import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { clearMobRuntimeRegistry, setMobPosition } from "./mobRuntimeRegistry";
import { clearPartyRuntimeRegistry, registerPartyRuntimePosition } from "./partyRuntimeRegistry";
import { installCombatClock } from "./combatClock";
import { createDeathKnightRunes } from "./combatActors";
import { useCombatStore, PLAYER_AURA_ENTITY_ID } from "./combatStore";
import { usePartyStore } from "./partyStore";
import { talentNodesForTree } from "./talentCatalog";

let now = 1_000;
let restoreClock: (() => void) | undefined;

function ability(name: string) {
  const found = useCombatStore.getState().abilities.find((candidate) => candidate.name === name);
  if (!found) throw new Error("Missing Death Knight ability: " + name);
  return found;
}

function learnActiveAbility(name: string) {
  const found = ability(name);
  if (found.talentNodeId) {
    useCombatStore.setState((state) => ({
      talentRanks: { ...state.talentRanks, [found.talentNodeId!]: 1 },
    }));
  }
  return found;
}

function registerTarget(id = "dk-target", position: readonly [number, number, number] = [2, 0, 0]) {
  useCombatStore.getState().registerMob(id, { name: id, maxHealth: 1_000_000, xpReward: 0 });
  setMobPosition(id, position);
  useCombatStore.getState().selectMob(id);
}

function selectPartyMember(index = 0, raceId: "undead" | "human" = "human") {
  const initial = usePartyStore.getState().members[index];
  if (!initial) throw new Error("Expected a party member for the Death Knight test.");
  usePartyStore.setState((state) => ({
    members: state.members.map((member) => member.id === initial.id
      ? { ...member, raceId, health: 1 }
      : member),
  }));
  registerPartyRuntimePosition(initial.id, [2, 0, 0]);
  usePartyStore.getState().selectMember(initial.id);
  return initial.id;
}

function setButchery(rank: number, runicPower = 0) {
  const node = talentNodesForTree("death-knight-blood").find((candidate) => candidate.name === "Butchery");
  if (!node) throw new Error("Missing Death Knight Butchery talent.");
  useCombatStore.setState((state) => ({
    talentRanks: { ...state.talentRanks, [node.id]: rank },
    resource: runicPower,
    resourcePools: { ...state.resourcePools, "runic-power": runicPower },
  }));
}

function registerXpTarget(id: string, xpReward: number) {
  useCombatStore.getState().registerMob(id, { name: id, maxHealth: 1, xpReward });
  setMobPosition(id, [2, 0, 0]);
}

describe("Death Knight source-backed runtime mechanics", () => {
  beforeEach(() => {
    now = 1_000;
    restoreClock = installCombatClock(() => now);
    clearMobRuntimeRegistry();
    clearPartyRuntimeRegistry();
    useCombatStore.getState().initializeCharacter({ classId: "death-knight", level: 80, xp: 0 });
    useCombatStore.setState({ resource: 100, resourcePools: { "runic-power": 100 } });
    usePartyStore.getState().initializeParty("death-knight-source-runtime", 80,
      useCombatStore.getState().health, "tank", 5);
  });

  afterEach(() => {
    restoreClock?.();
    restoreClock = undefined;
  });

  it("heals a friendly Undead with Death Coil and rejects a living ally", () => {
    const allyId = selectPartyMember(0, "human");
    const deathCoil = ability("Death Coil");
    const rejected = useCombatStore.getState().castAbility(deathCoil.id, {
      targetActorId: allyId,
      now,
    });
    expect(rejected).toMatchObject({ ok: false, reason: "condition-not-met" });

    usePartyStore.setState((state) => ({
      members: state.members.map((member) => member.id === allyId
        ? { ...member, raceId: "undead" }
        : member),
    }));
    now = 3_000;
    const healed = useCombatStore.getState().castAbility(deathCoil.id, {
      targetActorId: allyId,
      now,
    });
    expect(healed.ok).toBe(true);
    expect(healed.healing).toBeGreaterThan(0);
    expect(usePartyStore.getState().members.find((member) => member.id === allyId)!.health).toBeGreaterThan(1);
  });

  it("uses Death Coil's damaging branch against a hostile living target", () => {
    registerTarget();
    const deathCoil = ability("Death Coil");
    const attempts = [1_000, 3_000, 5_000].map((castAt) => {
      now = castAt;
      useCombatStore.setState({ resource: 100, resourcePools: { "runic-power": 100 } });
      return useCombatStore.getState().castAbility(deathCoil.id, { now });
    });
    expect(attempts.every((result) => result.ok)).toBe(true);
    expect(attempts.some((result) => result.damage > 0)).toBe(true);
    expect(attempts.every((result) => result.healing === 0)).toBe(true);
  });

