import type { TalentModifier } from "./talentModifiers";
import { WOW335_TALENT_NODES } from "./wow335Talents.generated";

export const WOW335_DRUID_MASTER_SHAPESHIFTER_TALENT_ID = "talent-1915";

export type Wow335DruidShapeshiftForm = "bear" | "cat" | "moonkin" | "tree-of-life";

const masterShapeshifterTalent = WOW335_TALENT_NODES.find(
  (talent) => talent.id === WOW335_DRUID_MASTER_SHAPESHIFTER_TALENT_ID,
) ?? (() => {
  throw new Error(`Generated Druid talent ${WOW335_DRUID_MASTER_SHAPESHIFTER_TALENT_ID} is missing`);
})();

function normalizedRank(rank: number): number {
  return Number.isFinite(rank)
    ? Math.max(0, Math.min(masterShapeshifterTalent.rankDescriptions.length, Math.trunc(rank)))
    : 0;
}

/**
 * The generated rank tooltip has a separate bonus for each shapeshift form.
 * Return only the active form's modifier so the clauses cannot leak globally.
 */
export function wow335DruidMasterShapeshifterModifiersForForm(
  rank: number,
  form: Wow335DruidShapeshiftForm | null,
): readonly TalentModifier[] {
  const normalized = normalizedRank(rank);
  if (normalized <= 0 || !form) return [];
  const description = masterShapeshifterTalent.rankDescriptions[normalized - 1] ?? "";
  const clauses = {
    bear: {
      pattern: /Bear Form\s*-\s*Increases physical damage by\s+(\d+(?:\.\d+)?)%/i,
      kind: "damage-percent" as const,
      scope: "physical damage",
    },
    cat: {
      pattern: /Cat Form\s*-\s*Increases melee critical strike chance by\s+(\d+(?:\.\d+)?)%/i,
      kind: "critical-chance-percent" as const,
      scope: "melee critical strike chance",
    },
    moonkin: {
      pattern: /Moonkin Form\s*-\s*Increases Arcane and Nature damage by\s+(\d+(?:\.\d+)?)%/i,
      kind: "damage-percent" as const,
      scope: "Arcane and Nature damage",
    },
    "tree-of-life": {
      pattern: /Tree of Life Form\s*-\s*Increases healing by\s+(\d+(?:\.\d+)?)%/i,
      kind: "healing-percent" as const,
      scope: "healing",
    },
  } as const;
  const clause = clauses[form];
  const amount = Number(description.match(clause.pattern)?.[1] ?? 0);
  if (!Number.isFinite(amount) || amount <= 0) return [];

  return [{
    kind: clause.kind,
    amount,
    unit: "percent",
    scope: clause.scope,
    sourceTalentId: WOW335_DRUID_MASTER_SHAPESHIFTER_TALENT_ID,
    sourceTalentName: "Master Shapeshifter",
    rank: normalized,
    description,
  }];
}

/** Resolve the stock WoW shapeshift spell IDs used by the active aura runtime. */
export function wow335DruidShapeshiftFormForSpellId(spellId: number): Wow335DruidShapeshiftForm | null {
  switch (spellId) {
    case 5487: // Bear Form
    case 9634: // Dire Bear Form
      return "bear";
    case 768: // Cat Form
      return "cat";
    case 24858: // Moonkin Form
      return "moonkin";
    case 33891: // Tree of Life
    case 65139: // Generated Tree of Life form row
      return "tree-of-life";
    default:
      return null;
  }
}

/** Extract a form from the canonical aura IDs written by generated WoW forms. */
export function wow335DruidShapeshiftFormForAuraId(auraId: string): Wow335DruidShapeshiftForm | null {
  const spellId = auraId.match(/^wow335:(\d+):/)?.[1];
  return spellId === undefined ? null : wow335DruidShapeshiftFormForSpellId(Number(spellId));
}

/** Find an active generated shapeshift aura on the requested actor. */
export function wow335DruidShapeshiftFormForAuras(
  auras: readonly {
    readonly definition: { readonly id: string };
    readonly targetId: string;
    readonly expiresAt: number | null;
  }[],
  actorId: string,
  now: number,
): Wow335DruidShapeshiftForm | null {
  const matching = auras
    .filter((aura) => aura.targetId === actorId && (aura.expiresAt === null || aura.expiresAt > now))
    .map((aura) => wow335DruidShapeshiftFormForAuraId(aura.definition.id))
    .filter((form): form is Wow335DruidShapeshiftForm => form !== null);
  // Normally the aura system removes the previous form. Taking the most recent
  // active form also makes stale imported form auras deterministic.
  return matching.at(-1) ?? null;
}