import { describe, it, expect, vi, beforeEach } from 'vitest'

const { mockMkdir, mockWriteFile, mockUnlink } = vi.hoisted(() => ({
  mockMkdir: vi.fn().mockResolvedValue(undefined),
  mockWriteFile: vi.fn().mockResolvedValue(undefined),
  mockUnlink: vi.fn().mockResolvedValue(undefined),
}))

vi.mock('fs/promises', () => ({
  __esModule: true,
  default: { mkdir: mockMkdir, writeFile: mockWriteFile, unlink: mockUnlink },
  mkdir: mockMkdir,
  writeFile: mockWriteFile,
  unlink: mockUnlink,
}))

import { saveImage, validateImageMagicBytes, deleteImageFile } from '@/lib/storage'

function makeJpegBuffer(): Buffer {
  const b = Buffer.alloc(12)
  b[0] = 0xff; b[1] = 0xd8; b[2] = 0xff
  return b
}

function makePngBuffer(): Buffer {
  const b = Buffer.alloc(12)
  b[0] = 0x89; b[1] = 0x50; b[2] = 0x4e; b[3] = 0x47
  return b
}

function makeWebpBuffer(): Buffer {
  const b = Buffer.alloc(12)
  b[0] = 0x52; b[1] = 0x49; b[2] = 0x46; b[3] = 0x46
  b[8] = 0x57; b[9] = 0x45; b[10] = 0x42; b[11] = 0x50
  return b
}

function makeIcoBuffer(): Buffer {
  const b = Buffer.alloc(12)
  b[0] = 0x00; b[1] = 0x00; b[2] = 0x01; b[3] = 0x00
  return b
}

function makeFileFromBuffer(buf: Buffer, type: string): File {
  return new File([new Uint8Array(buf)], 'test.img', { type })
}

beforeEach(() => {
  vi.clearAllMocks()
  mockMkdir.mockResolvedValue(undefined)
  mockWriteFile.mockResolvedValue(undefined)
  mockUnlink.mockResolvedValue(undefined)
})

// ─── validateImageMagicBytes ──────────────────────────────────────────────────

describe('validateImageMagicBytes', () => {
  it('accepts a valid JPEG', async () => {
    const file = makeFileFromBuffer(makeJpegBuffer(), 'image/jpeg')
    expect(await validateImageMagicBytes(file, 'image/jpeg')).toBe(true)
  })

  it('accepts a valid PNG', async () => {
    const file = makeFileFromBuffer(makePngBuffer(), 'image/png')
    expect(await validateImageMagicBytes(file, 'image/png')).toBe(true)
  })

  it('accepts a valid WebP', async () => {
    const file = makeFileFromBuffer(makeWebpBuffer(), 'image/webp')
    expect(await validateImageMagicBytes(file, 'image/webp')).toBe(true)
  })

  it('accepts a valid ICO', async () => {
    const file = makeFileFromBuffer(makeIcoBuffer(), 'image/x-icon')
    expect(await validateImageMagicBytes(file, 'image/x-icon')).toBe(true)
  })

  it('rejects JPEG buffer declared as PNG', async () => {
    const file = makeFileFromBuffer(makeJpegBuffer(), 'image/png')
    expect(await validateImageMagicBytes(file, 'image/png')).toBe(false)
  })

  it('rejects unknown MIME type', async () => {
    const file = makeFileFromBuffer(makeJpegBuffer(), 'image/bmp')
    expect(await validateImageMagicBytes(file, 'image/bmp')).toBe(false)
  })

  it('rejects a random buffer as JPEG', async () => {
    const file = makeFileFromBuffer(Buffer.from([0x00, 0x01, 0x02]), 'image/jpeg')
    expect(await validateImageMagicBytes(file, 'image/jpeg')).toBe(false)
  })
})

// ─── saveImage ────────────────────────────────────────────────────────────────

describe('saveImage', () => {
  it('creates the product directory and writes file', async () => {
    const buf = Buffer.from('fakeimage')
    const url = await saveImage('prod-123', buf, 'photo.jpg')

    expect(mockMkdir).toHaveBeenCalledWith(expect.stringContaining('prod-123'), { recursive: true })
    expect(mockWriteFile).toHaveBeenCalled()
    expect(url).toMatch(/^\/uploads\/prod-123\//)
    expect(url).toMatch(/photo\.jpg$/)
  })

  it('sanitizes filename (removes special chars)', async () => {
    const buf = Buffer.from('fakeimage')
    const url = await saveImage('prod-123', buf, 'my photo (1).JPG')
    expect(url).toMatch(/my_photo__1_\.jpg$/)
  })

  it('returns a URL starting with /uploads/', async () => {
    const url = await saveImage('prod-abc', Buffer.from('x'), 'img.png')
    expect(url).toMatch(/^\/uploads\/prod-abc\//)
  })
})

// ─── deleteImageFile ──────────────────────────────────────────────────────────

describe('deleteImageFile', () => {
  it('calls unlink with the correct path', async () => {
    await deleteImageFile('/uploads/prod-1/image.jpg')
    expect(mockUnlink).toHaveBeenCalledWith(expect.stringContaining('/uploads/prod-1/image.jpg'))
  })
})