  it("absorbs three quarters of magical damage up to half of maximum health", () => {
    const shell = ability("Anti-Magic Shell");
    expect(useCombatStore.getState().castAbility(shell.id, { now }).ok).toBe(true);
    const aura = useCombatStore.getState().auras.find((candidate) => candidate.targetId === PLAYER_AURA_ENTITY_ID
      && candidate.definition.name === "Anti-Magic Shell");
    expect(aura?.absorbs[0]).toMatchObject({
      remaining: Math.round(useCombatStore.getState().maxHealth * 0.5),
      fraction: 0.75,
      schools: ["holy", "fire", "nature", "frost", "shadow", "arcane"],
    });

    now += 1;
    expect(useCombatStore.getState().damagePlayer(100, "fire")).toBe(25);
    expect(useCombatStore.getState().auras.find((candidate) => candidate.instanceId === aura!.instanceId)
      ?.absorbs[0].remaining).toBe(Math.round(useCombatStore.getState().maxHealth * 0.5) - 75);
  });

  it("blocks harmful magic controls during Anti-Magic Shell while allowing physical controls", () => {
    const shell = ability("Anti-Magic Shell");
    expect(useCombatStore.getState().castAbility(shell.id, { now }).ok).toBe(true);
    const addControlAttacker = (id: string, school: "shadow" | "physical") => {
      useCombatStore.getState().registerMob(id, {
        name: id,
        maxHealth: 1_000,
        xpReward: 0,
        attacks: [{
          id: `${id}-stun`,
          name: "Stunning attack",
          delivery: "projectile",
          target: "primary",
          school,
          animation: "attack",
          range: 30,
          cooldownMs: 1_000,
          damageMultiplier: 0,
          effect: { kind: "control", mechanic: "stun", durationMs: 5_000 },
        }],
      });
      setMobPosition(id, [2, 0, 0]);
      useCombatStore.getState().damageMob(id, 1, now);
      return useCombatStore.getState().mobs[id].nextAttackAt;
    };

    const magicReadyAt = addControlAttacker("magic-stun", "shadow");
    useCombatStore.getState().advanceMobCombat(magicReadyAt, [0, 0, 0]);
    expect(useCombatStore.getState().mobs["magic-stun"].attackRevision).toBe(1);
    expect(useCombatStore.getState().controlledUntil).toBe(0);

    const physicalReadyAt = addControlAttacker("physical-stun", "physical");
    useCombatStore.getState().advanceMobCombat(physicalReadyAt, [0, 0, 0]);
    expect(useCombatStore.getState().mobs["physical-stun"].attackRevision).toBe(1);
    expect(useCombatStore.getState().controlledUntil).toBeGreaterThan(physicalReadyAt);
  });

  it("places Anti-Magic Zone at the selected point and protects party members within 10 yards", () => {
    const inRangeAlly = selectPartyMember(0, "human");
    const outOfRangeAlly = usePartyStore.getState().members[1].id;
    usePartyStore.setState((state) => ({
      members: state.members.map((member) => ({ ...member, health: 1 })),
    }));
    registerPartyRuntimePosition(inRangeAlly, [5, 0, 0]);
    registerPartyRuntimePosition(outOfRangeAlly, [11, 0, 0]);
    const antiMagicZone = learnActiveAbility("Anti-Magic Zone");
    const cast = useCombatStore.getState().castAbility(antiMagicZone.id, {
      now,
      groundPosition: [0, 0, 0],
    });

    expect(cast.ok).toBe(true);
    expect(useCombatStore.getState().summons).toContainEqual(expect.objectContaining({
      creatureId: 28306,
      position: [0, 0, 0],
      expiresAt: now + 10_000,
      antiMagicZone: expect.objectContaining({ radius: 10, absorbFraction: 0.75 }),
    }));
    const partyAuras = useCombatStore.getState().auras.filter((aura) => (
      aura.definition.utilityTags?.includes("wow335-death-knight-anti-magic-zone")
    ));
    expect(partyAuras.map((aura) => aura.targetId)).toEqual(expect.arrayContaining([
      PLAYER_AURA_ENTITY_ID,
      inRangeAlly,
    ]));
    expect(partyAuras.map((aura) => aura.targetId)).not.toContain(outOfRangeAlly);
    expect(partyAuras.find((aura) => aura.targetId === inRangeAlly)?.absorbs[0]).toMatchObject({
      remaining: expect.any(Number),
      fraction: 0.75,
      schools: ["holy", "fire", "nature", "frost", "shadow", "arcane"],
    });
    expect(partyAuras.find((aura) => aura.targetId === inRangeAlly)!.absorbs[0].remaining).toBeGreaterThan(10_000);

