/**
 * i18n-io — existing-catalogue reader (fail-closed on malformed JSON) +
 * atomic writer (tmp + rename, no residue).
 */
import { describe, it, expect, beforeEach, afterEach } from 'vitest'
import { mkdtempSync, mkdirSync, readdirSync, readFileSync, rmSync, writeFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { readExistingI18n, writeFileAtomic } from '../i18n-io.js'

let root: string
beforeEach(() => { root = mkdtempSync(join(tmpdir(), 'i18n-io-')) })
afterEach(() => { rmSync(root, { recursive: true, force: true }) })

function writeLocale(locale: string, module: string, content: string): string {
  const dir = join(root, 'src', 'i18n', 'locales', locale)
  mkdirSync(dir, { recursive: true })
  const p = join(dir, `${module}.json`)
  writeFileSync(p, content, 'utf-8')
  return p
}

describe('scaffold-component / i18n-io — readExistingI18n', () => {
  it('returns parsed catalogues only for locales whose file exists', () => {
    writeLocale('fr', 'crm', JSON.stringify({ contact: { list: { title: 'Contacts' } } }))
    writeLocale('de', 'crm', JSON.stringify({ contact: { list: { title: 'Kontakte' } } }))
    const { existingI18n, malformed } = readExistingI18n(root, 'crm')
    expect(malformed).toEqual([])
    expect(Object.keys(existingI18n).sort()).toEqual(['de', 'fr'])
    expect((existingI18n.fr as { contact: { list: { title: string } } }).contact.list.title).toBe('Contacts')
  })

  it('reports a malformed locale file in malformed[] and never returns it silently', () => {
    const bad = writeLocale('fr', 'crm', '{ "contact": ')
    writeLocale('en', 'crm', JSON.stringify({ contact: {} }))
    const { existingI18n, malformed } = readExistingI18n(root, 'crm')
    // Fail-closed input: the caller must refuse to write — the historical
    // silent overwrite wiped whole modules' manual translations.
    expect(malformed).toEqual([bad])
    expect(existingI18n.fr).toBeUndefined()
    expect(existingI18n.en).toBeDefined()
  })

  it('treats a non-object JSON root (array / string) as malformed', () => {
    const arr = writeLocale('fr', 'crm', '["not", "a", "catalogue"]')
    const str = writeLocale('it', 'crm', '"just a string"')
    const { existingI18n, malformed } = readExistingI18n(root, 'crm')
    expect(malformed.sort()).toEqual([arr, str].sort())
    expect(Object.keys(existingI18n)).toEqual([])
  })

  it('reads only the requested module, other namespaces untouched', () => {
    writeLocale('fr', 'crm', JSON.stringify({ contact: {} }))
    writeLocale('fr', 'billing', JSON.stringify({ invoice: {} }))
    const { existingI18n } = readExistingI18n(root, 'crm')
    expect(Object.keys(existingI18n.fr as Record<string, unknown>)).toEqual(['contact'])
  })
})

describe('scaffold-component / i18n-io — writeFileAtomic', () => {
  it('overwrites in place and leaves no .tmp-* residue', () => {
    const p = writeLocale('fr', 'crm', '{"old": true}')
    writeFileAtomic(p, '{"new": true}\n')
    expect(readFileSync(p, 'utf-8')).toBe('{"new": true}\n')
    const siblings = readdirSync(join(root, 'src', 'i18n', 'locales', 'fr'))
    expect(siblings.filter((f) => f.includes('.tmp-'))).toEqual([])
  })

  it('creates missing parent directories', () => {
    const p = join(root, 'src', 'i18n', 'locales', 'it', 'crm.json')
    writeFileAtomic(p, '{}\n')
    expect(readFileSync(p, 'utf-8')).toBe('{}\n')
  })
})