/**
 * @vitest-environment node
 */
import { beforeEach, describe, expect, it, vi } from 'vitest'

vi.mock('@/lib/core/config/redis', () => ({
  getRedisClient: () => null,
}))

vi.mock('@/lib/core/config/env', () => ({
  env: { REDIS_URL: undefined },
}))

import type { TableEvent } from '@/lib/table/events'
import { appendTableEvent, getLatestTableEventId, readTableEventsSince } from '@/lib/table/events'

/** Module-level memory buffer can't be reset without vi.resetModules — use a
 *  unique tableId per test to avoid cross-test bleed. */
let seq = 0
function uniqueTableId(): string {
  seq++
  return `table-events-test-${seq}`
}

function cellEvent(tableId: string): TableEvent {
  return {
    kind: 'cell',
    tableId,
    rowId: 'row-1',
    groupId: 'group-1',
    status: 'running',
  }
}

describe('getLatestTableEventId (memory buffer)', () => {
  beforeEach(() => {
    vi.clearAllMocks()
  })

  it('returns 0 for a table with no events, without allocating a stream', async () => {
    const tableId = uniqueTableId()
    expect(await getLatestTableEventId(tableId)).toBe(0)
    // A pure read must not have created a buffer: appending afterwards still
    // starts the sequence at 1.
    const entry = await appendTableEvent(cellEvent(tableId))
    expect(entry?.eventId).toBe(1)
  })

  it('returns the latest assigned eventId after appends', async () => {
    const tableId = uniqueTableId()
    await appendTableEvent(cellEvent(tableId))
    const second = await appendTableEvent(cellEvent(tableId))
    expect(second?.eventId).toBe(2)
    expect(await getLatestTableEventId(tableId)).toBe(2)
  })

  it('tailing from the latest id yields no replayed events', async () => {
    const tableId = uniqueTableId()
    await appendTableEvent(cellEvent(tableId))
    await appendTableEvent(cellEvent(tableId))
    const latest = await getLatestTableEventId(tableId)
    const result = await readTableEventsSince(tableId, latest)
    expect(result).toEqual({ status: 'ok', events: [] })
  })

  it('a subsequent append is visible to a reader tailing from the prior latest', async () => {
    const tableId = uniqueTableId()
    await appendTableEvent(cellEvent(tableId))
    const latest = await getLatestTableEventId(tableId)
    await appendTableEvent(cellEvent(tableId))
    const result = await readTableEventsSince(tableId, latest)
    expect(result.status).toBe('ok')
    if (result.status === 'ok') {
      expect(result.events).toHaveLength(1)
      expect(result.events[0].eventId).toBe(latest + 1)
    }
  })
})