import {
  type CorrelatedPayment,
  decideWebhookTransition,
  type WebhookTransitionInput,
} from './webhook-policy.ts'
import type { PayplePaymentLookupResult } from '../_shared/payple.ts'

function assert(condition: boolean, message: string): asserts condition {
  if (!condition) throw new Error(message)
}

function assertEquals(actual: unknown, expected: unknown, message: string): void {
  const a = JSON.stringify(actual)
  const e = JSON.stringify(expected)
  if (a !== e) throw new Error(`${message}: expected ${e}, got ${a}`)
}

const OLD_ORDER = 'D3RO-20260801090000-user-oid1'
const CURRENT_ORDER = 'D3RO-20260901090000-user-oid2'
const NOW = new Date('2026-09-15T00:00:00.000Z')

function correlated(overrides: Partial<CorrelatedPayment> = {}): CorrelatedPayment {
  return {
    user_id: '00000000-0000-4000-8000-000000000001',
    tier: 'pro',
    operation_id: '00000000-0000-4000-8000-0000000000aa',
    payer_id: 'payer-billing-key',
    current_order_id: CURRENT_ORDER,
    ...overrides,
  }
}

function lookup(orderId: string, overrides: Partial<PayplePaymentLookupResult> = {}): PayplePaymentLookupResult {
  return {
    PCD_PAY_RST: 'success',
    PCD_PAY_CODE: 'PCHK0000',
    PCD_PAY_MSG: 'ok',
    PCD_PAY_OID: orderId,
    PCD_PAY_TYPE: 'card',
    PCD_PAYER_ID: 'payer-billing-key',
    PCD_PAY_TOTAL: '9900',
    PCD_PAY_TIME: '20260901090000',
    ...overrides,
  }
}

function input(overrides: Partial<WebhookTransitionInput>): WebhookTransitionInput {
  return {
    kind: 'payment',
    orderId: CURRENT_ORDER,
    lookup: lookup(CURRENT_ORDER),
    correlated: correlated(),
    expectedAmount: 9900,
    now: NOW,
    ...overrides,
  }
}

Deno.test('payment of the current order grants the correlated tier for one period', () => {
  const decision = decideWebhookTransition(input({}))
  assert(decision.kind === 'apply', `expected apply, got ${decision.kind}`)
  assertEquals(decision.amount, 9900, 'amount')
  const args = decision.args
  assertEquals(args.p_event_id, `payment:${CURRENT_ORDER}`, 'event id')
  assertEquals(args.p_event_type, 'payment.completed', 'event type')
  assertEquals(args.p_entitled, true, 'entitled')
  assertEquals(args.p_tier, 'pro', 'tier')
  assertEquals(args.p_status, 'active', 'status')
  assertEquals(args.p_auto_renewing, true, 'auto renewing')
  assertEquals(args.p_provider_order_id, CURRENT_ORDER, 'order id')
  assertEquals(args.p_provider_resource_id, 'payer-billing-key', 'resource id')
  // 20260901090000 KST = 2026-09-01T00:00:00Z
  assertEquals(args.p_event_created_at, '2026-09-01T00:00:00.000Z', 'event time is payment time')
  assertEquals(args.p_current_period_start, '2026-09-01T00:00:00.000Z', 'period start')
  assertEquals(args.p_current_period_end, '2026-10-01T00:00:00.000Z', 'period end')
  assertEquals(args.p_cancel_at, null, 'no cancel_at')
})

Deno.test('payment of an older registered order is still applied (ordering is the RPC cursor)', () => {
  const decision = decideWebhookTransition(input({
    orderId: OLD_ORDER,
    lookup: lookup(OLD_ORDER, { PCD_PAY_TIME: '20260801090000' }),
  }))
  assert(decision.kind === 'apply', 'payments are not order-scoped')
})

