/**
 * @module tests/integration/vfs-rename-containment
 * @description A cross-directory rename must MOVE the containment edge, not
 * accumulate one per parent. The pre-fix rename added the new parent's
 * Contains edge but skipped removing the old one ("not critical") — leaving
 * the entity a child of BOTH directories: readdir(oldDir) kept listing it,
 * re-creating the old path showed the name twice (the duplicate-readdir /
 * "cosmetic ghost" field report), and tree-walking consumers saw the file in
 * two places. Also covers the repair sweep (repairIndex → vfs.repairContainment)
 * that heals ghosts left by earlier versions, and move-to-root (whose edge
 * used to be skipped entirely).
 */
import { describe, it, expect, beforeEach, afterEach } from 'vitest'
import { Brainy, VerbType } from '../../src/index.js'

describe('VFS rename moves the containment edge (no ghost in the old directory)', () => {
  let brain: any

  beforeEach(async () => {
    process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
    brain = new Brainy({ requireSubtype: false, storage: { type: 'memory' }, silent: true, dimensions: 384 })
    await brain.init()
    await brain.vfs.mkdir('/a', { recursive: true })
    await brain.vfs.mkdir('/b', { recursive: true })
  })
  afterEach(async () => {
    await brain.close?.().catch(() => {})
  })

  it('cross-directory move: old dir stops listing it, new dir lists it exactly once', async () => {
    await brain.vfs.writeFile('/a/x.txt', 'v1')
    await brain.vfs.rename('/a/x.txt', '/b/x.txt')

    expect(await brain.vfs.readdir('/a')).toEqual([])
    expect(await brain.vfs.readdir('/b')).toEqual(['x.txt'])
    expect(String(await brain.vfs.readFile('/b/x.txt'))).toBe('v1')
  })

  it('re-creating the old path lists each name exactly once in each directory', async () => {
    await brain.vfs.writeFile('/a/x.txt', 'moved away')
    await brain.vfs.rename('/a/x.txt', '/b/x.txt')
    await brain.vfs.writeFile('/a/x.txt', 'new file at old path')

    const a = (await brain.vfs.readdir('/a')) as string[]
    const b = (await brain.vfs.readdir('/b')) as string[]
    expect(a).toEqual(['x.txt']) // exactly once — the pre-fix ghost made this list the moved entity too
    expect(b).toEqual(['x.txt'])
    expect(String(await brain.vfs.readFile('/a/x.txt'))).toBe('new file at old path')
    expect(String(await brain.vfs.readFile('/b/x.txt'))).toBe('moved away')
  })

  it('repeated moves never accumulate containment edges', async () => {
    await brain.vfs.writeFile('/a/f.txt', 'wanderer')
    for (let i = 0; i < 3; i++) {
      await brain.vfs.rename('/a/f.txt', '/b/f.txt')
      await brain.vfs.rename('/b/f.txt', '/a/f.txt')
    }
    expect(await brain.vfs.readdir('/a')).toEqual(['f.txt'])
    expect(await brain.vfs.readdir('/b')).toEqual([])

    // Exactly ONE containment edge exists on the entity.
    const stat = await brain.vfs.stat('/a/f.txt')
    const edges = await brain.related({ to: stat.entityId, type: VerbType.Contains })
    expect(edges).toHaveLength(1)
  })

  it('move to the root gets a containment edge (used to be skipped → orphan)', async () => {
    await brain.vfs.writeFile('/a/up.txt', 'to the top')
    await brain.vfs.rename('/a/up.txt', '/up.txt')

    const rootListing = (await brain.vfs.readdir('/')) as string[]
    expect(rootListing).toContain('up.txt')
    expect(await brain.vfs.readdir('/a')).toEqual([])
    expect(String(await brain.vfs.readFile('/up.txt'))).toBe('to the top')
  })
})

describe('repairIndex() heals pre-fix containment ghosts (vfs.repairContainment)', () => {
  let brain: any

  beforeEach(async () => {
    process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
    brain = new Brainy({ requireSubtype: false, storage: { type: 'memory' }, silent: true, dimensions: 384 })
    await brain.init()
    await brain.vfs.mkdir('/a', { recursive: true })
    await brain.vfs.mkdir('/b', { recursive: true })
  })
  afterEach(async () => {
    await brain.close?.().catch(() => {})
  })

  /** Reproduce the PRE-FIX defect state: file lives at /b/g.txt but a stale
   *  vfs-contains edge from /a lingers (what old renames left behind). */
  const synthesizeGhost = async () => {
    await brain.vfs.writeFile('/b/g.txt', 'ghost target')
    const fileId = (await brain.vfs.stat('/b/g.txt')).entityId
    const aId = (await brain.vfs.stat('/a')).entityId
    await brain.relate({
      from: aId,
      to: fileId,
      type: VerbType.Contains,
      subtype: 'vfs-contains',
      metadata: { isVFS: true }
    })
    return { fileId, aId }
  }

  it('a stale old-parent edge is removed; listings become honest', async () => {
    const { fileId } = await synthesizeGhost()
    // The defect state is visible: /a lists a file whose path says /b.
    expect((await brain.vfs.readdir('/a')) as string[]).toContain('g.txt')

    await brain.repairIndex()

    expect(await brain.vfs.readdir('/a')).toEqual([])
    expect(await brain.vfs.readdir('/b')).toEqual(['g.txt'])
    const edges = await brain.related({ to: fileId, type: VerbType.Contains })
    expect(edges).toHaveLength(1)
  })

  it("a user's own knowledge Contains edge onto the file survives the repair", async () => {
    const { fileId } = await synthesizeGhost()
    // A knowledge-graph containment from a NON-directory entity (a collection
    // curating the file) — same verb TYPE, not a vfs-contains edge. The repair
    // must remove only VFS containment ghosts, never user knowledge edges.
    // (Edges dedupe by (from,to,type), so the user edge needs its own source.)
    const collectionId = await brain.add({
      data: 'reading list',
      type: 'collection',
      metadata: { kind: 'curation' }
    })
    await brain.relate({ from: collectionId, to: fileId, type: VerbType.Contains, subtype: 'curates' })

    await brain.repairIndex()

    const edges = await brain.related({ to: fileId, type: VerbType.Contains })
    const subtypes = edges.map((e: any) => e.subtype).sort()
    // The stale vfs ghost edge is gone; the correct vfs edge + the user's
    // curation edge remain.
    expect(subtypes).toEqual(['curates', 'vfs-contains'])
    expect(edges.find((e: any) => e.subtype === 'curates')?.from).toBe(collectionId)
  })

  it('a missing expected edge is restored (entity unreachable from its own directory)', async () => {
    await brain.vfs.writeFile('/b/lost.txt', 'find me')
    const fileId = (await brain.vfs.stat('/b/lost.txt')).entityId
    // Simulate total edge loss (an older damage shape).
    for (const e of await brain.related({ to: fileId, type: VerbType.Contains })) {
      await brain.unrelate(e.id)
    }
    expect((await brain.vfs.readdir('/b')) as string[]).not.toContain('lost.txt')

    await brain.repairIndex()

    expect((await brain.vfs.readdir('/b')) as string[]).toContain('lost.txt')
  })
})