import { readPurchaseDevice, rememberPurchaseDevice } from '@/utils/purchase-device-preference'

describe('purchase device preference', () => {
  beforeEach(() => { localStorage.clear() })
  afterEach(() => { jest.restoreAllMocks() })

  it('isolates users and remembers an explicit empty selection', () => {
    expect(rememberPurchaseDevice(1, 10)).toBe(true)
    expect(rememberPurchaseDevice(2, 20)).toBe(true)
    expect(readPurchaseDevice(1)).toBe(10)
    expect(readPurchaseDevice(2)).toBe(20)
    expect(rememberPurchaseDevice(1, '')).toBe(true)
    expect(readPurchaseDevice(1)).toBeNull()
    expect(readPurchaseDevice(2)).toBe(20)
  })

  it('does not share a fallback key when user identity is missing', () => {
    expect(rememberPurchaseDevice(null, 10)).toBe(false)
    expect(readPurchaseDevice(null)).toBeNull()
    expect(localStorage.length).toBe(0)
  })

  it('ignores corrupt preferences and tolerates unavailable browser storage', () => {
    rememberPurchaseDevice(1, 10)
    localStorage.setItem(localStorage.key(0), '{broken')
    expect(readPurchaseDevice(1)).toBeNull()
    jest.spyOn(Storage.prototype, 'getItem').mockImplementation(() => { throw new Error('disabled') })
    jest.spyOn(Storage.prototype, 'setItem').mockImplementation(() => { throw new Error('disabled') })
    expect(readPurchaseDevice(1)).toBeNull()
    expect(rememberPurchaseDevice(1, 10)).toBe(false)
  })
})