Deno.test('payment whose reconciled amount differs from the tier price is rejected', () => {
  for (const total of ['29900', 'not-a-number', undefined]) {
    const decision = decideWebhookTransition(input({
      lookup: lookup(CURRENT_ORDER, { PCD_PAY_TOTAL: total }),
    }))
    assertEquals(decision, { kind: 'reject', status: 422, error: 'payment_amount_mismatch' }, `total ${total}`)
  }
  const unpricedTier = decideWebhookTransition(input({ expectedAmount: undefined }))
  assertEquals(unpricedTier.kind, 'reject', 'tier without a price cannot be paid')
})

Deno.test('lookup payer different from the correlated payer is rejected', () => {
  const decision = decideWebhookTransition(input({
    lookup: lookup(CURRENT_ORDER, { PCD_PAYER_ID: 'payer-other' }),
  }))
  assertEquals(decision, { kind: 'reject', status: 401, error: 'payment_owner_mismatch' }, 'owner')
})

Deno.test('cancellation not confirmed by the Payple lookup is rejected', () => {
  for (const state of [undefined, '승인완료']) {
    const decision = decideWebhookTransition(input({
      kind: 'cancellation',
      lookup: lookup(CURRENT_ORDER, { PCD_PAY_STATE: state }),
    }))
    assertEquals(decision, { kind: 'reject', status: 409, error: 'cancellation_not_confirmed' }, `state ${state}`)
  }
})

Deno.test('confirmed cancellation of the current order revokes entitlement now', () => {
  for (const state of ['승인취소완료', 'canceled']) {
    const decision = decideWebhookTransition(input({
      kind: 'cancellation',
      lookup: lookup(CURRENT_ORDER, { PCD_PAY_STATE: state, PCD_PAY_TOTAL: '1' }),
    }))
    assert(decision.kind === 'apply', `expected apply for ${state}`)
    const args = decision.args
    assertEquals(args.p_event_id, `cancel:${CURRENT_ORDER}:${state}`, 'event id')
    assertEquals(args.p_event_type, 'webhook.payment_canceled', 'event type')
    assertEquals(args.p_entitled, false, 'not entitled')
    assertEquals(args.p_tier, 'free', 'tier')
    assertEquals(args.p_status, 'canceled', 'status')
    assertEquals(args.p_auto_renewing, false, 'auto renewing')
    assertEquals(args.p_event_created_at, NOW.toISOString(), 'event time is now')
    assertEquals(args.p_current_period_start, null, 'period start untouched')
    assertEquals(args.p_current_period_end, NOW.toISOString(), 'period ends now')
    assertEquals(args.p_cancel_at, NOW.toISOString(), 'cancel_at now')
    assertEquals(args.p_provider_order_id, CURRENT_ORDER, 'order id')
  }
})

Deno.test('confirmed cancellation of an older order is ignored and keeps the paid period', () => {
  const decision = decideWebhookTransition(input({
    kind: 'cancellation',
    orderId: OLD_ORDER,
    lookup: lookup(OLD_ORDER, { PCD_PAY_STATE: '승인취소완료', PCD_PAY_TIME: '20260801090000' }),
  }))
  assertEquals(decision, {
    kind: 'ignore',
    reason: 'canceled_order_not_current',
    eventId: `cancel:${OLD_ORDER}:승인취소완료`,
    eventCreatedAt: NOW.toISOString(),
    eventType: 'webhook.payment_canceled',
    providerResourceId: 'payer-billing-key',
  }, 'old order refund must not revoke the current subscription')
})

Deno.test('confirmed cancellation while no current order is on record is ignored', () => {
  const decision = decideWebhookTransition(input({
    kind: 'cancellation',
    correlated: correlated({ current_order_id: null }),
    lookup: lookup(CURRENT_ORDER, { PCD_PAY_STATE: '승인취소완료' }),
  }))
  assertEquals(decision.kind, 'ignore', 'fail safe: unknown current order never revokes')
})