Add first-time-setup registration flow

Summary:
Ref T1536. Currently, when you install Phabricator you're dumped on the login screen and have to consult the documentation to learn about `bin/accountadmin`.

Instead, detect that an install is running first-time setup:

  - It has no configured providers; and
  - it has no user accounts.

We can safely deduce that such an install isn't configured yet, and let the user create an admin account from the web UI.

After they login, we raise a setup issue and lead them to configure authentication.

(This could probably use some UI and copy tweaks.)

Test Plan:
{F46738}

{F46739}

Reviewers: chad, btrahan

Reviewed By: chad

CC: aran

Maniphest Tasks: T1536

Differential Revision: https://secure.phabricator.com/D6228

src/applications/auth/controller/PhabricatorAuthRegisterController.php

@@ -20,10 +20,15 @@ final class PhabricatorAuthRegisterController
       return $this->renderError(pht('You are already logged in.'));
     }
 
+    $is_setup = false;
     if (strlen($this->accountKey)) {
       $result = $this->loadAccountForRegistrationOrLinking($this->accountKey);
       list($account, $provider, $response) = $result;
       $is_default = false;
+    } else if ($this->isFirstTimeSetup()) {
+      list($account, $provider, $response) = $this->loadSetupAccount();
+      $is_default = true;
+      $is_setup = true;
     } else {
       list($account, $provider, $response) = $this->loadDefaultAccount();
       $is_default = true;
@@ -213,6 +218,10 @@ final class PhabricatorAuthRegisterController
               $editor->changePassword($user, $envelope);
             }
 
+            if ($is_setup) {
+              $editor->makeAdminUser($user, true);
+            }
+
             $account->setUserPHID($user->getPHID());
             $provider->willRegisterAccount($account);
             $account->save();
@@ -319,24 +328,53 @@ final class PhabricatorAuthRegisterController
           ->setError($e_realname));
     }
 
-    $form->appendChild(
-      id(new AphrontFormSubmitControl())
-        ->addCancelButton($this->getApplicationURI('start/'))
-        ->setValue(pht('Register Phabricator Account')));
+    $submit = id(new AphrontFormSubmitControl());
 
-    $title = pht('Phabricator Registration');
+    if ($is_setup) {
+      $submit
+        ->setValue(pht('Create Admin Account'));
+    } else {
+      $submit
+        ->addCancelButton($this->getApplicationURI('start/'))
+        ->setValue(pht('Register Phabricator Account'));
+    }
+
+
+    $form->appendChild($submit);
 
     $crumbs = $this->buildApplicationCrumbs();
-    $crumbs->addCrumb(
-      id(new PhabricatorCrumbView())
-        ->setName(pht('Register')));
-    $crumbs->addCrumb(
-      id(new PhabricatorCrumbView())
-        ->setName($provider->getProviderName()));
+
+    if ($is_setup) {
+      $crumbs->addCrumb(
+        id(new PhabricatorCrumbView())
+          ->setName(pht('Setup Admin Account')));
+        $title = pht('Welcome to Phabricator');
+    } else {
+      $crumbs->addCrumb(
+        id(new PhabricatorCrumbView())
+          ->setName(pht('Register')));
+      $crumbs->addCrumb(
+        id(new PhabricatorCrumbView())
+          ->setName($provider->getProviderName()));
+        $title = pht('Phabricator Registration');
+    }
+
+    $welcome_view = null;
+    if ($is_setup) {
+      $welcome_view = id(new AphrontErrorView())
+        ->setSeverity(AphrontErrorView::SEVERITY_NOTICE)
+        ->setTitle(pht('Welcome to Phabricator'))
+        ->appendChild(
+          pht(
+            'Installation is complete. Register your administrator account '.
+            'below to log in. You will be able to configure options and add '.
+            'other authentication mechanisms (like LDAP or OAuth) later on.'));
+    }
 
     return $this->buildApplicationPage(
       array(
         $crumbs,
+        $welcome_view,
         $error_view,
         $form,
       ),
@@ -381,6 +419,13 @@ final class PhabricatorAuthRegisterController
     return array($account, $provider, $response);
   }
 
+  private function loadSetupAccount() {
+    $provider = new PhabricatorAuthProviderPassword();
+    $account = $provider->getDefaultExternalAccount();
+    $response = null;
+    return array($account, $provider, $response);
+  }
+
   private function loadProfilePicture(PhabricatorExternalAccount $account) {
     $phid = $account->getProfileImagePHID();
     if (!$phid) {