Provide Social Auth settings: functionality

Thanks!

1. +++ b/src/SocialAuthUserManager.php
   @@ -98,11 +98,25 @@ class SocialAuthUserManager {
   +      // Check if Admin can authenticate.
   +      if($config->get('disable_admin_login')){
   +        if($drupal_user->id() == 1) {
   +          return $this->redirect('user.login');
   +        }
   +      }
   

   I'd prefer this logic to be place in a different method. Thus, implementers which do not use the authenticateUser method can check this setting. Also, use drupal_set_message to let the user knows why he couldn't log in.

2. +++ b/src/SocialAuthUserManager.php
   @@ -98,11 +98,25 @@ class SocialAuthUserManager {
   +      // Check for Disabled roles.
   +      $disabled_roles = $config->get('disabled_roles');
   +      foreach($disabled_roles as $role){
   +        if(!empty($role) && $drupal_user->hasRole($role)){
   +          return $this->redirect('user.login');
   +        }
   +      }
   

   Same as above.

3. +++ b/src/SocialAuthUserManager.php
   @@ -124,7 +138,14 @@ class SocialAuthUserManager {
   +        if($config->get('redirect_user_form')) {
   +          return $this->redirect('entity.user.edit_form', [
   +            'user' => $drupal_user->id(),
   +          ]);
   +        }
   +        else{
   +          return $this->redirect('user.page');
   +        }
   

   Same here. Plus, I think if the new created user is not redirected to the edit form, it should be redirected to post_login_path

This looks better, but I have a few suggestions.

1. +++ b/src/SocialAuthUserManager.php
   @@ -100,9 +105,17 @@ class SocialAuthUserManager {
   +      if ($redirect = $this->isAdminDisabled($drupal_user)) {
   ...
   +      if ($redirect = $this->isUserDisabled($drupal_user)) {
   
   @@ -124,7 +137,12 @@ class SocialAuthUserManager {
   +        if ($redirect = $this->redirectToUserForm($drupal_user)) {
   

   I think it is better if this methods return TRUE/FALSE values. First, it would allow implementers which don't use the authenticateUser method to provide their own messages/functionality. Second, you avoid the assignment operation inside the if clause

2. +++ b/src/SocialAuthUserManager.php
   @@ -333,6 +351,92 @@ class SocialAuthUserManager {
   +      drupal_set_message($this->t('Authentication for Admin is disabled for Security Reasons.'), 'error');
   

   '..for Admin (user 1).'

3. +++ b/src/SocialAuthUserManager.php
   @@ -333,6 +351,92 @@ class SocialAuthUserManager {
   +        drupal_set_message($this->t('Authentication for @role is disabled for Security Reasons.', array('@role' => $role)), 'error');
   

   '.. is disabled.'

Here's a new patch for this issue.

What do you mean by following the first suggestion?