// Web e2e scenario: startup auto-selection keeps the hero on screen.
//
// A page load with a workspace already registered runs
// `WorkspacesService.startInitialSelection`: it connects the most recent
// workspace and opens its blank session. `openState` flips to `loading` the
// moment `open()` lands, which used to drive `data-phase=settling` on the
// conversation root — `visibility:hidden` over the composer seat and the
// header for the whole `session.history` round-trip, so the center column went
// blank and repainted, reading as a full-page refresh on every launch.
//
// The unit spec pins the phase condition over hand-built stores. What only the
// assembled application can show is that the path a user actually takes
// reaches it: the real selection service, the real client session opening over
// the real /api transport, and a real browser deciding what is painted.
//
// The round-trip against a loopback host is far too fast to observe, so this
// scenario HOLDS the `session.history` response open at the browser's network
// boundary and asserts the visible frame while it is in flight. That gate is
// what makes the assertions non-vacuous: with the exemption reverted the held
// window is exactly when `settling` is painted and the composer is hidden.
//
// Zero model calls: registering a workspace and opening its blank session are
// host RPCs with no model involvement. A stray stream would fail loud with
// NO_ADAPTER.
import type { Browser, Page } from 'playwright'
import { chromium } from 'playwright'
import { afterAll, beforeAll, describe, expect, it, onTestFailed } from 'vitest'
import { acknowledgeReloadConnectionLoss, launchWebScaffold, watchConsole, type WebScaffold } from './scaffold.ts'
import { connectFreshWorkspace, newEnglishPage, saveFailureShot } from './support.ts'

/** Wire path of the history round-trip the conversation root waits out (POST /api/session.history). */
const HISTORY_ROUTE = '**/api/session.history'

/**
 * The conversation root's own phase attribute. `div` disambiguates it from the
 * composer textarea, which carries an unrelated `data-phase` of its own.
 */
const ROOT_PHASE = 'div[data-phase]'

/** Every distinct `data-phase` the conversation root shows, in order, across one page load. */
function recordedPhases(page: Page): Promise<string[]> {
  return page.evaluate(() => (window as unknown as { __conversationPhases: string[] }).__conversationPhases)
}

describe('web e2e: startup auto-selection', () => {
  let scaffold: WebScaffold
  let browser: Browser
  let page: Page
  let tripwire: ReturnType<typeof watchConsole>

  beforeAll(async () => {
    scaffold = await launchWebScaffold({})
    browser = await chromium.launch()
    page = await newEnglishPage(browser)
    tripwire = watchConsole(page)
    await page.goto(scaffold.baseUrl, { waitUntil: 'load' })
    await page.waitForSelector('[class*="frame"]', { timeout: 30_000 })
    // A registered workspace is the precondition for auto-selection: the first
    // load has nothing to select, so the reload below is the path under test.
    await connectFreshWorkspace(page, scaffold.workspaceCwd, 'startup-auto-selection')
  }, 180_000)

  afterAll(async () => {
    await browser?.close()
    await scaffold?.close()
  })

  it('keeps the hero and the composer on screen while the auto-selected blank session opens', async () => {
    onTestFailed(() => saveFailureShot(page, 'web-e2e-startup-auto-selection'))
    // Runs before any page script on the reload below, so the first phase the
    // root ever renders is recorded, not just the ones after a listener attaches.
    await page.addInitScript(() => {
      const phases: string[] = []
      ;(window as unknown as { __conversationPhases: string[] }).__conversationPhases = phases
      setInterval(() => {
        const phase = document.querySelector('div[data-phase]')?.getAttribute('data-phase')
        if (phase === null || phase === undefined) return
        if (phases[phases.length - 1] !== phase) phases.push(phase)
      }, 8)
    })

    let releaseHistory = (): void => {}
    const historyHeld = new Promise<void>((resolve) => { releaseHistory = resolve })
    let historyRequested = (): void => {}
    const historyInFlight = new Promise<void>((resolve) => { historyRequested = resolve })
    let gated = false
    await page.route(HISTORY_ROUTE, async (route) => {
      // Only the auto-selection's own round-trip is held; later pages must not
      // deadlock behind a gate this test has already released.
      if (gated) { await route.continue(); return }
      gated = true
      historyRequested()
      await historyHeld
      await route.continue()
    })

    const warningsBefore = tripwire.warnings.length
    await page.reload({ waitUntil: 'commit' })
    await historyInFlight

    // The frame a user sees while the session is still opening: hero phase, the
    // hero title, and a composer that is actually painted (`settling` hides the
    // seat with `visibility:hidden`, which Playwright reports as not visible).
    await page.waitForSelector(ROOT_PHASE, { timeout: 15_000 })
    expect(await page.locator(ROOT_PHASE).first().getAttribute('data-phase')).toBe('hero')
    expect(await page.getByText("Let's start building").isVisible()).toBe(true)
    expect(await page.locator('textarea').first().isVisible()).toBe(true)

    releaseHistory()
    await page.locator('textarea:enabled[placeholder="Describe what you want to build"]')
      .waitFor({ timeout: 15_000 })
    acknowledgeReloadConnectionLoss(tripwire, warningsBefore)

    // Settling is not merely absent from the frame sampled above: the root
    // never entered it at any point of the load.
    expect(await recordedPhases(page)).toEqual(['hero'])
    expect(tripwire.pageErrors).toEqual([])
  }, 120_000)
})