Add validations to admin settings (#10348)

* Add validations to admin settings

- Validate correct HTML markup
- Validate presence of contact username & e-mail
- Validate that all usernames are valid
- Validate that enums have expected values

* Fix code style issue

* Fix tests

app/models/form/admin_settings.rb

@@ -3,49 +3,90 @@
 class Form::AdminSettings
   include ActiveModel::Model
 
-  delegate(
-    :site_contact_username,
-    :site_contact_username=,
-    :site_contact_email,
-    :site_contact_email=,
-    :site_title,
-    :site_title=,
-    :site_short_description,
-    :site_short_description=,
-    :site_description,
-    :site_description=,
-    :site_extended_description,
-    :site_extended_description=,
-    :site_terms,
-    :site_terms=,
-    :registrations_mode,
-    :registrations_mode=,
-    :closed_registrations_message,
-    :closed_registrations_message=,
-    :open_deletion,
-    :open_deletion=,
-    :timeline_preview,
-    :timeline_preview=,
-    :show_staff_badge,
-    :show_staff_badge=,
-    :bootstrap_timeline_accounts,
-    :bootstrap_timeline_accounts=,
-    :theme,
-    :theme=,
-    :min_invite_role,
-    :min_invite_role=,
-    :activity_api_enabled,
-    :activity_api_enabled=,
-    :peers_api_enabled,
-    :peers_api_enabled=,
-    :show_known_fediverse_at_about_page,
-    :show_known_fediverse_at_about_page=,
-    :preview_sensitive_media,
-    :preview_sensitive_media=,
-    :custom_css,
-    :custom_css=,
-    :profile_directory,
-    :profile_directory=,
-    to: Setting
-  )
+  KEYS = %i(
+    site_contact_username
+    site_contact_email
+    site_title
+    site_short_description
+    site_description
+    site_extended_description
+    site_terms
+    registrations_mode
+    closed_registrations_message
+    open_deletion
+    timeline_preview
+    show_staff_badge
+    bootstrap_timeline_accounts
+    theme
+    min_invite_role
+    activity_api_enabled
+    peers_api_enabled
+    show_known_fediverse_at_about_page
+    preview_sensitive_media
+    custom_css
+    profile_directory
+  ).freeze
+
+  BOOLEAN_KEYS = %i(
+    open_deletion
+    timeline_preview
+    show_staff_badge
+    activity_api_enabled
+    peers_api_enabled
+    show_known_fediverse_at_about_page
+    preview_sensitive_media
+    profile_directory
+  ).freeze
+
+  UPLOAD_KEYS = %i(
+    thumbnail
+    hero
+    mascot
+  ).freeze
+
+  attr_accessor(*KEYS)
+
+  validates :site_short_description, :site_description, :site_extended_description, :site_terms, :closed_registrations_message, html: true
+  validates :registrations_mode, inclusion: { in: %w(open approved none) }
+  validates :min_invite_role, inclusion: { in: %w(disabled user moderator admin) }
+  validates :site_contact_email, :site_contact_username, presence: true
+  validates :site_contact_username, existing_username: true
+  validates :bootstrap_timeline_accounts, existing_username: { multiple: true }
+
+  def initialize(_attributes = {})
+    super
+    initialize_attributes
+  end
+
+  def save
+    return false unless valid?
+
+    KEYS.each do |key|
+      value = instance_variable_get("@#{key}")
+
+      if UPLOAD_KEYS.include?(key)
+        upload = SiteUpload.where(var: key).first_or_initialize(var: key)
+        upload.update(file: value)
+      else
+        setting = Setting.where(var: key).first_or_initialize(var: key)
+        setting.update(value: typecast_value(key, value))
+      end
+    end
+  end
+
+  private
+
+  def initialize_attributes
+    KEYS.each do |key|
+      instance_variable_set("@#{key}", Setting.public_send(key)) if instance_variable_get("@#{key}").nil?
+    end
+  end
+
+  def typecast_value(key, value)
+    if BOOLEAN_KEYS.include?(key)
+      value == '1'
+    else
+      value
+    end
+  end
 end