Update combat orchestration for multiplayer turns

startTurn resets energy/block for all players and draws 5 cards each,
also resets playersReady. resolveEnemyTurn iterates all enemies,
resets each enemy's block, and has each enemy act against player 0.
checkCombatEnd checks all enemies (victory) and any player (defeat).

src/combat.js

@@ -5,51 +5,76 @@ import { drawCards } from "./state.js";
 
 export function startTurn(state) {
   const dieResult = rollDie();
+
+  // reset energy and block for all players
+  const players = state.players.map((p) => ({
+    ...p,
+    energy: p.maxEnergy,
+    block: 0,
+  }));
+
   let next = {
     ...state,
-    player: {
+    players,
-      ...state.player,
+    // keep compat alias in sync
-      energy: state.player.maxEnergy,
+    player: players[0],
-      block: 0,
-    },
     combat: {
       ...state.combat,
       phase: "player_turn",
       dieResult,
       selectedCard: null,
+      playersReady: [],
     },
   };
-  next = drawCards(next, 5);
+
+  // draw 5 cards for each player
+  for (let i = 0; i < next.players.length; i++) {
+    next = drawCards(next, i, 5);
+  }
+
   return next;
 }
 
 export function resolveEnemyTurn(state) {
-  let next = {
+  // reset block on all enemies before they act
-    ...state,
+  const enemies = state.enemies.map((e) => ({ ...e, block: 0 }));
-    enemy: { ...state.enemy, block: 0 },
+  let next = { ...state, enemies, enemy: enemies[0] };
-  };
 
-  const action = resolveEnemyAction(
+  // each enemy acts; enemies target player 0 by default
-    next.enemy,
+  for (let i = 0; i < next.enemies.length; i++) {
-    next.combat.dieResult,
+    const enemy = next.enemies[i];
-    next.enemy.trackPosition,
+    const action = resolveEnemyAction(
-  );
+      enemy,
-
+      next.combat.dieResult,
-  if (action?.effects) {
+      enemy.trackPosition,
-    next = resolveEffects(next, action.effects, "enemy", "player");
-  }
-
-  let trackPosition = next.enemy.trackPosition;
-  if (next.enemy.actionType === "cube") {
-    trackPosition = Math.min(
-      trackPosition + 1,
-      (next.enemy.actionTrack || []).length - 1,
     );
+
+    if (action?.effects) {
+      // TODO: implement enemy targeting logic for multiplayer (random, lowest HP, etc.)
+      next = resolveEffects(
+        next,
+        action.effects,
+        { type: "enemy", index: i },
+        { type: "player", index: 0 },
+      );
+    }
+
+    // advance cube track for this enemy if applicable
+    if (enemy.actionType === "cube") {
+      const trackPosition = Math.min(
+        enemy.trackPosition + 1,
+        (enemy.actionTrack || []).length - 1,
+      );
+      const updatedEnemy = { ...next.enemies[i], trackPosition };
+      const updatedEnemies = next.enemies.map((e, j) =>
+        j === i ? updatedEnemy : e,
+      );
+      next = { ...next, enemies: updatedEnemies, enemy: updatedEnemies[0] };
+    }
   }
 
   return {
     ...next,
-    enemy: { ...next.enemy, trackPosition },
     combat: {
       ...next.combat,
       phase: "player_turn",
@@ -59,7 +84,7 @@ export function resolveEnemyTurn(state) {
 }
 
 export function checkCombatEnd(state) {
-  if (state.enemy.hp <= 0) return "victory";
+  if (state.enemies.every((e) => e.hp <= 0)) return "victory";
-  if (state.player.hp <= 0) return "defeat";
+  if (state.players.some((p) => p.hp <= 0)) return "defeat";
   return null;
 }

src/combat.test.js

@@ -49,13 +49,15 @@ describe("resolveEnemyTurn", () => {
 describe("checkCombatEnd", () => {
   test("returns 'victory' when enemy hp is 0", () => {
     let state = createCombatState("ironclad", "jaw_worm");
-    state = { ...state, enemy: { ...state.enemy, hp: 0 } };
+    const deadEnemy = { ...state.enemies[0], hp: 0 };
+    state = { ...state, enemy: deadEnemy, enemies: [deadEnemy] };
     expect(checkCombatEnd(state)).toBe("victory");
   });
 
   test("returns 'defeat' when player hp is 0", () => {
     let state = createCombatState("ironclad", "jaw_worm");
-    state = { ...state, player: { ...state.player, hp: 0 } };
+    const deadPlayer = { ...state.players[0], hp: 0 };
+    state = { ...state, player: deadPlayer, players: [deadPlayer] };
     expect(checkCombatEnd(state)).toBe("defeat");
   });
 
