/**
 * @module tests/integration/wait-for-indexed
 * @description THE READ BARRIER — `brain.waitForIndexed(path?, opts?)`. A
 * consumer that writes and then semantically recalls gets ONE honest barrier
 * instead of guessing. The contract pinned here:
 *
 * 1. SEMANTIC LEG: a deferred add followed by `waitForIndexed('semantic')`
 *    resolves only after the vector landed — the row is vector-searchable
 *    the moment the barrier returns.
 * 2. TYPED TIMEOUT: `timeoutMs` expiry REJECTS with
 *    WaitForIndexedTimeoutError carrying the leg + the pending count and
 *    naming the gauge — never a silent partial wait.
 * 3. NO-ARG: every projection at the head; today that means the deferred
 *    embed backlog is drained.
 * 4. SYNCHRONOUS LEGS: metadata/graph/aggregation resolve immediately by
 *    design today (they update inside the write path) — even while the
 *    semantic backlog is wedged.
 * 5. GAUGES: getIndexStatus().projections carries the per-leg numbers, and
 *    the top-level pendingEmbeds compat field agrees with the semantic one.
 * 6. GENERATION REFINEMENT: an empty backlog satisfies any generation
 *    immediately; a non-empty one falls back to the full drain.
 */
import { describe, it, expect, afterEach, vi } from 'vitest'
import { Brainy, WaitForIndexedTimeoutError } from '../../src/index.js'
import { NounType } from '../../src/types/graphTypes.js'

const brains: Brainy[] = []

async function memBrain(): Promise<Brainy> {
  const b = new Brainy({ storage: { type: 'memory' }, requireSubtype: false })
  await b.init()
  brains.push(b)
  return b
}

/**
 * Abandon a poisoned in-flight embed run (its embed promise never resolves —
 * production is covered by the worker's 60s hang guard; the test takes the
 * white-box shortcut for speed), then drain so teardown never wedges.
 */
async function unwedge(brain: Brainy): Promise<void> {
  ;(brain as unknown as { _embedWorkerFlight: Promise<void> | null })._embedWorkerFlight = null
  await brain.awaitPendingEmbeds()
}

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

describe('waitForIndexed — the read barrier', () => {
  it("SEMANTIC LEG: deferred add → waitForIndexed('semantic') resolves and the row is vector-searchable after", async () => {
    const brain = await memBrain()
    const embedSpy = vi.spyOn(brain, 'embed')

    const id = await brain.add({
      data: 'the quarterly revenue report for the northern region',
      type: NounType.Document,
      deferEmbedding: true,
      metadata: { kind: 'report' }
    })
    expect(embedSpy, 'no embed on the ack path').not.toHaveBeenCalled()
    expect(brain.pendingEmbedCount()).toBeGreaterThanOrEqual(1)

    await brain.waitForIndexed('semantic')

    // The barrier's meaning: backlog drained, vector real, row searchable.
    expect(brain.pendingEmbedCount(), 'barrier means drained').toBe(0)
    const after = await brain.get(id, { includeVectors: true })
    expect((after!.vector as number[]).length, 'real vector after the barrier').toBeGreaterThan(0)
    const hits = await brain.find({
      query: 'the quarterly revenue report for the northern region',
      searchMode: 'semantic',
      limit: 5
    })
    expect(hits.map((r) => r.id), 'vector-searchable after the barrier').toContain(id)
  })

  it('TYPED TIMEOUT: a hung embedder + timeoutMs rejects with the typed error naming the pending count and the gauge', async () => {
    const brain = await memBrain()
    const hang = vi
      .spyOn(brain, 'embed')
      .mockImplementation(() => new Promise<number[]>(() => {}))

    await brain.add({
      data: 'never lands while the embedder hangs',
      type: NounType.Document,
      deferEmbedding: true,
      metadata: {}
    })
    expect(brain.pendingEmbedCount()).toBe(1)

    let caught: unknown
    try {
      await brain.waitForIndexed('semantic', { timeoutMs: 200 })
    } catch (e) {
      caught = e
    }

    expect(caught, 'expiry REJECTS — never a silent partial wait').toBeInstanceOf(
      WaitForIndexedTimeoutError
    )
    const err = caught as WaitForIndexedTimeoutError
    expect(err.path).toBe('semantic')
    expect(err.timeoutMs).toBe(200)
    expect(err.pendingEmbeds).toBeGreaterThanOrEqual(1)
    // The message names what was still pending and the gauge to check.
    expect(err.message).toContain(`${err.pendingEmbeds} deferred embed`)
    expect(err.message).toContain('getIndexStatus().projections.semantic.pendingEmbeds')

