/**
 * @module tests/unit/brainy/lazy-notready-honor
 * @description THE SILENT-EMPTY TRAP pin (found during a fleet adoption,
 * SELF-ENGINE-PAIR-STANDARD): under `disableAutoRebuild: true`, the lazy
 * first-query path (`ensureIndexesLoaded`) assessed ONLY the vector index's
 * readiness — a native METADATA provider reporting not-ready (its strand
 * report) never blocked the completion latch, so the promised lazy rebuild
 * never fired and every `find()` silently returned `[]` on a populated
 * store (measured: 52 entities durable-but-unqueryable, first query
 * 0ms/0 rows). The law: a not-ready report from ANY provider falls through
 * to the rebuild — never a silent empty.
 *
 * White-box provider-double pattern per tests/unit/brainy/migration-deference.
 */
import { describe, it, expect, afterEach, vi } from 'vitest'
import { Brainy } from '../../../src/index.js'
import { NounType } from '../../../src/types/graphTypes.js'
import { createTestConfig } from '../../helpers/test-factory.js'

interface BrainInternals {
  index: { size(): number }
  metadataIndex: { isReady?: () => boolean }
  lazyRebuildCompleted: boolean
  ensureIndexesLoaded(): Promise<void>
  rebuildIndexesIfNeeded(force?: boolean): Promise<void>
}

const brains: Brainy[] = []

afterEach(async () => {
  for (const b of brains.splice(0)) await b.close().catch(() => {})
  vi.restoreAllMocks()
})

async function warmLazyBrain(): Promise<{ brain: Brainy; internals: BrainInternals }> {
  const brain = new Brainy(createTestConfig({ disableAutoRebuild: true }))
  await brain.init()
  brains.push(brain)
  for (let i = 0; i < 3; i++) {
    await brain.add({ data: `row ${i}`, type: NounType.Document, metadata: { i } })
  }
  const internals = brain as unknown as BrainInternals
  internals.lazyRebuildCompleted = false // simulate the cold first query
  return { brain, internals }
}

describe('lazy path honors EVERY provider’s not-ready report', () => {
  it('a not-ready METADATA provider blocks the completion latch and fires the rebuild', async () => {
    const { internals } = await warmLazyBrain()

    // The trap's shape: vector side looks fine (populated), metadata
    // provider says NOT ready — the old gate latched complete here.
    ;(internals.metadataIndex as { isReady?: () => boolean }).isReady = () => false
    const rebuildSpy = vi
      .spyOn(internals, 'rebuildIndexesIfNeeded')
      .mockResolvedValue(undefined)

    await internals.ensureIndexesLoaded()

    expect(rebuildSpy, 'not-ready metadata provider must fire the lazy rebuild').toHaveBeenCalledWith(true)
  })

  it('control: all providers ready/unknown+populated → latch completes, no rebuild', async () => {
    const { internals } = await warmLazyBrain()
    ;(internals.metadataIndex as { isReady?: () => boolean }).isReady = () => true
    const rebuildSpy = vi
      .spyOn(internals, 'rebuildIndexesIfNeeded')
      .mockResolvedValue(undefined)

    await internals.ensureIndexesLoaded()

    expect(rebuildSpy).not.toHaveBeenCalled()
    expect(internals.lazyRebuildCompleted).toBe(true)
  })
})