/**
 * @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 OLD 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).
 *
 * RE-POINTED to the health-gate law (a read never builds; a rebuild runs
 * entirely at open): `ensureIndexesLoaded()` is now a pure CHECK. A not-ready
 * report from ANY provider — metadata, vector, or graph — makes it THROW the
 * matching typed `*NotReadyError` rather than silently letting the read
 * proceed, and it NEVER calls `rebuildIndexesIfNeeded` (that is entirely
 * open()'s job now — see the second describe block below). The spirit is
 * unchanged: a not-ready report from any single provider can never be
 * shadowed into a silent empty result.
 *
 * White-box provider-double pattern per tests/unit/brainy/migration-deference.
 */
import { describe, it, expect, afterEach, vi } from 'vitest'
import { mkdtempSync, rmSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { Brainy, MetadataIndexNotReadyError } 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 }
  ensureIndexesLoaded(): void
  rebuildIndexesIfNeeded(force?: boolean): Promise<void>
}

const brains: Brainy[] = []
const dirs: string[] = []

afterEach(async () => {
  for (const b of brains.splice(0)) await b.close().catch(() => {})
  for (const d of dirs.splice(0)) rmSync(d, { recursive: true, force: true })
  vi.restoreAllMocks()
})

async function warmBrain(): 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
  return { brain, internals }
}

describe('the read gate honors EVERY provider’s not-ready report', () => {
  it('a not-ready METADATA provider refuses loudly — it never lets a read proceed, and it never rebuilds', async () => {
    const { internals } = await warmBrain()

    // The trap's shape: vector side looks fine (populated), metadata
    // provider says NOT ready — the OLD gate silently latched complete here.
    // The new gate refuses loudly instead; a read never triggers a rebuild.
    internals.metadataIndex.isReady = () => false
    const rebuildSpy = vi.spyOn(internals, 'rebuildIndexesIfNeeded').mockResolvedValue(undefined)

    expect(() => internals.ensureIndexesLoaded()).toThrow(MetadataIndexNotReadyError)
    expect(rebuildSpy, 'a read NEVER triggers a rebuild — building is entirely open()\'s job now').not.toHaveBeenCalled()
  })

  it('control: all providers ready/unknown+populated → the gate lets the read through, no rebuild', async () => {
    const { internals } = await warmBrain()
    internals.metadataIndex.isReady = () => true
    const rebuildSpy = vi.spyOn(internals, 'rebuildIndexesIfNeeded').mockResolvedValue(undefined)

    expect(() => internals.ensureIndexesLoaded()).not.toThrow()
    expect(rebuildSpy).not.toHaveBeenCalled()
  })
})

describe('the open-time build honors the same law: a needed rebuild runs at open, never deferred to a read', () => {
  it('disableAutoRebuild:true does not defer a needed rebuild past open() on a reopened, populated store', async () => {
    const dir = mkdtempSync(join(tmpdir(), 'brainy-lazy-notready-honor-'))
    dirs.push(dir)

    const writer = new Brainy(createTestConfig({ disableAutoRebuild: true, storage: { type: 'filesystem', path: dir } }))
    await writer.init()
    for (let i = 0; i < 3; i++) {
      await writer.add({ data: `row ${i}`, type: NounType.Document, metadata: { i } })
    }
    await writer.flush()
    await writer.close()

    // Fresh instance over the same store: its derived indexes start empty in
    // memory, so open()'s rebuildIndexesIfNeeded MUST fire (and complete)
    // before init() returns — even though disableAutoRebuild is true, there
    // is no first-query lazy path left to defer to.
    const reader = new Brainy(createTestConfig({ disableAutoRebuild: true, storage: { type: 'filesystem', path: dir } }))
    const internals = reader as unknown as { rebuildIndexesIfNeeded(force?: boolean): Promise<void> }
    const rebuildSpy = vi.spyOn(internals, 'rebuildIndexesIfNeeded')

    await reader.init()
    brains.push(reader)

    expect(rebuildSpy).toHaveBeenCalledTimes(1)
    const rows = await reader.find({ where: { i: 1 } })
    expect(rows.length).toBe(1)
  }, 30000)
})