export type EquipmentCategory = 'straight' | 'curve' | 'crush';
export type ShopTab = 'all' | EquipmentCategory;

export interface EquipmentDef {
  id: string;
  category: EquipmentCategory;
  /** UI에 보이는 영어 이름 */
  name: string;
  /** 별 개수. 기본 장비는 0 */
  price: number;
  isDefault: boolean;
}

const CATEGORIES: readonly EquipmentCategory[] = ['straight', 'curve', 'crush'];

const def = (id: string, category: EquipmentCategory, name: string, price: number): EquipmentDef =>
  ({ id, category, name, price, isDefault: price === 0 });

/** 스펙 표 순서이자 상점 정렬 순서(분류 → 기본 먼저 → 가격 오름차순 → 표 순서)다. */
export const EQUIPMENT: readonly EquipmentDef[] = [
  def('kitchen-knife', 'straight', 'Kitchen Knife', 0),
  def('cleaver', 'straight', 'Cleaver', 30),
  def('carrot-knife', 'straight', 'Carrot Knife', 40),
  def('katana', 'straight', 'Katana', 50),
  def('fantasy-dagger', 'straight', 'Fantasy Dagger', 50),
  def('laser-sword', 'straight', 'Laser Sword', 80),
  def('scalpel', 'curve', 'Scalpel', 0),
  def('pizza-cutter', 'curve', 'Pizza Cutter', 30),
  def('fountain-pen', 'curve', 'Fountain Pen', 30),
  def('mini-ufo', 'curve', 'Mini UFO', 50),
  def('magic-wand', 'curve', 'Magic Wand', 50),
  def('piston-press', 'crush', 'Piston Press', 0),
  def('robot-fist', 'crush', 'Robot Fist', 30),
  def('marshmallow-hammer', 'crush', 'Marshmallow Hammer', 40),
  def('cat-paw', 'crush', 'Cat Paw', 50),
];

export const DEFAULT_EQUIPMENT: Record<EquipmentCategory, string> = {
  straight: 'kitchen-knife',
  curve: 'scalpel',
  crush: 'piston-press',
};

/** 보유·장착을 단일 객체로 저장한다. 보유한 별 소비량은 보유 목록에서 계산한다. */
export interface EquipmentSave {
  version: 1;
  owned: string[];
  equipped: Record<EquipmentCategory, string>;
}

export function equipmentDef(id: string): EquipmentDef | undefined {
  return EQUIPMENT.find(d => d.id === id);
}

export function sanitizeEquipment(value: unknown): EquipmentSave {
  const raw = value && typeof value === 'object' && !Array.isArray(value) ? value as Record<string, unknown> : {};
  const rawOwned = Array.isArray(raw.owned) ? raw.owned : [];
  const owned = [...new Set([
    ...Object.values(DEFAULT_EQUIPMENT),
    ...rawOwned.filter((id): id is string => typeof id === 'string' && equipmentDef(id) !== undefined),
  ])];
  const rawEquipped = raw.equipped && typeof raw.equipped === 'object' && !Array.isArray(raw.equipped)
    ? raw.equipped as Record<string, unknown> : {};
  const equipped = { ...DEFAULT_EQUIPMENT };
  for (const category of CATEGORIES) {
    const id = rawEquipped[category];
    if (typeof id === 'string' && owned.includes(id) && equipmentDef(id)?.category === category) equipped[category] = id;
  }
  return { version: 1, owned, equipped };
}

export function spentStars(save: EquipmentSave): number {
  return save.owned.reduce((sum, id) => sum + (equipmentDef(id)?.price ?? 0), 0);
}

export function starBalance(earned: number, save: EquipmentSave): number {
  return Math.max(0, earned - spentStars(save));
}

export type ShopState = 'equipped' | 'owned' | 'affordable' | 'locked';

export function shopState(save: EquipmentSave, balance: number, id: string): ShopState {
  if (Object.values(save.equipped).includes(id)) return 'equipped';
  if (save.owned.includes(id)) return 'owned';
  return balance >= (equipmentDef(id)?.price ?? Infinity) ? 'affordable' : 'locked';
}

export function shopItems(tab: ShopTab): EquipmentDef[] {
  return EQUIPMENT.filter(d => tab === 'all' || d.category === tab);
}

/** 미보유이고 잔액이 충분하면 보유에 더하고 그 분류에 장착한 새 저장을, 아니면 null을 돌려준다. */
export function buyEquipment(save: EquipmentSave, earned: number, id: string): EquipmentSave | null {
  const item = equipmentDef(id);
  if (!item || item.isDefault || save.owned.includes(id)) return null;
  if (starBalance(earned, save) < item.price) return null;
  return {
    version: 1,
    owned: [...save.owned, id],
    equipped: { ...save.equipped, [item.category]: id },
  };
}

export function equipEquipment(save: EquipmentSave, id: string): EquipmentSave | null {
  const item = equipmentDef(id);
  if (!item || !save.owned.includes(id)) return null;
  return { version: 1, owned: [...save.owned], equipped: { ...save.equipped, [item.category]: id } };
}