export function parsePathAndParamsFromExpoGoLink(url: string): {
  pathname: string
  queryString: string
} {
  // If the URL is defined (default in Expo Go dev apps) and the URL has no path:
  // `exp://192.168.87.39:19000/` then use the default `exp://192.168.87.39:19000/--/`

  const href = parsePathFromExpoGoLink(url)
  const results = href.match(/([^?]*)(\?.*)?/)
  return {
    pathname: results?.[1] ?? '',
    queryString: results?.[2] ?? '',
  }
}

export function parsePathFromExpoGoLink(url: string): string {
  // If the URL is defined (default in Expo Go dev apps) and the URL has no path:
  // `exp://192.168.87.39:19000/` then use the default `exp://192.168.87.39:19000/--/`
  return url.match(/exps?:\/\/.*?\/--\/(.*)/)?.[1] ?? ''
}

// This is only run on native.
function extractExactPathFromURL(url: string): string {
  if (
    // If a universal link / app link / web URL is used, we should use the path
    // from the URL, while stripping the origin.
    url.match(/^https?:\/\//)
  ) {
    const { origin, href, hostname } = new URL(url)

    if (hostname === 'exp.host' || hostname === 'u.expo.dev') {
      // These are QR code generate deep-link that always like to the '/' path
      // TODO: In the future, QR code may link to a specific path and this logic will need to be udpated
      return ''
    }

    return href.replace(origin, '')
  }

  const isExpoGo =
    typeof globalThis.expo !== 'undefined' && globalThis.expo?.modules?.ExpoGo

  // Handle special URLs used in Expo Go: `/--/pathname` -> `pathname`
  if (
    isExpoGo &&
    // while not exhaustive, `exp` and `exps` are the only two schemes which
    // are passed through to other apps in Expo Go.
    url.match(/^exp(s)?:\/\//)
  ) {
    const pathname = parsePathFromExpoGoLink(url)
    if (pathname) {
      return fromDeepLink('a://' + pathname)
    }
    // Match the `?.*` segment of the URL.
    const queryParams = url.match(/exps?:\/\/.*\?(.*)/)?.[1]
    if (queryParams) {
      return fromDeepLink('a://?' + queryParams)
    }

    return ''
  }

  // TODO: Support dev client URLs

  return fromDeepLink(url)
}

/** Major hack to support the makeshift expo-development-client system. */
function isExpoDevelopmentClient(url: URL): boolean {
  return url.hostname === 'expo-development-client'
}

function fromDeepLink(url: string): string {
  let res: URL | null
  try {
    // This is for all standard deep links, e.g. `foobar://` where everything
    // after the `://` is the path.
    res = new URL(url)
  } catch {
    /**
     * We failed to parse the URL. This can occur for a variety of reasons, including:
     * - Its a partial URL (e.g. `/route?query=param`).
     * - It has a valid App scheme, but the scheme isn't a valid URL scheme (e.g. `my_app://`)
     */

    // If `url` is already a path (starts with `/`), return it as-is
    // This prevents incorrect rewrites when URL is in query params (e.g. `/?url=https://example.com`)
    if (url.startsWith('/')) {
      return url
    }

    /**
     * App schemes are not valid URL schemes, so they will fail to parse.
     * We need to strip the scheme from these URLs
     */
    return url.replace(/^[^:]+:\/\//, '')
  }

  if (isExpoDevelopmentClient(res)) {
    if (!res.searchParams.get('url')) {
      return ''
    }
    const incomingUrl = res.searchParams.get('url')!
    return extractExactPathFromURL(decodeURI(incomingUrl))
  }

  let results = ''

  if (res.host) {
    results += res.host
  }

  if (res.pathname) {
    results += res.pathname
  }

  const qs = !res.search
    ? ''
    : // @ts-ignore: `entries` is not on `URLSearchParams` in some typechecks.
      [...res.searchParams.entries()]
        .map(([k, v]) => `${k}=${decodeURIComponent(v)}`)
        .join('&')

  if (qs) {
    results += '?' + qs
  }

  return results
}

export function extractExpoPathFromURL(_prefixes: string[], url = '') {
  return (
    extractExactPathFromURL(url)
      // TODO: We should get rid of this, dropping specificities is not good
      .replace(/^\//, '')
  )
}

export function adjustPathname(url: { hostname?: string | null; pathname: string }) {
  if (url.hostname === 'exp.host' || url.hostname === 'u.expo.dev') {
    // drop the first two segments from pathname:
    return url.pathname.split('/').slice(2).join('/')
  }
  return url.pathname
}

export const extractPathFromURL = extractExpoPathFromURL