/** 고스톱 패 정보 (docs/games/gostop.md §3.1): 화투 48장 + 보너스패. */
import { HWATU, hwatuBonus } from '@bg/engine';

export type CardId = number;
export type CardKind = 'gwang' | 'yeol' | 'tti' | 'pi';
export type DanKind = 'hong' | 'cheong' | 'cho';

export interface CardInfo {
  id: CardId;
  /** 1..12, 0 for bonus cards. */
  month: number;
  kind: CardKind;
  /** 피 값: 일반 피 1, 쌍피 2, 2피 보너스 2, 3피 보너스 3, 그 밖 0. */
  piValue: 0 | 1 | 2 | 3;
  bi?: true;
  godori?: true;
  dan?: DanKind;
  gukjin?: true;
  bonus?: true;
  name: string;
}

export type BonusSetting = 'none' | '2+1' | '3+1';
export const BONUS_COUNT: Record<BonusSetting, number> = { none: 0, '2+1': 3, '3+1': 4 };

export const GUKJIN: CardId = 32;
export const BI_GWANG: CardId = 44;

function base(id: CardId): CardInfo {
  const c = HWATU[id]!;
  const kind: CardKind = c.kind === 'ssangpi' ? 'pi' : (c.kind as CardKind);
  const info: CardInfo = { id, month: c.month, kind, piValue: c.piValue as 0 | 1 | 2, name: c.name };
  if (c.tags.includes('rain')) info.bi = true;
  if (c.tags.includes('godori')) info.godori = true;
  if (c.tags.includes('gukjin')) {
    info.gukjin = true;
    info.name = '9월 열끗·국진(국화)';
  }
  if (c.tti && c.tti !== 'plain') info.dan = c.tti;
  return info;
}

const REGULAR: CardInfo[] = HWATU.map((c) => base(c.id));
const BONUS_TABLES: CardInfo[][] = [0, 1, 2, 3, 4].map((n) =>
  hwatuBonus(n).map((b) => ({ id: b.id, month: 0, kind: 'pi' as const, piValue: b.piValue as 2 | 3, bonus: true as const, name: b.name })),
);

/** Card info; `nb` = number of bonus cards in play (the last bonus id is the 3피). */
export function cardInfo(id: CardId, nb: number): CardInfo {
  if (id < 48) {
    const c = REGULAR[id];
    if (!c) throw new Error(`gostop: unknown card ${id}`);
    return c;
  }
  const c = BONUS_TABLES[nb]?.[id - 48];
  if (!c) throw new Error(`gostop: unknown bonus card ${id} (bonus ${nb})`);
  return c;
}

export const isBonus = (id: CardId): boolean => id >= 48;
export const monthOf = (id: CardId): number => (id >= 48 ? 0 : Math.floor(id / 4) + 1);

export function fullDeck(nb: number): CardId[] {
  return Array.from({ length: 48 + nb }, (_, i) => i);
}

/** Card value for automatic choices (§8.5): 광 > 열끗 > 띠 > 쌍피(피 값 2 이상) > 피. */
export function cardValue(id: CardId, nb: number): number {
  const c = cardInfo(id, nb);
  if (c.kind === 'gwang') return 5;
  if (c.kind === 'yeol') return 4;
  if (c.kind === 'tti') return 3;
  return c.piValue >= 2 ? 2 : 1;
}

/** Two floor cards of a month are interchangeable when kind and 피 값 are the same (§5.2). */
export function sameKind(a: CardId, b: CardId, nb: number): boolean {
  const x = cardInfo(a, nb);
  const y = cardInfo(b, nb);
  return x.kind === y.kind && x.piValue === y.piValue;
}

/** Best of two (or more) cards by value, ties → lower id. */
export function bestCard(ids: CardId[], nb: number): CardId {
  return [...ids].sort((a, b) => cardValue(b, nb) - cardValue(a, nb) || a - b)[0]!;
}

/** Display kind for the client (matches the shared HwatuCard component). */
export type ViewKind = 'gwang' | 'yeol' | 'tti' | 'pi' | 'ssangpi' | 'bonus';

export interface CardView {
  /** Unique per round so leak tests can spot hidden cards. */
  key: string;
  id: CardId;
  month: number;
  kind: ViewKind;
  tti?: 'hong' | 'cheong' | 'cho' | 'plain';
  name: string;
  piValue: number;
}

export function cardView(id: CardId, nb: number, keyPrefix: string): CardView {
  const c = cardInfo(id, nb);
  const kind: ViewKind = c.bonus ? 'bonus' : c.kind === 'pi' && c.piValue >= 2 ? 'ssangpi' : c.kind;
  const out: CardView = { key: `${keyPrefix}c${id}`, id, month: c.month, kind, name: c.name, piValue: c.piValue };
  if (c.kind === 'tti') out.tti = c.dan ?? 'plain';
  return out;
}