import { describe, expect, it } from 'vitest'
import { store } from './store'
import type { StreamEvent, SurfaceSnapshot } from './contracts'

// U4/R5：surface.updated 投影的 revision 守卫——旧修订/重复事件不得覆盖新修订；
// 服务端快照是唯一权威（KTD8 单一状态所有者）。

function surfEvent(seq: number, surfaceId: string, revision: number, title: string): StreamEvent<SurfaceSnapshot> {
  return {
    seq, conversationId: 'c1', ts: new Date().toISOString(), v: 1, type: 'surface.updated',
    payload: {
      identity: { surfaceId, owner: 'alice', pluginId: 'generative-ui', conversationId: 'c1' },
      compat: { schemaVersion: 1, catalogVersion: 'ui-v1' },
      revision, activationEpoch: 1,
      spec: { title, nodes: [{ type: 'markdown', id: 'n1', markdown: 'x' }] },
    },
  }
}

describe('surface.updated projection', () => {
  it('新事件入库；旧修订与重复事件不覆盖', () => {
    store.applyEvent(surfEvent(1, 's1', 1, '初版'))
    store.applyEvent(surfEvent(2, 's1', 2, '修订二'))
    store.applyEvent(surfEvent(3, 's1', 1, '迟到的旧修订'))
    store.applyEvent(surfEvent(4, 's1', 2, '重复事件'))
    const list = store.getState().surfaces
    expect(list).toHaveLength(1)
    expect(list[0].revision).toBe(2)
    expect(list[0].spec.title).toBe('修订二')
  })

  it('多页面并存，互不覆盖', () => {
    store.applyEvent(surfEvent(5, 's2', 1, '页面二'))
    const list = store.getState().surfaces
    expect(list.filter(x => String(x.identity.surfaceId) === 's1')).toHaveLength(1)
    expect(list.filter(x => String(x.identity.surfaceId) === 's2')).toHaveLength(1)
  })
})