Account: Composition to handle User and its identities

We have a lot of things that act upon a user record and one or more of it's identities at the same time:
* Sing up: Create a user and it's initial identity
* Rename:  Change the username and create a new identity, turn old into an alias
* Cancel Account: Remove user and all their identities.

In order to keep the User and Identity behaviour isolated but still have a this logic represented in a sinle place the Account model deals with all these things.

We could have overwritten the User#create, User#update and User#destroy methods instead. But then we would always create identities, even if we only need a user (for example in tests).

1 files changed, 57 insertions, 0 deletions

diff --git a/users/app/models/account.rb b/users/app/models/account.rb
new file mode 100644
index 0000000..5368a1b
--- /dev/null
+++ b/users/app/models/account.rb
@@ -0,0 +1,57 @@
+#
+# A Composition of a User record and it's identity records.
+#
+class Account
+
+  attr_reader :user
+
+  def initialize(user = nil)
+    @user = user
+  end
+
+  # Returns the user record so it can be used in views.
+  def self.create(attrs)
+    @user = User.create(attrs).tap do |user|
+      Identity.create_for user
+    end
+  end
+
+  def update(attrs)
+    if attrs[:password_verifier].present?
+      update_login(attrs[:login])
+      @user.update_attributes attrs.slice(:password_verifier, :password_salt)
+    end
+    # TODO: move into identity controller
+    update_pgp_key(attrs[:public_key]) if attrs.has_key? :public_key
+    @user.save && save_identities
+    @user.refresh_identity
+  end
+
+  def destroy
+    return unless @user
+    Identity.by_user_id.key(@user.id).each do |identity|
+      identity.destroy
+    end
+    @user.destroy
+  end
+
+  protected
+
+  def update_login(login)
+    return unless login.present?
+    @old_identity = Identity.for(@user)
+    @user.login = login
+    @new_identity = Identity.for(@user) # based on the new login
+    @old_identity.destination = @user.email_address # alias old -> new
+  end
+
+  def update_pgp_key(key)
+    @new_identity ||= Identity.for(@user)
+    @new_identity.set_key(:pgp, key)
+  end
+
+  def save_identities
+    @new_identity.try(:save) && @old_identity.try(:save)
+  end
+
+end