/** Coin Madness: manual, sequential stages. All dates are UTC epoch milliseconds. */
export const PRODUCT = 'coin_madness';
export interface CoinConfig {
  enabled: boolean; approved: boolean; periodId: string; startsAt: number; endsAt: number;
  minLevel: number; priceCents: number; title: string;
  stages: Array<{ wins: number; coins: number }>;
}
export interface CoinState {
  config: CoinConfig; paidAt: number; orderNo: string; reservedOrder: string;
  stage: number; progress: number; lastLevel: number; settled: boolean;
}
export function parse<T>(value: any): T | null {
  try { return typeof value === 'string' ? JSON.parse(value) : value || null; } catch { return null; }
}
export function validConfig(raw: any): raw is CoinConfig {
  const integer = (n: any, min: number) => Number.isSafeInteger(n) && n >= min;
  return !!raw && raw.enabled === true && raw.approved === true
    && typeof raw.periodId === 'string' && /^[a-zA-Z0-9_-]{1,64}$/.test(raw.periodId)
    && integer(raw.startsAt, 1) && integer(raw.endsAt, raw.startsAt + 1)
    && integer(raw.minLevel, 0) && integer(raw.priceCents, 1)
    && typeof raw.title === 'string' && raw.title.length > 0 && raw.title.length <= 40
    && Array.isArray(raw.stages) && raw.stages.length > 0 && raw.stages.length <= 50
    && raw.stages.every((s: any) => integer(s.wins, 1) && integer(s.coins, 1))
    && Number.isSafeInteger(raw.stages.reduce((n: number, s: any) => n + s.coins, 0));
}
export function createState(config: CoinConfig, level: number): CoinState {
  return { config: JSON.parse(JSON.stringify(config)), paidAt: 0, orderNo: '', reservedOrder: '',
    stage: 0, progress: 0, lastLevel: level, settled: false };
}
export function active(state: CoinState, now: number): boolean {
  return !!state && now >= state.config.startsAt && now < state.config.endsAt && !state.settled;
}
export function win(state: CoinState, level: number, now: number, isVictory: boolean, infinite: boolean): CoinState {
  const next: CoinState = JSON.parse(JSON.stringify(state));
  if (!Number.isSafeInteger(level) || level <= next.lastLevel) return next;
  const singleNewLevel = level === next.lastLevel + 1;
  next.lastLevel = level; // Includes waiting-for-claim wins and syncs: never bank them.
  const target = next.config.stages[next.stage];
  if (active(next, now) && next.paidAt > 0 && now >= next.paidAt && target
    && isVictory && !infinite && singleNewLevel && next.progress < target.wins) next.progress++;
  return next;
}
export function reward(state: CoinState, now: number, expired: boolean): { state: CoinState; coins: number } {
  const next: CoinState = JSON.parse(JSON.stringify(state));
  if (expired ? now < next.config.endsAt : !active(next, now)) throw new Error('活动时间不允许此操作');
  const target = next.config.stages[next.stage];
  const coins = next.paidAt > 0 && !next.settled && target && next.progress >= target.wins ? target.coins : 0;
  if (!expired && !coins) throw new Error('当前阶段尚未达标');
  if (coins) { next.stage++; next.progress = 0; }
  if (expired) next.settled = true;
  return { state: next, coins };
}