import { describe, expect, it } from 'vitest'
import { DocumentStorageInMemory } from '../../src/document-storage/document-storage-in-memory.js'
import { DocumentStorageKV } from '../../src/document-storage/document-storage-kv.js'
import { EventSourcedDocumentStorage } from '../../src/document-storage/event-sourced-document-storage.js'
import { EventStorageKV } from '../../src/event-storage/event-storage-kv.js'
import { KVStorageInMemory } from '../../src/kv-storage/kv-storage-in-memory.js'
import { collect, KVStorageCounting } from '../helpers.js'
import { runDocumentStorageSuite } from './document-storage.suite.js'

const indexes = { users: ['email', 'age'] }

runDocumentStorageSuite('DocumentStorageInMemory', () => new DocumentStorageInMemory())
runDocumentStorageSuite('DocumentStorageInMemory (indexed)', () => new DocumentStorageInMemory({ indexes }))
runDocumentStorageSuite('DocumentStorageKV', () => new DocumentStorageKV(new KVStorageInMemory()))
runDocumentStorageSuite('EventSourced (in-memory projections)', () => {
  const kv = new KVStorageInMemory()
  return new EventSourcedDocumentStorage(new EventStorageKV(kv), new DocumentStorageInMemory({ indexes }))
})
runDocumentStorageSuite('EventSourced (KV projections)', () => {
  const kv = new KVStorageInMemory()
  return new EventSourcedDocumentStorage(new EventStorageKV(kv), new DocumentStorageKV(kv.child('projections')))
})

describe('DocumentStorageInMemory indexes', () => {
  it('keeps the equality index in sync with updates and deletes', async () => {
    const users = new DocumentStorageInMemory({ indexes }).child('users')
    await users.set('1', { email: 'a', age: 1 })
    await users.set('2', { email: 'b', age: 1 })
    await users.update('1', { $set: { email: 'c' } })
    await users.delete('2')
    expect(await collect(users.find({ email: 'a' }))).toEqual([])
    expect(await collect(users.find({ email: 'c' }))).toEqual([{ key: '1', data: { email: 'c', age: 1 } }])
    expect(await collect(users.find({ age: { $eq: 1 } }))).toHaveLength(1)
  })
})

describe('EventSourcedDocumentStorage', () => {
  function setup() {
    const kv = new KVStorageCounting()
    const events = new EventStorageKV(kv)
    const projections = new DocumentStorageKV(kv.child('projections'))
    return { kv, events, projections, docs: new EventSourcedDocumentStorage(events, projections) }
  }

  it('records resolved changes as history and replays any version', async () => {
    const users = setup().docs.child('users')
    await users.set('1', { n: 5 })
    await users.update('1', { $inc: { n: 1 } })
    await users.delete('1')
    await users.set('1', { n: 10 })
    expect((await collect(users.history('1'))).map((e) => e.data)).toEqual([
      { op: 'set', doc: { n: 5 } },
      { op: 'patch', set: { n: 6 }, unset: [] },
      { op: 'delete' },
      { op: 'set', doc: { n: 10 } },
    ])
    expect(await users.getAt('1', 2)).toEqual({ n: 6 })
    expect(await users.child('1').getAt(3)).toBeUndefined()
    expect(await users.get('1')).toEqual({ n: 10 })
  })

  it('heals a projection left behind by a crash between append and projection write', async () => {
    const { docs, events } = setup()
    const users = docs.child('users')
    await users.set('1', { n: 1 })
    await events.child('users').append('1', [{ op: 'patch', set: { n: 2 }, unset: [] }]) // projection never written
    expect(await users.get('1')).toEqual({ n: 1 })
    expect(await users.update('1', { $inc: { n: 1 } })).toEqual({ n: 3 })
    await events.child('users').append('2', [{ op: 'set', doc: { n: 7 } }]) // first write crashed
    expect(await users.catchUp('2')).toEqual({ n: 7 })
    expect(await users.get('2')).toEqual({ n: 7 })
  })

  it('two instances incrementing the same document converge', async () => {
    const kv = new KVStorageInMemory()
    const make = () => new EventSourcedDocumentStorage(new EventStorageKV(kv), new DocumentStorageKV(kv.child('projections'))).child('users')
    const a = make()
    const b = make()
    await a.set('1', { n: 0 })
    await Promise.all([...Array(5)].flatMap(() => [a.update('1', { $inc: { n: 1 } }), b.update('1', { $inc: { n: 1 } })]))
    expect(await a.get('1')).toEqual({ n: 10 })
  })

  it('a write is a projection read, an append and a projection write', async () => {
    const { docs, kv } = setup()
    await docs.child('users').set('1', { n: 1 })
    kv.reset()
    await docs.child('users').update('1', { $inc: { n: 1 } })
    expect(kv.calls).toEqual({ readMany: 2, writeIfAbsent: 1, writeMany: 1 })
  })
})