    expect(useCombatStore.getState().damagePlayer(100, "fire")).toBe(25);
    expect(useCombatStore.getState().damagePlayer(100, "physical")).toBe(100);

    registerPartyRuntimePosition(inRangeAlly, [11, 0, 0]);
    now += 250;
    useCombatStore.getState().tick(0.25, now);
    expect(useCombatStore.getState().auras.some((aura) => aura.targetId === inRangeAlly
      && aura.definition.utilityTags?.includes("wow335-death-knight-anti-magic-zone"))).toBe(false);
  });

  it("spends Bone Shield's four charges on landed damage while keeping its reduction non-stacking", () => {
    const boneShield = learnActiveAbility("Bone Shield");
    const boneCast = useCombatStore.getState().castAbility(boneShield.id, { now });
    expect(boneCast.reason).toBeUndefined();
    expect(boneCast.ok).toBe(true);
    const auraId = useCombatStore.getState().auras.find((aura) => aura.definition.name === "Bone Shield")!.instanceId;

    for (const remaining of [3, 2, 1]) {
      now += 1;
      expect(useCombatStore.getState().damagePlayer(10, "fire")).toBe(8);
      expect(useCombatStore.getState().auras.find((aura) => aura.instanceId === auraId)?.stacks).toBe(remaining);
    }
    now += 1;
    expect(useCombatStore.getState().damagePlayer(10, "fire")).toBe(8);
    expect(useCombatStore.getState().auras.some((aura) => aura.instanceId === auraId)).toBe(false);
    now += 1;
    expect(useCombatStore.getState().damagePlayer(10, "fire")).toBe(10);
  });

  it("converts exactly one spent Blood Rune for Blood Tap without activating a Frost Rune", () => {
    const initialRunes = createDeathKnightRunes().map((rune) => (
      rune.slot === 0 || rune.slot === 2 ? { ...rune, readyAt: now + 10_000 } : rune
    ));
    useCombatStore.setState({ deathKnightRunes: initialRunes });
    const bloodTap = ability("Blood Tap");
    expect(useCombatStore.getState().castAbility(bloodTap.id, { now }).ok).toBe(true);

    const runes = useCombatStore.getState().deathKnightRunes;
    expect(runes.filter((rune) => rune.type === "death")).toEqual([
      expect.objectContaining({ slot: 0, baseType: "blood", readyAt: now, deathRuneExpiresAt: now + 20_000 }),
    ]);
    expect(runes.find((rune) => rune.slot === 2)).toMatchObject({ type: "frost", readyAt: now + 10_000 });
    expect(runes.filter((rune) => rune.readyAt <= now)).toHaveLength(5);
  });

  it("consumes Deathchill only on Icy Touch, Howling Blast, Frost Strike, or Obliterate", () => {
    registerTarget();
    const deathchill = learnActiveAbility("Deathchill");
    expect(useCombatStore.getState().castAbility(deathchill.id, { now }).ok).toBe(true);
    const auraId = useCombatStore.getState().auras.find((aura) => (
      aura.definition.utilityTags?.includes("wow335-deathchill-next-critical")
    ))!.instanceId;

    now = 3_000;
    expect(useCombatStore.getState().castAbility(ability("Chains of Ice").id, { now }).ok).toBe(true);
    expect(useCombatStore.getState().auras.some((aura) => aura.instanceId === auraId)).toBe(true);

    now = 5_000;
    const icyTouch = ability("Icy Touch");
    expect(useCombatStore.getState().castAbility(icyTouch.id, { now }).ok).toBe(true);
    expect(useCombatStore.getState().auras.some((aura) => aura.instanceId === auraId)).toBe(false);
    expect(useCombatStore.getState().combatEvents.some((event) => (
      event.abilityId === icyTouch.id && event.kind === "damage" && event.critical
    ))).toBe(true);
  });

