Add NodeAction: an append-only log of who did what to a nodeHEADmaster

node_id/page_id/user_id are lookup and ordering only -- all three
nullify on delete, so an entry outlives its actor and its subject.
Everything that must survive those deletions lives in a mandatory
metadata jsonb written once at creation: the actor's username, the
node's human-readable name (pinned to the default locale), and
action-specific extras such as publish's title from/to.

NodeAction.record! is the single constructor, so every entry gets
the same baseline metadata without each call site re-implementing
it. occurred_at is one field for live and backfilled entries alike;
inferred_from distinguishes them -- nil means witnessed at the
moment it happened, populated names how a backfilled entry was
estimated.

Instrumented so far: publish (crediting the actual publisher,
threaded through from the controller -- previously nobody had the
act of publishing recorded anywhere), revert's discard_autosave and
destroy_draft branches, and translation destroy. publish_draft! now
runs in a transaction so the promotion and its log entry land
together. The remaining verbs follow once this mechanism has proven
itself.

1 files changed, 33 insertions, 0 deletions

diff --git a/app/models/node_action.rb b/app/models/node_action.rb
new file mode 100644
index 0000000..f32b5b7
--- /dev/null
+++ b/app/models/node_action.rb
@@ -0,0 +1,33 @@
+class NodeAction < ApplicationRecord
+  belongs_to :node, optional: true
+  belongs_to :page, optional: true
+  belongs_to :user, optional: true
+
+  validates :action, presence: true
+  validates :occurred_at, presence: true
+
+  def self.record!(node:, action:, user: nil, page: nil, locale: nil, **extra)
+    create!(
+      :node        => node,
+      :page        => page,
+      :user        => user,
+      :action      => action,
+      :locale      => locale,
+      :occurred_at => Time.now,
+      :metadata    => {
+        "username"                 => user&.login,
+        "human_readable_node_name" => Globalize.with_locale(I18n.default_locale) {
+                                        node&.head&.title || node&.draft&.title
+                                      },
+      }.merge(extra.stringify_keys)
+   )
+  end
+
+  def actor_name
+    metadata["username"] || "unknown"
+  end
+
+  def subject_name
+    metadata["human_readable_node_name"] || node&.unique_name || "deleted node"
+  end
+end