    hang.mockRestore()
    await unwedge(brain)
    expect(brain.pendingEmbedCount()).toBe(0)
  })

  it('NO-ARG: waitForIndexed() waits on the pending-embed drain (every projection at the head)', async () => {
    const brain = await memBrain()
    await brain.add({
      data: 'a deferred capture that the bare barrier must cover',
      type: NounType.Document,
      deferEmbedding: true,
      metadata: {}
    })
    expect(brain.pendingEmbedCount()).toBeGreaterThanOrEqual(1)

    await brain.waitForIndexed()

    expect(
      brain.pendingEmbedCount(),
      'the bare barrier drained the only asynchronous projection'
    ).toBe(0)
  })

  it('SYNCHRONOUS LEGS: metadata/graph/aggregation resolve immediately — even while the semantic backlog is wedged', async () => {
    const brain = await memBrain()

    // Quiet brain first: all three legs resolve on a brain with no backlog.
    await brain.add({ data: 'quiet row', type: NounType.Document, metadata: { q: 1 } })
    await brain.awaitPendingEmbeds()
    await brain.waitForIndexed('metadata')
    await brain.waitForIndexed('graph')
    await brain.waitForIndexed('aggregation')

    // The stronger pin: these projections update inside the write path today,
    // so their leg resolves immediately BY DESIGN — independent of a wedged
    // semantic backlog. (If any of them incorrectly delegated to the embed
    // drain, this test would hang.)
    const hang = vi
      .spyOn(brain, 'embed')
      .mockImplementation(() => new Promise<number[]>(() => {}))
    await brain.add({
      data: 'wedged deferred row',
      type: NounType.Document,
      deferEmbedding: true,
      metadata: {}
    })
    expect(brain.pendingEmbedCount()).toBe(1)

    await brain.waitForIndexed('metadata')
    await brain.waitForIndexed('graph')
    await brain.waitForIndexed('aggregation')

    hang.mockRestore()
    await unwedge(brain)
  })

  it('GAUGES: getIndexStatus().projections carries the per-leg shape, and the compat field agrees', async () => {
    const brain = await memBrain()
    await brain.add({ data: 'gauge row', type: NounType.Document, metadata: { g: 1 } })
    await brain.awaitPendingEmbeds()

    const status = await brain.getIndexStatus()
    expect(status.projections).toEqual({
      semantic: { pendingEmbeds: 0 },
      metadata: { synchronous: true },
      graph: { synchronous: true },
      aggregation: { pendingBackfills: 0, pendingCatchUps: 0 }
    })
    // Compat: the existing top-level gauge stays and agrees.
    expect(status.pendingEmbeds).toBe(0)

    // The semantic gauge is honest while a backlog exists.
    const hang = vi
      .spyOn(brain, 'embed')
      .mockImplementation(() => new Promise<number[]>(() => {}))
    await brain.add({
      data: 'backlogged row',
      type: NounType.Document,
      deferEmbedding: true,
      metadata: {}
    })
    const busy = await brain.getIndexStatus()
    expect(busy.projections.semantic.pendingEmbeds).toBeGreaterThanOrEqual(1)
    expect(busy.pendingEmbeds).toBe(busy.projections.semantic.pendingEmbeds)

    hang.mockRestore()
    await unwedge(brain)
  })

  it('GENERATION REFINEMENT: an empty backlog satisfies any generation immediately; a non-empty one falls back to the full drain', async () => {
    const brain = await memBrain()
    await brain.add({ data: 'generation row', type: NounType.Document, metadata: {} })
    await brain.awaitPendingEmbeds()

    // Empty backlog: the semantic watermark is at the head — >= any committed G.
    await brain.waitForIndexed('semantic', { generation: 1 })

    // Non-empty backlog: the conservative full drain (a superset of the
    // requested wait, never a partial one).
    await brain.add({
      data: 'second generation row',
      type: NounType.Document,
      deferEmbedding: true,
      metadata: {}
    })
    await brain.waitForIndexed('semantic', { generation: 1 })
    expect(brain.pendingEmbedCount(), 'the fallback is the full drain').toBe(0)
  })
})