website/tools/authentication/authenticationFromServerSide.ts

import type { AxiosInstance, AxiosResponse } from "axios"
import type { GetServerSideProps, GetServerSidePropsContext } from "next"

import { api } from "../api"
import { Cookies } from "../cookies"
import type { RefreshTokenResponse, Tokens } from "./index"
import { Authentication } from "./Authentication"
import type { UserCurrent } from "../../models/User"

export const fetchRefreshToken = async (
  refreshToken: string,
): Promise<Tokens> => {
  const { data } = await api.post<RefreshTokenResponse>(
    "/users/refresh-token",
    {
      refreshToken,
    },
  )
  return { ...data, refreshToken }
}

interface AuthenticationFromServerSideOptions {
  shouldBeAuthenticated: boolean

  /** allows to fetch data server side with the authenticated user, the callback should returns the data that will be transfer to the component as props */
  fetchData?: (
    context: GetServerSidePropsContext,
    api: AxiosInstance,
  ) => Promise<{ [key: string]: any }>
}

export const authenticationFromServerSide = (
  options: AuthenticationFromServerSideOptions,
): GetServerSideProps => {
  const { shouldBeAuthenticated, fetchData } = options

  return async (context) => {
    const cookies = new Cookies(context.req.headers.cookie)
    const refreshToken = cookies.get("refreshToken")
    let tokens: Tokens | null = null
    if (refreshToken != null) {
      try {
        tokens = await fetchRefreshToken(refreshToken)
      } catch {
        cookies.remove("refreshToken")
      }
    }
    if (!shouldBeAuthenticated) {
      if (tokens != null) {
        return {
          redirect: {
            destination: "/application",
            permanent: false,
          },
        }
      } else {
        let data: any = {}
        if (fetchData != null) {
          data = await fetchData(context, api)
        }
        if (data.notFound != null) {
          return data
        }
        return { props: data }
      }
    } else {
      if (tokens == null) {
        return {
          redirect: {
            destination: "/authentication/signin",
            permanent: false,
          },
        }
      } else {
        try {
          let data: any = {}
          const authentication = new Authentication(tokens)
          const { data: currentUser } = await authentication.api.get<
            unknown,
            AxiosResponse<UserCurrent>
          >("/users/current")
          if (fetchData != null) {
            data = await fetchData(context, authentication.api)
          }
          if (data.notFound != null) {
            return data
          }
          return {
            props: { authentication: { tokens, ...currentUser }, ...data },
          }
        } catch {
          return {
            notFound: true,
          }
        }
      }
    }
  }
}