import { describe, expect, it, vi } from 'vitest'
import { KVOutbox, type OutboxEntry } from '../../src/kv-storage/kv-outbox.js'
import { KVStorageInMemory } from '../../src/kv-storage/kv-storage-in-memory.js'
import { RetryTimer } from '../../src/utils/retry-timer.js'
import { StorageUnavailableError } from '../../src/utils/errors.js'

describe('KVOutbox', () => {
  it('replays entries in order once the source is reachable, and survives a restart', async () => {
    const store = new KVStorageInMemory()
    let online = false
    const sent: OutboxEntry[] = []
    const send = async (entry: OutboxEntry) => {
      if (!online) throw new StorageUnavailableError('offline')
      sent.push(entry)
    }
    const firstRetry = new RetryTimer({ baseDelay: 5, maxDelay: 5 })
    const first = new KVOutbox(store, send, firstRetry)
    await first.push({ type: 'write', entries: [['a', 1]] })
    await first.push({ type: 'remove', keys: ['a'] })
    expect(first.size).toBe(2)
    expect(first.pending.has('a')).toBe(true)

    firstRetry.stop() // the first session ends...
    await first.replay() // ...once its in-flight replay attempt has failed
    // A new session over the same store picks up the queue.
    const second = new KVOutbox(store, send, new RetryTimer({ baseDelay: 5, maxDelay: 5 }))
    online = true
    await second.load()
    await vi.waitFor(() => expect(second.size).toBe(0))
    expect(sent).toEqual([
      { type: 'write', entries: [['a', 1]] },
      { type: 'remove', keys: ['a'] },
    ])
    expect(await store.readMany(['~q/o/000000000001', '~q/o/000000000002'])).toEqual([undefined, undefined])
  })
})