/** @jest-environment node */

import { mkdir, mkdtemp, readFile, readdir, rm, writeFile } from 'fs/promises'
import os from 'os'
import path from 'path'
import { NextRequest } from 'next/server'
import { getServerSession } from 'next-auth'

import { POST } from '@/app/api/materials/upload/complete/route'
import {
  mergeUploadChunksAtomically,
} from '@/lib/material-upload-merge'
import { MaterialUploadStorageReservationManager } from '@/lib/material-upload-storage-reservation'
import { cancelUploadSessionSeal } from '@/lib/material-upload-session-seal'
import {
  deleteUploadSession,
  getOwnedUploadSession,
} from '@/lib/upload-sessions'

jest.mock('next-auth', () => ({
  getServerSession: jest.fn(),
}))

jest.mock('@/lib/auth', () => ({ authOptions: {} }))

jest.mock('@/lib/upload-sessions', () => ({
  deleteUploadSession: jest.fn(),
  getOwnedUploadSession: jest.fn(),
  isSafeUploadId: jest.fn((uploadId: string) => /^upload-[A-Za-z0-9-]+$/.test(uploadId)),
}))

function completeRequest(uploadId = 'upload-test-1') {
  return new NextRequest('http://localhost/api/materials/upload/complete', {
    method: 'POST',
    headers: { 'content-type': 'application/json' },
    body: JSON.stringify({ uploadId, originalFileName: 'video.mp4' }),
  })
}

describe('material upload complete safety', () => {
  let uploadRoot: string
  const uploadId = 'upload-test-1'
  const fileName = 'video.mp4'
  const fileBytes = Buffer.from('abcdefgh')

  beforeEach(async () => {
    jest.clearAllMocks()
    uploadRoot = await mkdtemp(path.join(os.tmpdir(), 'material-complete-'))
    process.env.UPLOAD_DIR = uploadRoot
    ;(getServerSession as jest.Mock).mockResolvedValue({ user: { id: 'user-1' } })
    ;(getOwnedUploadSession as jest.Mock).mockResolvedValue({
      fileName,
      fileSize: fileBytes.length,
      totalChunks: 2,
      chunkSize: 4,
      chunks: new Map(),
      createdAt: Date.now(),
      userId: 'user-1',
    })
    ;(deleteUploadSession as jest.Mock).mockResolvedValue(undefined)

    const tempDir = path.join(uploadRoot, 'temp', uploadId)
    await mkdir(tempDir, { recursive: true })
    await writeFile(path.join(tempDir, 'meta.json'), '{}')
    await writeFile(path.join(tempDir, 'chunk-0'), fileBytes.subarray(0, 4))
    await writeFile(path.join(tempDir, 'chunk-1'), fileBytes.subarray(4))
  })

  afterEach(async () => {
    delete process.env.UPLOAD_DIR
    await rm(uploadRoot, { recursive: true, force: true })
  })

  test('首次成功响应丢失后，第二次 complete 幂等返回同一个完整文件', async () => {
    const firstResponse = await POST(completeRequest())
    const firstBody = await firstResponse.json()
    expect(firstResponse.status).toBe(200)
    expect(await readFile(firstBody.existingFilePath)).toEqual(fileBytes)
    await expect(readFile(path.join(uploadRoot, 'temp', uploadId, 'chunk-0')))
      .rejects.toMatchObject({ code: 'ENOENT' })

    const secondResponse = await POST(completeRequest())
    const secondBody = await secondResponse.json()
    expect(secondResponse.status).toBe(200)
    expect(secondBody.existingFilePath).toBe(firstBody.existingFilePath)
    expect(secondBody.fileSize).toBe(fileBytes.length)
    expect(await readFile(secondBody.existingFilePath)).toEqual(fileBytes)
  })

  test('cancelled 终态让 complete 结构化 fail-closed', async () => {
    await cancelUploadSessionSeal(uploadId)

    const response = await POST(completeRequest())
    const body = await response.json()

    expect(response.status).toBe(409)
    expect(body.code).toBe('UPLOAD_SESSION_CANCELLED')
    await expect(readFile(path.join(uploadRoot, 'temp', uploadId, 'chunk-0')))
      .resolves.toEqual(fileBytes.subarray(0, 4))
    expect(deleteUploadSession).not.toHaveBeenCalled()
  })

  test('合并前磁盘不足时 fail-closed 并返回可识别的 507 错误', async () => {
    const reservations = new MaterialUploadStorageReservationManager(
      100,
      async () => BigInt(1_000),
    )
    await expect(
      reservations.acquire(uploadRoot, 901),
    ).rejects.toMatchObject({
      status: 507,
      code: 'UPLOAD_STORAGE_LOW',
    })
  })

  test('合并预留会持续扣住额度，后续分片不能吃掉尚未写入的空间', async () => {
    const reservations = new MaterialUploadStorageReservationManager(
      100,
      async () => BigInt(1_000),
    )
    const releaseMerge = await reservations.acquire(uploadRoot, 700)
    expect(reservations.snapshot()).toEqual({ reservedBytes: BigInt(700) })

    await expect(reservations.acquire(uploadRoot, 201)).rejects.toMatchObject({
      status: 507,
      code: 'UPLOAD_STORAGE_LOW',
    })

    releaseMerge()
    const releaseChunk = await reservations.acquire(uploadRoot, 201)
    expect(reservations.snapshot()).toEqual({ reservedBytes: BigInt(201) })
    releaseChunk()
    expect(reservations.snapshot()).toEqual({ reservedBytes: BigInt(0) })
  })

  test('原子改名失败时删除本次 partial，不留下占盘半成品', async () => {
    const chunkPath = path.join(uploadRoot, 'chunk.bin')
    const occupiedOutputPath = path.join(uploadRoot, 'occupied-output')
    await writeFile(chunkPath, Buffer.from('safe'))
    await mkdir(occupiedOutputPath)

    await expect(mergeUploadChunksAtomically({
      chunks: [{ path: chunkPath, expectedBytes: 4 }],
      expectedTotalBytes: 4,
      outputPath: occupiedOutputPath,
    })).rejects.toBeTruthy()

    expect(
      (await readdir(uploadRoot)).filter((name) => name.startsWith('occupied-output.partial-')),
    ).toEqual([])
  })
})