import { PLANS, type PlanId } from "./usageMeter";

export type PlanRightsCopy = {
  headline: string;
  /** 比價卡上 4～5 條短權益 */
  bullets: string[];
  /** 結帳頁：你會得到 */
  rights: string[];
  /** 結帳頁：額度 */
  quota: string[];
  notes: string[];
};

type TFn = (key: string, params?: Record<string, string | number>) => string;

/** 購買／比價用文案（用量首頁不堆字）— 由 i18n keys 組成 */
export function getPlanRights(id: PlanId, t: TFn): PlanRightsCopy {
  const p = PLANS[id];
  const caps = {
    copy: p.soft_caps.ai_copy,
    research: p.soft_caps.ai_research,
    search: p.soft_caps.web_search,
    image: p.soft_caps.ai_image,
  };
  return {
    headline: t(`plan.${id}.headline`),
    bullets: [
      t(`plan.${id}.bullet1`, { n: p.monthly_credits }),
      t(`plan.${id}.bullet2`),
      t(`plan.${id}.bullet3`),
      t(`plan.${id}.bullet4`),
    ],
    rights: [
      t(`plan.${id}.right1`),
      t(`plan.${id}.right2`),
      t(`plan.${id}.right3`),
    ],
    quota: [
      t(`plan.${id}.quota1`, { n: p.monthly_credits, price: p.price_label }),
      t(`plan.${id}.quota2`, caps),
    ],
    notes: [t(`plan.${id}.note1`), t(`plan.${id}.note2`)],
  };
}

export function planCtaLabel(current: PlanId, target: PlanId, t: TFn): string {
  if (current === target) return t("plan.cta.current");
  const order: PlanId[] = ["free", "starter", "pro"];
  const a = order.indexOf(current);
  const b = order.indexOf(target);
  if (b > a) return t("plan.cta.upgrade");
  if (b < a) return t("plan.cta.downgrade");
  return t("plan.cta.switch");
}