import { test } from 'node:test'
import assert from 'node:assert/strict'
import { useTaskProgressLoop } from '../src/shared/composables/useTaskProgressLoop.ts'
import {
  TASK_POLL_VISIBLE_INTERVAL_MS,
  getTaskPollBackoffMs,
} from '../src/shared/task-progress-config.ts'

const tick = (ms = 0) => new Promise<void>((r) => globalThis.setTimeout(r, ms))

interface SinkEntry {
  fn: () => void
  ms: number
  id: unknown
}

function setupWindow(sink?: SinkEntry[]) {
  const storage = new Map<string, string>()
  ;(globalThis as Record<string, unknown>).window = {
    localStorage: {
      getItem: (k: string) => storage.get(k) ?? null,
      setItem: (k: string, v: string) => { storage.set(k, v) },
      removeItem: (k: string) => { storage.delete(k) },
    },
    setTimeout: (fn: () => void, ms: number) => {
      const id = globalThis.setTimeout(fn, ms)
      sink?.push({ fn, ms, id })
      return id
    },
    clearTimeout: (id: unknown) => globalThis.clearTimeout(id as number),
    setInterval: (fn: () => void, ms: number) => globalThis.setInterval(fn, ms),
    clearInterval: (id: unknown) => globalThis.clearInterval(id as number),
  }
}

interface FakeDoc {
  setVisibility: (s: string) => void
  dispatch: () => void
}

function installFakeDocument(): FakeDoc {
  let state = 'visible'
  const listeners = new Map<string, Array<(e?: unknown) => void>>()
  ;(globalThis as Record<string, unknown>).document = {
    get visibilityState() { return state },
    get hidden() { return state !== 'visible' },
    addEventListener: (type: string, fn: (e?: unknown) => void) => {
      const arr = listeners.get(type) ?? []
      arr.push(fn)
      listeners.set(type, arr)
    },
    removeEventListener: (type: string, fn: (e?: unknown) => void) => {
      const arr = listeners.get(type) ?? []
      listeners.set(type, arr.filter((f) => f !== fn))
    },
  }
  return {
    setVisibility: (s) => { state = s },
    dispatch: () => { for (const fn of listeners.get('visibilitychange') ?? []) fn() },
  }
}

let scopeCounter = 0

type Item = { taskId?: number; status?: string }

interface SeqHarness {
  loop: ReturnType<typeof useTaskProgressLoop<Item>>
  attempts: number[]
  terminalCalls: Array<{ taskId: number; status: string }>
}

/** 顺序驱动的轮询循环：fetchImpl 依状态返回成功/失败；自动首轮会被吸收 */
function makeSequenceLoop(
  fetchImpl: () => Promise<{ items: Item[] }>,
  sink?: SinkEntry[],
): SeqHarness {
  setupWindow(sink)
  const attempts: number[] = []
  const terminalCalls: Array<{ taskId: number; status: string }> = []
  const loop = useTaskProgressLoop<Item>({
    scope: `recover-${scopeCounter++}`,
    fetchProgress: async () => fetchImpl(),
    extractTaskId: (d) => d?.taskId,
    extractStatus: (d) => d?.status,
    getIntervalMs: () => TASK_POLL_VISIBLE_INTERVAL_MS,
    onTerminal: (taskId, _d, status) => { terminalCalls.push({ taskId, status }) },
    onError: (_e, attempt) => { attempts.push(attempt ?? -1) },
  })
  loop.reset([1])
  return { loop, attempts, terminalCalls }
}

test('test_recovery_after_failure', async () => {
  let fail = true
  const h = makeSequenceLoop(async () => {
    if (fail) throw new Error('boom')
    return { items: [{ taskId: 1, status: 'SUCCESS' }] }
  })
  await tick(10)
  assert.equal(h.attempts.length, 1, '首轮自动轮询失败计入 attempt 0')
  fail = false
  await h.loop.refreshOnce()
  assert.equal(h.terminalCalls.length, 1, '失败后成功恢复触发终态')
  assert.equal(h.terminalCalls[0].status, 'SUCCESS')
  assert.deepEqual(h.loop.taskIds.value, [], '终态任务移除')
  h.loop.dispose()
})

test('test_backoff_reset_after_success', async () => {
  let mode: 'fail' | 'ok' = 'fail'
  const h = makeSequenceLoop(async () => {
    if (mode === 'fail') throw new Error('x')
    return { items: [] }
  })
  await tick(10)
  await h.loop.refreshOnce()
  mode = 'ok'
  await h.loop.refreshOnce()
  mode = 'fail'
  await h.loop.refreshOnce()
  assert.deepEqual(h.attempts, [0, 1, 0], '成功清零后下一次失败从 attempt 0 起')
  h.loop.dispose()
})