  it("heals Death Strike for five percent of maximum health per active disease", () => {
    registerTarget();
    const icyTouch = ability("Icy Touch");
    const plagueStrike = ability("Plague Strike");
    const deathStrike = ability("Death Strike");
    expect(useCombatStore.getState().castAbility(icyTouch.id, { now }).ok).toBe(true);
    now = 3_000;
    useCombatStore.setState((state) => ({ ...state, health: 1 }));
    const oneDisease = useCombatStore.getState().castAbility(deathStrike.id, { now });
    expect(oneDisease.ok).toBe(true);
    expect(oneDisease.healing).toBeGreaterThan(0);

    now = 5_000;
    expect(useCombatStore.getState().castAbility(plagueStrike.id, { now }).ok).toBe(true);
    useCombatStore.setState((state) => ({
      ...state,
      health: 1,
      deathKnightRunes: createDeathKnightRunes(now),
    }));
    now = 7_000;
    const twoDiseases = useCombatStore.getState().castAbility(deathStrike.id, { now });
    expect(twoDiseases.ok).toBe(true);
    expect(twoDiseases.healing).toBeGreaterThan(oneDisease.healing);
    expect(twoDiseases.healing).toBeCloseTo(oneDisease.healing * 2, -1);
  });

  it.each([
    { rank: 1, expectedRunicPower: 10 },
    { rank: 2, expectedRunicPower: 20 },
  ])("grants Butchery rank $rank's runic power on an eligible player kill", ({ rank, expectedRunicPower }) => {
    const targetId = `butchery-rank-${rank}`;
    registerXpTarget(targetId, 1_000);
    setButchery(rank);

    const result = useCombatStore.getState().damageMob(targetId, 10, now);

    expect(result.killed).toBe(true);
    expect(useCombatStore.getState().resource).toBe(expectedRunicPower);
    expect(useCombatStore.getState().resourcePools["runic-power"]).toBe(expectedRunicPower);
  });

  it("caps Butchery at the runic power maximum", () => {
    const targetId = "butchery-cap-target";
    registerXpTarget(targetId, 1_000);
    setButchery(2, 95);

    useCombatStore.getState().damageMob(targetId, 10, now);

    expect(useCombatStore.getState().resource).toBe(100);
    expect(useCombatStore.getState().resourcePools["runic-power"]).toBe(100);
  });

  it("does not grant Butchery without the talent or for a target with no XP reward", () => {
    const noTalentTargetId = "butchery-no-talent-target";
    registerXpTarget(noTalentTargetId, 1_000);
    setButchery(0);
    useCombatStore.getState().damageMob(noTalentTargetId, 10, now);
    expect(useCombatStore.getState().resourcePools["runic-power"]).toBe(0);

    const noXpTargetId = "butchery-no-xp-target";
    registerXpTarget(noXpTargetId, 0);
    setButchery(2);
    useCombatStore.getState().damageMob(noXpTargetId, 10, now + 1);
    expect(useCombatStore.getState().resourcePools["runic-power"]).toBe(0);
  });

  it("does not grant Butchery for a party or pet killing blow", () => {
    setButchery(2);
    const partyActorId = usePartyStore.getState().members[0].id;
    for (const [targetId, actorId] of [
      ["butchery-party-target", partyActorId],
      ["butchery-pet-target", "butchery-test-pet"],
    ] as const) {
      registerXpTarget(targetId, 1_000);
      useCombatStore.getState().damageMob(targetId, 10, now, {
        actorId,
        role: "damage",
        abilityId: "test-non-player-kill",
      });
    }

    expect(useCombatStore.getState().resourcePools["runic-power"]).toBe(0);
  });

  it("applies Improved Rune Tap's rank-specific healing and cooldown reductions", () => {
    useCombatStore.setState((state) => ({
      ...state,
      health: 1,
      talentRanks: { ...state.talentRanks, "talent-1941": 1 },
    }));
    const runeTap = ability("Rune Tap");
    const baseline = useCombatStore.getState().castAbility(runeTap.id, { now });
    expect(baseline.ok).toBe(true);
    now = 3_000;
    useCombatStore.setState((state) => ({
      ...state,
      health: 1,
      cooldowns: {},
      deathKnightRunes: createDeathKnightRunes(now),
      talentRanks: { ...state.talentRanks, "talent-1942": 3 },
    }));
    const improved = useCombatStore.getState().castAbility(runeTap.id, { now });
    expect(improved.ok).toBe(true);
    expect(improved.healing).toBeCloseTo(baseline.healing * 2, -1);
    expect(useCombatStore.getState().cooldowns[runeTap.id]).toBe(now + 30_000);
  });
});