healer-man/src/game/mobAi.test.ts

import { describe, expect, it } from "vitest";
import {
  DEFAULT_BOSS_COMBAT_PROFILE,
  DEFAULT_MOB_COMBAT_PROFILE,
  canMobMove,
  canMobSwing,
  createMobCombatProfile,
  firstMobSwingAt,
  isMobInAttackRange,
  isMobOutsideLeash,
  mobMovementSpeed,
  mobMovementSpeedMultiplier,
  mobSwingIntervalMultiplier,
  moveMobToward,
  nextMobSwingAt,
  planarDistanceSquared,
  resolveMobAiTransition,
  type MobAiStatus,
} from "./mobAi";

const home = [0, 0, 0] as const;
const normal = createMobCombatProfile({ level: 1 });

function transition(overrides: Partial<Parameters<typeof resolveMobAiTransition>[0]> = {}) {
  return resolveMobAiTransition({
    phase: "idle",
    dead: false,
    engaged: false,
    playerAlive: true,
    position: home,
    homePosition: home,
    targetPosition: [10, 0, 0],
    profile: normal,
    ...overrides,
  });
}

describe("mob combat profiles", () => {
  it("scales damage by level and provides larger boss reach and leash", () => {
    const mob = createMobCombatProfile({ level: 4 });
    const boss = createMobCombatProfile({ boss: true, level: 4 });
    expect(mob.attackDamage).toBe(12);
    expect(boss.attackDamage).toBe(20);
    expect(boss.attackRange).toBeGreaterThan(mob.attackRange);
    expect(boss.leashRange).toBeGreaterThan(mob.leashRange);
    expect(DEFAULT_MOB_COMBAT_PROFILE.attackDamage).toBe(6);
    expect(DEFAULT_BOSS_COMBAT_PROFILE.attackDamage).toBe(14);
  });

  it("clamps malformed overrides without mutating exported defaults", () => {
    const profile = createMobCombatProfile({
      level: Number.NaN,
      overrides: {
        chaseSpeed: -5,
        swingIntervalMs: 0,
        attackDamage: Number.NaN,
        leashRange: 12,
      },
    });
    expect(profile).toMatchObject({ chaseSpeed: 0, swingIntervalMs: 1, attackDamage: 6, leashRange: 12 });
    expect(DEFAULT_MOB_COMBAT_PROFILE.chaseSpeed).toBe(3.25);
  });
});

describe("mob AI phase transitions", () => {
  it("does not aggro from proximity without an explicit engagement", () => {
    expect(transition({ targetPosition: [1, 0, 0] }).phase).toBe("idle");
  });

  it("chases an engaged distant target and attacks only inside reach with line of sight", () => {
    expect(transition({ engaged: true }).phase).toBe("chasing");
    expect(transition({ engaged: true, targetPosition: [3, 0, 0] }).phase).toBe("attacking");
    expect(transition({ engaged: true, targetPosition: [3, 0, 0], lineOfSight: false }).phase).toBe("chasing");
  });

  it("returns when the target dies, disappears, or crosses the leash", () => {
    expect(transition({ engaged: true, playerAlive: false }).phase).toBe("returning");
    expect(transition({ engaged: true, targetPosition: null }).phase).toBe("returning");
    expect(transition({ engaged: true, targetPosition: [normal.leashRange + 1, 0, 0] }).phase).toBe("returning");
    expect(transition({ engaged: true, position: [normal.leashRange + 1, 0, 0] }).phase).toBe("returning");
  });

  it("keeps an evading mob returning until home, then requests one reset", () => {
    const returning = transition({
      phase: "returning",
      engaged: false,
      position: [4, 0, 0],
      targetPosition: null,
    });
    expect(returning).toMatchObject({ phase: "returning", clearThreat: true, restoreAtHome: false, cancelSwing: true });

    const homeResult = transition({
      phase: "returning",
      engaged: false,
      position: [normal.returnTolerance / 2, 0, 0],
      targetPosition: null,
    });
    expect(homeResult).toMatchObject({ phase: "idle", clearThreat: true, restoreAtHome: true });
  });

  it("makes death terminal until an explicit alive/reset state is supplied", () => {
    expect(transition({ phase: "attacking", dead: true, engaged: true }).phase).toBe("dead");
    expect(transition({ phase: "dead", dead: false, engaged: true }).phase).toBe("idle");
  });
});