test('test_interval_returns_to_base', async () => {
  const sink: SinkEntry[] = []
  let fail = true
  const h = makeSequenceLoop(async () => {
    if (fail) throw new Error('x')
    return { items: [] }
  }, sink)
  await tick(10)
  assert.equal(h.attempts.length, 1, '首轮失败')
  assert.equal(sink.at(-1)?.ms, getTaskPollBackoffMs(1), '失败后按退避间隔续轮（后端故障时不再高频撞库）')
  fail = false
  // 手动触发下一轮自动轮询（模拟定时器到点；先清掉真实定时器避免僵尸 timer）
  const last = sink.at(-1) as SinkEntry
  globalThis.clearTimeout(last.id)
  last.fn()
  await tick(10)
  assert.equal(sink.at(-1)?.ms, TASK_POLL_VISIBLE_INTERVAL_MS, '成功后回到正常间隔')
  assert.equal(sink.some((e) => e.ms === getTaskPollBackoffMs(0)), false, '自动轮询阶段无 in-flight 重试定时器残留')
  h.loop.dispose()
})

test('test_recovery_cycle_repeat', async () => {
  let fail = true
  const h = makeSequenceLoop(async () => {
    if (fail) throw new Error('x')
    return { items: [] }
  })
  await tick(10)
  // 失败-成功 × 2，再失败
  fail = false
  await h.loop.refreshOnce()
  fail = true
  await h.loop.refreshOnce()
  fail = false
  await h.loop.refreshOnce()
  fail = true
  await h.loop.refreshOnce()
  assert.deepEqual(h.attempts, [0, 0, 0], '多次失败-成功循环每次从 attempt 0 重新起')
  h.loop.dispose()
})

test('test_recovery_partial_items', async () => {
  let fail = true
  const h = makeSequenceLoop(async () => {
    if (fail) throw new Error('x')
    return { items: [{ taskId: 1, status: 'RUNNING' }] }
  })
  await tick(10)
  fail = false
  await h.loop.refreshOnce()
  fail = true
  await h.loop.refreshOnce()
  assert.equal(h.loop.taskStatuses.value[1], 'RUNNING', '部分成功落地状态')
  assert.deepEqual(h.attempts, [0, 0], '有 items 的响应视为成功，计数归零')
  h.loop.dispose()
})

test('test_recovery_with_foreground', async () => {
  const doc = installFakeDocument()
  setupWindow()
  let fail = true
  const attempts: number[] = []
  const loop = useTaskProgressLoop<Item>({
    scope: `recover-fore-${scopeCounter++}`,
    fetchProgress: async () => {
      if (fail) throw new Error('x')
      return { items: [{ taskId: 1, status: 'RUNNING' }] }
    },
    extractTaskId: (d) => d?.taskId,
    extractStatus: (d) => d?.status,
    getIntervalMs: () => TASK_POLL_VISIBLE_INTERVAL_MS,
    onError: (_e, attempt) => { attempts.push(attempt ?? -1) },
  })
  loop.reset([1])
  await tick(10)
  assert.equal(attempts.length, 1, '可见状态下首轮失败')
  doc.setVisibility('hidden')
  fail = false
  doc.setVisibility('visible')
  doc.dispatch()
  await tick(20)
  assert.equal(loop.taskStatuses.value[1], 'RUNNING', '切回前台立即刷新并恢复成功')
  fail = true
  await loop.refreshOnce()
  assert.deepEqual(attempts, [0, 0], '前台恢复成功后计数归零')
  loop.dispose()
  delete (globalThis as Record<string, unknown>).document
})

test('test_recovery_after_many_failures', async () => {
  let fail = true
  const h = makeSequenceLoop(async () => {
    if (fail) throw new Error('x')
    return { items: [{ taskId: 1, status: 'SUCCESS' }] }
  })
  await tick(10)
  for (let i = 0; i < 7; i++) {
    await h.loop.refreshOnce()
  }
  assert.equal(h.attempts.length, 8, '连续失败累计 attempt')
  assert.deepEqual(h.attempts, [0, 1, 2, 3, 4, 5, 6, 7])
  fail = false
  await h.loop.refreshOnce()
  assert.equal(h.terminalCalls.length, 1, '长失败链后仍可恢复')
  assert.equal(h.terminalCalls[0].status, 'SUCCESS')
  // SUCCESS 后任务已移除；重新 add 再制造失败，验证计数重新从 0 起
  fail = true
  h.loop.add(1)
  await tick(10)
  assert.equal(h.attempts[8], 0, '恢复后重新从 0 起')
  h.loop.dispose()
})

test('test_recovery_timing_assert', async () => {
  // attempt → 退避延迟映射：500,1000,2000,4000,8000,封顶 10000
  const expected = [500, 1000, 2000, 4000, 8000, 10000, 10000]
  for (let i = 0; i < expected.length; i++) {
    assert.equal(getTaskPollBackoffMs(i), expected[i], `attempt ${i} 退避延迟`)
  }
  let fail = true
  const h = makeSequenceLoop(async () => {
    if (fail) throw new Error('x')
    return { items: [] }
  })
  await tick(10)
  await h.loop.refreshOnce()
  fail = false
  await h.loop.refreshOnce()
  fail = true
  await h.loop.refreshOnce()
  assert.deepEqual(h.attempts, [0, 1, 0], '观察到的 attempt 序列')
  assert.equal(getTaskPollBackoffMs(h.attempts[0]), 500, '失败从 500ms 起')
  assert.equal(getTaskPollBackoffMs(h.attempts[1]), 1000, '二次失败 1000ms')
  assert.equal(getTaskPollBackoffMs(h.attempts[2]), 500, '恢复后重新从 500ms 起')
  h.loop.dispose()
})