/**
 * @module tests/integration/readdir-no-duplicate-replace
 * @description A re-created path must NOT show up twice in readdir. The reported
 * defect (memory-vm) was readdir serving DUPLICATE entries for re-created paths,
 * rooted in a delete that left a ghost (partial removal) whose next delete read
 * null metadata and skipped unposting the stale Contains edge. With full-removal
 * deletes there is no ghost, so the edge is always unposted and the path appears
 * exactly once after any number of delete→recreate cycles.
 */
import { describe, it, expect, beforeEach, afterEach } from 'vitest'
import * as fs from 'node:fs'
import * as os from 'node:os'
import * as path from 'node:path'
import { Brainy } from '../../src/index.js'

describe('readdir shows a re-created path exactly once (no duplicate on replace)', () => {
  let dir: string
  let brain: any

  beforeEach(async () => {
    process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
    dir = fs.mkdtempSync(path.join(os.tmpdir(), 'brainy-readdir-'))
    brain = new Brainy({ requireSubtype: false, storage: { type: 'filesystem', path: dir }, silent: true, dimensions: 384 })
    await brain.init()
  })
  afterEach(async () => {
    await brain.close?.().catch(() => {})
    fs.rmSync(dir, { recursive: true, force: true })
  })

  it('delete then re-create the same file path — readdir lists it once', async () => {
    await brain.vfs.mkdir('/d', { recursive: true })
    await brain.vfs.writeFile('/d/x.txt', 'v1')
    expect(await brain.vfs.readdir('/d')).toEqual(['x.txt'])

    await brain.vfs.unlink('/d/x.txt')
    expect(await brain.vfs.readdir('/d')).toEqual([])

    await brain.vfs.writeFile('/d/x.txt', 'v2')
    const listing = (await brain.vfs.readdir('/d')) as string[]
    expect(listing).toEqual(['x.txt']) // exactly once — no ghost duplicate
    expect(listing.filter((n) => n === 'x.txt')).toHaveLength(1)
  })

  it('survives several delete→recreate cycles without accumulating duplicates', async () => {
    await brain.vfs.mkdir('/c', { recursive: true })
    for (let i = 0; i < 4; i++) {
      await brain.vfs.writeFile('/c/f.txt', `gen ${i}`)
      await brain.vfs.unlink('/c/f.txt')
    }
    await brain.vfs.writeFile('/c/f.txt', 'final')
    const listing = (await brain.vfs.readdir('/c')) as string[]
    expect(listing).toEqual(['f.txt'])
    expect(await brain.vfs.readFile('/c/f.txt')).toBeDefined()
  })
})