import { test } from 'node:test'
import assert from 'node:assert/strict'
import {
  isRetryableStatus,
  deleteWithRetry,
  runWithConcurrency,
} from '../delete-utils.js'

const noSleep = () => Promise.resolve()

test('isRetryableStatus 僅對暫時性狀態碼回傳 true', () => {
  for (const s of [429, 502, 503, 504]) assert.equal(isRetryableStatus(s), true)
  for (const s of [200, 204, 400, 401, 403, 404, 500]) {
    assert.equal(isRetryableStatus(s), false)
  }
})

test('deleteWithRetry 成功(204)時不重試', async () => {
  let calls = 0
  const client = {
    async deleteResource() {
      calls += 1
      return 204
    },
  }
  const result = await deleteWithRetry(client, 'u', { sleep: noSleep })
  assert.equal(result.status, 204)
  assert.equal(calls, 1)
})

test('deleteWithRetry 對暫時性錯誤重試後成功', async () => {
  const statuses = [503, 503, 204]
  let i = 0
  const client = {
    async deleteResource() {
      return statuses[i++]
    },
  }
  const result = await deleteWithRetry(client, 'u', { sleep: noSleep })
  assert.equal(result.status, 204)
  assert.equal(result.attempts, 3)
})

test('deleteWithRetry 對永久性錯誤(403)立即停止重試', async () => {
  let calls = 0
  const client = {
    async deleteResource() {
      calls += 1
      return 403
    },
  }
  const result = await deleteWithRetry(client, 'u', { sleep: noSleep })
  assert.equal(result.status, 403)
  assert.equal(calls, 1)
})

test('deleteWithRetry 對網路例外重試至次數用盡並回傳 error', async () => {
  let calls = 0
  const client = {
    async deleteResource() {
      calls += 1
      throw new Error('network down')
    },
  }
  const result = await deleteWithRetry(client, 'u', { attempts: 3, sleep: noSleep })
  assert.equal(result.status, 0)
  assert.match(result.error.message, /network down/)
  assert.equal(calls, 3)
})

test('runWithConcurrency 回傳對應輸入順序的結果', async () => {
  const items = [1, 2, 3, 4, 5]
  const out = await runWithConcurrency(items, async (n) => n * 2, 2)
  assert.deepEqual(out, [2, 4, 6, 8, 10])
})

test('runWithConcurrency 不超過併發上限', async () => {
  let active = 0
  let maxActive = 0
  const items = Array.from({ length: 10 }, (_, i) => i)
  await runWithConcurrency(
    items,
    async () => {
      active += 1
      maxActive = Math.max(maxActive, active)
      await Promise.resolve()
      active -= 1
    },
    3,
  )
  assert.ok(maxActive <= 3, `maxActive=${maxActive} 應 <= 3`)
})

test('runWithConcurrency 對空陣列回傳空陣列', async () => {
  const out = await runWithConcurrency([], async () => 1, 4)
  assert.deepEqual(out, [])
})