Adding some standard OpenID Connect providers (Google, Facebook) (WIP):

* frontend

server/lib/conversejs/params.ts

@@ -85,14 +85,18 @@ async function getConverseJSParams (
       )
     } else {
       try {
-        const customOidc = ExternalAuthOIDC.singleton('custom')
-        if (await customOidc.isOk()) {
-          const authUrl = customOidc.getConnectUrl()
-          const buttonLabel = customOidc.getButtonLabel()
-          if (authUrl && buttonLabel) {
-            externalAuthOIDC = {
-              buttonLabel: buttonLabel,
-              url: authUrl
+        const oidcs = ExternalAuthOIDC.allSingletons()
+        for (const oidc of oidcs) {
+          if (await oidc.isOk()) {
+            const authUrl = oidc.getConnectUrl()
+            const buttonLabel = oidc.getButtonLabel()
+            if (authUrl && buttonLabel) {
+              externalAuthOIDC ??= []
+              externalAuthOIDC.push({
+                type: oidc.type,
+                buttonLabel: buttonLabel,
+                url: authUrl
+              })
             }
           }
         }

server/lib/external-auth/oidc.ts

@@ -1,6 +1,7 @@
 import type { RegisterServerOptions } from '@peertube/peertube-types'
 import type { Request, Response, CookieOptions } from 'express'
 import type { ExternalAccountInfos, AcceptableAvatarMimeType } from './types'
+import type { ExternalAuthOIDCType } from '../../../shared/lib/types'
 import { ExternalAuthenticationError } from './error'
 import { getBaseRouterRoute } from '../helpers'
 import { canonicalizePluginUri } from '../uri/canonicalize'
@@ -68,8 +69,6 @@ async function getRandomBytes (size: number): Promise<Buffer> {
   })
 }
 
-type ExternalAuthOIDCType = 'custom' | 'google' | 'facebook'
-
 /**
  * This class handles the external OpenId Connect provider, if defined.
  */