get-page-model.ts

import { Configuration, initialize } from '@bloomreach/spa-sdk'

import { BrPage, BrVisitor } from '../types'
import { brHttpClient as httpClient } from '../utils'

type Request = Configuration['request']
type HttpConnection = Request['connection']

export type Options = {
  /**
   * We need to pass some headers for the initialize function to work.
   * Pass trough all headers from the Request object.
   */
  headers?: Record<string, string | string[] | undefined>
  /**
   * HttpConnection string, required from Bloomreach Relevance module to retrieve IP address of user
   */
  connection?: HttpConnection
  /**
   * Visitor object required for Bloomreach Relevance to personalize the page model response
   */
  visitor?: BrVisitor
  /**
   * Whether the URL rewriter is disabled within the CMS.
   * This is the case for old < 14.2 version of Bloomreach.
   * When deploying newer versions of Bloomreach (14.3+) this will be set to true trough ENV settings
   */
  disableUrlRewriter?: boolean
  /**
   * When "disableUrlRewriter" is set to false, we need the sessionId added to the cookies
   * by Bloomreach when the site is is requested from the CMS in preview mode.
   */
  legacySessionId?: string
}

// Key for session ID cookie for legacy implementation (using url rewriter)
export const SESSION_COOKIE = 'JSESSIONID'

export async function getPageModel(apiUrl: string, path: string, opts: Options): Promise<BrPage> {
  const { headers = {}, connection, visitor, disableUrlRewriter = false, legacySessionId } = opts

  if (!apiUrl) {
    throw new Error(`Need a valid Bloomreach api url to fetch a pageModel! Got: ${String(apiUrl)}`)
  }

  if (!path) {
    throw new Error(`Need a valid path to fetch a pageModel! Got: ${String(path)}`)
  }

  // When the URL rewriter is enabled, we need to initialize the "legacy" way
  if (!disableUrlRewriter) {
    return legacyInitialize(apiUrl, path, legacySessionId)
  }

  const request: Request = {
    path,
    connection,
    headers: {
      ...(headers['x-forwarded-for'] ? { 'x-forwarded-for': headers['x-forwarded-for'] } : {}),
    },
  }

  const configuration: Configuration = {
    cmsBaseUrl: apiUrl,
    visitor,
    request,
    httpClient,
  }

  if (process.env.NODE_ENV !== 'production') {
    console.log(`Fetching: ${apiUrl}/resourceapi${path}`)
  }

  return initialize(configuration)
}

/**
 * The initialize function from the SDK does not support Bloomreach 14.0.0 and older.
 * Hence we need to make do a plain fetch to the API when we're still using the old version
 * of bloomreach in combination with the URL rewriter.
 *
 * To avoid having to duplicate more code, we create an object that is similar to the object
 * that the "initialize" function from the SDK returns.
 */
async function legacyInitialize(apiUrl: string, path: string, sessionId?: string): Promise<BrPage> {
  const url = `${apiUrl}/resourceapi${path}`

  if (process.env.NODE_ENV !== 'production') {
    console.log(`Legacy] Fetching: ${url}`)
  }

  try {
    const res = await fetch(url, {
      method: 'GET',
      // To authenticate the api call in preview mode we need to forward the JSESSIONID cookie
      // that bloomreach adds to the request made in preview mode
      headers: sessionId !== undefined ? { Cookie: `${SESSION_COOKIE}=${sessionId}` } : {},
    })
    const pageModel = await res.json()
    return {
      toJSON: () => pageModel,
      // eslint-disable-next-line @typescript-eslint/no-empty-function
      getVisitor: () => {},
    } as BrPage
  } catch (err) {
    console.error(`[Legacy] Failed to initialize pageModel.`, err)
    return {} as BrPage
  }
}