import { mkdtempSync, readFileSync, readdirSync, rmSync, writeFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { afterEach, describe, expect, it } from 'vitest'
import { writeFileAtomic } from '../fs.js'

let dir: string

afterEach(() => {
  if (dir) rmSync(dir, { recursive: true, force: true })
})

describe('fs — writeFileAtomic', () => {
  it('writes new content and leaves NO temp file behind', async () => {
    dir = mkdtempSync(join(tmpdir(), 'ss-atomic-'))
    const target = join(dir, 'verdict.md')
    await writeFileAtomic(target, '# Audit\ncontenu')
    expect(readFileSync(target, 'utf8')).toBe('# Audit\ncontenu')
    expect(readdirSync(dir)).toEqual(['verdict.md'])
  })

  it('replaces an existing file in place (idempotent re-run)', async () => {
    dir = mkdtempSync(join(tmpdir(), 'ss-atomic-'))
    const target = join(dir, 'verdict.md')
    writeFileSync(target, 'ancien contenu')
    await writeFileAtomic(target, 'nouveau contenu')
    expect(readFileSync(target, 'utf8')).toBe('nouveau contenu')
    expect(readdirSync(dir)).toEqual(['verdict.md'])
  })

  it('creates missing parent directories', async () => {
    dir = mkdtempSync(join(tmpdir(), 'ss-atomic-'))
    const target = join(dir, '_audit', 'nested', 'verdict.md')
    await writeFileAtomic(target, 'ok')
    expect(readFileSync(target, 'utf8')).toBe('ok')
  })
})