import type { WebviewToExtension } from './types'
import { describe, expect, it } from 'vitest'
import { DefinitionLinks } from './definitionLinks'

function setup(version: number | undefined): { links: DefinitionLinks, sent: WebviewToExtension[], probes: () => { id: number, version: number, offset: number }[] } {
  const sent: WebviewToExtension[] = []
  const links = new DefinitionLinks(msg => sent.push(msg))
  links.setVersion(version)
  const probes = (): { id: number, version: number, offset: number }[] => sent.flatMap(msg => msg.type === 'probeDefinition' ? [{ id: msg.id, version: msg.version, offset: msg.offset }] : [])
  return { links, sent, probes }
}

describe('definitionLinks', () => {
  it('问到「没有」后移开再指回来会重新问，语言扩展启动好了就能链上', () => {
    const { links, probes } = setup(1)
    links.point(54)
    links.answer(probes()[0].id, false)
    expect(links.linked).toBeUndefined()

    links.point(undefined)
    links.point(54)
    const [first, second] = probes()
    expect(second).toEqual({ id: second.id, version: 1, offset: 54 })
    expect(second.id).not.toBe(first.id)

    links.answer(second.id, true)
    expect(links.linked).toBe(54)
  })

  it('修饰键 + 点击名字总交给扩展端去跳，问到过「没有」也一样', () => {
    const { links, sent, probes } = setup(1)
    links.point(54)
    links.answer(probes()[0].id, false)

    expect(links.click(54)).toBe(true)
    expect(sent.at(-1)).toEqual({ type: 'goToDefinition', version: 1, offset: 54 })
  })

  it('还指着同一个名字不重问', () => {
    const { links, probes } = setup(1)
    links.point(54)
    links.point(54)
    expect(probes()).toHaveLength(1)
  })

  it('迟到的旧回答丢掉，只认最近一次询问的回答', () => {
    const { links, probes } = setup(1)
    links.point(54)
    links.point(79)
    links.point(54)
    const [stale, , latest] = probes()
    links.answer(latest.id, true)
    links.answer(stale.id, false)
    expect(links.linked).toBe(54)
  })

  it('松开修饰键或移开就不链接，之后到的回答也不再挂上', () => {
    const { links, probes } = setup(1)
    links.point(54)
    const [probe] = probes()
    links.answer(probe.id, true)
    expect(links.linked).toBe(54)

    links.point(undefined)
    expect(links.linked).toBeUndefined()
    links.answer(probe.id, true)
    expect(links.linked).toBeUndefined()
  })

  it('换了文档版本：正指着的名字按新版本重问，旧版本的回答丢掉', () => {
    const { links, probes } = setup(1)
    links.point(54)
    links.setVersion(2)
    const [old, renewed] = probes()
    expect(renewed).toEqual({ id: renewed.id, version: 2, offset: 54 })

    links.answer(old.id, true)
    expect(links.linked).toBeUndefined()
    links.answer(renewed.id, true)
    expect(links.linked).toBe(54)
  })

  it('还没收到文档时不问，点击也不拦', () => {
    const { links, sent } = setup(undefined)
    links.point(54)
    expect(links.click(54)).toBe(false)
    expect(sent).toEqual([])
  })

  it('没指着名字的点击不拦', () => {
    const { links } = setup(1)
    expect(links.click(undefined)).toBe(false)
  })
})