202,13 @@ public final class EquipmentSessions implements AutoCloseable {
             && sheets.identify(attempt.player.getInventory().getItemInOffHand()).filter(attempt.character::equals).isPresent();
     }
 
+    /** Current transferable character snapshot for a still-authorized server-thread action. */
+    public synchronized Optional<CharacterRecord> currentRecord(Active session) {
+        var attempt = active.get(session.player());
+        return current(session) && attempt != null && attempt.record != null
+            ? Optional.of(attempt.record) : Optional.empty();
+    }
+
     /** Apply a persisted progression revision to the still-current active session. */
     public synchronized boolean acknowledgeProgress(Active session, BigInteger expectedRevision, CharacterRecord saved) {
         var attempt = active.get(session.player());

src/nativeTest/java/games/dmg/fantasystick/BasicAttackNativeTest.java

@@ -0,0 +1,114 @@
+package games.dmg.fantasystick;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import java.nio.file.Path;
+import java.time.Clock;
+import java.time.Instant;
+import java.time.ZoneId;
+import java.time.ZoneOffset;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+class BasicAttackNativeTest {
+    @TempDir Path data;
+    @BeforeAll static void bootstrap() throws Exception { NativeRuntime.bootstrap(); }
+
+    @Test void successfulHitsStartAnExactOneSecondCadenceButCancelledDamageDoesNot() throws Exception {
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data);
+            f.players.put(a.core.id, a.player); f.activate(a);
+            var sessions = (games.dmg.fantasystick.session.EquipmentSessions)
+                FantasyStickLifecycleNativeTest.Fixture.field(f.plugin, "sessions");
+            var active = sessions.active(a.core.id).orElseThrow();
+            var clock = new MutableClock(Instant.parse("2026-09-19T00:00:00Z"));
+            var basic = new games.dmg.fantasystick.combat.BasicAttack(sessions, clock);
+            var target = mock(org.bukkit.entity.LivingEntity.class);
+            var cancelled = new java.util.concurrent.atomic.AtomicBoolean(true);
+            doAnswer(call -> {
+                var source = mock(org.bukkit.damage.DamageSource.class);
+                when(source.getCausingEntity()).thenReturn(a.player);
+                when(source.getDirectEntity()).thenReturn(a.player);
+                var event = new org.bukkit.event.entity.EntityDamageByEntityEvent(a.player, target,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.ENTITY_ATTACK, source, (Double) call.getArgument(0));
+                event.setCancelled(cancelled.get());
+                basic.acceptedDamage(event);
+                return null;
+            }).when(target).damage(anyDouble(), same(a.player));
+            var input = new games.dmg.fantasystick.session.ControlInput(a.player, active, 1, "",
+                games.dmg.fantasystick.session.ControlInput.Kind.BASIC_ATTACK,
+                games.dmg.fantasystick.session.ControlInput.Gesture.ATTACK, target, 0, 1,
+                () -> sessions.current(active));
+            basic.accept(input); // Cancelled: no cadence spent.
+            cancelled.set(false);
+            basic.accept(input); // Accepted at t=0.
+            clock.advance(java.time.Duration.ofMillis(999)); basic.accept(input);
+            verify(target, times(2)).damage(1.0, a.player);
+            clock.advance(java.time.Duration.ofMillis(1)); basic.accept(input);
+            verify(target, times(3)).damage(1.0, a.player);
+            a.core.inventory.setItemInOffHand(null); f.changed(a);
+            clock.advance(java.time.Duration.ofSeconds(1)); basic.accept(input);
+            verifyNoMoreInteractions(target);
+        }
+    }
+
+    @Test void partyCancellationPreventsDamageAndDoesNotSpendThePackagedAttackCadence() throws Exception {
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data);
+            var b = new FantasyStickLifecycleNativeTest.Actor(data);
+            f.players.put(a.core.id, a.player); f.players.put(b.core.id, b.player);
+            f.activate(a); f.activate(b);
+            var parties = PartyLifecycleNativeTest.parties(f);
+            var party = parties.create(a.core.id).orElseThrow();
+            assertTrue(parties.accept(b.core.id, parties.invite(a.core.id, party.id(), b.core.id).orElseThrow().id()));
+            var events = new java.util.ArrayList<org.bukkit.event.entity.EntityDamageByEntityEvent>();
+            doAnswer(call -> {
+                var source = mock(org.bukkit.damage.DamageSource.class);
+                when(source.getCausingEntity()).thenReturn(a.player);
+                when(source.getDirectEntity()).thenReturn(a.player);
+                var event = new org.bukkit.event.entity.EntityDamageByEntityEvent(a.player, b.player,
+                    org.bukkit.event.entity.EntityDamageEvent.DamageCause.ENTITY_ATTACK, source, (Double) call.getArgument(0));
+                events.add(event); f.dispatcher.accept(event); return null;
+            }).when(b.player).damage(anyDouble(), same(a.player));
+            a.core.inventory.getInventory().setSelectedSlot(1);
+            f.dispatcher.accept(new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, b.player, true));
+            assertEquals(1, events.size()); assertTrue(events.getFirst().isCancelled());
+            assertTrue(parties.leave(a.core.id, party.id()));
+            f.dispatcher.accept(new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, b.player, true));
+            assertEquals(2, events.size()); assertFalse(events.getLast().isCancelled());
+            f.dispatcher.accept(new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, b.player, true));
+            assertEquals(2, events.size(), "The accepted second hit starts cadence; the cancelled first hit did not");
+        }
+    }
+
+    @Test void packagedBasicStickInputDealsOneLowStrengthHitWithoutVanillaContinuation() throws Exception {
+        try (var f = new FantasyStickLifecycleNativeTest.Fixture(data)) {
+            f.plugin.setEnabled(true);
+            var a = new FantasyStickLifecycleNativeTest.Actor(data);
+            f.players.put(a.core.id, a.player); f.activate(a);
+            a.core.inventory.getInventory().setSelectedSlot(1);
+            var target = mock(org.bukkit.entity.LivingEntity.class);
+            var attack = new io.papermc.paper.event.player.PrePlayerAttackEntityEvent(a.player, target, true);
+            f.dispatcher.accept(attack);
+            assertTrue(attack.isCancelled(), "The icon stick must never continue into vanilla damage");
+            verify(target).damage(1.0, a.player);
+            a.core.inventory.setItemInOffHand(null); f.changed(a); f.awaitCharacterAndReceipt(a);
+            assertEquals(org.bukkit.Material.DIAMOND_SWORD, a.core.inventory.getItem(0).getType());
+            assertTrue(a.core.inventory.getItem(1) == null || a.core.inventory.getItem(1).isEmpty(),
+                "Exit restores the ordinary item that occupied the basic-stick slot");
+        }
+    }
+
+    private static final class MutableClock extends Clock {
+        private Instant now;
+        MutableClock(Instant now) { this.now = now; }
+        void advance(java.time.Duration duration) { now = now.plus(duration); }
+        @Override public ZoneId getZone() { return ZoneOffset.UTC; }
+        @Override public Clock withZone(ZoneId zone) { return this; }
+        @Override public Instant instant() { return now; }
+    }
+}

