import { test } from 'node:test'
import assert from 'node:assert/strict'

// Vor dem Import von config.js setzen (jede Testdatei laeuft in einem eigenen Prozess)
process.env.ABO_TEST_EMAILS = 'test@example.invalid'
const { chargesFrom, redeemedDiscount } = await import('../server/services/offerDiscount.js')
const { adminOfferView } = await import('../server/services/offers.js')

test('Abbuchungen: vom Anker aus, Monatsende wie bei Stripe', () => {
  assert.deepEqual(chargesFrom('2026-09-26T08:00:00.000Z', '2026-09-26T08:00:00.000Z', 3), [
    '2026-09-26T08:00:00.000Z', '2026-10-26T08:00:00.000Z', '2026-11-26T08:00:00.000Z',
  ])
  // 31. bleibt Anker: Februar kuerzer, danach wieder der 31.
  assert.deepEqual(chargesFrom('2026-01-31T10:00:00.000Z', '2026-01-31T10:00:00.000Z', 4), [
    '2026-01-31T10:00:00.000Z', '2026-02-28T10:00:00.000Z', '2026-03-31T10:00:00.000Z', '2026-04-30T10:00:00.000Z',
  ])
  // Ab einem Zeitpunkt mitten im Abrechnungsmonat: naechste Abbuchung
  assert.deepEqual(chargesFrom('2026-01-15T10:00:00.000Z', '2026-03-20T12:00:00.000Z', 2), [
    '2026-04-15T10:00:00.000Z', '2026-05-15T10:00:00.000Z',
  ])
  assert.deepEqual(chargesFrom(null, '2026-03-20T12:00:00.000Z', 2), [])
})

test('Angebot beim Abschluss, Leistung sofort: Abbuchungen 1..N rabattiert', () => {
  const sub = { startedAt: '2026-09-26T08:00:00.000Z', trialEnd: null }
  const d = redeemedDiscount({ months: 2, appliedAt: '2026-09-26T08:00:05.000Z', attachedLater: false }, sub)
  assert.deepEqual(d, { known: true, firstChargeAt: '2026-09-26T08:00:00.000Z', endsAt: '2026-11-26T08:00:00.000Z', subscriptionEndsAt: null })
})

test('Angebot beim Abschluss, Beginn nach Widerrufsfrist: Rabatt ab Leistungsbeginn', () => {
  const sub = { startedAt: '2026-09-26T08:00:00.000Z', trialEnd: '2026-10-13T04:00:00.000Z' }
  const d = redeemedDiscount({ months: 2, appliedAt: '2026-09-26T08:00:05.000Z', attachedLater: false }, sub)
  assert.equal(d.firstChargeAt, '2026-10-13T04:00:00.000Z')
  assert.equal(d.endsAt, '2026-12-13T04:00:00.000Z')
})

test('Testkonto (Coupon nach der ersten Abbuchung): Abbuchungen 2..N+1', () => {
  const sub = { startedAt: '2026-09-26T08:00:00.000Z', trialEnd: null }
  const d = redeemedDiscount({ months: 2, appliedAt: '2026-09-26T08:00:05.000Z', attachedLater: true }, sub)
  assert.equal(d.firstChargeAt, '2026-10-26T08:00:00.000Z')
  assert.equal(d.endsAt, '2026-12-26T08:00:00.000Z')
})

test('Laufendes Abo: ab der naechsten Abbuchung nach dem Anhaengen', () => {
  const sub = { startedAt: '2026-03-14T09:00:00.000Z', trialEnd: null }
  const d = redeemedDiscount({ months: 2, appliedAt: '2026-09-26T20:00:00.000Z', attachedLater: true }, sub)
  assert.equal(d.firstChargeAt, '2026-10-14T09:00:00.000Z')
  assert.equal(d.endsAt, '2026-12-14T09:00:00.000Z')
})

test('Abo endet vor dem Rabatt: Abo-Ende wird gemeldet, sonst nicht', () => {
  const base = { startedAt: '2026-09-26T08:00:00.000Z', trialEnd: null }
  const offer = { months: 3, appliedAt: '2026-09-26T08:00:05.000Z', attachedLater: false }
  assert.equal(redeemedDiscount(offer, { ...base, cancelAt: '2026-10-26T08:00:00.000Z' }).subscriptionEndsAt, '2026-10-26T08:00:00.000Z')
  assert.equal(redeemedDiscount(offer, { ...base, endedAt: '2026-10-01T08:00:00.000Z' }).subscriptionEndsAt, '2026-10-01T08:00:00.000Z')
  assert.equal(redeemedDiscount(offer, { ...base, cancelAt: '2027-09-26T08:00:00.000Z' }).subscriptionEndsAt, null)
})

test('Ohne Abo-Dokument ist das Rabattende unbekannt', () => {
  assert.deepEqual(redeemedDiscount({ months: 2, appliedAt: '2026-09-26T08:00:05.000Z', attachedLater: false }, null), { known: false })
  assert.deepEqual(redeemedDiscount({ months: 2, appliedAt: null, attachedLater: true }, { startedAt: '2026-09-26T08:00:00.000Z' }), { known: false })
})

test('Admin-Ansicht: Rabatt nur bei eingeloesten Angeboten, Testkonto erkannt', () => {
  const doc = {
    $id: 'offer-1', $createdAt: '2026-09-26T07:00:00.000Z', status: 'aktiv', scope: 'neu', months: 2,
    monthlyPriceCents: 2500, regularPriceCents: 5000, validUntil: '2026-10-27T00:00:00.000Z',
    appliedAt: '2026-09-26T08:00:05.000Z', stripeSubscriptionId: 'sub_1', customerId: 'c1',
  }
  const sub = { $id: 'sub_1', startedAt: '2026-09-26T08:00:00.000Z', trialEnd: null }
  const normal = adminOfferView(doc, { name: 'Kunde', email: 'kunde@example.invalid' }, sub)
  assert.equal(normal.testAccount, false)
  assert.equal(normal.discount.endsAt, '2026-11-26T08:00:00.000Z')
  const testView = adminOfferView(doc, { name: 'Test', email: 'TEST@example.invalid' }, sub)
  assert.equal(testView.testAccount, true)
  assert.equal(testView.discount.endsAt, '2026-12-26T08:00:00.000Z')
  const running = adminOfferView({ ...doc, scope: 'laufend', appliedAt: '2026-10-01T12:00:00.000Z' }, { email: 'kunde@example.invalid' }, sub)
  assert.equal(running.discount.firstChargeAt, '2026-10-26T08:00:00.000Z')
  assert.equal(adminOfferView({ ...doc, status: 'offen', appliedAt: null }, { email: 'kunde@example.invalid' }, null).discount, null)
  assert.deepEqual(adminOfferView(doc, { email: 'kunde@example.invalid' }, undefined).discount, { known: false })
})