import {
  test as base,
  expect,
  type ConsoleMessage,
  type Response,
  type WebError,
} from '@playwright/test'

type FailureKind = 'console.error' | 'pageerror' | 'same-origin 5xx' | 'weberror'

type BrowserFailure = {
  kind: FailureKind
  detail: string
}

type E2EFailureGuardFixtures = {
  e2eFailureGuard: void
  /**
   * Same-origin paths whose failed responses this spec provokes on purpose.
   *
   * A `fetch` the app handles in code still makes the browser log "Failed to
   * load resource", so a spec asserting a refusal (B40: signing in with a
   * revoked passkey) would otherwise fail the guard for doing its job. Declaring
   * the path — rather than allowing 4xx broadly — keeps an unhandled request
   * failure in any other spec a failure. It is an option so a spec declares it
   * once with `test.use`, instead of pushing at exactly the right moment
   * mid-test.
   */
  expectedRequestFailurePaths: string[]
}

const loadFailurePrefix = 'Failed to load resource'

const missingFaviconConsoleError =
  'Failed to load resource: the server responded with a status of 404 (Not Found)'

const errorDetail = (error: Error): string => error.stack ?? error.message

const responseDetail = (response: Response): string =>
  `${response.status()} ${response.request().method()} ${response.url()}`

const consoleDetail = (message: ConsoleMessage): string => {
  const { url, lineNumber, columnNumber } = message.location()
  const location = url ? ` (${url}:${lineNumber}:${columnNumber})` : ''
  return `${message.text()}${location}`
}

const isAllowedConsoleError = (
  message: ConsoleMessage,
  origin: string | null,
  expectedRequestFailurePaths: string[],
): boolean => {
  const { url } = message.location()
  if (!url || origin === null) return false

  const location = new URL(url)
  if (location.origin !== origin) return false

  // The app intentionally has no /favicon.ico asset yet.
  if (message.text() === missingFaviconConsoleError) return location.pathname === '/favicon.ico'

  return (
    message.text().startsWith(loadFailurePrefix) &&
    expectedRequestFailurePaths.includes(location.pathname)
  )
}

export const test = base.extend<E2EFailureGuardFixtures>({
  expectedRequestFailurePaths: [[], { option: true }],
  e2eFailureGuard: [
    async ({ baseURL, context, expectedRequestFailurePaths, page }, use) => {
      const failures: BrowserFailure[] = []
      const origin = baseURL ? new URL(baseURL).origin : null

      const onConsole = (message: ConsoleMessage) => {
        if (
          message.type() !== 'error' ||
          isAllowedConsoleError(message, origin, expectedRequestFailurePaths)
        ) {
          return
        }
        failures.push({ kind: 'console.error', detail: consoleDetail(message) })
      }
      const onPageError = (error: Error) => {
        failures.push({ kind: 'pageerror', detail: errorDetail(error) })
      }
      const onResponse = (response: Response) => {
        if (
          response.status() >= 500 &&
          origin !== null &&
          new URL(response.url()).origin === origin
        ) {
          failures.push({ kind: 'same-origin 5xx', detail: responseDetail(response) })
        }
      }
      const onWebError = (webError: WebError) => {
        failures.push({ kind: 'weberror', detail: errorDetail(webError.error()) })
      }

      page.on('console', onConsole)
      page.on('pageerror', onPageError)
      page.on('response', onResponse)
      context.on('weberror', onWebError)

      // S8 — the home story-video embed is a YouTube iframe; e2e must stay
      // hermetic (CI network must never gate a home-page test on the real
      // player loading — same spirit as the S2/S3 feed stubs).
      await context.route('https://www.youtube-nocookie.com/**', (route) => route.abort())

      // S10 — the campaign-home pixel spec publishes a Meta Pixel ID into the
      // shared test DB, so concurrent specs may render the home with the base
      // code. Fulfill the external script locally (never a real request to
      // Meta): a blocked network would trip the console-error guard below.
      await context.route('https://connect.facebook.net/**', (route) =>
        route.fulfill({ body: '', contentType: 'application/javascript' }),
      )

      await use()

      page.off('console', onConsole)
      page.off('pageerror', onPageError)
      page.off('response', onResponse)
      context.off('weberror', onWebError)

      if (failures.length) {
        const details = failures
          .map(({ kind, detail }, index) => `${index + 1}. [${kind}] ${detail}`)
          .join('\n\n')
        throw new Error(`Unexpected browser/runtime failures:\n\n${details}`)
      }
    },
    { auto: true },
  ],
})

export { expect }