src/nativeTest/java/games/dmg/fantasystick/FantasyStickLifecycleNativeTest.java

@@ -63,6 +63,8 @@ class FantasyStickLifecycleNativeTest {
             assertEquals(3, fixture.timers.size(), "Presentation, combat-provenance cleanup and session particles");
             assertTrue(fixture.order.indexOf("PartyCombat") >= 0);
             assertTrue(fixture.order.indexOf("PartyCombat") < recipe);
+            assertTrue(fixture.order.indexOf("BasicAttack") >= 0);
+            assertTrue(fixture.order.indexOf("BasicAttack") < recipe);
             assertNotNull(fixture.command);
             assertEquals("EquipmentAdminCommand", fixture.command.getExecutor().getClass().getSimpleName());
             assertTrue(fixture.tasks.isEmpty());

src/test/java/games/dmg/fantasystick/combat/BasicAttackTest.java

@@ -0,0 +1,20 @@
+package games.dmg.fantasystick.combat;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.math.BigInteger;
+import org.junit.jupiter.api.Test;
+
+class BasicAttackTest {
+    @Test void followsTheApprovedStrengthFormulaWithoutAStatCap() {
+        assertEquals(BigInteger.ONE, BasicAttack.damage(BigInteger.ZERO));
+        assertEquals(BigInteger.ONE, BasicAttack.damage(BigInteger.TEN));
+        assertEquals(BigInteger.ONE, BasicAttack.damage(BigInteger.valueOf(11)));
+        assertEquals(BigInteger.ONE, BasicAttack.damage(BigInteger.valueOf(12)));
+        assertEquals(BigInteger.TWO, BasicAttack.damage(BigInteger.valueOf(14)));
+        var huge = BigInteger.TEN.pow(1000);
+        assertEquals(huge.subtract(BigInteger.TEN).divide(BigInteger.TWO), BasicAttack.damage(huge));
+        assertThrows(IllegalArgumentException.class, () -> BasicAttack.damage(BigInteger.valueOf(-1)));
+        assertThrows(NullPointerException.class, () -> BasicAttack.damage(null));
+    }
+}