import { beforeEach, describe, expect, it, vi } from 'vitest'

// The optional-module helpers run against a fake KV store: the modules' clients are
// replaced, so each test asserts what the helper asked for.
const mocks = vi.hoisted(() => {
  const store = new Map<string, number>()
  return {
    store,
    kvClient: null as null | {
      incr: (key: string) => Promise<number>
      expire: (key: string, seconds: number) => Promise<number>
      get: <T>(key: string) => Promise<T | null>
    },
    expire: vi.fn(async () => 1),
  }
})

vi.mock('@/shared/api', () => ({
  kv: () => mocks.kvClient,
  nats: () => null,
  s3: () => null,
  ensureCollection: vi.fn(async () => {}),
  upsertPoints: vi.fn(async () => {}),
  searchPoints: vi.fn(async () => []),
}))
vi.mock('@/shared/config', () => ({
  getEnv: () => ({ QDRANT_URL: undefined }),
}))

import { consumeUploadQuota, embed, UPLOADS_PER_MINUTE, uploadsLeft } from '@/shared/lib/optional'

function fakeKv() {
  mocks.kvClient = {
    incr: async (key: string) => {
      const next = (mocks.store.get(key) ?? 0) + 1
      mocks.store.set(key, next)
      return next
    },
    expire: mocks.expire,
    get: async <T>(key: string) => (mocks.store.has(key) ? (mocks.store.get(key) as T) : null),
  }
}

describe('consumeUploadQuota', () => {
  beforeEach(() => {
    mocks.store.clear()
    mocks.expire.mockClear()
    fakeKv()
  })

  it('allows the uploads of the minute up to the limit, refuses the next, and sets the window once', async () => {
    let last: { allowed: boolean; remaining: number } | null = null
    for (let i = 0; i < UPLOADS_PER_MINUTE; i += 1) last = await consumeUploadQuota('visitor-1')
    expect(last).toEqual({ allowed: true, remaining: 0 })

    expect(await consumeUploadQuota('visitor-1')).toEqual({ allowed: false, remaining: 0 })
    expect(mocks.expire).toHaveBeenCalledTimes(1)
  })

  it('counts each visitor separately', async () => {
    await consumeUploadQuota('visitor-1')
    expect(await uploadsLeft('visitor-2')).toBe(UPLOADS_PER_MINUTE)
  })

  it('is null, and counts nothing, when KV is not linked', async () => {
    mocks.kvClient = null
    expect(await consumeUploadQuota('visitor-1')).toBeNull()
    expect(await uploadsLeft('visitor-1')).toBeNull()
  })
})

describe('embed', () => {
  const dot = (x: number[], y: number[]) => x.reduce((sum, value, i) => sum + value * (y[i] ?? 0), 0)

  it('is stable for the same text, and orthogonal for text with no word in common', () => {
    const a = embed('plan the launch')
    expect(embed('plan the launch')).toEqual(a)
    expect(dot(a, a)).toBeCloseTo(1)
    expect(dot(a, embed('zebra quartz'))).toBeCloseTo(0)
  })
})