@@ -64,3 +66,81 @@ describe("checkCombatEnd", () => {
     expect(checkCombatEnd(state)).toBeNull();
   });
 });
+
+describe("startTurn - multiplayer", () => {
+  test("resets energy and block for all players, draws 5 each", () => {
+    let state = createCombatState(["ironclad", "ironclad"], ["jaw_worm"]);
+    state = {
+      ...state,
+      players: state.players.map((p) => ({ ...p, energy: 0, block: 5 })),
+    };
+    const next = startTurn(state);
+    expect(next.players[0].energy).toBe(3);
+    expect(next.players[0].block).toBe(0);
+    expect(next.players[0].hand).toHaveLength(5);
+    expect(next.players[1].energy).toBe(3);
+    expect(next.players[1].block).toBe(0);
+    expect(next.players[1].hand).toHaveLength(5);
+  });
+
+  test("playersReady resets on startTurn", () => {
+    let state = createCombatState(["ironclad", "ironclad"], ["jaw_worm"]);
+    state = {
+      ...state,
+      combat: { ...state.combat, playersReady: [0, 1] },
+    };
+    const next = startTurn(state);
+    expect(next.combat.playersReady).toEqual([]);
+  });
+});
+
+describe("resolveEnemyTurn - multiplayer", () => {
+  test("all enemies act, block resets for each", () => {
+    let state = createCombatState(["ironclad"], ["jaw_worm", "jaw_worm"]);
+    state = {
+      ...state,
+      enemies: state.enemies.map((e) => ({ ...e, block: 3 })),
+      combat: { ...state.combat, dieResult: 1 },
+    };
+    const next = resolveEnemyTurn(state);
+    // die result 1 is defend (3 hit + 1 block), so block resets then gains 1
+    expect(next.enemies[0].block).toBe(1);
+    expect(next.enemies[1].block).toBe(1);
+    expect(next.combat.turn).toBe(state.combat.turn + 1);
+  });
+});
+
+describe("checkCombatEnd - multiplayer", () => {
+  test("victory when all enemies at 0 hp", () => {
+    let state = createCombatState(["ironclad"], ["jaw_worm", "jaw_worm"]);
+    state = {
+      ...state,
+      enemies: state.enemies.map((e) => ({ ...e, hp: 0 })),
+    };
+    expect(checkCombatEnd(state)).toBe("victory");
+  });
+
+  test("no victory if only one enemy at 0 hp", () => {
+    let state = createCombatState(["ironclad"], ["jaw_worm", "jaw_worm"]);
+    state = {
+      ...state,
+      enemies: [
+        { ...state.enemies[0], hp: 0 },
+        { ...state.enemies[1], hp: 5 },
+      ],
+    };
+    expect(checkCombatEnd(state)).toBeNull();
+  });
+
+  test("defeat when any player at 0 hp", () => {
+    let state = createCombatState(["ironclad", "ironclad"], ["jaw_worm"]);
+    state = {
+      ...state,
+      players: [
+        { ...state.players[0], hp: 0 },
+        { ...state.players[1], hp: 11 },
+      ],
+    };
+    expect(checkCombatEnd(state)).toBe("defeat");
+  });
+});

src/state.js

@@ -185,6 +185,8 @@ export function endTurn(state, playerIndex) {
     };
   }
 
+  if (state.combat.playersReady.includes(playerIndex)) return state;
+
   const player = state.players[playerIndex];
   const updatedPlayer = {
     ...player,

src/state.test.js

@@ -217,4 +217,12 @@ describe("endTurn - indexed player", () => {
     expect(next.combat.phase).toBe("enemy_turn");
     expect(next.combat.playersReady).toHaveLength(2);
   });
+
+  test("calling endTurn twice for the same player does not add duplicate to playersReady", () => {
+    let state = createCombatState(["ironclad", "ironclad"], ["jaw_worm"]);
+    state = endTurn(state, 0);
+    const next = endTurn(state, 0);
+    expect(next.combat.playersReady).toHaveLength(1);
+    expect(next.combat.phase).toBe("player_turn");
+  });
 });