/** @jest-environment node */

import {
  MATERIAL_UPLOAD_REQUEST_LIMITS,
  MaterialUploadRequestError,
  MaterialUploadRequestLimiter,
  validateMaterialUploadFormData,
  validateMaterialUploadRequestHeaders,
} from '@/lib/material-upload-request-guard'

type FakeFile = {
  name: string
  size: number
  arrayBuffer: () => Promise<ArrayBuffer>
}

function fakeFile(name: string, size: number): FakeFile {
  return {
    name,
    size,
    arrayBuffer: jest.fn(async () => new ArrayBuffer(0)),
  }
}

function fakeFormData(entries: Array<[string, string | FakeFile]>): FormData {
  return {
    entries: () => entries[Symbol.iterator](),
    get: (field: string) => entries.find(([key]) => key === field)?.[1] ?? null,
  } as unknown as FormData
}

function expectGuardError(action: () => unknown, status: number, code: string) {
  try {
    action()
    throw new Error('expected guard error')
  } catch (error) {
    expect(error).toBeInstanceOf(MaterialUploadRequestError)
    expect(error).toMatchObject({ status, code })
  }
}

describe('material upload request guard', () => {
  test('requires a bounded multipart Content-Length before parsing', () => {
    expectGuardError(
      () => validateMaterialUploadRequestHeaders(new Headers({
        'content-type': 'multipart/form-data; boundary=test',
      })),
      411,
      'CONTENT_LENGTH_REQUIRED',
    )

    expect(validateMaterialUploadRequestHeaders(new Headers({
      'content-length': String(MATERIAL_UPLOAD_REQUEST_LIMITS.maxRequestBytes),
      'content-type': 'multipart/form-data; boundary=test',
    }))).toBe(MATERIAL_UPLOAD_REQUEST_LIMITS.maxRequestBytes)

    expectGuardError(
      () => validateMaterialUploadRequestHeaders(new Headers({
        'content-length': String(MATERIAL_UPLOAD_REQUEST_LIMITS.maxRequestBytes + 1),
        'content-type': 'multipart/form-data; boundary=test',
      })),
      413,
      'UPLOAD_REQUEST_TOO_LARGE',
    )
  })

  test('forces a 5MB direct source file onto the chunk upload path', () => {
    const source = fakeFile('source.zip', 5 * 1024 * 1024)
    expectGuardError(
      () => validateMaterialUploadFormData(fakeFormData([['zipFile', source]])),
      413,
      'CHUNK_UPLOAD_REQUIRED',
    )
    expect(source.arrayBuffer).not.toHaveBeenCalled()
  })

  test('rejects excessive file counts and image field limits before decoding', () => {
    const tooMany = Array.from({ length: 51 }, (_, index) => (
      ['modelImages', fakeFile(`${index}.jpg`, 1)] as [string, FakeFile]
    ))
    expectGuardError(
      () => validateMaterialUploadFormData(fakeFormData(tooMany)),
      413,
      'TOO_MANY_UPLOAD_FILES',
    )

    expectGuardError(
      () => validateMaterialUploadFormData(fakeFormData([
        ['previewImage', fakeFile('cover.png', 8 * 1024 * 1024 + 1)],
      ])),
      413,
      'UPLOAD_FILE_TOO_LARGE',
    )

    expectGuardError(
      () => validateMaterialUploadFormData(fakeFormData([
        ['modelImages', fakeFile('gallery.jpg', 16 * 1024 * 1024 + 1)],
      ])),
      413,
      'UPLOAD_FILE_TOO_LARGE',
    )
  })

  test('allows an existing merged source with bounded image metadata request', () => {
    expect(() => validateMaterialUploadFormData(fakeFormData([
      ['existingFilePath', 'uploads/temp/upload-1/merged.mp4'],
      ['previewImage', fakeFile('cover.jpg', 1024)],
    ]))).not.toThrow()
  })
})

describe('material upload request limiter', () => {
  test('hands the only slot to one waiter and releases it on every completion', async () => {
    const limiter = new MaterialUploadRequestLimiter(1, 1)
    const releaseFirst = await limiter.acquire()
    const secondAcquire = limiter.acquire()

    expect(limiter.snapshot()).toEqual({ active: 1, waiting: 1 })
    await expect(limiter.acquire()).rejects.toMatchObject({
      status: 503,
      code: 'UPLOAD_BUSY',
      retryAfterSeconds: 3,
    })

    releaseFirst()
    const releaseSecond = await secondAcquire
    expect(limiter.snapshot()).toEqual({ active: 1, waiting: 0 })

    releaseSecond()
    releaseSecond()
    expect(limiter.snapshot()).toEqual({ active: 0, waiting: 0 })
  })
})