/**
 * @module tests/integration/read-surface-readiness
 * @description THE READ-SURFACE READINESS GATE (a production blackout's
 * brainy half): with `disableAutoRebuild: true`, init defers index builds —
 * and before this gate, only find() waited for the lazy rebuild while
 * related() and every VFS path served EMPTY from the not-ready providers
 * (writes acked into canonical, readback empty — fifteen live minutes).
 * The pins: on a fresh instance over a populated store, the FIRST read on
 * every surface serves truth (it waits for the build), never empty.
 */
import { describe, it, expect, afterEach } from 'vitest'
import { mkdtempSync, rmSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { Brainy } from '../../src/index.js'
import { NounType, VerbType } from '../../src/types/graphTypes.js'

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

async function openLazy(dir: string): Promise<Brainy> {
  const brain = new Brainy({
    storage: { type: 'filesystem', path: dir },
    requireSubtype: false,
    silent: true,
    disableAutoRebuild: true
  })
  await brain.init()
  brains.push(brain)
  return brain
}

describe('read-surface readiness gate', () => {
  it('related() as the FIRST read on a fresh lazy instance serves truth, never empty', async () => {
    const dir = mkdtempSync(join(tmpdir(), 'brainy-readgate-'))
    dirs.push(dir)
    const writer = await openLazy(dir)
    const a = await writer.add({ data: 'hub row', type: NounType.Document, metadata: { n: 1 } })
    const b = await writer.add({ data: 'leaf row', type: NounType.Document, metadata: { n: 2 } })
    await writer.relate({ from: a, to: b, type: VerbType.RelatedTo })
    await writer.flush()
    await brains.pop()!.close()

    // Fresh instance: indexes deferred at open. The production shape called
    // related() FIRST (no find() to trigger the old, only gate).
    const reader = await openLazy(dir)
    const rels = await reader.related({ from: a })
    expect(rels.length, 'the FIRST related() read waits for the build and serves').toBeGreaterThan(0)
    expect(rels.some((r) => r.to === b || (r as { target?: string }).target === b)).toBe(true)
  }, 120000)

  it('a metadata-filtered read as the FIRST read serves truth, never empty', async () => {
    const dir = mkdtempSync(join(tmpdir(), 'brainy-readgate2-'))
    dirs.push(dir)
    const writer = await openLazy(dir)
    await writer.add({ data: 'tagged row', type: NounType.Document, metadata: { team: 'atlas' } })
    await writer.flush()
    await brains.pop()!.close()

    const reader = await openLazy(dir)
    const rows = await reader.find({ where: { team: 'atlas' } })
    expect(rows.length, 'filtered find on a cold lazy instance serves').toBe(1)
  }, 120000)
})