import { afterEach, describe, expect, it, vi } from 'vitest'
import { initializeLocale, locale, setLocale, t, formatNumber } from './index'

afterEach(() => {
	vi.restoreAllMocks()
	localStorage.clear()
	initializeLocale()
})

describe('Resolve the language before rendering', () => {
	it('keeps English default with a French browser', () => {
		vi.spyOn(navigator, 'language', 'get').mockReturnValue('fr-FR')
		localStorage.clear()
		initializeLocale()
		expect([locale.value, document.documentElement.lang]).toEqual(['en', 'en'])
	})
	it.each([null, 'en', 'fr', 'unsupported'])(
		'resolves stored %s independently of browser language',
		(stored) => {
			if (stored) localStorage.setItem('renewcms-language', stored)
			initializeLocale()
			expect([locale.value, document.documentElement.lang]).toEqual(
				stored === 'fr' ? ['fr', 'fr'] : ['en', 'en'],
			)
		},
	)
	it('defaults to English when preference storage is unreadable', () => {
		setLocale('fr')
		vi.spyOn(Storage.prototype, 'getItem').mockImplementation(() => {
			throw new Error('denied')
		})
		initializeLocale()
		expect([locale.value, document.documentElement.lang]).toEqual(['en', 'en'])
	})
})

describe('Remember language on this browser', () => {
	it('restores the selected French language on initialization', () => {
		setLocale('fr')
		initializeLocale()
		expect(locale.value).toBe('fr')
	})
	it('switches when storage cannot be written', () => {
		vi.spyOn(Storage.prototype, 'setItem').mockImplementation(() => {
			throw new Error('denied')
		})
		setLocale('fr')
		expect([t('Log in'), document.documentElement.lang]).toEqual(['Se connecter', 'fr'])
	})
	it('formats numbers according to the selected locale', () => {
		setLocale('fr')
		expect(formatNumber(1234.5)).toBe(new Intl.NumberFormat('fr').format(1234.5))
	})
})