feat: refactor resource owner password grant (#1443)

## What kind of change does this PR introduce?

Was passing through the code and found that a re-ordering was slightly
easier to read for me. Let me know your thoughts

---------

Co-authored-by: joel <[email protected]>

internal/api/token.go

@@ -117,27 +117,29 @@ func (a *API) ResourceOwnerPasswordGrant(ctx context.Context, w http.ResponseWri
 
  grantParams.FillGrantParams(r)
 
- if params.Email != "" {
+ switch {
+ case params.Email != "" && config.External.Email.Enabled:
  provider = "email"
- if !config.External.Email.Enabled {
- return badRequestError("Email logins are disabled")
- }
  user, err = models.FindUserByEmailAndAudience(db, params.Email, aud)
- } else if params.Phone != "" {
+
+ case params.Phone != "" && config.External.Phone.Enabled:
  provider = "phone"
- if !config.External.Phone.Enabled {
- return badRequestError("Phone logins are disabled")
- }
  params.Phone = formatPhoneNumber(params.Phone)
  user, err = models.FindUserByPhoneAndAudience(db, params.Phone, aud)
- } else {
+
+ case !config.External.Email.Enabled:
+ return badRequestError("Email logins are disabled")
+
+ case !config.External.Phone.Enabled:
+ return badRequestError("Phone logins are disabled")
+
+ default:
  return oauthError("invalid_grant", InvalidLoginMessage)
  }
 
- if err != nil {
- if models.IsNotFoundError(err) {
- return oauthError("invalid_grant", InvalidLoginMessage)
- }
+ if err != nil && models.IsNotFoundError(err) {
+ return oauthError("invalid_grant", InvalidLoginMessage)
+ } else if err != nil {
  return internalServerError("Database error querying schema").WithInternalError(err)
  }