class UserAdminLanguageTest

class UserAdminLanguageTest extends BrowserTestBase {
    
    /**
     * A user with permission to access admin pages and administer languages.
     *
     * @var \Drupal\user\UserInterface
     */
    protected $adminUser;
    
    /**
     * A non-administrator user for this test.
     *
     * @var \Drupal\user\UserInterface
     */
    protected $regularUser;
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'user',
        'language',
        'language_test',
        'user_language_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // User to add and remove language.
        $this->adminUser = $this->drupalCreateUser([
            'administer languages',
            'access administration pages',
        ]);
        // User to check non-admin access.
        $this->regularUser = $this->drupalCreateUser();
    }
    
    /**
     * Tests that admin language is not configurable in single language sites.
     */
    public function testUserAdminLanguageConfigurationNotAvailableWithOnlyOneLanguage() : void {
        $this->drupalLogin($this->adminUser);
        $this->setLanguageNegotiation();
        $path = 'user/' . $this->adminUser
            ->id() . '/edit';
        $this->drupalGet($path);
        // Ensure administration pages language settings widget is not available.
        $this->assertSession()
            ->fieldNotExists('edit-preferred-admin-langcode');
    }
    
    /**
     * Tests that admin language negotiation is configurable only if enabled.
     */
    public function testUserAdminLanguageConfigurationAvailableWithAdminLanguageNegotiation() : void {
        $this->drupalLogin($this->adminUser);
        $this->addCustomLanguage();
        $path = 'user/' . $this->adminUser
            ->id() . '/edit';
        // Checks with user administration pages language negotiation disabled.
        $this->drupalGet($path);
        // Ensure administration pages language settings widget is not available.
        $this->assertSession()
            ->fieldNotExists('edit-preferred-admin-langcode');
        // Checks with user administration pages language negotiation enabled.
        $this->setLanguageNegotiation();
        $this->drupalGet($path);
        // Ensure administration pages language settings widget is available.
        $this->assertSession()
            ->fieldExists('edit-preferred-admin-langcode');
    }
    
    /**
     * Tests that the admin language is configurable only for administrators.
     *
     * If a user has the permission "access administration pages" or
     * "view the administration theme", they should be able to see the setting to
     * pick the language they want those pages in.
     *
     * If a user does not have that permission, it would confusing for them to
     * have a setting for pages they cannot access, so they should not be able to
     * set a language for those pages.
     */
    public function testUserAdminLanguageConfigurationAvailableIfAdminLanguageNegotiationIsEnabled() : void {
        $this->drupalLogin($this->adminUser);
        // Adds a new language, because with only one language, setting won't show.
        $this->addCustomLanguage();
        $this->setLanguageNegotiation();
        $path = 'user/' . $this->adminUser
            ->id() . '/edit';
        $this->drupalGet($path);
        // Ensure administration pages language setting is visible for admin.
        $this->assertSession()
            ->fieldExists('edit-preferred-admin-langcode');
        // Ensure administration pages language setting is visible for editors.
        $editor = $this->drupalCreateUser([
            'view the administration theme',
        ]);
        $this->drupalLogin($editor);
        $path = 'user/' . $editor->id() . '/edit';
        $this->drupalGet($path);
        $this->assertSession()
            ->fieldExists('edit-preferred-admin-langcode');
        // Ensure administration pages language setting is hidden for non-admins.
        $this->drupalLogin($this->regularUser);
        $path = 'user/' . $this->regularUser
            ->id() . '/edit';
        $this->drupalGet($path);
        $this->assertSession()
            ->fieldNotExists('edit-preferred-admin-langcode');
    }
    
    /**
     * Tests the actual language negotiation.
     */
    public function testActualNegotiation() : void {
        $this->drupalLogin($this->adminUser);
        $this->addCustomLanguage();
        $this->setLanguageNegotiation();
        // Even though we have admin language negotiation, so long as the user has
        // no preference set, negotiation will fall back further.
        $path = 'user/' . $this->adminUser
            ->id() . '/edit';
        $this->drupalGet($path);
        $this->assertSession()
            ->pageTextContains('Language negotiation method: language-default');
        $this->drupalGet('xx/' . $path);
        $this->assertSession()
            ->pageTextContains('Language negotiation method: language-url');
        // Set a preferred language code for the user.
        $edit = [];
        $edit['preferred_admin_langcode'] = 'xx';
        $this->drupalGet($path);
        $this->submitForm($edit, 'Save');
        // Test negotiation with the URL method first. The admin method will only
        // be used if the URL method did not match.
        $this->drupalGet($path);
        $this->assertSession()
            ->pageTextContains('Language negotiation method: language-user-admin');
        $this->drupalGet('xx/' . $path);
        $this->assertSession()
            ->pageTextContains('Language negotiation method: language-url');
        // Test negotiation with the admin language method first. The admin method
        // will be used at all times.
        $this->setLanguageNegotiation(TRUE);
        $this->drupalGet($path);
        $this->assertSession()
            ->pageTextContains('Language negotiation method: language-user-admin');
        $this->drupalGet('xx/' . $path);
        $this->assertSession()
            ->pageTextContains('Language negotiation method: language-user-admin');
        // Make sure 'language-user-admin' plugin does not fail when a route is
        // restricted to POST requests and language negotiation with the admin
        // language method is used.
        $this->drupalGet('/user-language-test/form');
        $this->submitForm([], 'Send');
        $this->assertSession()
            ->statusCodeEquals(200);
        // Unset the preferred language code for the user.
        $edit = [];
        $edit['preferred_admin_langcode'] = '';
        $this->drupalGet($path);
        $this->submitForm($edit, 'Save');
        $this->drupalGet($path);
        $this->assertSession()
            ->pageTextContains('Language negotiation method: language-default');
        $this->drupalGet('xx/' . $path);
        $this->assertSession()
            ->pageTextContains('Language negotiation method: language-url');
    }
    
    /**
     * Sets the User interface negotiation detection method.
     *
     * Enables the "Account preference for administration pages" language
     * detection method for the User interface language negotiation type.
     *
     * @param bool $admin_first
     *   Whether the admin negotiation should be first.
     */
    public function setLanguageNegotiation($admin_first = FALSE) {
        $edit = [
            'language_interface[enabled][language-user-admin]' => TRUE,
            'language_interface[enabled][language-url]' => TRUE,
            'language_interface[weight][language-user-admin]' => $admin_first ? -12 : -8,
            'language_interface[weight][language-url]' => -10,
        ];
        $this->drupalGet('admin/config/regional/language/detection');
        $this->submitForm($edit, 'Save settings');
    }
    
    /**
     * Helper method for adding a custom language.
     */
    public function addCustomLanguage() {
        $langcode = 'xx';
        // The English name for the language.
        $name = $this->randomMachineName(16);
        $edit = [
            'predefined_langcode' => 'custom',
            'langcode' => $langcode,
            'label' => $name,
            'direction' => LanguageInterface::DIRECTION_LTR,
        ];
        $this->drupalGet('admin/config/regional/language/add');
        $this->submitForm($edit, 'Add custom language');
    }

}