google.ts

import type { H3Event } from 'h3'
import {
  eventHandler,
  createError,
  getQuery,
  getRequestURL,
  sendRedirect,
} from 'h3'
import { withQuery, parsePath } from 'ufo'
import { ofetch } from 'ofetch'
import { defu } from 'defu'
import { useRuntimeConfig } from '#imports'
import type { OAuthConfig } from '#auth-utils'

export interface OAuthGoogleConfig {
  /**
   * Google OAuth Client ID
   * @default process.env.NUXT_OAUTH_GOOGLE_CLIENT_ID
   */
  clientId?: string;

  /**
   * Google OAuth Client Secret
   * @default process.env.NUXT_OAUTH_GOOGLE_CLIENT_SECRET
   */
  clientSecret?: string;

  /**
   * Google OAuth Scope
   * @default []
   * @see https://developers.google.com/identity/protocols/oauth2/scopes#google-sign-in
   * @example ['email', 'openid', 'profile']
   */
  scope?: string[];

  /**
   * Google OAuth Authorization URL
   * @default 'https://accounts.google.com/o/oauth2/v2/auth'
   */
  authorizationURL?: string;

  /**
   * Google OAuth Token URL
   * @default 'https://oauth2.googleapis.com/token'
   */
  tokenURL?: string;

  /**
   * Redirect URL post authenticating via google
   * @default '/auth/google'
   */
  redirectUrl: '/auth/google';
}

export function googleEventHandler({
  config,
  onSuccess,
  onError,
}: OAuthConfig<OAuthGoogleConfig>) {
  return eventHandler(async (event: H3Event) => {
    // @ts-ignore
    config = defu(config, useRuntimeConfig(event).oauth?.google, {
      authorizationURL: 'https://accounts.google.com/o/oauth2/v2/auth',
      tokenURL: 'https://oauth2.googleapis.com/token',
    }) as OAuthGoogleConfig
    const { code } = getQuery(event)

    if (!config.clientId) {
      const error = createError({
        statusCode: 500,
        message: 'Missing NUXT_OAUTH_GOOGLE_CLIENT_ID env variables.',
      })
      if (!onError) throw error
      return onError(event, error)
    }

    const redirectUrl = getRequestURL(event).href
    if (!code) {
      config.scope = config.scope || ['email', 'profile']
      // Redirect to Google Oauth page
      return sendRedirect(
        event,
        withQuery(config.authorizationURL as string, {
          response_type: 'code',
          client_id: config.clientId,
          redirect_uri: redirectUrl,
          scope: config.scope.join(' '),
        })
      )
    }

    const body: any = {
      grant_type: 'authorization_code',
      redirect_uri: parsePath(redirectUrl).pathname,
      client_id: config.clientId,
      client_secret: config.clientSecret,
      code,
    }
    const tokens: any = await ofetch(config.tokenURL as string, {
      method: 'POST',
      body,
    }).catch((error) => {
      return { error }
    })
    if (tokens.error) {
      const error = createError({
        statusCode: 401,
        message: `Google login failed: ${
          tokens.error?.data?.error_description || 'Unknown error'
        }`,
        data: tokens,
      })
      if (!onError) throw error
      return onError(event, error)
    }

    const accessToken = tokens.access_token
    const user: any = await ofetch(
      'https://www.googleapis.com/oauth2/v3/userinfo',
      {
        headers: {
          Authorization: `Bearer ${accessToken}`,
        },
      }
    )

    return onSuccess(event, {
      tokens,
      user,
    })
  })
}