import { describe, it, expect } from 'vitest'
import {
  evaluateEpisodeQuota,
  evaluateContinueQuota,
  priceForUnlock,
  day_window_start,
} from '../src/quota.js'

const rules = {
  free_episodes: 3,
  free_continue_per_day: 2,
  prices: { episode: 30, branch: 50, ending: 80, continue: 5 },
}

describe('quota: 前 N 集免费分界', () => {
  it('第 1..N 集免费，价 0', () => {
    for (let ep = 1; ep <= 3; ep++) {
      const r = evaluateEpisodeQuota({ rules, episode_number: ep })
      expect(r.free).toBe(true)
      expect(r.price_points).toBe(0)
    }
  })
  it('第 N+1 集起收费，价为 episode 价目', () => {
    const r = evaluateEpisodeQuota({ rules, episode_number: 4 })
    expect(r.free).toBe(false)
    expect(r.price_points).toBe(30)
    expect(r.free_quota_left).toBe(0)
  })
  it('free_episodes 缺省=0 时第 1 集即收费', () => {
    const r = evaluateEpisodeQuota({ rules: { prices: { episode: 9 } }, episode_number: 1 })
    expect(r.free).toBe(false)
    expect(r.price_points).toBe(9)
  })
})

describe('quota: 每日 K 次免费续写耗尽后转收费 + 窗口重置', () => {
  it('未用满 K 次免费', () => {
    const r = evaluateContinueQuota({ rules, used_today: 0 })
    expect(r.free).toBe(true)
    expect(r.free_quota_left).toBe(2)
  })
  it('用到第 K 次仍剩 1 次时免费', () => {
    expect(evaluateContinueQuota({ rules, used_today: 1 }).free).toBe(true)
  })
  it('用满 K 次后转收费', () => {
    const r = evaluateContinueQuota({ rules, used_today: 2 })
    expect(r.free).toBe(false)
    expect(r.price_points).toBe(5)
    expect(r.free_quota_left).toBe(0)
  })
  it('窗口起点是 UTC 当日 0 点（窗口重置依据）', () => {
    const w = day_window_start(new Date('2026-06-15T13:22:00Z'))
    expect(w).toEqual(new Date('2026-06-15T00:00:00.000Z'))
  })
})

describe('quota: branch/ending 解锁价目', () => {
  it('branch/ending 取对应价目', () => {
    expect(priceForUnlock({ rules, kind: 'branch' }).price_points).toBe(50)
    expect(priceForUnlock({ rules, kind: 'ending' }).price_points).toBe(80)
  })
})