describe("mob ranges and status modifiers", () => {
  const active = (kind: MobAiStatus["kind"], magnitude?: number): MobAiStatus => ({
    kind,
    endsAt: 5_000,
    ...(magnitude === undefined ? {} : { magnitude }),
  });

  it("uses planar reach plus a separate vertical tolerance", () => {
    expect(planarDistanceSquared([0, 0, 0], [3, 20, 4])).toBe(25);
    expect(isMobInAttackRange([0, 0, 0], [3, 1, 3], normal)).toBe(true);
    expect(isMobInAttackRange([0, 0, 0], [3, normal.attackHeightTolerance + 1, 3], normal)).toBe(false);
    expect(isMobOutsideLeash([0, 0, 0], [normal.leashRange + 1, 0, 0], home, normal)).toBe(true);
  });

  it("blocks directed movement for stun, root, and fear but lets expired controls lapse", () => {
    for (const kind of ["stun", "root", "fear"] as const) {
      expect(mobMovementSpeedMultiplier([active(kind)], 1_000)).toBe(0);
      expect(canMobMove("chasing", false, [active(kind)], 1_000)).toBe(false);
    }
    expect(mobMovementSpeedMultiplier([{ kind: "root", endsAt: 999 }], 1_000)).toBe(1);
  });

  it("uses the strongest slow and scales chase/return speeds", () => {
    const statuses = [active("slow", 0.25), active("slow", 0.5)];
    expect(mobMovementSpeedMultiplier(statuses, 1_000)).toBe(0.5);
    expect(mobMovementSpeed(normal, "chasing", statuses, 1_000)).toBeCloseTo(normal.chaseSpeed * 0.5);
    expect(mobMovementSpeed(normal, "returning", [], 1_000)).toBe(normal.returnSpeed);
    expect(mobMovementSpeed(normal, "attacking", [], 1_000)).toBe(0);
  });

  it("converts attack-speed reduction into a longer swing interval", () => {
    const statuses = [active("attack-speed", 0.2)];
    expect(mobSwingIntervalMultiplier(statuses, 1_000)).toBeCloseTo(1.25);
    expect(nextMobSwingAt(1_000, normal, statuses)).toBe(3_000);
    expect(firstMobSwingAt(1_000, normal)).toBe(2_600);
  });

  it("allows a rooted melee swing but rejects stun, fear, range, height, LOS, and early timers", () => {
    const base = {
      phase: "attacking" as const,
      dead: false,
      engaged: true,
      playerAlive: true,
      targetAvailable: true,
      distanceToTarget: normal.attackRange,
      verticalDistance: 0,
      lineOfSight: true,
      now: 2_000,
      nextSwingAt: 2_000,
      profile: normal,
    };
    expect(canMobSwing({ ...base, statuses: [active("root")] })).toBe(true);
    expect(canMobSwing({ ...base, statuses: [active("stun")] })).toBe(false);
    expect(canMobSwing({ ...base, statuses: [active("fear")] })).toBe(false);
    expect(canMobSwing({ ...base, distanceToTarget: normal.attackRange + 0.01 })).toBe(false);
    expect(canMobSwing({ ...base, verticalDistance: normal.attackHeightTolerance + 0.01 })).toBe(false);
    expect(canMobSwing({ ...base, lineOfSight: false })).toBe(false);
    expect(canMobSwing({ ...base, now: 1_999 })).toBe(false);
  });
});

describe("mob steering", () => {
  it("moves into caller-owned storage without overshooting", () => {
    const out: [number, number, number] = [99, 99, 99];
    expect(moveMobToward([0, 0, 0], [3, 4, 0], 2, out)).toBe(false);
    expect(out[0]).toBeCloseTo(1.2);
    expect(out[1]).toBeCloseTo(1.6);
    expect(out[2]).toBe(0);
    expect(moveMobToward(out, [3, 4, 0], 10, out)).toBe(true);
    expect(out).toEqual([3, 4, 0]);
  });

  it("contains malformed coordinates instead of poisoning scene transforms", () => {
    const out: [number, number, number] = [0, 0, 0];
    expect(moveMobToward([Number.NaN, 2, 3], [5, 6, 7], 1, out)).toBe(false);
    expect(out).toEqual([0, 2, 3]);
    expect(planarDistanceSquared([0, 0, 0], [Number.NaN, 0, 0])).toBe(Number.POSITIVE_INFINITY);
  });
});